Tabernaemontana pandacaqui Poir of the family Apocynaceae was chosen as a plant for further investigation on the basis of its ethnical use as a medicinal plant. This study deals with the isolation, purification and structure elucidation of the compound found to be biologically active.
The genus Tabernaemontana consists of about 120 species distributed over the (sub) tropical parts of the world. Over 250 different indole alkaloids have been isolated, many of them are of pharmaceutical interest, confirming its widespread use in tropical medicine as antiseptic. In the Philippines, record says that the milk juice is good for swelling. A crude chloroform extract of Philippine Tabernaemontana pandacaqui was also tested for anti-cancer activity and it showed a high degree of inhibition.
A modified bioautographic method was used to detect the anti-bacterial constituents of T. pandacaqui. The dried leaves were subjected to alcoholic extraction and fractionated into the chloroform soluble and butanol soluble constituents. A bioactive constituent was detected on the butanol fraction against B. subtilis using the said method. A bio-directed isolation was then conducted using different chromatographic methods. The bioactive compound has a high Rf values and are observed to be stable under chromatographic stresses. The study is still in progress. (Author)