Benzophenone C- and O‑Glucosides from Cyclopia genistoides (Honeybush) Inhibit Mammalian α‑Glucosidase
journal contributionposted on 26.12.2014, 00:00 by Theresa Beelders, D. Jacobus Brand, Dalene de Beer, Christiaan J. Malherbe, Sithandiwe E. Mazibuko, Christo J. F. Muller, Elizabeth Joubert
An enriched fraction of an aqueous extract prepared from the aerial parts of Cyclopia genistoides Vent. yielded a new benzophenone di-C,O-glucoside, 3-C-β-d-glucopyranosyl-4-O-β-d-glucopyranosyliriflophenone (1), together with small quantities of a known benzophenone C-glucoside, 3-C-β-d-glucopyranosylmaclurin (2). The isolated compounds showed α-glucosidase inhibitory activity against an enzyme mixture extracted from rat intestinal acetone powder. Compound 2 exhibited significantly (p < 0.05) higher inhibitory activity (54%) than 1 (43%) at 200 μM. In vitro tests in several cell models showed that 1 and its 3-C-monoglucosylated derivative (3-C-β-d-glucopyranosyliriflophenone) were marginally effective (p ≥ 0.05) in increasing glucose uptake.