Solanum aculeastrum, a member of the Solanum genus, has a rich history of traditional use in various populations throughout tropical and southern Africa for treating different ailments. This study investigated the ant...Solanum aculeastrum, a member of the Solanum genus, has a rich history of traditional use in various populations throughout tropical and southern Africa for treating different ailments. This study investigated the antimicrobial activities of S. aculeastrum fruit extracts grown in Zambia against Escherichia coli (E. coli) (ATCC 25922), Staphylococcus aureus (S. aureus) (ATCC 25923), and Candida albicans (C. albicans). After being dried in an oven at 50°C for eight days, the fruits of S. aculeastrum were pulverised and subjected to extraction using methanol and distilled water as solvents. The resulting crude extract was then filtered, concentrated using a water bath, and packed into airtight containers separately. The disc diffusion method was employed to evaluate the antimicrobial activity of the extracts. The results showed that both the methanolic and aqueous extracts demonstrated antimicrobial activity against S. aureus and C. albicans, but not against E. coli. The zone of inhibition was greater in S. aureus than in C. albicans. This study highlights the importance of researching plants for their medicinal properties, which can pave the way for discovering natural product-based drugs with potential antimicrobial properties. These findings recommend further studies on plants used in African traditional medicine.展开更多
This study was evaluated the antimicrobial activities of the crude extract,different fractions,and compounds from the plant of Lomatogonium carinthiacum.The fractions of chloroform and compounds 5,2 and 6 exhibited st...This study was evaluated the antimicrobial activities of the crude extract,different fractions,and compounds from the plant of Lomatogonium carinthiacum.The fractions of chloroform and compounds 5,2 and 6 exhibited stronger antimicrobial activities.Compound 5 was the most active while Staphylococcus aureus and Candida albicans were sensitive to all the tested compounds.The existence of a relationship between the xanthone structures and inhibition of microorganism activity.The antimicrobial activity of this plant was reported here firstly.The results provided evidence that the studied plant extract,fractions as well as some of the isolated compounds might be potential sources of new antimicrobial drug.展开更多
In this study, laurel essential oils were obtained by using solvent-free microwave extraction (SFME) and hydrodistillation (HD) methods from Laurus nobilis leaves and determined their antioxidant and antimicrobial act...In this study, laurel essential oils were obtained by using solvent-free microwave extraction (SFME) and hydrodistillation (HD) methods from Laurus nobilis leaves and determined their antioxidant and antimicrobial activity. Extraction time was reduced by about 43% in SFME at 622 W and 67% in SFME at 249 W compared to hydrodistillation. Essential oil of laurel was extracted by SFME at 622 W (100%) and 249 W (40%) power levels and HD inhibited oxidation generated by ABTS radical by 93.88%, 94.13% and 92.06%, respectively. Trolox equivalent antioxidant capacities (TEAC) of essential oils were 0.18 mM/mL oil for SFME at 622 W, 1.36 mM/mL oil for SFME at 249 W and 2.40 mM/mL oil for HD (p < 0.05). Essential oils of L. nobilis were extracted by SFME at 100% and 40% power levels and HD inhibited linoleic acid peroxidation by 70.57%, 63.53% and 89.18% respectively. Inhibition effects of laurel essential oils obtained by SFME at different power levels and HD on DPPH radical cation oxidation were not significantly different. The strongest antioxidant activity against DPPH radical was found in the essential oil obtained by SFME at 100% power level. Essential oils displayed antimicrobial activity against Staphylococcus aureus 6538P, Escherichia coli O157:H7 and Salmonella typhimurium NRRL E 4463 except for Listeria monocytogenes. The inhibitory effect on Staphylococcus aureus 6538P survival of laurel oil obtained from SFME by using lower power level was found to be lower than that obtained from SFME at 100% power level and HD展开更多
Objective: To investigate phytochemical, antioxidant and antimicrobial activities of Kedrostis africana(K. africana).Methods: Dried tubers of K. africana were extracted in acetone, water and ethanol. The total phenol,...Objective: To investigate phytochemical, antioxidant and antimicrobial activities of Kedrostis africana(K. africana).Methods: Dried tubers of K. africana were extracted in acetone, water and ethanol. The total phenol, flavonoid, proanthocyanidin and tannin contents were determined spectrometrically. The antioxidant activity was examined using 2,2-diphenyl-1-picrylhydrazyl,2,2’-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt, nitric oxide and hydrogen peroxide assays. The antimicrobial activity was determined by agar dilution method using minimum inhibitory concentration against 3 g positive and three gram negative strains while four fungal strains were also investigated.Results: Total phenol, flavonoids, proanthocyanidin and tannin contents ranged from(5.32 ± 0.01) to(10.51 ± 0.01) mg GAE/g;(42.58 ± 0.02) to(529.23 ± 0.01) mg QE/g;(15.05 ± 0.00) to(585.64 ± 0.00) mg CE/g and(0.301 ± 0.010) to(0.937 ± 0.000) mg TAE/g, respectively. The IC_(50) values of the ethanol extract for 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) and hydrogen peroxide were 0.054 and 0.057 mg/mL,respectively, aqueous extract had an IC_(50) value of 0.135 7 mg/mL for nitric oxide while the acetone extract had an IC_(50) value of 0.300 mg/mL for 2,2-diphenyl-1-picrylhydrazyl.The ethanol extract demonstrated effective antimicrobial activity against the tested pathogenic species with minimum inhibitory concentrations values ranging from 2.5–5.0 mg/mL for bacteria and(0.312 5–5.000 0) mg/mL for fungi, respectively.Conclusions: The tuber of K. africana showed potent free radical scavenging property and antimicrobial activity.展开更多
<span style="font-family:Verdana;">Chemical investigation of the MeOH extract from the leaves of </span><i><span style="font-family:Verdana;">C.</span></i> <i...<span style="font-family:Verdana;">Chemical investigation of the MeOH extract from the leaves of </span><i><span style="font-family:Verdana;">C.</span></i> <i><span style="font-family:Verdana;">glauca</span></i> <span><span style="font-family:Verdana;">yielded nine known triterpenoids (</span><b><span style="font-family:Verdana;">1-9</span></b><span style="font-family:Verdana;">) belonging to the cycloartane and</span></span><span style="font-family:Verdana;"> friedelane series. Two of these compounds namely glaucartanoic acid A (</span><b><span style="font-family:Verdana;">1</span></b><span style="font-family:Verdana;">) and 3</span><i><span style="font-family:Verdana;">β</span></i><span style="font-family:Verdana;">,21</span><i><span style="font-family:Verdana;">β</span></i><span style="font-family:Verdana;">-dihydroxy-30-nor-(D:A)-friedoolean-20(29)-en-27-oic acid (</span><b><span style="font-family:Verdana;">5</span></b><span style="font-family:Verdana;">) were subjected to chemical derivatizations and afforded five new derivatives: diacetylglaucartanoic acid A (</span><b><span style="font-family:Verdana;">1a</span></b><span style="font-family:Verdana;">), 24-acetylglaucartanoic acid A (</span><b><span style="font-family:Verdana;">1b</span></b><span style="font-family:Verdana;">), glaucartanoic acid A methyl ester (</span><b><span style="font-family:Verdana;">1c</span></b><span style="font-family:Verdana;">), 24-methoxyglaucartanoic acid A methyl </span><span><span style="font-family:Verdana;">ester (</span><b><span style="font-family:Verdana;">1d</span></b><span style="font-family:Verdana;">), and 3</span><i><span style="font-family:Verdana;">β</span></i><span style="font-family:Verdana;">,21</span><i><span style="font-family:Verdana;">β</span></i><span style="font-family:Verdana;">-diacetoxy-30-nor-(D:A)-friedoolean-20(29)-en-27-oic</span></span><span style="font-family:Verdana;"> acid (</span><b><span style="font-family:Verdana;">5a</span></b><span style="font-family:Verdana;">). Their structures were assigned based on their NMR and MS data and by </span><span style="font-family:Verdana;">comparison with literature values. The MeOH extract, isolated compounds</span><span style="font-family:Verdana;"> and some new semi-synthetic derivatives were subjected to </span><i><span style="font-family:Verdana;">in</span></i> <i><span style="font-family:Verdana;">vitro</span></i><span style="font-family:Verdana;"> antimi</span><span style="font-family:Verdana;">crobial assays against a panel of pathogenic microorganisms, including</span><span style="font-family:Verdana;"> Gram-positive and Gram-negative bacteria, and fungi using broth microdilution method. The MeOH extract displayed activity towards all the tested patho</span><span style="font-family:Verdana;">genic bacterial and fungal strains with good activity (MIC < 100 μg/mL)</span><span style="font-family:Verdana;"> against </span><i><span style="font-family:Verdana;">Staphylococcus</span></i> <i><span style="font-family:Verdana;">aureus</span></i><span style="font-family:Verdana;"> ATCC25923 and </span><i><span style="font-family:Verdana;">Shigella</span></i> <i><span style="font-family:Verdana;">flexneri</span></i><span style="font-family:Verdana;"> SDINT. Compounds </span><b><span style="font-family:Verdana;">3</span></b><span style="font-family:Verdana;"> and </span><b><span style="font-family:Verdana;">5</span></b><span style="font-family:Verdana;"> showed the most potent antimicrobial effect.</span>展开更多
