α‐Glucosidase Inhibitors from the Fungus Aspergillus terreus 3.05358

One new diketopiperazine alkaloid amauromine B ( 1 ), along with three known meroterpenoids, austalide B ( 2 ), austalides N and O ( 3 and 4 ), and two known steroids ( 5 and 6 ), was isolated and identified from the culture broth of the fungus Aspergillus terreus 3.05358. Their structures were elucidated by extensive spectroscopic techniques, including 2D‐NMR and MS analysis, the absolute configuration of 1 was unambiguously established by single crystal X‐ray diffraction analysis. All the isolates were evaluated for their inhibitory effects on α‐glucosidase. Amauromine B ( 1 ) and austalide N ( 3 ) exhibited more potent α‐glucosidase inhibitory activities than the positive control acarbose.     

Fatty acid composition and the characterization of a novel dioxo C18-fatty acid in the latex of Hevea brasiliensis

The fatty acids of the triacylglycerol fraction of the latex of the rubber plant consists of 97% of a C₁₈ furanoid fatty acid, 10,13-epoxy-11-methyloctadeca-10,12-dienoic. The free fatty acid fraction is composed of a more equally distributed mixture of 16:0, 18:0, 18:1, 18:2 and the furanoid acid. A novel dioxo fatty acid, 10,13-dioxo-11-methyloctadecanoic, was also isolated and characterized.     

褪黑素抗肿瘤机制的研究进展

褪黑素是新近引起人们广泛注意的天然抗肿瘤药物，对多种恶性或良性肿瘤具有明显抑制作用。其抗瘤机制复杂而广泛，主要包括调节雌激素作用通路，影响细胞周期，调节生长因子，干扰钙调素和微管蛋白功能，增加细胞间缝隙连接，对细胞代谢的影响以及抗氧化作用和免疫增强作用等。对于褪黑素作用机制的全面了解将有助于其进一步应用于临床。