Tyrosinase Inhibitors from Galls of Rhus javanica Leaves and Their Effects on Insects

• Published in: Zeitschrift für Naturforschung C. A journal of biosciences Vol. 58; no. 9; pp. 719 - 725
• Main Authors: Kubo, Isao, Kinst-Hori, Ikuyo, Nihei, Ken-Ichi, Soria, Frida, Takasaki, Midori, Calderón, José S., Céspedes, Carlos L.
• Format: Journal Article
• Language: English
• Published: Germany Verlag der Zeitschrift für Naturforschung 01.09.2003
• Subjects: Agaricales - enzymology; Animals; Enzyme Inhibitors - chemistry; Enzyme Inhibitors - isolation & purification; Enzyme Inhibitors - pharmacology; Free Radical Scavengers; Gallae Rhois; Gallic Acid - chemistry; Gallic Acid - isolation & purification; Gallic Acid - pharmacology; Insect Growth Inhibitory Activity; Insecta; Insecticides - chemistry; Insecticides - isolation & purification; Insecticides - toxicity; Monophenol Monooxygenase - antagonists & inhibitors; Plant Leaves - chemistry; Plants, Medicinal - chemistry; Rhus - chemistry; Tyrosinase Inhibitory Activity
• ISSN: 0939-5075; 1865-7125
• DOI: 10.1515/znc-2003-9-1022

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 ʟ-3,4-dihydroxyphenylalanine (ʟ-DOPA) catalyzed by tyrosinase (EC 1.14.18.1) with an IC of 22 μᴍ. 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.