Bioactive components of three Hypericum species from Tunisia: A comparative study

The methanolic extracts of H. perforatum, H. perfoliatum and the endemic H. ericoides Ssp Roberti from Tunisia were investigated for the first time. Reversed phase high performance liquid chromatography coupled to diode array detection (RP-HPLC-DAD) was employed for the determination of the main constituents (flavonoids, naphtodianthrones and phloroglucinols). Separation was performed on a Hypersil ODS column with a gradient solvent system of 0.3% phosphoric acid-acetonitrile and methanol. Fifteen components among them 3 phenolic acids (chlorogenic, syringic and ferulic acid), 5 flavonols (rutin, hyperoside, isoquercitrin, quercitrin and quercetin), 1 biflavonoid (I3, II8-biapigenin), 4 naphtodianthrones (pseudoprotohypericin, protohypericin, psuedohypericin and hypericin) and 2 phloroglucinols (hyperforin and adhyperforin) have been identified. Higher contents of phenolic acids and some flovonols were found in H. ericoides Ssp Roberti extracts while H. perforatum showed higher content of naphtodianthrones and phloroglucinols. The latter species could be considered as a rich source of hypericin, hyperforin and their derivatives.