title: Hypoglycemic diterpenoids from Tinospora crispa.
abstract: 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 α-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.
authors.affiliation: School of Pharmacy, College of Medicine, National Taiwan University, 1 Jen-Ai Road, Taipei 10051, Taiwan, Republic of China.
authors.forename: Sio-Hong
authors.initials: SH
authors.lastname: Lam
authors.forename: Chi-Tun
authors.initials: CT
authors.lastname: Ruan
authors.forename: Po-Hung
authors.initials: PH
authors.lastname: Hsieh
authors.forename: Ming-Jai
authors.initials: MJ
authors.lastname: Su
authors.forename: Shoei-Sheng
authors.initials: SS
authors.lastname: Lee
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000032:analysis / Q000378:metabolism; D003921:Diabetes Mellitus, Experimental / Q000097:blood / Q000188:drug therapy*; D004224:Diterpenes / Q000097:blood / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D007004:Hypoglycemic Agents / Q000097:blood / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D051379:Mice; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D013311:Streptozocin / Q000494:pharmacology; D031610:Tinospora / Q000737:chemistry*
chemical_list: C571466:2-O-lactoylborapetoside B; C571464:6'-O-lactoylborapetoside B; D001786:Blood Glucose; D004224:Diterpenes; D007004:Hypoglycemic Agents; C571465:tinocrispol A; D013311:Streptozocin