In order to obtain novel secondary metabolites, a deep sea inhabiting fungus Aspergillus versicolor CXCTD-06-6a was investigated. One new diketopiperazine brevianamide W(1a), as well as five known diketopiperazine alk...In order to obtain novel secondary metabolites, a deep sea inhabiting fungus Aspergillus versicolor CXCTD-06-6a was investigated. One new diketopiperazine brevianamide W(1a), as well as five known diketopiperazine alkaloids, diketopiperazine V(1b), brevianamide Q(2), brevianamide R(3), brevianamide K(4), and brevianamide E(5), were isolated from the Et OAc extract of the fermentation broth. Their structures were elucidated by spectroscopy techniques(NMR, MS). The six compounds exhibited moderate radical scavenging activity against DPPH with clearance ratio of 55.0%(1a and 1b), 53.7%(2), 46.2%(3), 61.4%(4) and 19.3%(5) at a concentration of 13.9 μmol L-1, respectively; while the positive control ascorbic acid showed a ratio of 70.3% at the concentration of 28.4 μmol L-1.展开更多
Seaweeds are known to exhibit various antimicrobial properties, since it harbours an enormous range of indigenous bioactive compounds. The emergence of drug resistant strains has directed to the identification of pros...Seaweeds are known to exhibit various antimicrobial properties, since it harbours an enormous range of indigenous bioactive compounds. The emergence of drug resistant strains has directed to the identification of prospective metabolites from seaweed and its endophytes, thereby exploiting the properties in resisting bacterial diseases. The current study was aimed to assess the antimicrobial activity of extracts obtained from Ulva reticulate, for which metabolites of Ulva reticulata and its endophytes were extracted and assessed against human pathogens like Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Salmonella typhi, and Bacillus subtilis. It was observed that the hexane extract of isolate VITDSJ2 was effective against all the tested pathogens but a significant inhibition was observed for Staphylococcus aureus and Escherichia coli. Further, Gas chromatography coupled with Mass spectroscopy （GC-MS） revealed the existence of phenol, 3, 5-bis （1, 1-dimethylethyl） in the crude hexane extract which is well-known to possess antibacterial activity. The effective isolate VITDSJ2 was identified to be the closest neighbour of Pseudomonas smtzeri by phenotypic and genotypic methods. The crude extracts of the seaweed Ulva reticulata was also screened for antibacterial activity and the hexane extract was effective in showing inhibition against all the tested pathogens. The compound in the crude extract of Ulva reticulata was identified as hentriacontane using GC-MS. The extracts obtained from dichloromethane did not show significant activity in comparison with the hexane extracts. Hence the metabolites of Ulva reticulata and the bacterial secondary metabolites of the endophytes could be used in the treatment of bacterial infections.展开更多
Bacillus subtilis produces many chemlcally-dwerse seconaary metaDolltes or interest to chemists ano biologlsts. Based on this, this review gives a detailed overview of the natural components produced by B. subtilis in...Bacillus subtilis produces many chemlcally-dwerse seconaary metaDolltes or interest to chemists ano biologlsts. Based on this, this review gives a detailed overview of the natural components produced by B. subtilis including cyclic lipopeptides, polypeptides, proteins （enzymes）, and non-peptide products. Their structures, bioactive ac- tivities and the relevant variants as novel lead structures for drug discovery are also described. The challenging effects of fermentation metabolites, isolation and purification, as well as the overproduction of bioactive com- pounds from B. subtilis by metabolic engineering, ＇~ere also highlighted. Systematically exploring biosynthetic routes and the functions of secondary metabolites from 13. subtilis may not only be beneficial in improving yields of the products, but also in helping them to be used in food industry and public medical service on a large-scale.展开更多
Symbionts are microorganisms residing in multicellular hosts(e.g., plants and animals), and they have been witnessed to be a rich source of diverse functional molecules. This review describes structures and biological...Symbionts are microorganisms residing in multicellular hosts(e.g., plants and animals), and they have been witnessed to be a rich source of diverse functional molecules. This review describes structures and biological activities of symbiont-derived secondary metabolites commonly referred to as "natural products", and highlights that symbiotic microbes represent an underexplored reservoir of natural products with unique scaffolds and promising significance in managing human healthcare and agricultural production.展开更多
基金supported by Chinese National Science Fund (No. 41176120)Promotive Research Fund for Excellent Young and Middle-aged Scientists of Shandong Province (No. BS2010HZ027)+1 种基金Specialized Research Fund for the Doctoral Program of Higher Education (No. 20100132120026)the Fifty First Postdoctoral Fund of China (2012M511552)
文摘In order to obtain novel secondary metabolites, a deep sea inhabiting fungus Aspergillus versicolor CXCTD-06-6a was investigated. One new diketopiperazine brevianamide W(1a), as well as five known diketopiperazine alkaloids, diketopiperazine V(1b), brevianamide Q(2), brevianamide R(3), brevianamide K(4), and brevianamide E(5), were isolated from the Et OAc extract of the fermentation broth. Their structures were elucidated by spectroscopy techniques(NMR, MS). The six compounds exhibited moderate radical scavenging activity against DPPH with clearance ratio of 55.0%(1a and 1b), 53.7%(2), 46.2%(3), 61.4%(4) and 19.3%(5) at a concentration of 13.9 μmol L-1, respectively; while the positive control ascorbic acid showed a ratio of 70.3% at the concentration of 28.4 μmol L-1.