Lutzomyia evansi is a phlebotomine insect endemic to Colombia’s Caribbean coast and is considered the main vector of visceral and cutaneous leishmaniasis in the region. Specific studies of the direct effects generate...Lutzomyia evansi is a phlebotomine insect endemic to Colombia’s Caribbean coast and is considered the main vector of visceral and cutaneous leishmaniasis in the region. Specific studies of the direct effects generated by bacteria in the digestive tract of the insect vectors, under Leishmania infantum using in vitro models, represent a novel alternative as a control strategy for the transmission of leishmaniasis and also provide the opportunity to detect natural products or antimicrobial peptides with different biological activities. In this study, we evaluate the leishmanicidal and antimicrobial activities of Pantoea ananatis, Ochrobactrum anthropi and Enterobacter cloacae, isolated from the digestive tract of Lutzomyia evansi and the susceptibility of these bacteria to commonly used antibiotics. The antagonistic effect of Pantoea ananatis, Ochrobactrum anthropi and Enterobacter cloacae was evaluated against six species of human pathogenic bacteria and against stationary (Metacyclic-like) and exponential promastigotes (Procyclic-like) of Leishmania infantum (BCN-GFP strain) by co-culture assays for 24 hours. The activity of the bacterial isolates on Leishmania infantum promastigotes was quantified by flow cytometry. The susceptibility of the bacterial strains to clinically used antibiotics was analyzed by antibiogram. The highest percentage of inhibition was observed against exponential promastigotes with bacterial concentrations of 10<sup>8</sup> CFU/ml of Enterobacter cloacae (77.29% ± 0.6%) and Pantoea ananatis (70.17% ± 1.1%). The extracts produced by three bacterial isolates showed similar biological activity (13 mm - 22 mm inhibition halos) against all tested bacteria;however, significant differences were observed with respect to gram-positive bacteria (P < 0.003557). The most active antibacterial activity was displayed against the pathogenic bacteria Bacillus cereus. Ochrobactrum anthropi was the isolate with the highest number of antibiotic resistance patterns while Pantoea ananatis and Enterobacter cloacae showed greater susceptibility to the evaluated antibiotics. The growth inhibitory activity of exponential Leishmania infantum promastigotes shown by extracts of Enterobacter cloacae and Pantoea ananantis suggests that the presence of these bacteria in the vector intestine may affect the parasite development to metacyclic stages, infective to human hosts. This in turn confers said bacteria, a potential in controlling the transmission of Leishmania spp. that deserves to be studied in depth.展开更多
Objective:To investigate the relationship between triterpenoid saponin content and antioxidant,antimicrobial,and α-glucosidase inhibitory activities of 70%ethanolic,butanolic,aqueous,supernate and precipitate extract...Objective:To investigate the relationship between triterpenoid saponin content and antioxidant,antimicrobial,and α-glucosidase inhibitory activities of 70%ethanolic,butanolic,aqueous,supernate and precipitate extracts of Juglans regia leaves.Methods:Triterpenoid saponins of different Juglans regia leaf extracts were measured by the vanillin method.Antioxidant activity was evaluated against DPPH and ABTS free radicals.We also assessed α-glucosidase inhibitory and antimicrobial activities of the leaf extracts.Pearson’s correlation coefficient was evaluated to determine the correlation between the saponin content and biological activities.Results:The butanolic extract was most effective against DPPH with an IC50of 6.63μg/mL,while the aqueous extract showed the highest scavenging activity against ABTS free radical with an IC50of 42.27μg/mL.Pearson’s correlation analysis indicated a strong negative correlation (r=-0.956) between DPPH radical scavenging activity (IC50) and the saponin content in the samples examined.In addition,the aqueous extract showed the best α-glucosidase inhibitory activity compared with other extracts.All the extracts had fair antibacterial activity against Bacillus subtilis,Escherichia coli,and Klebsiella pneumoniae except for the aqueous extract.Conclusions:Juglans regia extracts show potent antioxidant,antimicrobial,and α-glucosidase inhibitory activities.There is a correlation between saponin levels in Juglans regia leaf extracts and the studied activities.However,additional research is required to establish these relationships by identifying the specific saponin molecules responsible for these activities and elucidating their mechanisms of action.展开更多
This study has been conducted to analyze the chemical composition and antimicrobial, antioxidant and antiplasmodial properties of ethanol extracts of Pycnostachys erici-rosenii R.E.Fr and Leucas martinicensis (Jack.) ...This study has been conducted to analyze the chemical composition and antimicrobial, antioxidant and antiplasmodial properties of ethanol extracts of Pycnostachys erici-rosenii R.E.Fr and Leucas martinicensis (Jack.) R.Br that are not yet well known. The HPLC-DAD-MS-ESI<sup>+</sup> method was used to investigate the chemical profile, the disc diffusion and microdilution method for the antimicrobial activities, the DPPH and FRAP assays for antioxidant property and SYBR Green I-based growth inhibition assay on Pf 3D7 (CQ-sensitive) strain for antiplasmodial properties. The results indicated significant amounts of hydroxybenzoic acid, flavonol and hydroxycinnamic acid in the two species. The total polyphenols analysis gave 209.0 ± 16.1 mg GAE/100g DW for P. erici-rosenii and 175.3 ± 1.6 mg GAE/100g DW for L. martinicensis while for total flavonoids analysis 33.4 ± 1.8 mg TE/100g DW was found for P. erici-rosenii and 39.6 ± 0.6 mg TE/100g DW for L. martinicensis. Moreover, antimicrobial tests revealed 0.125 mg/mL on E. faecalis ATCC25922 for ethanol extracts P. erici-rosenii and L. martinicensis. The antioxidant assays revealed IC<sub>50</sub> 56.17 μg/mL and 78.43 μg/mL for DPPH assay, and 112.03 μM TE/100mL and 90.46 μM TE/100mL) for FRAP assay for ethanol extracts of P. erici-rosenii and L. martinicensis respectively. Finally, for Antiplasmodial activity, IC<sub>50</sub> was 4.07 μg/mL for P. erici-rosenii and 12.29 μg/mL for L. martinicensis. Therefore, the antimicrobial, the antioxidant, and the antiplasmodial results suggest that the ethanolic extracts of the aerial parts of P. erici-rosenii and L. martinicensis contain compounds with antimicrobial, antioxidant, and antiplasmodial properties, which can be searched in new drug discovery for treatment of infectious diseases.展开更多
Silver nanoparticles are versatile nanomaterials that have found numerous applications in various fields.The use of plant extract for the synthesis of silver is a green and sustainable approach.Clerodendron phlomoides...Silver nanoparticles are versatile nanomaterials that have found numerous applications in various fields.The use of plant extract for the synthesis of silver is a green and sustainable approach.Clerodendron phlomoides leaves extract has been found to contain various phytochemicals,such as phenols,flavonoids,tannins,and alkaloids,which possess reducing and stabilizing properties that can aid the production of silver particles.In this paper,morphological and topographical analyses were performed on silver nanoparticles.The biosynthesized silver nanoparticles showed antimicrobial potential against wound pathogens.SEM and TEM micrographs revealed that the particles were sphere and nanosized,which makes them suitable for various biomedical applications.展开更多
