Determination of flavonoids in extracts of Epilobii angustifolii herba by HPTLC-densitometry

Epilobium angustifolium L., Oenotheraceae is used in folk medicine. The herb is rich in polyphenolic compounds such as flavonol-3-O-glycosides, phenolic acids and tannins [1]. Flavonoids analyses have shown that quercetin glycosides are predominant in Epilobium angustifolium [2]. Several studies suggest that at least flavonoids are partly responsible for the biological action of the herb [3, 4].

The separation and quantitative determination of quercetin glycosides in methanolic and aqueous extracts of Epilobii angustifolii herba by HPTLC-densitometry was established. Ethyl acetate/formic acid/water 68:2.5:03 was used as a mobile phase and silica gel as a stationary phase.

The flavonoids were more abundant in the aqueous extract than in the methanolic one. In both extracts quercetin glucuronide was the dominating compound, 2.12% and 1.78% respectively.

Our method is fast, easy and selective particularly for quercetin glucuronide determination in Epilobium extracts.

References: 1. PDR for Herbal Medicines (1998), Medical Economics Company, Montvale, New Jersey 2. Ducrey, B. et al. (1995), Phytochemistry 38: 129. 3. Tita, B. et al. (2001), Farmaco 56: 341. 4. Kiss, A. et al. (2006), Pharmazie 61: 66.