Glucosinolates in alugbati (Basella rubra)

Glucosinolates comprise a group of sulfur - containing glucoside which are known to exhibit biological activities with potential benefits to human health. In previous work it was found that the leaves of alugbati contain significantly high levels of glucosinolates, results that called for a more thorough investigation on these compounds in the plant. Four glucosinolates (GSL) were tentatively identified in alugbati. LC-MS analysis suggested the presence of sinigrin (allyl GSL), glucolepidiin (ethyl GSL), mercaptomethyl glucosinolate and a cinnamic glycoside glucocheirolin-6\u27 -O-sinapoyl-β-D-thioglucoside. This is the first report on these compounds in the Basselaceae. A compound present in the red - stemmed alugbati variety was not detected in the green - stemmed type; otherwise, both varieties exhibited similar glucosinolate profiles and individual glucosinolates were found in roughly the same proportions. Alugbati samples grown under different planting regimes were analyzed to determine the effects of traditional, organic and innovative farming practices on the glucosinolate content. Results showed that in general, the biosynthesis of specific glucosinolates was relatively unaffected by the planting conditions. The only notable differences observed were the levels of the major compound, which could be glucocheirolin-6\u27-sinapoyl-β-D-thioglucoside, which significantly decreased with the application of fertilizer and/or pesticide. The optimum hydrolysis procedure for alugbati glucosinolates was determined. The addition of exogenous myrosinase and the cofactor ascorbic acid increased the yield of hydrolysis products. The dichloromethane extracts of hydrolysates consisted of several metabolites which were identified by GC-MS analysis to be possible degradation compounds of the glucosinolate hydrolysis products such as those coming from sinigrin and the cinnamic glycoside. Other compounds that have been reported to possess health promoting and allelopathic properties were also identified in the DCM extracts