Copper nanoparticles(CuNPs)have emerged as a promising alternative due to their unique antimicrobial properties.The synthesis of CuNPs using Asparagus racemosus,commonly known as Shatavari,offers a sustainable and env...Copper nanoparticles(CuNPs)have emerged as a promising alternative due to their unique antimicrobial properties.The synthesis of CuNPs using Asparagus racemosus,commonly known as Shatavari,offers a sustainable and environmentally friendly approach to producing nanomaterials.Moreover,the resulting CuNPs have been found to possess excellent antibacterial,and antioxidant properties,which further expands their potential applications in medicine and environmental remediation.In this article,we discussed the in vitro characterization of the CuNPs.In vitro studies revealed that CuNPs have the potential for biomedical applications and as a base nanomaterial for the construction of drug delivery and targeting vehicles.展开更多
Objective:To investigate the chemical composition,antioxidant and antimicrobial activities of essential oil of Santolina chamaecyparissus L.cultivated in Algeria.Methods:The chemical composition of hydrodistilled esse...Objective:To investigate the chemical composition,antioxidant and antimicrobial activities of essential oil of Santolina chamaecyparissus L.cultivated in Algeria.Methods:The chemical composition of hydrodistilled essential oil from flowering aerial parts has been analyzed by gas chromatograph and gas chromatograph-mass spectrometer techniques.The antioxidant activities conducted by 2,2-diphenyl-1-picrylhydrazyl scavenging test andβ-carotene bleaching test.The antimicrobial activity was realised by agar disc diffusion method and cornell medical index was determined by agar dilution method in solid medium.Results:About 36 components accounting more than 82%of the total oil were identified.Oxygenated monoterpenes was the main fraction(54.66%)and was represented by artemisia ketone(40.33%)as major component of this oil.The other major constituents were(Z)-thujone(9.82%),(2Z,6E)-farnesol(7.30%)and limonene(6.87%)and concerning antiradical scavenging test(2,2-diphenyl-1-picrylhydrazyl)had demonstrated a weak activity obtained with an EC_(50) of(43.01±8.04)and moderate activity for β-carotene bleaching test(47.00±3.13)at 120 min.In the other hand,this oil was found effective against all tested strains except Pseudomonas aeruginosa and Aspergillus species.This activity was ranging from 10 mm to 24 mm with the lowest minimum inhibitory concentration value between under 0.070μg/mL to upper 9μg/mL.Conclusions:The results provided evidence that the studied plant might indeed be potential sources of natural antioxidant and antimicrobial agents.展开更多
To explore pharmaceutical actinobacteria from salty environments in Siberia,8 soil samples were collected from different depths of Gudzhirganskoe saline lake,the Republic of Buryatia,Russia.Totally,635 actinobacterial...To explore pharmaceutical actinobacteria from salty environments in Siberia,8 soil samples were collected from different depths of Gudzhirganskoe saline lake,the Republic of Buryatia,Russia.Totally,635 actinobacterial strains affiliated with 21 genera in 12 families of 7 orders were obtained by culture-dependent approaches.The predominant genus was Streptomyces(74.5%),followed by Microbacterium(4.9%),Agromyces(3.5%),Nocardiopsis(3.0%),and Kitasatospora(2.5%).Seven strains showed relatively low 16 S rRNA similarities(<98.65%)with validly described species.Seventy-seven strains were selected as representatives to evaluate their antimicrobial activities and underlying mechanisms by paper-disk diffusion method and a double fluorescent protein reporter system(pDualrep 2),respectively.Streptomyces sp.S 6 b 3-1 was highlighted due to its strong inhibitory activities against Gram-positive bacteria and underlying antibacterial mechanism by inducing the SOS response in the reporter system.LG-1,(R)-6-[1-(benzoyloxy)ethyl]-phenazine-1-carboxylic acid,an analogue of saphenamycin was finally isolated from the culture broth of Streptomyces strain.This study preliminarily explored the actinobacterial diversity of soil samples collected in the highly alkaline and saline lake Gudzhirganskoe by culture-dependent approach and their capacity to produce antibiotics for the first time,which revealed that it deserves to make more efforts to discover new actinobacterial species and potential new antibiotics from the saline lake in Eastern Siberia.展开更多
The present study aimed at determining the chemical constituents of Solanum coagulans and their antimicrobial activities. The compounds were isolated by various chromatographic techniques and their structures were elu...The present study aimed at determining the chemical constituents of Solanum coagulans and their antimicrobial activities. The compounds were isolated by various chromatographic techniques and their structures were elucidated on the basis of extensive spectroscopic analysis, chemical methods, and comparison with reported spectroscopic data. One new phenolic glycoside, methyl salicylate 2-O-β-D-glucopyranosyl-(1→2)-β-D-glucopyranoside(1), together with 12 known compounds(2–13), were isolated from the aerial parts of Solanum coagulans. Compound 1 was a new phenolic glycoside, and 2–6 were isolated from Solanum genus for the first time. The antimicrobial activities of the isolated compounds were also evaluated. Compound 7 showed remarkable antifungal activity against T. mentagrophytes, M. gypseum and E. floccosum with MIC values being 3.13, 1.56 and 3.13 μg·m L^(-1), respectively.展开更多
Bacterial endophytes are beneficial to their hosts as they can fix nitrogen in the soil and make it available to the host.Endophytic bacteria also secrete plant growth-promoting hormones to support their host plants u...Bacterial endophytes are beneficial to their hosts as they can fix nitrogen in the soil and make it available to the host.Endophytic bacteria also secrete plant growth-promoting hormones to support their host plants under normal as well as stress conditions.The current study aimed to isolate endophytic bacteria from different parts of Calotropis procera,i.e.,roots,stem and leaves of Calotropis procera(Ait.)W.T.Aiton.Plants were collected from the Lundkhwar,district Mardan.A total of 12 bacterial strains,i.e.,six from roots,three from the stem and three from the leaves were isolated.The strains were screened for their growth-promoting activity in rice plants because rice shows a quick and easy response to the bioactive compounds present in the culture filtrate(CF)of the potent endophytic strains.The rice plants were cultivated in pots containing 30 mL of 0.8%w/v water-agar medium.The pots were placed in a growth chamber,operated at 28±0.3℃ for 14 h(day);and 25±0.3℃ for 10 h(night),at 70%relative-humidity.Among the isolated strains,R1,S1,S3,L1,R5 and R6 showed visible growth promotion in rice plants.The biochemical analysis revealed that the strains were able to produce indole acetic acid(IAA)and flavonoids in higher quantities.Moreover,the strains also produced bioactive compounds that inhibited the growth of Escherichia coli and Aspergillus flavus using the well diffusion method.From the results,it was concluded that these strains can secrete potent compounds that can promote the host plant growth and inhibit the growth of pathogenic microorganisms and,therefore,can be used as bio-fertilizer and bio-control agents.展开更多
