Isolation and structural elucidation of secondary metabolites from marine Streptomyces sp. SCSIO 1934 / 中国中药杂志

Marine Actinobacteria are emerging as new resources for bioactive natural products with promise in novel drug discovery. In recent years, the richness and diversity of marine Actinobacteria from the South China Sea and their ability in producing bioactive products have been investigated. The objective of this work is to isolate and identify bioactive secondary metabolites from a marine actinobacterium SCSIO 1934 derived from sediments of South China Sea. The strain was identified as a Streptomyces spieces by analyzing its 16S rDNA sequence. Streptomyces sp. SCSIO 1934 was fermented under optimized conditions and seven bioactive secondary metabolites were isolated and purified by chromatographic methods including colum chromatography over silica gel and Sephadex LH-20. Their structures were elucidated as 17-O-demethylgeldanamycin (1), lebstatin (2), 17-O-demethyllebstatin (3), nigericin (4), nigericin sodium salt (5), abierixin (6), respectively, by detailed NMR spectroscopic data (1H, 13C, COSY, HSQC and HMBC). This work provided a new marine actinobacterium Streptomyces sp. SCSIO 1934, capable of producing diverse bioactive natural products.

Isolation and structure determination of cypritibetquinone A and B, two new phenanthraquinones from Cypripedium tibeticum / 药学学报

Aim To study the chemical constituents of Cypripedium tibeticum. Methods Compounds were isolated by repeated silica gel chromatography and purified on Sephadex LH-20 and structures were determined by spectral analysis. Results Cypritibetquinones A and B were isolated from the ethyl acetate residue and their structures were determined as 7-hydroxy-2-methoxy-1, 4-phenanthraquinone ( 1 ) and 7-hydroxy-2,10-dimethoxy-1,4-phenanthraquinone ( 2 ), respectively, by extensive spectral analyses. Conclusion Cypritibetquinones A and B are two new phenanthraquinones.

Clinical research on cholangioenterostomy without stent tube drainage / 中国普通外科杂志

Objective To investigate the feasibility of cholangioenterostomy without stent tube drainage. (Methods) In this study 52 cases anastomosed without stent tube drainage (group A) and 56 cases with stent tube drainage (control,group B) were included. The patients′course of therapy and recovery, postoperative follow-up and reoperation were compared between group A and B. Results The rate of bile leakage was (5.8)% (3/52) in group A and 3.6%(2/56) in group B, respectively ,which was not significant(P