Phytochemical Investigation and Antimicrobial Evaluation Of The Root Bark of Stereospermum Kunthianum Cham

Abstract

The traditional medicinal system continues to play an essential role in health care, with about 80% of the world’s inhabitants relying mainly on traditional medicines for their primary health care. The genus of Stereospermum is known to possess medicinal properties in every part of the plant. S. kunthianum is one of the medicinal plants that has been claimed to be used traditionally to treat several illnesses such stomachaches, toothache, snake bite, gonorrhea, evil eyes, diarrhea, skin diseases, and headaches. Therefore, this study was focused on the phytochemical isolation and antimicrobial activities of the root bark of S. kunthianum Cham. The dried and powdered root bark of the plant was exhaustively extracted with methanol/chloroform (1:1, v/v) by maceration at room temperature. The extract was then filtered and evaporated using a rotary evaporator. Phytochemical screening of the extract was carried out and lead to presence of some secondary metabolites, such as glycosides, alkaloids, tannins and anthraquinone. The isolation of pure compound was made by column chromatography controlled by TLC using petroleum ether in increasing amount of ethyl acetate for polarity. The chemical study of the root bark extract of S. kunthianum afforded one pure compound whose structure were established as 6-trans-p methoxycinnamoyl catalpol using spectroscopic data (1H NMR, 13C NMR) and literature reports. The crude extracts and isolated compounds were subjected to biological evaluation against four bacterial strains (Bacillus subtilis, Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli) and one fungus (Candida albicum). The zone of growth inhibition of extract and isolated compounds were compared with standard drugs like gentamycin and clotrimazole. The result showed that the isolated compound more activity against all the tested strains, compared to the crude extract. Therefore, biological activities displayed by the root extract and constituents of the root of S. kunthianum Cham confirm the traditional uses of this plant against various bacterial ailments