RESUMO
Abstract Phellinus mushrooms have been traditionally used for various medicinal purposes. Protocatechuic acid, which was previously reported to be a component in some Phellinus mushrooms, has some pharmacological effects. This study aimed to validate a HPLC method for the quantitative analysis of the protocatechuic acid contents in the extracts from different Phellinus mushroom species collected in Thailand. HPLC was carried out using a C18 column and the gradient mobile phases of 0.1% formic acid in water and 0.1% formic acid in acetonitrile. Method validation was performed to assure the linearity, accuracy, precision, limit of detection and limit of quantitation of the analytical method. The linearity range of protocatechuic acid was 1 - 10 µg/ml. The average recovery was 104.16%. The method was shown to be precise with the RSD of repeatability and intermediate precision at less than 3%. The protocatechuic contents in 11 Phellinus mushrooms were in the range of less than 0.0099 - 0.4121 %w/w of the extract. The developed HPLC method was reliable and suitable for the quantitative analysis of protocatechuic acid content in Phellinus mushrooms.