Identification of hydroxychavicol and its dimers, the lipase inhibitors contained in the Indonesian spice, Eugenia polyantha

Inhibition of pancreatic lipase is effective for a prevention of obesity. Eugenia polyantha is a tropical tree whose leaves are known as a spice and also as an ingredient for Jamu, the traditional medicine of Indonesia. We found inhibitory activity against pancreatic lipase in the extract of E. polyantha leaves. Purification of the active principals resulted in isolation of hydroxychavicol, and two structurally new dimers. All of the isolated compounds showed inhibitory activity against the porcine pancreatic lipase and high content of hydroxychavicol (1.83 wt%) indicated this compound to be responsible for the majority of inhibitory activity of E. polyantha extract. Furthermore, hydroxychavicol is reported to possess anti-carcinogenic, anti-oxidant, anti-microbial and anti-inflammatory activity which is related to traditional usage of this plant. These results offer this plant as an attractive material for treating various health problems including obesity

α-Amylase Inhibitory Triterpene fromAbrus precatoriusLeaves

In the screening experiments for porcine pancreatic α-amylase inhibitors in 18 plants obtained from Indonesia, a potent inhibitory activity was detected in the extract of leaves of Abrus precatorius. The enzyme assay-guided fractionation of the extract led to the isolation of a triterpene ketone, lupenone (1), as a potent α-amylase inhibitor, together with 24- methylenecycloartenone (2) and luteolin (3). The mode of inhibition of compound 1 against porcine pancreatic α -amylase was a mixed inhibition. This is the first report that describes the potent α -amylase inhibitory activity of the low-polar triterpene ketone similar to compound 1. A comparison of the activities of the isolate and related compounds indicated the importance of C-3 ketone and the lupane skeleton in the α -amylase inhibitory activity