Essential oil(EO)has significant antifungal activity.However,there is limited information on the mechanism of the synergistic antifungal effect of the effective components of EO against fungi.In the present study,mole...Essential oil(EO)has significant antifungal activity.However,there is limited information on the mechanism of the synergistic antifungal effect of the effective components of EO against fungi.In the present study,molecular electrostatic potential and molecular docking were used for the first time to investigate the synergistic antifungal mechanism of eugenol and citral small molecule(C_(EC))against Penicillium roqueforti.The results showed that the C_(EC)treatment made the activity ofβ-(1,3)-glucan synthase(GS)and chitin synthase(CS)decreas by 20.2%and 11.1%,respectively,and the contents of which decreased by 85.0%and 27.9%,respectively compared with the control group.Molecular docking revealed that C EC small molecules could bind to GS and CS through different amino acid residues,inhibiting their activity and synthesis.The C EC can combine with tryptophan,tyrosine,and phenylalanine in the cell membrane,causing damage to the cell membrane.The binding sites between small molecules and amino acids were mainly around the OH group.In addition,C EC affected the energy metabolism system and inhibited the glycolysis pathway.Simultaneously,C EC treatment reduced the ergosterol content in the cell membrane by 58.2%compared with the control group.Finally,changes in𝛽-galactosidase,metal ion leakage,and relative conductivity confirmed the destruction of the cell membrane,which resulted in the leakage of cell contents.The above results showed that C EC can kill P.roqueforti by inhibiting energy metabolism and destroying the integrity of the cell membrane.展开更多
The harmof Aspergillus flavus(A.flavus)and aflatoxin is a severe food safety problemworldwide,which causes huge economic losses every year.Therefore,it is urgent to control the growth of A.flavus and the biosynthesis ...The harmof Aspergillus flavus(A.flavus)and aflatoxin is a severe food safety problemworldwide,which causes huge economic losses every year.Therefore,it is urgent to control the growth of A.flavus and the biosynthesis of aflatoxin.Plant-derived natural compounds are superior to synthetic fungicide in inhibiting the growth of A.flavus benefiting from their high safety to the environment,humans and stock,and low cost.This study aimed to evaluate the antifungal effects and potential antifungal mechanisms of three plant-derived compounds(octanal,nonanal and decanal)against A.flavus.We determined the minimum inhibitory concentrations(MICs)and action mechanism of the three volatile aldehydes on A.flavus and also performed calcofluor white(CW)staining for visualizing the distribution of septa.Cell respiration metabolism and the pathogenicity on maize kernels were also carried out to evaluate the efficacy of the three volatile aldehydes on the growth of A.flavus.The results showed that the three volatile aldehydes could inhibit the germination of spores and mycelial growth of A.flavus,the MICs on spores and mycelia were:octanal(1.0 and 0.5μL/mL),nonanal(0.5 and 2.0μL/mL),and decanal(1 and 5μL/mL).The three volatile aldehydes could strongly damage the integrity of both the cell wall and the cell membrane of A.flavus.Meanwhile,they could decrease the content of total lipid and inhibit respiration metabolism of A.flavus cell.Results of in vitro antifungal test showed that all the three volatile aldehydes could effectively prevent the growth of A.flavus on maize kernels.The study revealed that octanal,nonanal and decanal could effectively inhibit the growth of A.flavus both in culture medium and on maize kernels to different extent.The results confirmed that the plant-derived compounds could be developed into promising antifungal agents applied in the preservation of grains.This study provides a theoretical basis for the research and application of potential antifungal agents.展开更多
