Isolation and Characterization of Triterpenoid Saponins from Ficus natalensis subsp. leprieurii Leaves

Abstract

Ficus natalensis subsp. leprieurii also known as the natal fig is a fruit-producing tree belonging to the family Moraceae and widely distributed in African countries and cultivated in Egypt. F. natalensis is common with a myriad of traditional and medicinal importance. Owing to the increased demand for natural products with new structural compositions, the current study aimed to separate and elucidate the structure of triterpenoid saponins from F. natalensis leaves. Our previous biological investigation of F. natalensis leaves revealed its potent antioxidant and anti-inflammatory characteristics, and its ability to alleviate Cd-induced reproductive toxicity. Phytochemical investigation of F. natalensis leaves revealed the separation and structure elucidation of seven (1–7) compounds belonging to triterpenoid saponins using NMR and MS data and identified for the first time in F. natalensis. The isolated compounds were identified as 3-O-β-D-glucopyranosyl (1 → 4) β-D-glucopyranosyl (1 → 4)–α-L-rhamnopyranosyl-quinovic acid-28-O-β-D-glucopyranosyl (1 → 4)–α-L-rhamnopyranosyl (1 → 2)–α-L-arabinopyranoside ester (1), 3-O-β-D-glucopyranosyl (1 → 4) α-L rhamnopyranosyl-quinovic acid-28-O-β-D-glucopyranosyl (1 → 4)–α-L-rhamnopyranosyl (1 → 2) α-L-arabinopyranoside (2), 3-O-β-D-glucopyranosyl–quinovic acid-28-O-β-D-glucopyranosyl ester (3), as 3-O-α-L-rhamnopyranosyl-quinovic acid-28-O-β-D-glucopyranoside ester (4), 3-O-β-D-glucopyranosyl oleanolic acid (5), 3-methoxy-oleanolic acid-28-O-α-L-rhamnopyranoside (6), and 3-O-α-L-rhamnopyranosyl-oleanolic acid-28-O-β-D-glucopyranoside ester (7). Among the identified compounds, compounds 1 and 2 were identified for the first time in nature according to Reaxys and Web of Science database.