Tannins, saponins, phlobatannins, flavonoids, anthraquinones, terpenoids, steroids, alkaloids, carbohydrates and glycosides distribution in four medicinal plants belonging to different families were investigated and compared. The medicinal plants investigated were Carica papaya, Ocimum gratissimum, Adenia cissampeloides and Cymbopogan citratus. All the plants were found to contain tannins, flavonoids, terpenoids, steroids and carbohydrates while anthraquinones were absent in all. Alkaloids were absent only in O. gratissimum and C. citratus. Glycosides were absent only in C. papaya, saponins were absent only in O. gratissimum while phlobatannins were absent only in C. citratus. Extraction of oils was carried out by solvent extraction and steam distillation methods and the percentage yield of extracts by each method was determined. Solvent extraction method gave percentage yield of 7.40, 6.30, 6.75 and 5.63% for C. papaya, O. gratissimum, A. cissampeloides and C. citratus respectively. For steam distillation, C. papaya, O. gratissimum, A. cissampeloides and C. citratus gave percentage yield of 5.60, 5.80, 5.44 and 3.82% respectively. The significance of the plants in traditional medicine and the importance of the distribution of these chemical constituents were discussed with respect to the role of these plants in ethnomedicine in Nigeria. © 2011 Academic Journals.
