摘要 :
The enantiospecific syntheses of both enantiomers of bacillamide C and neobacillamide A are described, along with the measurement of their optical activities, leading to the revision of the proposed absolute configurations of thes...
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The enantiospecific syntheses of both enantiomers of bacillamide C and neobacillamide A are described, along with the measurement of their optical activities, leading to the revision of the proposed absolute configurations of these natural products.
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Harmful algal blooms have become a great challenge to global aquatic ecosystems over the past decades. Given their low toxicity, high selectivity, and environment-friendly properties, the use of natural products and their analogue...
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Harmful algal blooms have become a great challenge to global aquatic ecosystems over the past decades. Given their low toxicity, high selectivity, and environment-friendly properties, the use of natural products and their analogues as algicides has proven to be particularly efficient. In the present study, algicidal activity of naturally occurring bacillamides A-C, alkaloid (1), and neobacillamide A, as well as their synthetic analogues were investigated intensively. Bioassay results showed that, relative to natural bacillamide alkaloids, aniline-derived analogue (10d) exhibited higher algicidal potential against three freshwater harmful algae Mycrocyctis aeruginosa, Scenedesmus obliquus, and Chlorella pyrenoidosa, suggesting that it could be used as a promising lead compound to develop novel algicide for controlling harmful algal blooms.
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A straightforward access to 2-alkyl and 2-arylthiazolines by condensation of-aminothiols on nitriles, catalyzed by phosphotungstic acid (2%) under microwave irradiation, is described. This method has been directly applied to a sho...
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A straightforward access to 2-alkyl and 2-arylthiazolines by condensation of-aminothiols on nitriles, catalyzed by phosphotungstic acid (2%) under microwave irradiation, is described. This method has been directly applied to a short and efficient synthesis of bacillamide A (16).
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Bacillamide (1) was isolated as a new algicide against the harmful dinoflagellate, Cochlodinium polykrikoides, from the marine bacterium, Bacillus sp. SY-1, and its structure was elucidated by extensive two-dimensional NMR techniq...
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Bacillamide (1) was isolated as a new algicide against the harmful dinoflagellate, Cochlodinium polykrikoides, from the marine bacterium, Bacillus sp. SY-1, and its structure was elucidated by extensive two-dimensional NMR techniques including ~1H-~(15)N HMBC analysis and mass analysis. Bacillamide showed algicidal activity against C. polykrikoides with LC_(50) of 3.2 μg/ml.
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Tryptamine derivatives such as tryptamine and bacillamides were strong algicidal compounds promising in controlling harmful algae blooms, but their bioactivity and application researches were hindered by extremely low natural prod...
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Tryptamine derivatives such as tryptamine and bacillamides were strong algicidal compounds promising in controlling harmful algae blooms, but their bioactivity and application researches were hindered by extremely low natural production rates. This study found an induced production of algicidal tryptamine derivatives by co-culture of marine Streptomyces with Bacillus mycoides, and optimised the culture method through changing important factors such as medium nutrition content, culture mode and pH value. The final established co-culture method used only 5g yeast extracts and 5g glycerol in 1L 75% sea water, but got a yield of 14.9mg/L N-acetyltryptamine, 2.8mg/L N-propanoyltryptamine, 3.0mg/L bacillamide A, 13.7mg/L bacillamide B and 9.6mg/L bacillamide C, which were all undetectable under normal culture conditions.
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Bacillamide C, a potential natural antialgae active compound, is produced by Bacillus atrophaeus C89 derived from marine sponge Dysidea avara. A nonribosomal peptide synthetase (NRPS) cluster is hypothesized to be involved in the ...
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Bacillamide C, a potential natural antialgae active compound, is produced by Bacillus atrophaeus C89 derived from marine sponge Dysidea avara. A nonribosomal peptide synthetase (NRPS) cluster is hypothesized to be involved in the biosynthesis of bacillamide C. The NRPS with a domain string of A1-PCP1-Cy-A2-PCP2-C can be divided into three functional modules. After heterologous expression and purification of module A1-PCP1 and module Cy-A2-PCP2, their catalytic activities were biochemically proven in vitro by the reaction with the apo-PCP domain transformed to the holo-PCP domain through a phosphopantetheinyl transferase, ATP, and substrate amino acids. Five- membered heterocyclic AlaCys(thiazole) with molecular weight of 172.0389 was detected. This proved the formation of the heterocyclic dipeptide AlaCys(thiazole), which is considered to be a building block for the biosynthesis of bacillamide. This study provides a basis for further biosynthesis of bacillamides.
