Divinyl ether synthase from garlic (Allium sativum L.) bulbs: sub‐cellular localization and substrate regio‐ and stereospecificity

Abstract
Sub‐cellular localization and some properties of 13‐hydroperoxide‐specific divinyl ether synthase from garlic bulbs were studied. Sub‐cellular fractions from garlic bulbs were incubated with [1−14C](9Z,11E,13S)‐13‐hydroperoxy‐9,11‐octa‐decadienoic acid (13‐HPOD). The predominant part of divinyl ether synthase activity from garlic bulbs was found in the microsomal fraction. The enzyme utilizes 13(S)‐HPOD as its preferential substrate. Other hydroperoxides, including 9(S)‐HPOD, gave much poorer yields of divinyl ethers. Unreacted hydroperoxide after incubation of 13(R,S)‐HPOD with enzyme was composed of up to 94% 13(R)‐HPOD. Thus, divinyl ether synthase possesses stereoselectivity, utilizing preferentially the (S)‐enantiomer.