Quantitative determination of some phytochemicals (phenol, flavonoid, saponin and alkaloid) in twenty-two Nigerian medicinal plants
Phytochemical screening of twenty-two (22) selected Nigerian medicinal plants were investigated. The plants include: Solenostemon monostychyus (P. Beauv.), Senna occidentalis (L.), Boerhaeria diffusa (L.), Phyllanthus amarus (Schum et Thonn), Alstonia congensis (De Wild), Acalypha wilkesiana (Mull. Arg.), Costus afer (Ker.), Asphilia africana (Pers.), Tridax procumbens (L.), Icacina tricantha (Oliv.), Psidium guajava (L.), Chenpodium species (L.), Azadirachta indica (Juss.), Mormordica charantia (L.), Calopogonium mucunoides (Vent.), Dalbergiella welwitschii (Bak.), Sida acuta (Burm.), Sphenocentrum jollyanum (Pierre), Newbouldia laevis (P. Beauv.), Cymbopogon citrates (D.C.), Citrus limon (L.) and Vernonia amygdalina (L.). The results of the qualitative analysis of these plants show that fifteen of the plants contained all the parameters analyzed in varying proportions. The percentage amount of saponin ranges from 0%w/v in B. diffusa to 5%w/v in A. wilkesiana; that of alkaloid ranges from 0%w/v in A. wilkesiana to 1.03%w/v in A. indica; while phenol (1.14%w/v) and flavonoid (1.34%w/v) were highest in D. welwitchi. It could be concluded that most Nigerian medicinal plants that are exploited traditionally for treatment of different ailments contain well known and studied phytochemicals such as flavonoid, phenol, saponin and alkaloid. The findings also indicate that flavonoid and phenol are present in D. welwitchi crude aqueous extract which have not been previously reported in literature.