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摘要 :
Nonribosomal peptide synthetases (NRPSs) are multi-modular enzymes involved in the biosynthesis of natural products. Bacillamide C was synthesized by Bacillus atrophaeus C89. A nonribosomal peptide synthetase (NRPS) cluster found ...
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Nonribosomal peptide synthetases (NRPSs) are multi-modular enzymes involved in the biosynthesis of natural products. Bacillamide C was synthesized by Bacillus atrophaeus C89. A nonribosomal peptide synthetase (NRPS) cluster found in the genome of B. atrophaeus C89 was hypothesized to be responsible for the biosynthesis of bacillamide C using alanine and cysteine as substrates. Here, the structure analysis of adenylation domains based on homologous proteins with known crystal structures indicated locations of the substrate-binding pockets. Molecular docking suggested alanine and cysteine as the potential substrates for the two adenylation domains in the NRPS cluster. Furthermore, biochemical characterization of the purified recombinant adenylation domains proved that alanine and cysteine were the optimum substrates for the two adenylation domains. The results provided the in vitro evidence for the hypothesis that the two adenylation domains in the NRPS of B. atrophaeus C89 preferentially select alanine and cysteine, respectively, as a substrate to synthesize bacillamide C. Furthermore, this study on substrates selectivity of adenylation domains provided basis for rational design of bacillamide analogs.
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Marine natural products with biological activity represent an important resource for marine drugs and biotechnological products;however, most marine natural products, especially those derived from sponges, have not been further de...
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Marine natural products with biological activity represent an important resource for marine drugs and biotechnological products;however, most marine natural products, especially those derived from sponges, have not been further developed because of the limited number of sources. The scale-up cultivation of the microbial source of sponge-derived natural products could provide a possible approach to solve this bottleneck problem. In this study, statistical Plackett-Burman (PB) design and Box-Behnken response surface methodology (RSM) were used to optimize the medium components to increase the production of bacillamide C by the Bacillus atrophaeus strain C89, which was associated with the marine sponge Dysidea avara. The obtained optimal medium consisted of 3.64 g/L corn starch, 6.29 g/L CaCO_3, 4.00 g/L soy peptone, 6.00 g/L peptone, 0.10g/L cysteine and 0.02 g/L tryptophan with artificial sea water (ASW). Using this optimized medium, the concentration of bacillamide C reached 70.85 mg/L in fed-batch cultivation in a 5-L fermentor at pH 7.70, which was 25.80-fold higher than the level observed in a shake flask using the basic medium. This study provides a potential approach for the production of bacillamide C and related derivatives, which was the first to optimize the cultivation of sponge-associated microbes for the production of marine natural products.
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摘要 :
Synthesis of fourteen analogues of bacillamide, a bioactive tryptamide alkaloid of marine origin, has been accomplished through a highly efficient convergent route. The present solvent-free protocol involves the formation of thiaz...
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Synthesis of fourteen analogues of bacillamide, a bioactive tryptamide alkaloid of marine origin, has been accomplished through a highly efficient convergent route. The present solvent-free protocol involves the formation of thiazole ring in the initial step followed by amide coupling between substituted ethyl 2-all收起
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A new sulphur-containing natural alkaloid named microbiaeratin (1a) was isolated, together with the known microbiaeratinin (2, bacillamide) from the culture filtrate of Microbispora aerata strain IMBAS-11A. The organism was isolat...
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A new sulphur-containing natural alkaloid named microbiaeratin (1a) was isolated, together with the known microbiaeratinin (2, bacillamide) from the culture filtrate of Microbispora aerata strain IMBAS-11A. The organism was isolated from penguin excrements collected on the Antarctic Livingston Island. The structure was elucidated by one- and two-dimensional NMR experiments and mass spectrometric investigations.
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