Angucycline and angucyclinone derivatives from the marine‐derived Streptomyces sp

• Published in: Chirality (New York, N.Y.) N.Y.), 2022-02, Vol.34 (2), p.421-427
• Main Authors: Liu, Ming, Yang, Ying‐Jie, Gong, Ge, Li, Zhi, Zhang, Lu, Guo, Lin, Xu, Bo, Zhang, Shu‐Min, Xie, Ze‐Ping
• Format: Article
• Language: English
• Subjects: Absolute configuration; angucycline; angucyclinone; Anthraquinones - chemistry; Anthraquinones - pharmacology; Antiinfectives and antibacterials; antimicrobial activity; Configurations; Crystallography; Microbial Sensitivity Tests; Minimum inhibitory concentration; Molecular Structure; Rhamnose; Stereochemistry; Stereoisomerism; Streptomyces; Streptomyces - chemistry; Streptomyces sp; structure elucidation
• ISSN: 0899-0042; 1520-636X
• DOI: 10.1002/chir.23394

Atramycin C (1), one new angucycline bearing an O‐6 rhamnose side chain, along with one new highly hydroxylated angucyclinone emycin G (2), and ten known analogs (3–12) were isolated from the marine‐derived Streptomyces sp. strain BHB‐032. Their structures were assigned by spectroscopic analysis and comparison with literature data. The absolute configuration of the sugar unit of 1 was assigned as 6‐O‐α‐l‐rhamnoside, based on the analysis of the coupling constants and chemical derivatization, whereas the absolute configuration of 2 was determined by X‐ray diffraction. Furthermore, the stereochemistry of saccharothrixin A (3) and SNA‐8073‐A (4) was established unequivocally by X‐ray crystallography for the first time. Compounds 1 and 2 exhibited moderate antimicrobial activities with minimum inhibitory concentration (MIC) values ranging from 16 to 64 μg/ml. One new angucycline bearing a rare O‐6 rhamnose side chain (1), along with one new highly hydroxylated angucyclinone emycin G (2), and ten known analogs were isolated from the marine‐derived Streptomyces sp. strain BHB‐032. Compounds 1 and 2 exhibited moderate antimicrobial activities with MIC values ranging from 16 to 64 μg/ml.