Chemical composition of the essential oil of Raphanus raphanistrum L. from Serbia

This work investigates volatile glucosinolate breakdown products in the essential oil of Raphanus raphanistrum L. (Brassicaceae) from Serbia. Fresh wholeplant material was subjected to hydrodistillation, and the obtained essential oil was analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). A total of 44 compounds were identified, representing 95% of the total chromatographic peak area. The oil was dominated by glucoraphasatin-derived isothiocyanates - (E)- and (Z)-4-methylthio-3-butenyl isothiocyanate (32.7% and 15.9%, respectively) - alongside several nitriles derived from aliphatic and aromatic glucosinolates (GSLs). Notably, octanenitrile and 6-(methylthio)hexanenitrile were detected. As their putative parent GSLs have not been reported for R. raphanistrum, these findings may indicate yet-undetected GSLs or alternate degradation routes. Whole-plant hydrodistillation yields a GSL-derived volatile pattern distinct from seed oils reported previously, underscoring tissue-specific biosynthesis and/or enzymatic processing. To our knowledge, this is the first evidence for octanenitrile and 6-(methylthio)hexanenitrile in R. raphanistrum. Further work with authentic standards and dual-column LRIs is recommended to confirm these tentative identifications.