A new abietane-type diterpenoid from roots of Burkea africana Hook (Fabaceae) with α-amylase inhibitory potential

• Published in: Natural product research Vol. 36; no. 16; pp. 4132 - 4139
• Main Authors: Feunaing, Romeo Toko, Tamfu, Alfred Ngenge, Ntchapda, Fidele, Gade, Isaac Silvere, Mbane, Martin Noah, Tagatsing, Maurice Fotsing, Talla, Emmanuel, Henoumont, Celine, Laurent, Sophie, Dinica, Rodica Mihaela
• Format: Journal Article
• Language: English
• Published: Abingdon Taylor & Francis 01.08.2022; Taylor & Francis Ltd
• Subjects: Amylases; antidiabetic potential; Betulinic acid; Burkea africana; chemical composition; Column chromatography; Diabetes mellitus; Diterpenes; NMR; Nuclear magnetic resonance; Roots; rubesanolidic acid; Ursolic acid; α-Amylase
• ISSN: 1478-6419; 1478-6427
• DOI: 10.1080/14786419.2021.1976176

A new abietane-type diterpenoid, rubesanolidic acid (1), alongside six known compounds including β-sitosterol (2), lupeol (3), betulinic acid (4) ursolic acid (5), β-sitosterol 3-O-β-D-glucopyranoside (6) and stigmasterol 3-O-β-D-glucopyranoside (7) were isolated from the roots of Burkea africana through column chromatography. Their structures were elucidated from spectroscopic analyses (UV, IR, MS, 1D and 2D NMR) data and by comparison with data from previous studies. The extract and compounds were tested for their α-amylase inhibition. The extract was more active than the isolated compounds with a percentage inhibition of 51.0 ± 2.5% at 400 µg/mL and was the only sample showing above 50% inhibition at this dose. Amongst the isolated compounds and at the dose of 400 µg/mL, the new diterpenoid Rubesanolidic acid exibited the highest percentage inhibition of α-amylase of 38.2 ± 2.0% while β-sitosterol showed the lowest inhibition of 9.6 ± 0.5%. The results indicate that B. africana is a potential source of antidiabetic compounds.