To study the structure-antifungal activity of vanillin against Aspergillus flavus(A.flavus),the susceptibilities of A.flavus to vanillin and its isomers(o-vanillin,2-hydroxy-4-methoxybenzaldehyde(HMB),2-hydroxy-5-meth...To study the structure-antifungal activity of vanillin against Aspergillus flavus(A.flavus),the susceptibilities of A.flavus to vanillin and its isomers(o-vanillin,2-hydroxy-4-methoxybenzaldehyde(HMB),2-hydroxy-5-methoxybenzaldehyde)and the possible antifungal mechanisms have been investigated.All the four volatile aldehydes could inhibit the germination of spores,and the minimum inhibitory concentrations(MICs)of them were in this order:vanillin(200μg/mL),o-vanillin(100μg/mL),2-hydroxy-5-methoxybenzaldehyde(100μg/mL),HMB(70μg/mL).The minimum fungicidal concentrations(MFCs)of them were in this order:vanillin(240μg/mL),o-vanillin(160μg/mL),HMB(140μg/mL),2-hydroxy-5-methoxybenzaldehyde(140μg/mL).Spore size was arrested at 0 h with the treatment of the four volatile aldehydes.Effects of the four volatile aldehydes on the cell wall and cell membrane integrity of A flavus were observed by calcofluor white(CW)staining and propidium iodide(PI)staining.The results showed that HMB exerted the strongest antifungal and fungicidal effects on the growth of A.flavus.The four volatile aldehydes had little influence on cell wall integrity after 3-hour treatment,however,they could strongly damage the cell membrane integrity.All the four volatile aldehydes could effectively prevent the growth of A.flavus on peanut seeds.The antifungal mechanisms of the four volatile aldehydes provide theoretical foundations for their development of new antifungal agents.展开更多
The antifungal activity and encapsulation properties of cinnamaldehyde-loaded microcapsules by tannic acid were investigated.The results showed that cinnamaldehyde exhibited a high in vitro antifungal effect against A...The antifungal activity and encapsulation properties of cinnamaldehyde-loaded microcapsules by tannic acid were investigated.The results showed that cinnamaldehyde exhibited a high in vitro antifungal effect against Aspergillus brasiliensis through altering the morphology of the hyphae,and its inhibition zone diameter(IZD)exceeded 15 mm with a minimum inhibitory concentration of 1.0 mg/mL.Cinnamaldehyde-loaded microcapsules crosslinked with tannic acid have a high encapsulation efficiency(92.53±5.20%)and antifungal activity(37.82±0.63 mm),and the retention rate was 2.5 times of that of unencapsulated cinnamaldehyde after 30-d storage at 37℃.Furthermore,the antifungal stability was enhanced(IZD 25.37 mm)after 60-d storage at 37℃ as compared with that of cinnamaldehyde(IZD 22.07 mm).The results of cell membrane integrity and the extracellular protein content also indicated that the microencapsulation could effectively protect cinnamaldehyde,delay the decrease of antifungal effect and improve its long-term antifungal activity against A.brasiliensis by increasing the retention rate of cinnamaldehyde after storage.展开更多
Penicillium italicum is the causal agent of citrus blue mold,which is a major threat to the global citrus fruit industry.Antofine,a natural phenanthroindolizidine alkaloid,is water-soluble and exhibits a broad range o...Penicillium italicum is the causal agent of citrus blue mold,which is a major threat to the global citrus fruit industry.Antofine,a natural phenanthroindolizidine alkaloid,is water-soluble and exhibits a broad range of biological activities.However,whether it can inhibit P italicum growth and the potential inhibitory mechanism remains to be elucidated.This study aimed to investigate the antifungal mechanism of antofine against P italicum using scanning electron microscopy,transmission electron microscopy(TEM),propidium iodide staining,and tandem mass tag-labeled quantitative proteomic analysis.Antofine was found to exhibit its preeminent antifungal activity against P italicum with a minimum inhibitory concentration of 1.56 mg/L and a minimum fungicidal concentration of 6.25 mg/L.The challenge test revealed that antofine inhibited the development of citrus blue mold during a 6-d P italicum-infected period.Antofine acted on its potential multitargets to inhibit P italicum growth by synergistically activating oxidative stress through accumulating excess reactive oxygen species,impairing membrane integrity.inducing membrane lipid peroxidation,and disrupting mitochondrial function,thereby disrupting the membrane system and reducing cell via-bility.Moreover,antofine treatment downregulated most differentially expressed proteins involved in carbon metabolism,pyruvate metabolism,and the tricarboxylic acid cycle(TCA)in P italicum mycelia,which may explain the mitochondrial decomposition observed by TEM and the de-clines in ATP levels as well as the activities of TCA-related enzymes.These results indicate that antofine treatment inhibited P italicum growth by targeting the cell membrane and mitochondria.展开更多
基金supported by the National Natural Science Foundation of China(32202192)Special fund for Taishan Scholars Project,and Shandong Provincial Natural Science Foundation(ZR2020MC213).
