[Show abstract][Hide abstract] ABSTRACT: Diospyros peregrina is an edible seasonal fruit found in coastal West Bengal, India. The fruits have been reported to possess a significant antioxidant activity. In this study, the aim was to isolate the lead compound responsible for the above-mentioned activity. The aqueous extract of D. peregrina fruit was subjected to dereplication coupled with an in vitro 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging assay. The n-butanol fraction of the aqueous extract of D. peregrina fruit exhibited significant antioxidant activity (IC(50), 131.10 µg mL(-1)) as compared with the parent extract (IC(50), 285.15 µg mL(-1)). The n-butanol fraction was subjected to silica gel column chromatographic separation coupled with a chemo-autographic study of column eluents, employing ethanolic DPPH as a spraying reagent. Two bioactive flavonoid glycosides, namely luteoline-4'-methyl-ether-7-O-glucoside and quercetin-3-O-(glucosyl)-glucoside, were identified to exhibit IC(50) values of 74.04 and 65.78 µg mL(-1), respectively in the DPPH assay.
Full-text · Article · Jan 2011 · Natural product research
[Show abstract][Hide abstract] ABSTRACT: In the present investigation, the anti-inflammatory activity of isolated bergapten from hydroalcoholic extract of Heracleum nepalense root was evaluated in vitro using human peripheral blood mononuclear cells (PBMCs). Bergapten exhibited significant inhibition of the production of pro-inflammatory cytokines, namely tumour necrotic factor-α (TNF-α) and interleukin-6 (IL-6) by PBMCs stimulated with lipopolysaccharide in a concentration-dependent manner.
Full-text · Article · Sep 2009 · Natural product research
[Show abstract][Hide abstract] ABSTRACT: Swietenine, a tetranortriterpenoid, was isolated from the Swietenia macrophylla seeds. The in vivo hypoglycemic activity was evaluated against neonatal-streptozotocin induced type 2 diabetic rats. Oral administration of swietenine at 25 and 50 mg/kg body weight per day to diabetic rats was found to possess significant dose dependant hypoglycemic and hypolipidemic activity in type 2 diabetic rats.