Objective:To evaluate the antioxidant and antimicrobial activity of methanolic extract extracts of selected Algerian medicinal plants.Methods:Antioxidant activity of extracts was evaluated in terms of radical scavengi...Objective:To evaluate the antioxidant and antimicrobial activity of methanolic extract extracts of selected Algerian medicinal plants.Methods:Antioxidant activity of extracts was evaluated in terms of radical scavenging potential(2,2-diphenyl-1-picrylhydrazyl)and β-carotene bleaching assay.Total phenolic contents and flavonoid contents were also measured.Antimicrobial activity of these plants was examined against Bacillus subtilis,Staphylococcus aureus,Escherichia coli,Pseudomonas aeruginosa and Candida albicans.Results:The values of IC_(50) ranged from 4.30μg/mL to 486.6μg/mL for the DPPH method,while total antioxidant activity using β-carotene/linoleic acid bleaching assay ranged from 17.03%to 86.13%.It was found that Pistacia lentiscus showed the highest antioxidant capacities using DPPH assay(IC_(50)=4.30μg/mL),while Populus trimula,Origanum glandulosum,Centaurea calcitrapa,Sysimbrium officinalis and Rhamnus alaternus showed the highest percent of total antioxidant activity in β-carotene/linoleic acid bleaching assay.Total phenolic and flavonoid contents ranged from 3.96 to 259.65 mg GAE/g extract and from 1.13 to 26.84 mg QE/g extract,respectively.The most interesting antimicrobial activity was obtained from Sysimbrium officinalis,Rhamnus alaternus,Origanum glandulosum,Cupressus sempervirens,Pinus halipensis and Centaurea calcitrapa.Conclusions:The results indicated that the plants tested may be potential sources for isolation of natural antioxidant and antimicrobial compounds.展开更多
[Objectives]To explore the antimicrobial and antioxidant activities of flavonoid and polysaccharide extracts from bulbs of Lycoris aurea.[Methods]The disc diffusion method was used to evaluate the antimicrobial activi...[Objectives]To explore the antimicrobial and antioxidant activities of flavonoid and polysaccharide extracts from bulbs of Lycoris aurea.[Methods]The disc diffusion method was used to evaluate the antimicrobial activity of flavonoid and polysaccharide extracts from the bulbs of L.aurea.The antioxidant activity was determined by scavenging of hydroxyl and 1,1-diphenyl-2-picrylhydrazine(DPPH)free radicals,and reducing ability.[Results]Flavonoids were effective on 7 microorganisms,but polysaccharides had no effect.Flavonoids had better hydroxyl free radical scavenging activity and reducing capacity than polysaccharides,but weaker than ascorbic acid.However,flavonoids had similar DPPH free radical activity to ascorbic acid.The strong antibacterial and antioxidant activities of flavonoids were mainly attributed to the high content of total phenols in the extract,which was(76.71±4.42)mg/g.[Conclusions]The study shows that flavonoids from bulbs of L.aurea could be regarded as a new potential source of natural bacterial inhibitors and antioxidants.展开更多
The rapid increase of bacterial resistance strains to multiple antibiotics has become a global public health concern. In the present study, actinomycetes from different districts of Libyan soil were isolated and scree...The rapid increase of bacterial resistance strains to multiple antibiotics has become a global public health concern. In the present study, actinomycetes from different districts of Libyan soil were isolated and screened for their inhibitory activity against pathogenic bacteria and fungi. Three hundred soil samples were taken from 77 diverse ecosystems, including deserts, forests, pastureland, and cropland located in different climatic regions in Libya. A total of 164 actinomycetes were obtained. Of 164 isolates, 38 (23.2%) isolates were morphologically and microscopically characterized by spore chain and surface morphology, aerial and substrate mycelia and soluble pigments. The preliminary classification of the isolates illustrates that all isolates belong to the genus Streptomyces. These isolates were further examined for their antagonistic potential against nine pathogenic bacteria and fungi. Out of 38, 11 (28.9%) isolates showed their capability to produce inhibitory substances against at least two tested strains. Among bacterial strains, Staphylococcus aureus was susceptible to almost all eleven isolates (90.9%), while Streptococcus pyogenes was found to be resistant to most selected isolates (18.2%). The isolate, 063 (Wadan soil-desert zone) was the only isolate that exhibited broad spectrum antimicrobial activity against all tested pathogenic microbes, and hence was selected for further study. According to its cultural, morphological, physiological, and biochemical characteristics, the isolate 063 was identified as Streptomyces rochei. The results obtained indicate that the Libyan soil, particularly in extreme environments, could be a potent source of bioactive metabolites with antimicrobial potency against a wide variety of microbial pathogens. Thus, this investigation suggested that exploring new habitats in unexplored and untapped regions of Libya could provide a promising source of biologically active compounds for therapeutic applications.展开更多
New cobalt(II) complex, [Co(O<sub>2</sub>C<sub>15</sub>H<sub>11</sub>N<sub>2</sub>S)<sub>2</sub>(OH<sub>2</sub>)<sub>2</sub>]∙2H<s...New cobalt(II) complex, [Co(O<sub>2</sub>C<sub>15</sub>H<sub>11</sub>N<sub>2</sub>S)<sub>2</sub>(OH<sub>2</sub>)<sub>2</sub>]∙2H<sub>2</sub>O (1∙2H<sub>2</sub>O), has been synthesized upon reaction of cobalt chloride hexahydrate (Co(Cl)<sub>2</sub>∙6H<sub>2</sub>O) with 3-methyl-1-Phenyl-4-(2-thienoyl)-pyrazol-5-one (referred as HL) in ethanol at room temperature. Single crystal X-ray diffraction (XRD), spectroscopic methods, and microelemental analyses were used to characterize 1∙2H<sub>2</sub>O. Compound 1∙2H<sub>2</sub>O crystallizes in the orthorhombic crystal system with a Pbca space group and with the cobalt atom being pseudo-octahedral coordinated. The broth microdilution technique was used to screen the free ligand (HL) and the complex (1∙2H<sub>2</sub>O) for antimicrobial activities. HL has a low activity (MIC > 100 μg/mL) on all microorganisms, whereas compound 1∙2H<sub>2</sub>O displayed moderate activity (10 ∙2H<sub>2</sub>O exhibited bactericidal and fungicidal activity respectively on all the bacteria and yeasts tested. These findings reveal that the antimicrobial activity of HL was enhanced upon coordination to Co(II) ion against all microorganisms (bacteria and fungus).展开更多
New cobalt(II) complex, [Co(O<sub>2</sub>C<sub>15</sub>H<sub>11</sub>N<sub>2</sub>S)<sub>2</sub>(OH<sub>2</sub>)<sub>2</sub>]∙2H<s...New cobalt(II) complex, [Co(O<sub>2</sub>C<sub>15</sub>H<sub>11</sub>N<sub>2</sub>S)<sub>2</sub>(OH<sub>2</sub>)<sub>2</sub>]∙2H<sub>2</sub>O (1∙2H<sub>2</sub>O), has been synthesized upon reaction of cobalt chloride hexahydrate (Co(Cl)<sub>2</sub>∙6H<sub>2</sub>O) with 3-methyl-1-Phenyl-4-(2-thienoyl)-pyrazol-5-one (referred as HL) in ethanol at room temperature. Single crystal X-ray diffraction (XRD), spectroscopic methods, and microelemental analyses were used to characterize 1∙2H<sub>2</sub>O. Compound 1∙2H<sub>2</sub>O crystallizes in the orthorhombic crystal system with a Pbca space group and with the cobalt atom being pseudo-octahedral coordinated. The broth microdilution technique was used to screen the free ligand (HL) and the complex (1∙2H<sub>2</sub>O) for antimicrobial activities. HL has a low activity (MIC > 100 μg/mL) on all microorganisms, whereas compound 1∙2H<sub>2</sub>O displayed moderate activity (10 ∙2H<sub>2</sub>O exhibited bactericidal and fungicidal activity respectively on all the bacteria and yeasts tested. These findings reveal that the antimicrobial activity of HL was enhanced upon coordination to Co(II) ion against all microorganisms (bacteria and fungus).展开更多
文摘Solanum aculeastrum, a member of the Solanum genus, has a rich history of traditional use in various populations throughout tropical and southern Africa for treating different ailments. This study investigated the antimicrobial activities of S. aculeastrum fruit extracts grown in Zambia against Escherichia coli (E. coli) (ATCC 25922), Staphylococcus aureus (S. aureus) (ATCC 25923), and Candida albicans (C. albicans). After being dried in an oven at 50°C for eight days, the fruits of S. aculeastrum were pulverised and subjected to extraction using methanol and distilled water as solvents. The resulting crude extract was then filtered, concentrated using a water bath, and packed into airtight containers separately. The disc diffusion method was employed to evaluate the antimicrobial activity of the extracts. The results showed that both the methanolic and aqueous extracts demonstrated antimicrobial activity against S. aureus and C. albicans, but not against E. coli. The zone of inhibition was greater in S. aureus than in C. albicans. This study highlights the importance of researching plants for their medicinal properties, which can pave the way for discovering natural product-based drugs with potential antimicrobial properties. These findings recommend further studies on plants used in African traditional medicine.