文摘Essential oil(EO)has significant antifungal activity.However,there is limited information on the mechanism of the synergistic antifungal effect of the effective components of EO against fungi.In the present study,molecular electrostatic potential and molecular docking were used for the first time to investigate the synergistic antifungal mechanism of eugenol and citral small molecule(C_(EC))against Penicillium roqueforti.The results showed that the C_(EC)treatment made the activity ofβ-(1,3)-glucan synthase(GS)and chitin synthase(CS)decreas by 20.2%and 11.1%,respectively,and the contents of which decreased by 85.0%and 27.9%,respectively compared with the control group.Molecular docking revealed that C EC small molecules could bind to GS and CS through different amino acid residues,inhibiting their activity and synthesis.The C EC can combine with tryptophan,tyrosine,and phenylalanine in the cell membrane,causing damage to the cell membrane.The binding sites between small molecules and amino acids were mainly around the OH group.In addition,C EC affected the energy metabolism system and inhibited the glycolysis pathway.Simultaneously,C EC treatment reduced the ergosterol content in the cell membrane by 58.2%compared with the control group.Finally,changes in𝛽-galactosidase,metal ion leakage,and relative conductivity confirmed the destruction of the cell membrane,which resulted in the leakage of cell contents.The above results showed that C EC can kill P.roqueforti by inhibiting energy metabolism and destroying the integrity of the cell membrane.
基金This study was funded by the Doctor Research Fund of Henan University of Technology(grant number 2019BS019)the Natural Science Research Projects of Education Department of Henan Province(21A550005).
文摘The harmof Aspergillus flavus(A.flavus)and aflatoxin is a severe food safety problemworldwide,which causes huge economic losses every year.Therefore,it is urgent to control the growth of A.flavus and the biosynthesis of aflatoxin.Plant-derived natural compounds are superior to synthetic fungicide in inhibiting the growth of A.flavus benefiting from their high safety to the environment,humans and stock,and low cost.This study aimed to evaluate the antifungal effects and potential antifungal mechanisms of three plant-derived compounds(octanal,nonanal and decanal)against A.flavus.We determined the minimum inhibitory concentrations(MICs)and action mechanism of the three volatile aldehydes on A.flavus and also performed calcofluor white(CW)staining for visualizing the distribution of septa.Cell respiration metabolism and the pathogenicity on maize kernels were also carried out to evaluate the efficacy of the three volatile aldehydes on the growth of A.flavus.The results showed that the three volatile aldehydes could inhibit the germination of spores and mycelial growth of A.flavus,the MICs on spores and mycelia were:octanal(1.0 and 0.5μL/mL),nonanal(0.5 and 2.0μL/mL),and decanal(1 and 5μL/mL).The three volatile aldehydes could strongly damage the integrity of both the cell wall and the cell membrane of A.flavus.Meanwhile,they could decrease the content of total lipid and inhibit respiration metabolism of A.flavus cell.Results of in vitro antifungal test showed that all the three volatile aldehydes could effectively prevent the growth of A.flavus on maize kernels.The study revealed that octanal,nonanal and decanal could effectively inhibit the growth of A.flavus both in culture medium and on maize kernels to different extent.The results confirmed that the plant-derived compounds could be developed into promising antifungal agents applied in the preservation of grains.This study provides a theoretical basis for the research and application of potential antifungal agents.
