New sterol esters from the flowers of Punica granatum Linn.

Two new beta-sitosterol esters have been isolated from the flowers of Punica granatum Linn. (Punicaceae) along with the known compounds n-tricosane (3), n-heptacosanyl n-hexanoate (4), olean-5,12-dien-3beta-ol-28-oic acid (5), and olean-12-en-3beta-ol-28-oic acid (6). The structures of the new phytosterols have been elucidated as stigmast-5-en-3beta-ol-3beta-dodecanoate (beta-sitosterol laurate, 1) and stigmast-5-en-3beta-ol-3beta-tetradecanoate (beta-sitosterol myristate, 2) on the basis of spectral data and chemical analyses.

A new steroidal glycoside and fatty acid esters from the stem bark of Tectona grandis Linn.

The phytochemical investigation of the bark of Tectona grandis Linn. afforded a new steroidal glycoside identified as beta-sitosterol-beta-D-[4'-linolenyl-6'-(tridecan-4'''-one-1'''-oxy)] glucuranopyranoside and three new fatty esters, 7'-hydroxy-n-octacosanoyl n-decanoate, 20'-hydroxy eicosanyl linolenate and 18'-hydroxy n-hexacosanyl n-decanoate, along with the known compounds n-docosane, lup-20(29)-en-3beta-ol, betulinic acid and stigmast-5-en-3-O-beta-D-glucopyranoside. Their stereostructures have been elucidated on the basis of spectral data analyses and chemical reactions.

Antidiabetic effect of Punica granatum flowers: effect on hyperlipidemia, pancreatic cells lipid peroxidation and antioxidant enzymes in experimental diabetes.

The present study investigated the effects of Punica granatum aqueous extract (PgAq) on streptozotocin (STZ) induced diabetic rats by measuring fasting blood glucose, lipid profiles (atherogenic index), lipid peroxidation (LPO) and activities of both non-enzymatic and enzymatic antioxidants. Diabetes was induced by single intraperitoneal injection of STZ (60 mg/kg) to albino Wistar rats. The increase in blood glucose level, total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), very low density lipoprotein (VLDL), LPO level with decrease in high density lipoprotein cholesterol (HDL-C), reduced glutathione (GSH) content and antioxidant enzymes namely, glutathione peroxidase (GPx), glutathione reductase (GR), glutathione-S-transferase (GST), superoxide dismutase (SOD) and catalase (CAT) were the salient features observed in diabetic rats. On the other hand, oral administration of PgAq at doses of 250 mg/kg and 500 mg/kg for 21 days resulted in a significant reduction in fasting blood glucose, TC, TG, LDL-C, VLDL-C and tissue LPO levels coupled with elevation of HDL-C, GSH content and antioxidant enzymes in comparison with diabetic control group. The results suggest that PG could be used, as a dietary supplement, in the treatment of chronic diseases characterized by atherogenous lipoprotein profile, aggravated antioxidant status and impaired glucose metabolism and also in their prevention.

New 4'-substituted flavones from the fruit peels of Citrus limon (L.) Burm.f.

Two new 4'-substituted flavones isolated from the fruit peels of Citrus limon (L.) Burm.f. (Rutaceae) have been characterized as 4'-(9'-ethylene-16'-methylnon-9',15'-dien-7',11'-oate)-5,7-dimethoxyflavone (limonflavonyl lactone A, 1) and 4'-(9'-ethylene-16'-methylnon-9',15'-dien-7',11'-oate)-5,7,3'-trimethoxyflavone (limonflavonyl lactone B, 2) on the basis of spectral data and chemical analyses. Both the flavones are reported for the first time from a plant source.