The heartwood of Pterocarpus marsupium is called as “Asana” in Ayurveda. Its aquatic infusion was used for treating “prameha,” which indicates a polyuria disease in modern medicine. In our research program to investigate a novel agent to improve hyperuricemia, we focused on the extract of Asana as a xanthine oxidase (XOD) inhibitor. Asana extract (50% ethanolic extract, PM-ext) showed 11%, 35%, and 38% inhibition at 50, 200, and 500 µg/mL, respectively. Subsequently, PM-ext was partitioned with ethyl acetate (AcOEt), butanol, and water. Among them, AcOEt-soluble fraction indicated the most potent XOD inhibitory activity and was consecutively fractionated using various liquid chromatography to obtain liquiritigenin (1), isoliquiritigenin (2), and marsupsin (3) as active principles. Compound 1 showed 16% inhibition at 200 µM while 2 showed 20%, 32%, and 46% inhibition at 50, 100, and 200 µM, respectively. Compound 3 showed 15% inhibition at 500 µM. This is the first report on the XOD inhibitory activity of 3. From these results, PM-ext is a promising candidate material for improvement of hyperuricemia. Here, Asana was recognized as an effective material against noncommunicable disease and is expected to be developed as a functional ingredient.
Determination of inhibitory activity of Salvia miltiorrhiza extracts on xanthine oxidase with a paper-based analytical device
