Glycoside constituents of Camellia amplexicaulis and their α-glucosidase inhibitory activity

Abstract

Four new glycosides, named amplexicosides A-D (1–4), and five known compounds: benzyl 2-[β-D-glucopyranosyl-(1→6)-β-D-glucopyranosyloxy]-benzoate (5), benzyl 2-neohesperidosyloxy-6-hydroxybenzoate (6), chrysandroside A (7), chrysandroside B (8) and camelliquercetiside C (9) were isolated from the branches and leaves of Camellia amplexicaulis (Pit.) Cohen-Stuart. Their structures were elucidated using HR-ESI-MS and 1D- and 2D-NMR spectra and compared to reported NMR data. All of the isolated compounds were screened in an α-glucosidase assay. Compounds 4, 8, and 9 significantly inhibited α-glucosidase with respective IC₅₀ values of 254.9 ± 4.2, 304.8 ± 11.9 and 228.1 ± 16.4 μM.

GRAPHICAL ABSTRACT

Keywords:

• Camellia amplexicaulis
• amplexicoside
• benzoate derivative
• flavonol glycoside
• α-glucosidase inhibitor

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Vietnam Academy of Science and Technology (Grant no. THTETN.02/21-23).