Volatile sulphur compounds make up a large group of different species found in a 43 plant families and 173 plant genera, including the most important family, Brassicaceae. Glucosinolates, β-thioglucoside-N- hydroxysulfates with variable side chains are secondary metabolites identified in over 16 different plant families. These compounds are found particularly in the Brassicaceae family, among which Brassica stands out. Isolation of the degraded glucosinolate products is performed by distillation and extraction. The glucosinolate identification is carried out by an indirect method by which is determinated the presence of degradation products by the action of the myosinase enzyme using GC-MS method. In this paper two different species of Brassica genus are processed, Brassica rupestris Raf. ssp. gongyloides L. (kohlrabi) and Bunias erucago L. (crested warty cabbage). Glucosinolates are chemically and biologically inactive, while components that are formed by their degradation are known by numerous anticancer, antimicrobial and antioxidant activities. Analysis results of Brassica rupestris Raf. ssp. gongyloides L. showed the presence of sinigrin, glucotropaeolin, glucolimnantin, glucoerucin, gluconasturitiin, but also S-methyl- L -cysteine sulfoxide characteristic for the Allium species. Samples of Bunias erucago L. are collected from two different locations; Marjan in Split and island Brač (Škrip). Analysis results of Bunias erucago L. from island Brač had shown the presence of glucotropaeoline and glucodehydroerucin while in the same plant taken from Marjan had been identified five types of glucosinolates: gluconapin, glucotropaeolin, heptyl glucosinolate, glucodehydroerucin and glucoerucin.