基金We thank the fourth national survey of traditional Chinese medicine resources(2018016)for funding this research.
文摘This study was evaluated the antimicrobial activities of the crude extract,different fractions,and compounds from the plant of Lomatogonium carinthiacum.The fractions of chloroform and compounds 5,2 and 6 exhibited stronger antimicrobial activities.Compound 5 was the most active while Staphylococcus aureus and Candida albicans were sensitive to all the tested compounds.The existence of a relationship between the xanthone structures and inhibition of microorganism activity.The antimicrobial activity of this plant was reported here firstly.The results provided evidence that the studied plant extract,fractions as well as some of the isolated compounds might be potential sources of new antimicrobial drug.
基金The TUBİTAK,The Scientific and Technologic Research Council of Turkey(Grant No.TOVAG 104 O 265)financially supported this study.
文摘In this study, laurel essential oils were obtained by using solvent-free microwave extraction (SFME) and hydrodistillation (HD) methods from Laurus nobilis leaves and determined their antioxidant and antimicrobial activity. Extraction time was reduced by about 43% in SFME at 622 W and 67% in SFME at 249 W compared to hydrodistillation. Essential oil of laurel was extracted by SFME at 622 W (100%) and 249 W (40%) power levels and HD inhibited oxidation generated by ABTS radical by 93.88%, 94.13% and 92.06%, respectively. Trolox equivalent antioxidant capacities (TEAC) of essential oils were 0.18 mM/mL oil for SFME at 622 W, 1.36 mM/mL oil for SFME at 249 W and 2.40 mM/mL oil for HD (p < 0.05). Essential oils of L. nobilis were extracted by SFME at 100% and 40% power levels and HD inhibited linoleic acid peroxidation by 70.57%, 63.53% and 89.18% respectively. Inhibition effects of laurel essential oils obtained by SFME at different power levels and HD on DPPH radical cation oxidation were not significantly different. The strongest antioxidant activity against DPPH radical was found in the essential oil obtained by SFME at 100% power level. Essential oils displayed antimicrobial activity against Staphylococcus aureus 6538P, Escherichia coli O157:H7 and Salmonella typhimurium NRRL E 4463 except for Listeria monocytogenes. The inhibitory effect on Staphylococcus aureus 6538P survival of laurel oil obtained from SFME by using lower power level was found to be lower than that obtained from SFME at 100% power level and HD
基金the financial support of Govan Mbeki Research Development Centre, University of Fort Hare, South Africa (Grant number: C127)
文摘Objective: To investigate phytochemical, antioxidant and antimicrobial activities of Kedrostis africana(K. africana).Methods: Dried tubers of K. africana were extracted in acetone, water and ethanol. The total phenol, flavonoid, proanthocyanidin and tannin contents were determined spectrometrically. The antioxidant activity was examined using 2,2-diphenyl-1-picrylhydrazyl,2,2’-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt, nitric oxide and hydrogen peroxide assays. The antimicrobial activity was determined by agar dilution method using minimum inhibitory concentration against 3 g positive and three gram negative strains while four fungal strains were also investigated.Results: Total phenol, flavonoids, proanthocyanidin and tannin contents ranged from(5.32 ± 0.01) to(10.51 ± 0.01) mg GAE/g;(42.58 ± 0.02) to(529.23 ± 0.01) mg QE/g;(15.05 ± 0.00) to(585.64 ± 0.00) mg CE/g and(0.301 ± 0.010) to(0.937 ± 0.000) mg TAE/g, respectively. The IC_(50) values of the ethanol extract for 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) and hydrogen peroxide were 0.054 and 0.057 mg/mL,respectively, aqueous extract had an IC_(50) value of 0.135 7 mg/mL for nitric oxide while the acetone extract had an IC_(50) value of 0.300 mg/mL for 2,2-diphenyl-1-picrylhydrazyl.The ethanol extract demonstrated effective antimicrobial activity against the tested pathogenic species with minimum inhibitory concentrations values ranging from 2.5–5.0 mg/mL for bacteria and(0.312 5–5.000 0) mg/mL for fungi, respectively.Conclusions: The tuber of K. africana showed potent free radical scavenging property and antimicrobial activity.