文摘Seaweeds are known to exhibit various antimicrobial properties, since it harbours an enormous range of indigenous bioactive compounds. The emergence of drug resistant strains has directed to the identification of prospective metabolites from seaweed and its endophytes, thereby exploiting the properties in resisting bacterial diseases. The current study was aimed to assess the antimicrobial activity of extracts obtained from Ulva reticulate, for which metabolites of Ulva reticulata and its endophytes were extracted and assessed against human pathogens like Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Salmonella typhi, and Bacillus subtilis. It was observed that the hexane extract of isolate VITDSJ2 was effective against all the tested pathogens but a significant inhibition was observed for Staphylococcus aureus and Escherichia coli. Further, Gas chromatography coupled with Mass spectroscopy （GC-MS） revealed the existence of phenol, 3, 5-bis （1, 1-dimethylethyl） in the crude hexane extract which is well-known to possess antibacterial activity. The effective isolate VITDSJ2 was identified to be the closest neighbour of Pseudomonas smtzeri by phenotypic and genotypic methods. The crude extracts of the seaweed Ulva reticulata was also screened for antibacterial activity and the hexane extract was effective in showing inhibition against all the tested pathogens. The compound in the crude extract of Ulva reticulata was identified as hentriacontane using GC-MS. The extracts obtained from dichloromethane did not show significant activity in comparison with the hexane extracts. Hence the metabolites of Ulva reticulata and the bacterial secondary metabolites of the endophytes could be used in the treatment of bacterial infections.
基金Supported by the National Natural Science Foundation of China(21376215)the National Science and Technology Major Project of New Drug,China(2012ZX09103101-075)+2 种基金the Innovative Research Platform co-constructed by Zhejiang University and Taizhou City,and the Science and Technology Project of Zhejiang Province(2014C33174)the Major State Basic Research Development Program of China(2011CB710803)the National High-Tech Research and Development Program of China(2012AA022302)
文摘Bacillus subtilis produces many chemlcally-dwerse seconaary metaDolltes or interest to chemists ano biologlsts. Based on this, this review gives a detailed overview of the natural components produced by B. subtilis including cyclic lipopeptides, polypeptides, proteins （enzymes）, and non-peptide products. Their structures, bioactive ac- tivities and the relevant variants as novel lead structures for drug discovery are also described. The challenging effects of fermentation metabolites, isolation and purification, as well as the overproduction of bioactive com- pounds from B. subtilis by metabolic engineering, ＇~ere also highlighted. Systematically exploring biosynthetic routes and the functions of secondary metabolites from 13. subtilis may not only be beneficial in improving yields of the products, but also in helping them to be used in food industry and public medical service on a large-scale.
基金supported by the National High Technology Research and Development Program of China(2013AA092901)the National Natural Science Foundation of China(81121062,21132004,81421091)
文摘Symbionts are microorganisms residing in multicellular hosts(e.g., plants and animals), and they have been witnessed to be a rich source of diverse functional molecules. This review describes structures and biological activities of symbiont-derived secondary metabolites commonly referred to as "natural products", and highlights that symbiotic microbes represent an underexplored reservoir of natural products with unique scaffolds and promising significance in managing human healthcare and agricultural production.
