ISOLATION AND STRUCTURAL ELUCIDATION OF PENTACYCLIC TRITERPENOIDS FROM MAPROUNEA-AFRICANA

Pentacyclic triterpenoids based on the taraxer-14-ene skeleton with a C-28 attached carboxylic acid group have been isolated from the roots of Maprounea africana. These compounds were identified as 1 beta,2 alp ha-dihydroxyaleuritolic acid 2,3-bis-p-hydroxybenzoate [1], 2 alpha-hy droxyaleuritolic acid 3-p-hydroxybenzoate [2], 2 alpha-hydroxyaleurito lic acid 2,3-bis-p-hydroxybenzoate [4], aleuritolic acid 3-p-hydroxybe nzoate [5], aleuritolic acid [6], and aleuritolic acid 3-acetate [7]. Compounds 1 and 2 are new triterpene esters. Compound 3 was previously reported as 7 beta-hydroxymaprounic acid 3-p-hydroxybenzoate [13]. Ho wever, based on detailed nmr studies, its structure has been revised.