Novel saponin and benzofuran isoflavonoid with in vitro anti-inflammatory and free radical scavenging activities from the stem bark of Pterocarpus erinaceus (Poir).

Graphical abstract Highlights • Isolation and identification of compounds from Pterocarpus erinaceus (Poir). • One new saponin and one new benzofuran isoflavonoid derivatives were characterized. • Evaluation of the DPPH scavenging activity and the in vitro anti-inflammatory activity (protein denaturation). Abstract The phytochemical study of the stem bark of Pterocarpus erinaceus led to the isolation of a new saponin (1) and a new benzofuran isoflavonoid (2) along with seven known compounds namely friedelin (3), triacontanoic acid (4), dotriacontanoic acid (5), 2,3-dihydroxypropyl hexacosanoate (6), octacosanoic acid (7), calycosin (8), stigmasterol glucoside (9). The structures of the new compounds were characterized on the basis of IR, UV, 1D and 2D NMR analyses in conjunction with EIMS, HRMS and literature review. The free radical scavenging activity and serum bovine albumin denaturation activity of the isolated compounds were evaluated. Compounds 2 (SC 50 , 12.63±0.86 μg/mL) and 8 (SC 50 , 42.53±1.77 μg/mL) showed antioxidant properties although lesser than that of the reference drug ascorbic acid (SC 50 , 5.99±0.59 μg/mL). Compound 3 (IC 50 , 14.87±1.51 μg/mL) was the most active against the denaturation of the protein followed by compounds 1 (IC 50 , 28.60±4.10 μg/mL) and 9 (IC 50 , 35.94±2.10 μg/mL). Sodium diclofenac (IC 50 , 7.20±0.97 μg/mL) was used as reference drug. [ABSTRACT FROM AUTHOR]