Polyprenylated phloroglucinol derivatives from Hypericum maculatum

Hypericum maculatum Cranz. is widely spread in all Bulgarian mountains and in many European countries. This species has been used in traditional medicine as an equivalent to the official drug Hyperici herba and has been given in several pharmacopoeias together with H. perforatum as a component of this drug [1,2]. Previous phytochemical studies of this plant have established the presence of naphthodianthrones hypericin and pseudohypericin, flavonoids kaemferol, quercetin, quercitrin, isoquercitrin, hyperoside, rutin, I3,II8-biapigenin and amentoflavone, xanthones norathiriol, maculatoxanthone, mangiferin, isomangiferin, kielcorin, phloroglucinol hyperforin as well as benzophenones annulatophenone, annulatophenonoside and acetylannulatophenonoside [3]. The extensive chromatographic procedure of the dichloromethane extract of the aerial parts of H. maculatum led to the isolation of five new (1-5) and five known (6-10) polyprenylated phloroglucinol derivatives as well as β-sitosterol. The new compounds were identified by means of spectral methods (MS, NMR, IR, UV). The cytotoxicity on SKW-3, BV-173 and K-562 tumor cell lines of these natural products were established using MTT test.

Fig. 1: Structures of compounds 1-10.

Acknowledgements: This research was supported by a grant from the Medicinal Science Council at Medical University of Sofia (Project 52/2013).

References:

[1] Kitanov (2000) Acta Pharm. (Zagreb) 50: 65 – 68.

[2] Martonfi et al. (2006) Biologia (Bratislava) 61: 473 – 478.

[3] Zheleva-Dimitrova et al. (2012) Nat. Prod. Res. 26: 1576 – 1583.