Project description:Seven new compounds, including one dimer novel skeleton, chamaecyformosanin A (1); three diterpenes, chamaecyformosanins B-D (2-4); one sesquiterpene, chamaecyformosanin E (5); and two monoterpenes, chamaecyformosanins F and G (6 and 7) were isolated from the methanol extract of the bark of Chamaecyparis obtusa var. formosana. Their structures were established by the mean of spectroscopic analysis and the comparison of NMR data with those of known analogues. Their structures were elucidated on the basis of physicochemical evidence, in-depth NMR spectroscopic analysis, and high-resolution mass spectrometry. Furthermore, the isolated compounds were subjected to an evaluation of their antimicrobial activity. Metabolites 1, 3, and 4 present antibacterial activities. It is worth mentioning that the chemical composition of the bark of C. obtusa var. formosana has never been studied in the past. This is the first time the barks from C. obtusa var. formosana were studied and two new skeleton compounds, 1 and 7, were obtained.
Project description:Chamaecyparis obtusa var. formosana is a species indigenous to Taiwan and has been used as a medicinal plant. It has been claimed that the hot water extracts of C. obtusa var. formosana leaves (CoLE) with flavonoids and proanthocyanidins have anti-oxidant and anti-hyperglycemic activities in vitro. This study further examines the anti-hyperglycemic activity of CoLE and its possible mechanisms in hyperglycemic rats. Hyperglycemia of rats was induced by streptozotocin (STZ) and high-fat diets (HFD). Hyperglycemic rats treated orally with 30 and 150 mg/kg CoLE were classified into LCO and HCO groups, respectively. After three-month treatment, both LCO and HCO groups showed improved glucose metabolism in oral glucose tolerance and postprandial blood glucose tests. Decrease in HOMA-IR, leptin and adiponectin levels of the HCO group revealed amelioration of insulin and leptin resistance. Obesity and accumulation of visceral fats induced by STZ and HFD could be alleviated in both HCO and LCO groups. These anti-diabetic effects might be contributed by inhibition of intestinal digested enzymes and protein tyrosine phosphatases (PTPases). Although other studies are necessary, these findings suggest that CoLE could be potentially used as a health complement for treating diabetes without significant toxicity.
