Vijitra Luang-In and John Trevor Rossiter

pp. 625 - 630

Abstract

This is the first report to assess the stability of authentic commercial isothiocyanates and nitriles incubated anaerobically at 37 °C over 24 hrs in various aqueous solutions including nutrient broths with/without the presence of bacterial cells,
and to assess the stability of these isothiocyanates in different buffers of pH 7.0 (Tris-Cl, phosphate buffer saline, and citrate
phosphate buffer) without bacterial cells. The presence of bacterial cells contributed to accelerating decline of both
isothiocyanates and nitriles in nutrient broths with greater effects on isothiocyanates as analysed by GC-MS. Allyl nitrile
was most unstable in nutrient broths and allylisothiocyanate was most unstable with cell incubation whereas erucin and
allylisothiocyanate were most unstable without cells. The decline of isothiocyanates was more rapid in buffers than in
deionized water and allylisothiocyanate was the most unstable in most buffers. Our results present a possible explanation
for the detection of the less than expected levels of isothiocyanate production upon glucosinolate metabolism in media or
buffers.

Keywords

• glucosinolate
• nitrile
• isothiocyanate
• bacterial cells
• buffers