Marine microorganisms have proven to be a rich source of natural products with unique structures and novel activities,due to their special living conditions.Macrolactins(MLNs),mostly produced by marine-derived microor...Marine microorganisms have proven to be a rich source of natural products with unique structures and novel activities,due to their special living conditions.Macrolactins(MLNs),mostly produced by marine-derived microorganisms,are a group of 24-membered lactone natural products,which exhibit potent antibacterial,antifungal,antiviral,anticancer,antiinfammatory,anti-angiogenic and other activities.Their extensive biological activities make them potential compounds for drug development.MLNs are biosynthesized via a type I polyketide synthase(PKS)pathway with diferent tailoring steps,such as epoxidation,glycosylation and acylation.These modifcation steps provide opportunities to diversify their structures by combinatorial biosynthesis strategies.This review mainly focuses on the newly discovered MLNs in the past fve years,including their biological activities and relevant biosynthetic studies.展开更多
Synthetic studies towards the C(3)-C(13) and C(14)-C(24) segments (3,4) of the potent antiviral and antitumor compound macrolactin A (1) are presented. Compound 3 was constructed via a convergent and facile approach, ...Synthetic studies towards the C(3)-C(13) and C(14)-C(24) segments (3,4) of the potent antiviral and antitumor compound macrolactin A (1) are presented. Compound 3 was constructed via a convergent and facile approach, exploiting Wittig olefination to generate the sensitive E, Z-diene moiety. Compound 4 was synthesized from the chiral-pool derived sulfone 39a via an α-alkylation-desulfonation reaction sequence. Cu(II)-catalyzed coupling of a Grignard reagent with an allylic bromide and Julia olefination were also investigated for the preparation of compound 4.展开更多
Marine-derived Bacillus strains have been proved to be a very promising source for natural product leads.However,transformation of environmental strains is much more difficult than that of domesticated strains.Here,we...Marine-derived Bacillus strains have been proved to be a very promising source for natural product leads.However,transformation of environmental strains is much more difficult than that of domesticated strains.Here,we report the development of an efficient and robust electroporation-based transformation system for marine-derived Bacillus marinus B-9987,which is a macrolactin antibiotics producer and a very promising biological control agent against fungal plant diseases.The transformation efficiency was greatly enhanced 103-fold by using unmethylated plasmid to bypass modification-restriction barrier,and using glycine betaine to protect cells from electrical damages during electroporation.Addition of HEPES and 2 mmol L?1MgCl2 further improved the efficiency by additional 2-fold,with a maximum value of 7.1×104 cfu/μg pHT3101.To demonstrate the feasibility and efficiency of the protocol,a green fluorescent protein reporter system was constructed;furthermore,phosphopantetheinyl transferase gene sfp,which is essential to the biosynthesis of polyketides and nonribosomal peptides,was overexpressed in B-9987,leading to increased production of macrolactin A by about 1.6-fold.In addition,this protocol is also applicable to marine-derived Bacillus licheniforms EI-34-6,indicating it could be a reference for other undomesticated Bacillus strains.To our knowledge,this is the first report regarding the transformation of marine-derived Bacillus strain.展开更多
基金This work was fnancially supported by the grants from the National Key R&D Program of China(2019YFC0312501)the National Natural Science Foundation of China(U1706206,31570032).
文摘Marine microorganisms have proven to be a rich source of natural products with unique structures and novel activities,due to their special living conditions.Macrolactins(MLNs),mostly produced by marine-derived microorganisms,are a group of 24-membered lactone natural products,which exhibit potent antibacterial,antifungal,antiviral,anticancer,antiinfammatory,anti-angiogenic and other activities.Their extensive biological activities make them potential compounds for drug development.MLNs are biosynthesized via a type I polyketide synthase(PKS)pathway with diferent tailoring steps,such as epoxidation,glycosylation and acylation.These modifcation steps provide opportunities to diversify their structures by combinatorial biosynthesis strategies.This review mainly focuses on the newly discovered MLNs in the past fve years,including their biological activities and relevant biosynthetic studies.
基金Project supported by the National Natural Science Foundation of Chinathe State Key Laboratory of Bio-organicNatural Products Chemistry
文摘Synthetic studies towards the C(3)-C(13) and C(14)-C(24) segments (3,4) of the potent antiviral and antitumor compound macrolactin A (1) are presented. Compound 3 was constructed via a convergent and facile approach, exploiting Wittig olefination to generate the sensitive E, Z-diene moiety. Compound 4 was synthesized from the chiral-pool derived sulfone 39a via an α-alkylation-desulfonation reaction sequence. Cu(II)-catalyzed coupling of a Grignard reagent with an allylic bromide and Julia olefination were also investigated for the preparation of compound 4.
基金supported by grants from the National Natural Science Foundation of China (31070072,31171201)the Program for New Century Excellent Talents in University (NCET-0900717)partially supported by the National Key Technologies Research and Development Program (2011BAE06B04)
文摘Marine-derived Bacillus strains have been proved to be a very promising source for natural product leads.However,transformation of environmental strains is much more difficult than that of domesticated strains.Here,we report the development of an efficient and robust electroporation-based transformation system for marine-derived Bacillus marinus B-9987,which is a macrolactin antibiotics producer and a very promising biological control agent against fungal plant diseases.The transformation efficiency was greatly enhanced 103-fold by using unmethylated plasmid to bypass modification-restriction barrier,and using glycine betaine to protect cells from electrical damages during electroporation.Addition of HEPES and 2 mmol L?1MgCl2 further improved the efficiency by additional 2-fold,with a maximum value of 7.1×104 cfu/μg pHT3101.To demonstrate the feasibility and efficiency of the protocol,a green fluorescent protein reporter system was constructed;furthermore,phosphopantetheinyl transferase gene sfp,which is essential to the biosynthesis of polyketides and nonribosomal peptides,was overexpressed in B-9987,leading to increased production of macrolactin A by about 1.6-fold.In addition,this protocol is also applicable to marine-derived Bacillus licheniforms EI-34-6,indicating it could be a reference for other undomesticated Bacillus strains.To our knowledge,this is the first report regarding the transformation of marine-derived Bacillus strain.
