Isolation and characterization of bioactive alkaloids and GC–MS based identification of volatile oil metabolites from fruits of Glycosmis pentaphylla and evaluation of their cytotoxic activity

Abstract

Glycosmis pentaphylla, a member of the Rutaceae family, has been extensively studied for its pharmacological activities, focusing mainly on the cytotoxic properties of its roots and stems. Conversely, limited researched has been done in terms of the phytochemical composition of the fruits. The objective of this study is to isolate and identify the bioactive compounds found in the fruits of G. pentaphylla and then evaluate their potential for anti-cancer activity in oral cancer CAL 27 cell lines. The extraction of bioactive compounds from fruits was done by maceration, and the isolation of alkaloids and volatile oil fractions (F1-F5) was performed by column chromatography. The alkaloids, such as 3-O-methoxyglycocitrine II, noracronycine, 1-hydroxy-3-methoxy-10-methyl-9-acridone and kokusaginine, were first isolated from the fruits of G. pentaphylla. Additionally, GC–MS analysis identified 78 metabolites. The isolated compounds and identified volatile oil fractions were explored for their anti-cancer activity by cell viability assay. Results demonstrated that isolated compounds were found inactive, while the volatile fraction F1 was found active in CAL 27 cell line. Fraction F1 impeded wound healing in CAL 27 cells by scratch assay, and significantly inhibited colony formation in colony formation assay. In cell cycle analysis, treatment with fraction F1 redistributed cells to the S and G2 phases of the cell cycle. α-elemol (2) is the major metabolite identified from the F1 fraction by GC–MS, which could be responsible for the anti-cancer activity. There is potential for future work to further isolate volatile oil metabolites and evaluate their anti-cancer activity through in-vivo techniques.