A Validated High-Performance Liquid Chromatography Method for Determination of Tannin-Related Marker Constituents Gallic Acid, Corilagin, Chebulagic Acid, Ellagic Acid and Chebulinic Acid in Four Terminalia Species from India

A validated rapid HPLC–PDA method was developed for identification and quantification of five tannin-related constituents gallic acid (GA), corilagin (CL), chebulagic acid (CB), ellagic acid (EA) and chebulinic acid (CN) in the extracts prepared from the bark and fruits of four Terminalia species available in India. The separation of the five analytes was achieved on an RP-18 column (4.6 × 250 mm, 5 µm) at 25°C using a solvent mixture comprising of acetonitrile and (0.05%) trifluoroacetic acid–water in a gradient elution mode. Limit of detection was 1.0, 0.5, 1.0, 0.5 and 1.0 μg/mL for GA, CL, CB, EA and CN, respectively. Similarly, limit of quantification was 2.5, 1.0, 2.5, 1.0 and 2.5 μg/mL for GA, CL, CB, EA and CN, respectively. Good linearity (r2 > 0.992) was observed for all the five compounds in wide concentration range. Using the developed HPLC method, the five analytes were identified and quantified in bark and fruit extracts of Terminalia chebula, Terminalia bellirica, Terminalia arjuna and Terminalia catappa. This is the first report of identification and quantification of the five tannin-related marker constituents in the bark and fruit extracts of T. chebula, T. bellirica, T. arjuna and T. catappa.