RESUMEN

As a defense mechanism of the leaves of Rhus javanica (Anacardiaceae) against the aphid Melaphis chinensis (Aphididae) attack, tannic acid is rapidly accumulated and forms galls along the midrib of the leaves resulting in a unique natural medicine Gallae Rhois. Tannic acid was found to inhibit the oxidation of L-3,4-dihydroxyphenylalanine (L-DOPA) catalyzed by tyrosinase (EC 1.14.18.1) with an IC50 of 22 microM. The aphid would detoxify the ingested toxic tannic acid to relatively nontoxic gallic acid, whereas the non-adapted pink bollworm Pectinophora gossypiella larvae are sensitive to the ingested tannic acid.

Asunto(s)

Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/farmacología , Ácido Gálico/química , Insecticidas/química , Monofenol Monooxigenasa/antagonistas & inhibidores , Hojas de la Planta/química , Rhus/química , Agaricales/enzimología , Animales , Inhibidores Enzimáticos/aislamiento & purificación , Depuradores de Radicales Libres , Ácido Gálico/aislamiento & purificación , Ácido Gálico/farmacología , Insectos , Insecticidas/aislamiento & purificación , Insecticidas/toxicidad , Plantas Medicinales/química