Glucosinolate profiling in Cleome gynandra L. aerial parts based on two extraction methods

Glucosinolates and their degradation products from Cleome gynandra L. are known for their beneficial effects in traditional medical use. As part of daily nutrient intake, the areal parts of this herb are cooked and consumed, whereas the residual water from boiling is discarded. However, it may contain valuable bioactive metabolites. Therefore, we focus our investigations on Cleome gynandra L. for the presence of glucosinolates using two extraction methods (conventional and unconventional) and according to the physiological stage of growth of the plant. The results showed that glucosinolate contents expressed in mg of glucocapparin/g dry matter (mg/g) differed quantitatively according to the extraction method and physiological development stage. Glucocapparin content was 8.24 mg/g dry matter for the methanolic extract (conventional method) compared to 5.01 mg/g dry matter for the aqueous extract at the fruiting stage of the plants. LC-MS and 1 H NMR analysis confirmed the identity of the major glucosinolate as glucocapparin. Quantification revealed the same variation trend in glucosinolate content according to the physiological stage of plant growth with the two extraction methods, i.e., 2.58, 4.74, and 5.01 mg glucocapparin/g dry matter for aqueous extracts (unconventional method) and according to the vegetative, flowering, and fruiting stages, respectively. However, it appears that aqueous extracts (cooking wastewater) obtained from areal parts of Cleome gynandra L. could constitute enriched extracts in glucosinolates from Cleome gynandra L. for phytoprotective applications from the fruiting stage.