HPLC quantitative analysis of protocatechuic acid contents in 11 Phellinus mushroom species collected in Thailand

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.

Antioxidant activity of Acanthopanax trifoliatus

The aim of this study was to investigate the antioxidant activity of extracts of various parts of Acanthopanax trifoliatus obtained by different extraction methods. The total phenolic and flavonoid contents of the extracts were also determined. The leaves, stems, stembark, roots and root bark of A. trifoliatus were extracted separately using decoction, maceration and refluxing methods. The extracts were analysed for free-radical-scavenging activity using the 1,1-diphenyl-2-picryl-hydrazyl scavenging assay and the thiobarbituric-acid-reactive substance method for the inhibition of lipid peroxidation of a rat brain homogenate. Total phenolic and total flavonoid contents of the extracts were measured by UV spectrophotometry. The leaf decoction extracts possessed a significantly stronger antioxidant activity as revealed by both methods. Total phenolic and flavonoid contents of the extracts were measured by UV spectrophotometry. The leaf decoction extracts possessed a significantly stronger antioxidant activity as revealed by both methods. Total phenolic and flavonoid contents of the extracts ranged from 2.16 to 21.79 g% chlorogenic acid equivalent and from 0.37 to 9.61 g% rutin equivalent, respectively. Analysis of the leaf decoction extract, which exhibited the most potent antioxidant activity, by thin-layer chromatography revealed flavonoid and polyphenolic compounds corresponding to rutin and chlorogenic acid. The leaf aqueous extracts showed a high level of antioxidative activity and contained high levels of both phenolic and flavonoid compounds. The magnitude of antioxidant activity corresponded with the level of phenolic and flavonoid compounds