Application of matrix solid-phase dispersion for HPLC analysis of polyphenol profile in 50-years old herbarium specimens of Polygonum aviculare

Voucher specimens stored in herbaria are valuable for comparative studies in chemotaxonomy and diversity of medicinal plants. They aid in proper identification of unknown material and plant samples stored in various institutions. However, herbaria specimens are under special protection and often phytochemists are not allowed to take samples for chemical analysis Therefore, only little is known about the stability of polyphenol compounds in plant material stored for decades or even centuries

In this study, we employed Matrix Solid-Phase Dispersion (MSPD) procedures [1] to prepare extracts for HPLC analysis using as little as 100 mg of plant material from up to 50-years old samples of Polygonum aviculare.

The one step extraction with C18 silica gel as dispersing phase in proportion of 1:4 of herbal material eluted with methanol was sufficient to obtain repeatable profiles comparable to classical solvent extraction. The major flavonoids such as quercetin-, myricetin- and kaempferol-glycosides were well preserved in most of the 20 analyzed herbarium samples as compared to the freshly prepared material from validated Polygoni avicularis herba. 100 mg of plant material was enough for extraction and did not provoke significant damage to the specimens. The samples despite differences in collection years and classification to various subspecific taxons were all very similar in terms of the TLC and HPLC profiles and content of major flavonoids. The tested method proves the concept of using MSPD as convenient approach for extraction of unique historical samples or when only small amounts are available.

• References

• 1 Dawidowicz AL. and Wianowska. Application of the MSPD Technique for the HPLC Analysis of Rutin in Sambucus nigra L.: The Linear Correlation of the Matrix Solid-Phase Dispersion Process. J Chromatogr Sci. 2009; 83: 914-918