Studies on the phenylethanoid glycosides with anti-complement activity from Paulownia tomentosa var. tomentosa wood

Abstract

Four epimeric phenylethanoid glycosides, including a new one, R,S-β-ethoxy-β-(3,4-dihydroxyphenyl)-ethyl-O-α-l-rhamnopyranosyl(1 → 3)-β-d-(6-O-E-caffeoyl)-glucopyranoside named isoilicifolioside A (1), and three known compounds, ilicifolioside A (2), campneoside II (3), and isocampneoside II (4), were isolated from Paulownia tomentosa var. tomentosa wood. The structures of the four compounds were elucidated by the interpretation of 1D and 2D NMR and MS spectra. This is the first report of the chemical profile of this tree. Compounds 1–4 exhibited excellent anti-complement activity with IC₅₀ values less than 74 μM, compared with tiliroside (IC₅₀ = 104 μM) and rosmarinic acid (IC₅₀ = 182 μM) that were used as positive controls.

Keywords:

• Paulownia tomentosa var. tomentosa
• epimeric phenylethanoid glycoside
• isoilicifolioside A
• anti-complementary activity

Acknowledgements

This project was financially supported by China Postdoctoral Science Foundation (20070410198), the Natural Science Foundation of Tianjin City and Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministry, China (no. 2008-101). We are also thankful to Dr Ji-Sook Ryu, Central Laboratory of Kangwon National University, for measuring the NMR spectra.