New Glucopyranosylglyceryl-N-Octenyl Adipate and Bioactivity of Retro and Condensed Chalcones from Toussaintia Orientalis

Abstract

1-(3-β-D-Glucopyranosylglycer-2-yl)-6-N-(oct-2-enyl)-adipate, [orientalin, 1] was isolated as a new metabolite from the polar leaf extracts of Toussaintia orientalis Verdc (Annonaceae), together with the glycoflavonoids afzelin and quercitrin, and the indolidinoids toussaintines A-C. The reversed chalcones 2-hydroxy-3,4,6-trimethoxychalcone (2) and 2-hydroxy-3,4,6- trimethoxydihydrochalcone (3), the condensed chalcone (+)-6a,12a-dihydro-6-phenyl-7-styryl- 6H,7H-[1]benzopyrano[4,3-][l]benzopyran (4), and mixtures of known triterpenoids and steroids were isolated from the less polar extracts of the root and stem bark of the same plant. The structures were established upon detailed analysis of spectroscopic data and other physical parameters. The chalcones exhibited antimicrobial, anti-inflammatory, antiproliferative and cytotoxic activity at varying efficacy levels, the reversed chalcone 2 demonstrating antiinflammatory potency against COX-2 enzyme that was superior to the standard drug Indomethacin. These results have further indicated the versatility of Annonaceae species in accumulating structurally varied natural products, some of them having unprecedented structures.

Keywords: Toussaintia orientalis; Annonaceae; orientalin, 1-(3-b-D-glucopyranosylglycer-2-yl)-6-N-(oct-2-enyl)-adipate; condensed and retrochalcones; anti-inflammatory.