文摘<span style="font-family:Verdana;">Chemical investigation of the MeOH extract from the leaves of </span><i><span style="font-family:Verdana;">C.</span></i> <i><span style="font-family:Verdana;">glauca</span></i> <span><span style="font-family:Verdana;">yielded nine known triterpenoids (</span><b><span style="font-family:Verdana;">1-9</span></b><span style="font-family:Verdana;">) belonging to the cycloartane and</span></span><span style="font-family:Verdana;"> friedelane series. Two of these compounds namely glaucartanoic acid A (</span><b><span style="font-family:Verdana;">1</span></b><span style="font-family:Verdana;">) and 3</span><i><span style="font-family:Verdana;">β</span></i><span style="font-family:Verdana;">,21</span><i><span style="font-family:Verdana;">β</span></i><span style="font-family:Verdana;">-dihydroxy-30-nor-(D:A)-friedoolean-20(29)-en-27-oic acid (</span><b><span style="font-family:Verdana;">5</span></b><span style="font-family:Verdana;">) were subjected to chemical derivatizations and afforded five new derivatives: diacetylglaucartanoic acid A (</span><b><span style="font-family:Verdana;">1a</span></b><span style="font-family:Verdana;">), 24-acetylglaucartanoic acid A (</span><b><span style="font-family:Verdana;">1b</span></b><span style="font-family:Verdana;">), glaucartanoic acid A methyl ester (</span><b><span style="font-family:Verdana;">1c</span></b><span style="font-family:Verdana;">), 24-methoxyglaucartanoic acid A methyl </span><span><span style="font-family:Verdana;">ester (</span><b><span style="font-family:Verdana;">1d</span></b><span style="font-family:Verdana;">), and 3</span><i><span style="font-family:Verdana;">β</span></i><span style="font-family:Verdana;">,21</span><i><span style="font-family:Verdana;">β</span></i><span style="font-family:Verdana;">-diacetoxy-30-nor-(D:A)-friedoolean-20(29)-en-27-oic</span></span><span style="font-family:Verdana;"> acid (</span><b><span style="font-family:Verdana;">5a</span></b><span style="font-family:Verdana;">). Their structures were assigned based on their NMR and MS data and by </span><span style="font-family:Verdana;">comparison with literature values. The MeOH extract, isolated compounds</span><span style="font-family:Verdana;"> and some new semi-synthetic derivatives were subjected to </span><i><span style="font-family:Verdana;">in</span></i> <i><span style="font-family:Verdana;">vitro</span></i><span style="font-family:Verdana;"> antimi</span><span style="font-family:Verdana;">crobial assays against a panel of pathogenic microorganisms, including</span><span style="font-family:Verdana;"> Gram-positive and Gram-negative bacteria, and fungi using broth microdilution method. The MeOH extract displayed activity towards all the tested patho</span><span style="font-family:Verdana;">genic bacterial and fungal strains with good activity (MIC < 100 μg/mL)</span><span style="font-family:Verdana;"> against </span><i><span style="font-family:Verdana;">Staphylococcus</span></i> <i><span style="font-family:Verdana;">aureus</span></i><span style="font-family:Verdana;"> ATCC25923 and </span><i><span style="font-family:Verdana;">Shigella</span></i> <i><span style="font-family:Verdana;">flexneri</span></i><span style="font-family:Verdana;"> SDINT. Compounds </span><b><span style="font-family:Verdana;">3</span></b><span style="font-family:Verdana;"> and </span><b><span style="font-family:Verdana;">5</span></b><span style="font-family:Verdana;"> showed the most potent antimicrobial effect.</span>
文摘Lutzomyia evansi is a phlebotomine insect endemic to Colombia’s Caribbean coast and is considered the main vector of visceral and cutaneous leishmaniasis in the region. Specific studies of the direct effects generated by bacteria in the digestive tract of the insect vectors, under Leishmania infantum using in vitro models, represent a novel alternative as a control strategy for the transmission of leishmaniasis and also provide the opportunity to detect natural products or antimicrobial peptides with different biological activities. In this study, we evaluate the leishmanicidal and antimicrobial activities of Pantoea ananatis, Ochrobactrum anthropi and Enterobacter cloacae, isolated from the digestive tract of Lutzomyia evansi and the susceptibility of these bacteria to commonly used antibiotics. The antagonistic effect of Pantoea ananatis, Ochrobactrum anthropi and Enterobacter cloacae was evaluated against six species of human pathogenic bacteria and against stationary (Metacyclic-like) and exponential promastigotes (Procyclic-like) of Leishmania infantum (BCN-GFP strain) by co-culture assays for 24 hours. The activity of the bacterial isolates on Leishmania infantum promastigotes was quantified by flow cytometry. The susceptibility of the bacterial strains to clinically used antibiotics was analyzed by antibiogram. The highest percentage of inhibition was observed against exponential promastigotes with bacterial concentrations of 10<sup>8</sup> CFU/ml of Enterobacter cloacae (77.29% ± 0.6%) and Pantoea ananatis (70.17% ± 1.1%). The extracts produced by three bacterial isolates showed similar biological activity (13 mm - 22 mm inhibition halos) against all tested bacteria;however, significant differences were observed with respect to gram-positive bacteria (P < 0.003557). The most active antibacterial activity was displayed against the pathogenic bacteria Bacillus cereus. Ochrobactrum anthropi was the isolate with the highest number of antibiotic resistance patterns while Pantoea ananatis and Enterobacter cloacae showed greater susceptibility to the evaluated antibiotics. The growth inhibitory activity of exponential Leishmania infantum promastigotes shown by extracts of Enterobacter cloacae and Pantoea ananantis suggests that the presence of these bacteria in the vector intestine may affect the parasite development to metacyclic stages, infective to human hosts. This in turn confers said bacteria, a potential in controlling the transmission of Leishmania spp. that deserves to be studied in depth.
基金supported by the Deanship of Scientific Research at Umm Al-Qura University(Grant code:22UQU4331128DSR77).
文摘Objective:To investigate the relationship between triterpenoid saponin content and antioxidant,antimicrobial,and α-glucosidase inhibitory activities of 70%ethanolic,butanolic,aqueous,supernate and precipitate extracts of Juglans regia leaves.Methods:Triterpenoid saponins of different Juglans regia leaf extracts were measured by the vanillin method.Antioxidant activity was evaluated against DPPH and ABTS free radicals.We also assessed α-glucosidase inhibitory and antimicrobial activities of the leaf extracts.Pearson’s correlation coefficient was evaluated to determine the correlation between the saponin content and biological activities.Results:The butanolic extract was most effective against DPPH with an IC50of 6.63μg/mL,while the aqueous extract showed the highest scavenging activity against ABTS free radical with an IC50of 42.27μg/mL.Pearson’s correlation analysis indicated a strong negative correlation (r=-0.956) between DPPH radical scavenging activity (IC50) and the saponin content in the samples examined.In addition,the aqueous extract showed the best α-glucosidase inhibitory activity compared with other extracts.All the extracts had fair antibacterial activity against Bacillus subtilis,Escherichia coli,and Klebsiella pneumoniae except for the aqueous extract.Conclusions:Juglans regia extracts show potent antioxidant,antimicrobial,and α-glucosidase inhibitory activities.There is a correlation between saponin levels in Juglans regia leaf extracts and the studied activities.However,additional research is required to establish these relationships by identifying the specific saponin molecules responsible for these activities and elucidating their mechanisms of action.
文摘This study has been conducted to analyze the chemical composition and antimicrobial, antioxidant and antiplasmodial properties of ethanol extracts of Pycnostachys erici-rosenii R.E.Fr and Leucas martinicensis (Jack.) R.Br that are not yet well known. The HPLC-DAD-MS-ESI<sup>+</sup> method was used to investigate the chemical profile, the disc diffusion and microdilution method for the antimicrobial activities, the DPPH and FRAP assays for antioxidant property and SYBR Green I-based growth inhibition assay on Pf 3D7 (CQ-sensitive) strain for antiplasmodial properties. The results indicated significant amounts of hydroxybenzoic acid, flavonol and hydroxycinnamic acid in the two species. The total polyphenols analysis gave 209.0 ± 16.1 mg GAE/100g DW for P. erici-rosenii and 175.3 ± 1.6 mg GAE/100g DW for L. martinicensis while for total flavonoids analysis 33.4 ± 1.8 mg TE/100g DW was found for P. erici-rosenii and 39.6 ± 0.6 mg TE/100g DW for L. martinicensis. Moreover, antimicrobial tests revealed 0.125 mg/mL on E. faecalis ATCC25922 for ethanol extracts P. erici-rosenii and L. martinicensis. The antioxidant assays revealed IC<sub>50</sub> 56.17 μg/mL and 78.43 μg/mL for DPPH assay, and 112.03 μM TE/100mL and 90.46 μM TE/100mL) for FRAP assay for ethanol extracts of P. erici-rosenii and L. martinicensis respectively. Finally, for Antiplasmodial activity, IC<sub>50</sub> was 4.07 μg/mL for P. erici-rosenii and 12.29 μg/mL for L. martinicensis. Therefore, the antimicrobial, the antioxidant, and the antiplasmodial results suggest that the ethanolic extracts of the aerial parts of P. erici-rosenii and L. martinicensis contain compounds with antimicrobial, antioxidant, and antiplasmodial properties, which can be searched in new drug discovery for treatment of infectious diseases.
