CHEMICAL CONSTITUENTS FROM THE ROOTS OF Calophyllum inophyllum L.

Abstract

Phytochemical investigation of the CH2Cl2 extract from the roots of C. inophyllum let to the isolation of five new chromanone derivatives, namely caloinophyllins A-E (1-5), along with nine known compounds (6-14), nobiletin (6), pentamethylquercetin (7), 3,5,7,4'-tetramethoxyflavone (8), 5,7,4'-trimethoxyflavone (9), 1,5-dihydroxyxanthone (10), 1,8-dimethoxyxanthone (11), caloxanthone B (12), 4-methoxycaffeic acid (13) and 1,6-dihydroxy-7-methoxyxanthone (14). The structures of five new compounds (1-5) were elucidated by using 1D and 2D-NMR spectroscopy. The structures of known compounds (6–14) were determined and confirmed by comparison of their 1H and 13C NMR spectroscopy data with the previous published data. Moreover, all isolated compounds were assessed for their in vitro cytotoxicity against the KB, HeLa S-3, MCF-7, HT-29 and Hep G2 human cancer cell lines. The results revealed that compound 5 showed a good cytotoxicity against five cancer cell lines with IC50 values in the range of 0.78-10.35 µM. Compound 14 showed a moderate activity against KB, HeLa S-3 and MCF-7 cell lines with IC50 values in the range of 18.19-25.84 µM and compounds 1, 2, 4 and 12 showed a weak activity with IC50 values in the range of 55.77-95.47 µM. The other compounds were inactive (IC50 > 100 µM) against five human cancer cell lines. In addition, all isolated compounds (1-14) were evaluated for their α-glucosidase inhibitory activity (yeast and rat small intestinal). All of them displayed no activity against both yeast (IC50 > 600 µM) and rat small intestinal (IC50 > 3,000 µM) α-glucosidase enzymes.