Background: Previous studies have shown antiviral, antibacterial and anti-inflammatory activity of alkaline extract of the leaves of Sasa senanensis Rehder (SE). However, active components have not been identified. We isolated the substances that exhibit anti-UV activity and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity from SE and estimated their putative structures.
Materials and methods: The anti-UV substances (SEE-1 and SEE-2) were isolated from SE by ethanolic extraction, Wakosil chromatography and recycled high-performance liquid chromatography (HPLC) at a yield of 0.22 and 0.18%, respectively. The structural analysis was carried out with (1)H-nuclear magnetic resonance (NMR), (13)C-NMR and UV absorption.
Results: SEE-1 exhibited approximately four-fold higher anti-UV activity and slightly lower DPPH radical-scavenging activity, compared to SE. SEE-1 was identified as p-coumaric acid derivative(s), a lignin precursor.
Conclusion: The present study demonstrated for the first time the presence of lignin precursors in SE, which may explain why SE exhibits many of the properties of lignin-carbohydrate complexes.