Isolation and structure elucidation of phenolic compounds fromCyclopia subternata Vogel (honeybush) intact plant and in vitrocultures

Adam Kokotkiewicz, Maria Luczkiewicz , Pawel Sowinski, Daniel Glod,

Krzysztof Gorynski, Adam Bucinski

Abstract

In the presented work, an insight was made into the polyphenolic composition of intact plant material and in vitro cultures of indigenous South African plant Cyclopia subternata Vogel (honeybush). Ethyl acetate fractions of methanol extracts were separated by means of gravity column chromatography and/or semipreparative HPLC on two serially connected monolithic RP-18 columns. The structures of the isolated compounds were determined by means of 1D and 2D NMR techniques and additionally confirmed by LC-DAD-ESI-MS. Apart from the previously described honeybush components, that is mangiferin (1), scolymoside (2), hesperidin (3) and narirutin (4), three additional compounds: iriflophenone 3-C-β-glucoside (benzophenone) (5), phloretin 3′,5′-di-C-β-glucoside (dihydrochalcone) (6), and isorhoifolin (flavone) (7) were identified for the first time in the herb of C. subternata. Additionally, three isoflavone glucosides, namely calycosin 7-O-β-glucoside (8), rothindin (9) and ononin (10), which had not been previously reported in Cyclopia plants, were identified in the callus of the above species. As far as the authors are concerned, this is the first report on the presence of benzophenone and dihydrochalcone derivatives

(calycosin 7-O-β-d glucoside) and Chengdu Biopurify Phytochemicals, Chengdu, China