ANTIMICROBIAL ACTIVITY OF A COMPOUND ISOLATED FROM AN OIL-MACERATED GARLIC EXTRACT

A compound showing antimicrobial activity was isolated from an oil-mac erated garlic extract by silica gel column chromatography and preparat ive TLC. On basis of the results of NMR and MS analyses, it was identi fied as Z-4,5,9-trithiadeca-1,6-diene-9-oxide (Z-10-devinylajoene; Z-1 0-DA). Z-10-DA exhibited a broad spectrum of antimicrobial activity ag ainst such microorganisms as grampositive and gram-negative bacteria a nd yeasts. The antimicrobial activity of Z-10-DA was comparable to tha t of Z-ajoene, but was superior to that of E-ajoene. Z-10-DA and Z-ajo ene are different in respect of substitution of the allyl group by the methyl group flanking a sulfinyl group. This result suggests that sub stitution by the methyl group would also be effective for the inhibiti on of microbial growth.