Abstract:A new glucosinolate, the 2-hydroxyethylglucosinolate was isolated and identified from seeds of Capparis masaikai Levl, with a yield of 3% of dry seed meal. Its enzymatic product at pH 6.0 was oxazolidine- 2 -thione. The thioglucosidase was extracted from seed meal powder with 1 N Nad, precipitated with ammonium sulfate, and futher purified by gel filtration on Sephadex G50 and being passed through a CM-cellulose column. The purified thioglucosidase was showed to be of Mr =116 kD, pI =5.05, consisted of two near equal subunits. It differs from the thioglucosidases isolated from the seeds of Cruciferae, which are glyco proteins with Mr = 140 kD and a carbohydrate content of 15%, in that it was showed not to contain carbohydrate.