Gas Chromatography-Mass Spectrometry (GC-MS) Assay of Bio- Active Compounds and Phytochemical Analyses in Three Species of Apocynaceae

Objective: Gas chromatography coupled with mass spectrometry (GC-MS) was used to analyze for phytochemicals and bioactive compounds in three species of Apocynacae, Gongronema latifolium, Vincetoxicum rossicum and Marsdenia edulis commonly found in tropical rainforest vegetation and used as food and traditional medicine by locals. Methods and Materials: Phytochemical analysis and GC-MS were carried out using leaf samples of the species following standard protocols. Quantitative phytochemical data were analyzed using analysis of variance (ANOVA) and significance tested at 5% level of probability. Bioactive compounds were identified by comparing the retention times with those of authentic compounds and spectral data obtained from National Institute of Standards and Technology (NIST) library. Results: Phytochemical analysis revealed presence of alkaloids, glycosides, tannins, saponins, terpenes, steroids, flavonoids and phenols. Among the three species, Gongronema latifolium was highest in flavonoids (28.40 %), Vincetoxicum rossicum was highest in steroids (17.25 %) while Marsdenia edulis was highest in terpenoids (18.17 %). GC-MS profiling of the species revealed biologically functional compounds with therapeutic properties including linoleic acid, phytol, neophytadiene, n-hexadecanoic acid, squalene, transfarnesol, 5-pentadecen-7-yne, and mercaptoacetic acid. Conclusion: The array of bioactive compounds present in the three species especially Gongronema latifolium, commonly used as food indicated their utility in pharmacognosy and drug manufacture. This is the first report of GC-MS based metabolite profiling to detect the various bioactive compounds in methanolic extracts of Vincetoxicum rossicum and Marsdenia edulis. We therefore recommend these species for further study in drug discovery trials.