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[摘要]:Three new diterpenoids, 2-O-lactoylborapetoside B (1), 6'-O-lactoylborapetoside B (2), and tinocrispol A (3), and nine known diterpenoids (4-12) were isolated from an EtOH extract of Tinospora crispa vines. Their structures were elucidated by spectroscopic analyses. The C-6 glucosyloxy group in borapetoside C (6) was revised to be alpha-oriented. The in vivo hypoglycemic activities of the major components, borapetosides A-C (4-6), were examined. Intraperitoneal injection of 4 and 6 (5 mg/kg) showed significant lowering of plasma glucose levels in normal and streptozotocin-induced type 1 diabetic mice. Borapetoside C increased glucose utilization in peripheral tissues and reduced hepatic gluconeogenesis, accounting for the hypoglycemic effect. |
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