CHARACTERIZATION AND MEASUREMENT OF HBR-REACTING ACIDS IN MUCUNA-PRURIENS AND URENA-LOBATA SEED OILS

Abstract

Seed oils of Mucuna pruriens (Leguminosae) and Urena lobata (Malvaceae) were found to contain HBr-reacting acids to the extent of 1.3 and 10.8% respectively. Acetylation of the M. pruriens seed oil, followed by saponification and separation of the acids, gave 12,13-dihydroxyoleic acid. From this and other evidence it is concluded that 12,13-epoxyoleic (vernolic) acid is present as a constituent of the glycerides. On the other hand, the cyclopropenoid material in U. lobata oil was characterised as a mixture of malvalic (4.8%) and sterculic (6%) acids by the gas-liquid chromatography (g.l.c.) of the silver nitrate-methanol treated methyl esters. Seed oils of Vernonia anthelmintica and Sterculia foetida were used as reference standards.