Conversion of Indole-3-acetaldehyde Oxime to 3-Indolylmethylglucosinolate in Sinapis alba

dl -Tryptophan(methylene)-¹⁴C and indole-3-acetaldehyde oxime(methylene)-¹⁴C were supplied to cut shoots of 7-day-old plants of Sinapis alba L. Although both compounds were effective as precursors of 3-indolylmethylglucosinolate, the incorporation of the aldoxime radioactivity was more effective than the incorporation of the amino acid radioactivity. This, together with other information, suggests that indole-3-acetaldehyde oxime is an intermediate in the biosynthesis of 3-indolylmethylglucosinolate from tryptophan.