Abstract

• Alstonia scholaris (L.) R. Br., commonly known as Taung-ma-yo, is a traditional plant renowned for its diverse range of biological activities. The present research work focused on the investigation of phytochemical constituents, screening of the antimicrobial activity of crude extracts, and the isolation and identification of echitamine alkaloid of A. scholaris bark. Preliminary phytochemical tests revealed the presence of alkaloids, α-amino acids, carbohydrates, flavonoids, glycosides, phenolic compounds, reducing sugars, saponins, tannins, steroids, and terpenoids in the bark. The antimicrobial activity of the ethyl acetate, 70 % ethanol, and watery extracts of the bark of A. scholaris was evaluated using the agar well diffusion method against six different microorganisms. Both ethyl acetate and 70 % ethanol extracts exhibited significant antimicrobial activity, with inhibition zone diameters ranging from 18 to 24 mm on all the tested microorganisms. The watery extract showed inhibition zone diameters of 12-17 mm against four microorganisms but it was not active against Pseudomonas aeruginosa and Escherichia coli. One of the alkaloids, echitamine, was isolated from the ethyl acetate extract of the bark sample using column chromatography, and it was identified by FT IR, 1H NMR, and 13C NMR spectral data. This study also demonstrates that A. scholaris has high source of phytochemicals. Reported literatures showed that the isolated alkaloid, echitamine, does not protoplasmic poison and is used as an astringent herb.