DEVELOPMENTAL ULTRASTRUTCTURE MICROSCOPY IN DRUG DISCOVERY FROM DIOSCOREA SPECIES

ABSTRACT Tubers of wild Dioscorea species (yam) are used as low-cost materials for the synthesis of steroids; cortisone and progesterone using the Marker Degradation chemical route. Decoctions from yam leaves and tubers are also used in ethnomedicine for regulating female fertility and alleviating painful periods and menopausal symptoms. It is now known that yam tuber extracts reduce and inhibit the proliferative action of breast cancer cells and reverse cardiovascular diseases. Due to current urgent needs and global interest in plants’ biodiversity advancement and drug discovery importance: Dioscorea composita and Dioscorea floribunda shoots were studied with Scanning Electron Microscopy (SEM) to detect anatomical types of trichomes compared to essential oil production as integrated into the ontogeny of the studied shoots and hydro-distilled oils from the same organs were characterized with Gas Chromatography/Mass Spectrometry (GC/MS). The SEM study revealed the presence of oil glands, the capitate type on the epidermal layers of parts studied which GC/MS analysis further revealed the components of the oils on the leaves to be Farnesene, Citronellyl acetate, Terpinene, Elemol, Nerolidol, Farnesol and Valerenyl acetate. This is the first time these phytoconstituents are reported in the species. In this light, microscopical methods supported by chromatography contribute to the rapid identification of novel lead compounds contributing to important drug discovery.