Characterization and Bioactive Properties of Essential Oils from Piper guineense, Afromomum danielli, and Afrostyrax lepidophyllus

The aim of the study was to characterize and determine the bioactive potentials of essential oils from selected Nigerian spices [Piper guineense (African black pepper), Afromomum danielli (African cardamom) and Afrostyrax lepidophyllus (country onion)] in Nigeria. Spices are popular among Nigerians, although most of the Nigerian spices grow in the wild. Some of these spices are lesser known owing to the localization of their usage and their under- utilization. Spices owe its biological and physiological to the presence of varying types of essential oils. The essential oils from these selected spices were extracted using steam distillation method and stored in a plastic container for analysis. The bioactive compounds present in the oils were identified using Gas Chromatography Mass Spectrometer (GC-MS). The results of the bioactive compounds of the EOs showed P. guineense had the least number of bioactive compounds (2-Octyl acetate, linalyl acetate, α-humulene, caryophyllene oxide, β-carophyllene, β-selinene, (E)-nerolidol and zingerone), followed by A. danielli (1,8-cineole, linalool, terpinen-4-ol, trans-(β)-ocimene, α-terpineol, carophyllene oxide, (Z)-linalool oxide (furanoid) and (E) linalool oxide (furanoid)), while A. lepidophyllus had the highest (1,2-benzenediol, 1,2-bis (trimethylsily) benzene, 1,4-phenylenebis (trimethyl), 2,2-dimethylpropanoic acid, 2-pyridinemethanamine, dimethyl trisulfide, disulfide, furan, methanamine, methyltris (trimethylsiloxane) silane, silicic acid and tetrasiloxane). The most abundant compound identified in P. guineense were 2-Octyl acetate and linalyl acetate which had relative abundance of 60.40% and 16.50% respectively. The most abundant compounds identified in A. danielli were 1,8-cineole and linalool with relative abundance of 37.20% and 31.30% respectively, while for A. lepidophyllus the most abundant was disulphide with the relative abundance of 52.30%. These bioactive compounds further suggest the antimicrobial and preservative properties of the oils.