Analgesics from Lonchocarpus eriocalyx Harms

Four lupane-type terpenoids, namely lupeol (1), friedelin (2), stigmasterol (3), and stigmasterol-3-O-glucoside (4) were isolated from the ethyl acetate extract of leaves of Lonchocarpus eriocalyx Harms. These compounds were obtained by extensive silica gel chromatography and their structures elucidated by 1D and 2D nuclear magnetic resonance (NMR) as well as comparison with literature data. The ethyl acetate, dichloromethane and methanol extracts (100 mg/Kg) had a pretreatment latency of 3.1±0.15, 3.0±0.01 and 3.5±0.12 at the zero minute. The post latency of 6.4±0.13 was observed for ethyl acetate at 30 minutes which confirmed its effectiveness to halt pain, while compounds 1 and 2 had pretreatment latency of 3.1±0.12 and 3.2±0.12, respectively. The isolated compounds from this medicinal plant along with their analgesic activity have been reported for the first time.