Constituents of Asperula cypria
The family Rubiaceae is represented by about 500 genera and 6000 species, with about 200 known Asperula species . Asperula species are traditionally used by Lebanese people to reduce blood pressure and inflammation/edema, and for diabetes . Moreover they are rich sources of antimicrobial agents . The chemical composition of genus Asperula characterized by the presence of iridoids, flavonoids and anthraquinone glycosides [4,5,6].
During our search on the aerial parts of Asperula cypria Ehrend., an endemic plant of Cyprus, a number of secondary metabolites were isolated from the methanol extract of the plant. The isolation was carried out with several chromatographic steps using VLC and open column chromatography over silica-gel, reverse phase silica gel (RP-18) and Sephadex LH-20 to produce a new and seven known compounds, four flavonoids together with two iridoids, and a triterpene. The structure of the known compounds was determined as kaempferol (1), kaempferol 3-O-β-D glucopyranoside (Astragalin) (2), quercetin-3-O-β-D-glucoside (isoquercitrin) (3), quercetin-3-O-β-D-galactopyranoside (hyperin) (4), asperulosidic acid (5), asperuloside (6), and oleanolic acid (7). The new compound was elucidated to be a phenylethane-C-glycoside, encountered for the first time in nature, by the extensive use of 1H NMR, 13CNMR\DEPT, 1H-1H COSY, NOESY, HSQC, HMBC and LC-MS experiments.
References: 1. Trease GE, Evans WC (1989) Pharmacognosy. English Language Book Society. Balliere Tindall. London.
2. Loizzo MR et al. (2008)J Ethnopharmacol 119: 109–116.
3. Kalyoncu F (2009) Iran J Pharm Res 8: 263–268.
4. Corrigan D et al. (1978) Phytochemistry 17: 1131–1133.
5. Borisov MI et al. (1972) Khim Prir Soedin 3: 281–285.
6. Constantinescu E (1974) Farmacia 22: 335–344.