Streptomyces Bingchenggensis Research Articles

Bingchamides A and B, two novel cyclic pentapeptides from the Streptomyces bingchenggensis: fermentation, isolation, structure elucidation and biological properties

Two novel cyclic pentapeptides, bingchamides A (1) and B (2), have been isolated from the organic extracts of the mycelium of Streptomyces bingchenggensis. The structures of 1 and 2 were elucidated on the basis of extensive 1D and 2D NMR, as well as HRESI-MS, electrospray ionization-MS, UV and IR spectroscopic data analysis. Bingchamides A (1) and B (2) exhibited in vitro cytotoxicity toward human colon carcinoma cell line HCT-116 with the IC(50) values of 14.1 and 18.0 microg ml(-1), respectively. The bingchamides A (1) and B (2) scaffolds are probably promising structures for the development of new antitumor agents.

Three new milbemycin derivatives from Streptomyces bingchenggensis

In the continuing study of the chemical compositions of the strain Streptomyces bingchenggensis, three new milbemycin derivatives, milbemycin α31 (1), secomilbemycins C (2), and D (3), were isolated. Their structures were established on the basis of extensive spectroscopic analysis.

Improvement of milbemycin-producing Streptomyces bingchenggensis by rational screening of ultraviolet- and chemically induced mutants

Milbemycin antibiotics are produced by Streptomyceshygroscopicus subsp. aureolacrimosus and a newly isolated Streptomyces bingchenggensis, respectively. According to the biosynthetic pathway of milbemycins generated by S.hygroscopicus subsp. aureolacrimosus, a rational screening procedure with UV irradiation and N-methyl-N′-nitroso-N-nitrosoguanidine (NTG) mutation was performed to obtain high milbemycin-producing S. bingchenggensis. Aminoacetic acid (Glycine)-resistant mutants (AAr), propionate-resistant mutants (PRPr), streptomycin-resistant mutants (STRr) and 2-deoxy-d-glucose-resistant mutants (DOGr) were selected successively. A strain S. bingchenggensis BC-109-6 with AAr, PRPr, STRr and DOGr was obtained and its production of milbemycin A3 and A4 reached 1,450 μg/ml, which was 80% higher than that of the ancestral strain S. bingchenggensis BC-101-4. The subculture experiments indicated that the hereditary characteristic of high productivity of S. bingchenggensis BC-109-6 was stable. The production of milbemycin A3 and A4 by S. bingchenggensis BC-109-6 in a 50-l fermentor could reach 1,380 μg/ml after 360 h batch fermentation.

New Seco-milbemycins from Streptomyces bingchenggensis: Fermentation, Isolation and Structure Elucidation

Two new seco-milbemycins have been isolated and characterized from the Streptomyces bingchenggensis. On the basis of detailed spectroscopic analysis and comparison with the reported data of milbemycin beta(14), their structures were established to be the seco-milbemycins of milbemycin beta(14). However, milbemycin beta(14) and the two new seco-milbemycins were not converted to each other during purification by silica gel column or storage in the MeOH extract at room temperature. The two new seco-milbemycins are the first discovered from milbemycin-producing microorganisms. They may play an important role in understanding and perfecting the proposed biosynthesis pathways of milbemycins.

Two New β‐Class Milbemycins from Streptomyces bingchenggensis: Fermentation, Isolation, Structure Elucidation and Biological Properties.

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