文摘Silver nanoparticles are versatile nanomaterials that have found numerous applications in various fields.The use of plant extract for the synthesis of silver is a green and sustainable approach.Clerodendron phlomoides leaves extract has been found to contain various phytochemicals,such as phenols,flavonoids,tannins,and alkaloids,which possess reducing and stabilizing properties that can aid the production of silver particles.In this paper,morphological and topographical analyses were performed on silver nanoparticles.The biosynthesized silver nanoparticles showed antimicrobial potential against wound pathogens.SEM and TEM micrographs revealed that the particles were sphere and nanosized,which makes them suitable for various biomedical applications.
文摘Copper nanoparticles(CuNPs)have emerged as a promising alternative due to their unique antimicrobial properties.The synthesis of CuNPs using Asparagus racemosus,commonly known as Shatavari,offers a sustainable and environmentally friendly approach to producing nanomaterials.Moreover,the resulting CuNPs have been found to possess excellent antibacterial,and antioxidant properties,which further expands their potential applications in medicine and environmental remediation.In this article,we discussed the in vitro characterization of the CuNPs.In vitro studies revealed that CuNPs have the potential for biomedical applications and as a base nanomaterial for the construction of drug delivery and targeting vehicles.
文摘Objective:To investigate the chemical composition,antioxidant and antimicrobial activities of essential oil of Santolina chamaecyparissus L.cultivated in Algeria.Methods:The chemical composition of hydrodistilled essential oil from flowering aerial parts has been analyzed by gas chromatograph and gas chromatograph-mass spectrometer techniques.The antioxidant activities conducted by 2,2-diphenyl-1-picrylhydrazyl scavenging test andβ-carotene bleaching test.The antimicrobial activity was realised by agar disc diffusion method and cornell medical index was determined by agar dilution method in solid medium.Results:About 36 components accounting more than 82%of the total oil were identified.Oxygenated monoterpenes was the main fraction(54.66%)and was represented by artemisia ketone(40.33%)as major component of this oil.The other major constituents were(Z)-thujone(9.82%),(2Z,6E)-farnesol(7.30%)and limonene(6.87%)and concerning antiradical scavenging test(2,2-diphenyl-1-picrylhydrazyl)had demonstrated a weak activity obtained with an EC_(50) of(43.01±8.04)and moderate activity for β-carotene bleaching test(47.00±3.13)at 120 min.In the other hand,this oil was found effective against all tested strains except Pseudomonas aeruginosa and Aspergillus species.This activity was ranging from 10 mm to 24 mm with the lowest minimum inhibitory concentration value between under 0.070μg/mL to upper 9μg/mL.Conclusions:The results provided evidence that the studied plant might indeed be potential sources of natural antioxidant and antimicrobial agents.
基金Supported by the CAMS Innovation Fund for Medical Sciences(No.CIFMS 2021-I 2 M-1-028)the Beijing Natural Science Foundation(No.7222256)+5 种基金the National Natural Science Foundation of China(No.82011530051)the Kunlun Talented People,High-end Innovation and Entrepreneurship talents Plan,Qinghai Province,China,for Chenghang SUN,the Talent Training Project of Basic Research Fund of Heilongjiang Department of Education Item to Chunmei XUE(No.2020-KYYWF-0238)the Sino-Hungarian Bilateral S&T Cooperation Projects from 2019 to 2020(Chinese Project:8-11)partly supported by the Russian Foundation for Basic Research(Nos.NCFS-RFBR 20-54-53014,18-44-030021 r_а)the Russian Science Foundation(No.20-74-10031)partially within the framework of the State Assignment(No.121030100229-1)for Institute of General and Experimental Biology,Siberian Branch,Russian Academy of Sciences。
文摘To explore pharmaceutical actinobacteria from salty environments in Siberia,8 soil samples were collected from different depths of Gudzhirganskoe saline lake,the Republic of Buryatia,Russia.Totally,635 actinobacterial strains affiliated with 21 genera in 12 families of 7 orders were obtained by culture-dependent approaches.The predominant genus was Streptomyces(74.5%),followed by Microbacterium(4.9%),Agromyces(3.5%),Nocardiopsis(3.0%),and Kitasatospora(2.5%).Seven strains showed relatively low 16 S rRNA similarities(<98.65%)with validly described species.Seventy-seven strains were selected as representatives to evaluate their antimicrobial activities and underlying mechanisms by paper-disk diffusion method and a double fluorescent protein reporter system(pDualrep 2),respectively.Streptomyces sp.S 6 b 3-1 was highlighted due to its strong inhibitory activities against Gram-positive bacteria and underlying antibacterial mechanism by inducing the SOS response in the reporter system.LG-1,(R)-6-[1-(benzoyloxy)ethyl]-phenazine-1-carboxylic acid,an analogue of saphenamycin was finally isolated from the culture broth of Streptomyces strain.This study preliminarily explored the actinobacterial diversity of soil samples collected in the highly alkaline and saline lake Gudzhirganskoe by culture-dependent approach and their capacity to produce antibiotics for the first time,which revealed that it deserves to make more efforts to discover new actinobacterial species and potential new antibiotics from the saline lake in Eastern Siberia.
基金supported by the National Natural Science Foundation of China(Nos.81225024,31170334)partial financial support of the National Science and Technology Support Program of China(2013BAI11B02)
文摘The present study aimed at determining the chemical constituents of Solanum coagulans and their antimicrobial activities. The compounds were isolated by various chromatographic techniques and their structures were elucidated on the basis of extensive spectroscopic analysis, chemical methods, and comparison with reported spectroscopic data. One new phenolic glycoside, methyl salicylate 2-O-β-D-glucopyranosyl-(1→2)-β-D-glucopyranoside(1), together with 12 known compounds(2–13), were isolated from the aerial parts of Solanum coagulans. Compound 1 was a new phenolic glycoside, and 2–6 were isolated from Solanum genus for the first time. The antimicrobial activities of the isolated compounds were also evaluated. Compound 7 showed remarkable antifungal activity against T. mentagrophytes, M. gypseum and E. floccosum with MIC values being 3.13, 1.56 and 3.13 μg·m L^(-1), respectively.
基金This research was supported by the Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(2017R1D1A1B04035601).
文摘Bacterial endophytes are beneficial to their hosts as they can fix nitrogen in the soil and make it available to the host.Endophytic bacteria also secrete plant growth-promoting hormones to support their host plants under normal as well as stress conditions.The current study aimed to isolate endophytic bacteria from different parts of Calotropis procera,i.e.,roots,stem and leaves of Calotropis procera(Ait.)W.T.Aiton.Plants were collected from the Lundkhwar,district Mardan.A total of 12 bacterial strains,i.e.,six from roots,three from the stem and three from the leaves were isolated.The strains were screened for their growth-promoting activity in rice plants because rice shows a quick and easy response to the bioactive compounds present in the culture filtrate(CF)of the potent endophytic strains.The rice plants were cultivated in pots containing 30 mL of 0.8%w/v water-agar medium.The pots were placed in a growth chamber,operated at 28±0.3℃ for 14 h(day);and 25±0.3℃ for 10 h(night),at 70%relative-humidity.Among the isolated strains,R1,S1,S3,L1,R5 and R6 showed visible growth promotion in rice plants.The biochemical analysis revealed that the strains were able to produce indole acetic acid(IAA)and flavonoids in higher quantities.Moreover,the strains also produced bioactive compounds that inhibited the growth of Escherichia coli and Aspergillus flavus using the well diffusion method.From the results,it was concluded that these strains can secrete potent compounds that can promote the host plant growth and inhibit the growth of pathogenic microorganisms and,therefore,can be used as bio-fertilizer and bio-control agents.
