Bark acids of seven Calophyllum species (Guttiferae)

Abstract

Calophyllum bracteatum, C. calaba(var. calaba), C. moonii(=C. soulattri), C. thwaitesii, C. trapezifolium, C. Walkeri, and C. zeylanicum(=C. lankaensis) have been examined for their bark acids. A new acid, calozeylanic acid, has been isolated from three species and has been identified as (2R,3R)-2,3-dimethyl-5-hydroxy-6-(3-methylbutyl)-6-(3,7-dimethylocta-3,6-dienyl)-8-(2-carboxy-1-phenylethyl)-2,3,6,7-tetrahydrobenzopyran-4,7-dione. Four species were found to be different, having the enantioner of apetalic acid, isoapetalic acid and a minor acid identified as the structural isomer of the latter.