REVERSED-PHASE LIQUID-CHROMATOGRAPHIC SEPARATION AND IDENTIFICATION OF CONSTITUENTS OF URUSHIOL IN THE SAP OF THE LAC TREE, RHUS-VERNICIFERA

Urushiol in the sap of lac tree, R. vernicifera, is directly separated into more than 10 components by reversed-phase liquid chromatography using acetonitrile-water-acetic acid (80:20:2 of 90:10:2) as the eluent. The 1H NMR parameters, especially those for the triolefinic components, are presented. New substances, 3-(10''Z, 13''E, 15''Z-heptadecatrienyl)catechol and 4-(8''Z, 11'',E, 13''Z-pentadecatrienyl)catechol, were found, although they were contaminated with 3-(10''Z, 13''Z, 16''-heptadecatrienyl)catechol and 4-(8''Z, 11''Z, 14''-pentadecatrienyl)catechol, respectively. The quantitation by this separation system with refractive index detection nearly coincides with the weight content of each component. Samples from 2 different sources, Hupei and Kiangsi in China, were analyzed by this method.