基金the financial support of the Doctor Research Fund of Henan University of Technology(2019BS019)the Natural Science Research Projects of Education Department of Henan Province(21A550005)the Innovative Funds plan of Henan University of Technology(2020ZKCJ17)。
文摘To study the structure-antifungal activity of vanillin against Aspergillus flavus(A.flavus),the susceptibilities of A.flavus to vanillin and its isomers(o-vanillin,2-hydroxy-4-methoxybenzaldehyde(HMB),2-hydroxy-5-methoxybenzaldehyde)and the possible antifungal mechanisms have been investigated.All the four volatile aldehydes could inhibit the germination of spores,and the minimum inhibitory concentrations(MICs)of them were in this order:vanillin(200μg/mL),o-vanillin(100μg/mL),2-hydroxy-5-methoxybenzaldehyde(100μg/mL),HMB(70μg/mL).The minimum fungicidal concentrations(MFCs)of them were in this order:vanillin(240μg/mL),o-vanillin(160μg/mL),HMB(140μg/mL),2-hydroxy-5-methoxybenzaldehyde(140μg/mL).Spore size was arrested at 0 h with the treatment of the four volatile aldehydes.Effects of the four volatile aldehydes on the cell wall and cell membrane integrity of A flavus were observed by calcofluor white(CW)staining and propidium iodide(PI)staining.The results showed that HMB exerted the strongest antifungal and fungicidal effects on the growth of A.flavus.The four volatile aldehydes had little influence on cell wall integrity after 3-hour treatment,however,they could strongly damage the cell membrane integrity.All the four volatile aldehydes could effectively prevent the growth of A.flavus on peanut seeds.The antifungal mechanisms of the four volatile aldehydes provide theoretical foundations for their development of new antifungal agents.
基金greatly appreciate the joint support for study by projects of the National key R&D program(2016YFD0400801)National First-class Discipline of Food Science and Technology(JUFSTR20180204)program of "Collaborative innovation center of food safety and quality control in Jiangsu Province".
文摘The antifungal activity and encapsulation properties of cinnamaldehyde-loaded microcapsules by tannic acid were investigated.The results showed that cinnamaldehyde exhibited a high in vitro antifungal effect against Aspergillus brasiliensis through altering the morphology of the hyphae,and its inhibition zone diameter(IZD)exceeded 15 mm with a minimum inhibitory concentration of 1.0 mg/mL.Cinnamaldehyde-loaded microcapsules crosslinked with tannic acid have a high encapsulation efficiency(92.53±5.20%)and antifungal activity(37.82±0.63 mm),and the retention rate was 2.5 times of that of unencapsulated cinnamaldehyde after 30-d storage at 37℃.Furthermore,the antifungal stability was enhanced(IZD 25.37 mm)after 60-d storage at 37℃ as compared with that of cinnamaldehyde(IZD 22.07 mm).The results of cell membrane integrity and the extracellular protein content also indicated that the microencapsulation could effectively protect cinnamaldehyde,delay the decrease of antifungal effect and improve its long-term antifungal activity against A.brasiliensis by increasing the retention rate of cinnamaldehyde after storage.
基金funded by the National Natural Science Foundation of China(Nos.32002104 and 32060703)the Jiangxi Provincial Natural Science Foundation of China(No.20212BAB205011).
文摘Penicillium italicum is the causal agent of citrus blue mold,which is a major threat to the global citrus fruit industry.Antofine,a natural phenanthroindolizidine alkaloid,is water-soluble and exhibits a broad range of biological activities.However,whether it can inhibit P italicum growth and the potential inhibitory mechanism remains to be elucidated.This study aimed to investigate the antifungal mechanism of antofine against P italicum using scanning electron microscopy,transmission electron microscopy(TEM),propidium iodide staining,and tandem mass tag-labeled quantitative proteomic analysis.Antofine was found to exhibit its preeminent antifungal activity against P italicum with a minimum inhibitory concentration of 1.56 mg/L and a minimum fungicidal concentration of 6.25 mg/L.The challenge test revealed that antofine inhibited the development of citrus blue mold during a 6-d P italicum-infected period.Antofine acted on its potential multitargets to inhibit P italicum growth by synergistically activating oxidative stress through accumulating excess reactive oxygen species,impairing membrane integrity.inducing membrane lipid peroxidation,and disrupting mitochondrial function,thereby disrupting the membrane system and reducing cell via-bility.Moreover,antofine treatment downregulated most differentially expressed proteins involved in carbon metabolism,pyruvate metabolism,and the tricarboxylic acid cycle(TCA)in P italicum mycelia,which may explain the mitochondrial decomposition observed by TEM and the de-clines in ATP levels as well as the activities of TCA-related enzymes.These results indicate that antofine treatment inhibited P italicum growth by targeting the cell membrane and mitochondria.