基金Supported by Algerian Ministry of Higher Education and Scientific Research.
文摘Objective:To evaluate the antioxidant and antimicrobial activity of methanolic extract extracts of selected Algerian medicinal plants.Methods:Antioxidant activity of extracts was evaluated in terms of radical scavenging potential(2,2-diphenyl-1-picrylhydrazyl)and β-carotene bleaching assay.Total phenolic contents and flavonoid contents were also measured.Antimicrobial activity of these plants was examined against Bacillus subtilis,Staphylococcus aureus,Escherichia coli,Pseudomonas aeruginosa and Candida albicans.Results:The values of IC_(50) ranged from 4.30μg/mL to 486.6μg/mL for the DPPH method,while total antioxidant activity using β-carotene/linoleic acid bleaching assay ranged from 17.03%to 86.13%.It was found that Pistacia lentiscus showed the highest antioxidant capacities using DPPH assay(IC_(50)=4.30μg/mL),while Populus trimula,Origanum glandulosum,Centaurea calcitrapa,Sysimbrium officinalis and Rhamnus alaternus showed the highest percent of total antioxidant activity in β-carotene/linoleic acid bleaching assay.Total phenolic and flavonoid contents ranged from 3.96 to 259.65 mg GAE/g extract and from 1.13 to 26.84 mg QE/g extract,respectively.The most interesting antimicrobial activity was obtained from Sysimbrium officinalis,Rhamnus alaternus,Origanum glandulosum,Cupressus sempervirens,Pinus halipensis and Centaurea calcitrapa.Conclusions:The results indicated that the plants tested may be potential sources for isolation of natural antioxidant and antimicrobial compounds.
基金Independent Application Project of Agricultural and Social Development Scientific Research in Hangzhou(20191203B31).
文摘[Objectives]To explore the antimicrobial and antioxidant activities of flavonoid and polysaccharide extracts from bulbs of Lycoris aurea.[Methods]The disc diffusion method was used to evaluate the antimicrobial activity of flavonoid and polysaccharide extracts from the bulbs of L.aurea.The antioxidant activity was determined by scavenging of hydroxyl and 1,1-diphenyl-2-picrylhydrazine(DPPH)free radicals,and reducing ability.[Results]Flavonoids were effective on 7 microorganisms,but polysaccharides had no effect.Flavonoids had better hydroxyl free radical scavenging activity and reducing capacity than polysaccharides,but weaker than ascorbic acid.However,flavonoids had similar DPPH free radical activity to ascorbic acid.The strong antibacterial and antioxidant activities of flavonoids were mainly attributed to the high content of total phenols in the extract,which was(76.71±4.42)mg/g.[Conclusions]The study shows that flavonoids from bulbs of L.aurea could be regarded as a new potential source of natural bacterial inhibitors and antioxidants.
文摘The rapid increase of bacterial resistance strains to multiple antibiotics has become a global public health concern. In the present study, actinomycetes from different districts of Libyan soil were isolated and screened for their inhibitory activity against pathogenic bacteria and fungi. Three hundred soil samples were taken from 77 diverse ecosystems, including deserts, forests, pastureland, and cropland located in different climatic regions in Libya. A total of 164 actinomycetes were obtained. Of 164 isolates, 38 (23.2%) isolates were morphologically and microscopically characterized by spore chain and surface morphology, aerial and substrate mycelia and soluble pigments. The preliminary classification of the isolates illustrates that all isolates belong to the genus Streptomyces. These isolates were further examined for their antagonistic potential against nine pathogenic bacteria and fungi. Out of 38, 11 (28.9%) isolates showed their capability to produce inhibitory substances against at least two tested strains. Among bacterial strains, Staphylococcus aureus was susceptible to almost all eleven isolates (90.9%), while Streptococcus pyogenes was found to be resistant to most selected isolates (18.2%). The isolate, 063 (Wadan soil-desert zone) was the only isolate that exhibited broad spectrum antimicrobial activity against all tested pathogenic microbes, and hence was selected for further study. According to its cultural, morphological, physiological, and biochemical characteristics, the isolate 063 was identified as Streptomyces rochei. The results obtained indicate that the Libyan soil, particularly in extreme environments, could be a potent source of bioactive metabolites with antimicrobial potency against a wide variety of microbial pathogens. Thus, this investigation suggested that exploring new habitats in unexplored and untapped regions of Libya could provide a promising source of biologically active compounds for therapeutic applications.
文摘New cobalt(II) complex, [Co(O<sub>2</sub>C<sub>15</sub>H<sub>11</sub>N<sub>2</sub>S)<sub>2</sub>(OH<sub>2</sub>)<sub>2</sub>]∙2H<sub>2</sub>O (1∙2H<sub>2</sub>O), has been synthesized upon reaction of cobalt chloride hexahydrate (Co(Cl)<sub>2</sub>∙6H<sub>2</sub>O) with 3-methyl-1-Phenyl-4-(2-thienoyl)-pyrazol-5-one (referred as HL) in ethanol at room temperature. Single crystal X-ray diffraction (XRD), spectroscopic methods, and microelemental analyses were used to characterize 1∙2H<sub>2</sub>O. Compound 1∙2H<sub>2</sub>O crystallizes in the orthorhombic crystal system with a Pbca space group and with the cobalt atom being pseudo-octahedral coordinated. The broth microdilution technique was used to screen the free ligand (HL) and the complex (1∙2H<sub>2</sub>O) for antimicrobial activities. HL has a low activity (MIC > 100 μg/mL) on all microorganisms, whereas compound 1∙2H<sub>2</sub>O displayed moderate activity (10 ∙2H<sub>2</sub>O exhibited bactericidal and fungicidal activity respectively on all the bacteria and yeasts tested. These findings reveal that the antimicrobial activity of HL was enhanced upon coordination to Co(II) ion against all microorganisms (bacteria and fungus).
文摘New cobalt(II) complex, [Co(O<sub>2</sub>C<sub>15</sub>H<sub>11</sub>N<sub>2</sub>S)<sub>2</sub>(OH<sub>2</sub>)<sub>2</sub>]∙2H<sub>2</sub>O (1∙2H<sub>2</sub>O), has been synthesized upon reaction of cobalt chloride hexahydrate (Co(Cl)<sub>2</sub>∙6H<sub>2</sub>O) with 3-methyl-1-Phenyl-4-(2-thienoyl)-pyrazol-5-one (referred as HL) in ethanol at room temperature. Single crystal X-ray diffraction (XRD), spectroscopic methods, and microelemental analyses were used to characterize 1∙2H<sub>2</sub>O. Compound 1∙2H<sub>2</sub>O crystallizes in the orthorhombic crystal system with a Pbca space group and with the cobalt atom being pseudo-octahedral coordinated. The broth microdilution technique was used to screen the free ligand (HL) and the complex (1∙2H<sub>2</sub>O) for antimicrobial activities. HL has a low activity (MIC > 100 μg/mL) on all microorganisms, whereas compound 1∙2H<sub>2</sub>O displayed moderate activity (10 ∙2H<sub>2</sub>O exhibited bactericidal and fungicidal activity respectively on all the bacteria and yeasts tested. These findings reveal that the antimicrobial activity of HL was enhanced upon coordination to Co(II) ion against all microorganisms (bacteria and fungus).
