Limonoids from Swietenia humilis and Guarea grandiflora (Meliaceae)

Two new limonoids, humilinolides E and F, were isolated from the seeds of S wietenia humilis Zucc. (Meliaceae). In addition, the known compounds humili nolides A-D, humilin B, swietenin C, methyl-2-hydroxy-3-beta-isobutyroxy- l -oxomeliac-8 (30)-enate, methyl-2-hydroxy-3-beta-tigloyloxy- 1-oxomeliac-8 (30)-enate and swietemahonin C were isolated for biological evaluation with swietenin and swietemahonin C reported for the first time from this specie s. From the seeds of Guarea grandiflora A.D.C. (Meliaceae) three protolimon oids, namely 21-alpha-acetylmelianone, melianone and melianodiol, and three limonoids, gedunin, 7-deacetoxy-7-oxogedunin and 6-alpha-acetoxygedunin, w ere obtained. The isolated compounds were identified by spectroscopic metho ds. Some of the limonoids and protolimonoids were evaluated for their effec ts on the European corn borer, Ostrinia nubilalis, in comparison with toose ndanin a commercial insecticide derived from Melia azederach. (C) 1998 Else vier Science Ltd. All rights reserved