ANALYSIS OF VOLATILE COMPONENTS IN ESSENTIAL OIL OF UPLAND WASABI ANDTHEIR INHIBITORY EFFECTS ON PLATELET-AGGREGATION

Inhibition of platelet aggregation was found in the essential oils ext racted from the various parts of upland wasabi (Wasabia japonica forma terrestris Hisauti). The antiplatelet activity increased in the order of leaves, rhizomes, petioles, and roots, To examine the inhibitory p rinciples in upland wasabi oil, components in each part of the essenti al oil were identified and measured, Most of the volatile components i n upland wasabi oils were omega-alkenyl isothiocyanates and omega-meth ylthioalkyl isothiocyanates, allyl isothiocyanate being the main compo nent in every oil, Essential oils from roots and petioles contained ra ther large amounts of omega-methylthioalkyl isothiocyanates. Although every authentic isothiocyanate inhibited platelet aggregation, omega-m ethylthioalkyl isothiocyanates were more inhibitory, which explained t he stronger inhibitory effects of essential oils from roots and petiol es on platelet aggregation,