Solvent extraction and its effect on phytochemical yield and antioxidant capacity of woody medicinal plant, Polyalthia bullata

Polyalthia bullata is a woody medicinal plant that contains antioxidant compounds. Finding a suitable solvent is important to obtain a high yield of antioxidants in the phenolic, flavonoid, and terpenoid families. In this study, from different solvent extracts, the leaf methanolic extract exhibited the highest total phenolic content (TPC), total flavonoid content (TFC), total terpenoid content (TTC), and total antioxidant activity. For woody parts of stem and roots, methanol was the best solvent for all phytochemicals except for phenolics, which accumulated in the roots and were extracted more efficiently using ethanol. However, the methanolic extracts from both tissues displayed the best antioxidant capacity. Gas chromatography-mass spectrometry (GC-MS) profiling data showed the presence of antioxidant compounds such as thymol, phytol, and neophytadiene in the leaf; trans-farnesol, n-hexadecanoic acid, and 9-Octadecenamide in the stem; and fatty acid (cis-vaccenic) and its methyl ester (11-Octadecanoic acid, methyl ester and [1,1’-bicyclopropyl]-2-octanoic acid, 2’-hexyl-methyl ester) in the roots. These findings reveal important compounds that are present in different plant parts of P. bullata.