Indoleacetonitriles—thermal degradation products of indole glucosinolates in commercial rapeseed (Brassica napus) meal

Commercial low‐glucosinolate rapeseed ( Brassica napus L) meal (LG RSM) was extracted with dichloromethane and subjected to chromatography on Sephadex LH‐20 to isolate indole‐containing compounds which were detected using TLC. Thin layer chromatography of dichloromethane extracts of various heat‐treated preparations of defatted low‐glucosinolate rapeseed cv Westar was also used to establish the origin of the major indole derivative. One of the minor components was identified as 3‐indoleacetonitrile (IAN) based on comparisons of GLC retention times and mass spectral data with authentic IAN. The major indole derivative was identified as 4‐hydroxy‐3‐indoleacetonitrile by comparison of mass spectral data with that for IAN and by establishing its precursor as 4‐hydroxy‐3‐indolylmethylglucosinolate.