Qualitative and quantitative screening of secondary metabolites in selected medicinal plants of Sri Lanka
MIS Safeena and Jayani Kalinga
Medicinal plants are valuable source of bioactive compounds such as secondary metabolites (SMs). Sri Lanka is a bio diversity hotspot of flora specially with untouched diverse nature of medicinal plants. The present study includes four endemics and one non endemic but a rare medicinal plant of the country. The methanolic crude extracts of these medicinal plants were qualitatively and quantitatively tested for alkaloids, phenols, flavonoids and tannins. The total phenolic compounds was found significantly higher amount in all tested plants specially in both leaves and flowers, followed by flavonoids, alkaloids and tannins. The highest amount of total phenolic compounds (80.28 ± 2.99 mg GAE/g dw) and tannin (30.81± 1.37 mg TAE/g dw) was resulted in O. octandra. Similarly, a significant high amount of total alkaloid content was recorded in B. ceylanica (3.55 ± 0.08 mg AE/g dw) and followed by in leaves (2.54±0.29) and flowers (0.07 ± 0.04) of W. antidysenterica which belongs to the family Apocynaceae. The total flavonoid content was highest in P. zatarhendi var tomentosa (147.37± 29.38mg RE/g dw) compare to all others. The results of this study prove that these endemic and native medicinal plants are rich reservoirs of therapeutically important SMs and can be explored them for maximum utilization in traditional and alternative medicine.