Validation and Standardization of Gallic Acid and Ellagic Acid in Quercus Infectoria, Terminalia Chebula, and Pistacia Integerrima.

Background: Due to its medicinal properties, Pistacia integerrima is in high demand and is extensively used as a key ingredient in various formulations. However, its popularity has led to its inclusion on the International Union for Conservation of Nature threatened category list. In Ayurvedic texts, such as Bhaishajaya Ratnavali, Quercus infectoria is recommended as a substitute for P. integerrima in different formulations. Additionally, Yogratnakar highlights that Terminalia chebula shares similar therapeutic properties with P. integerrima.

Objective: The objective of the current study was to gather scientific data on metabolite profiling and marker-based comparative analysis of Q. infectoria, T. chebula, and P. integerrima.

Methods: In present study, hydroalcoholic and aqueous extracts of all three plants were prepared and standardized for the comparative evaluation of secondary metabolites. TLC was carried out for the comparative fingerprinting of the extracts using chloroform-methanol-glacial acetic acid-water (60 + 8 + 32 + 10, by volume) as a solvent system. A fast, sensitive, selective, and robust HPLC method was developed to determine gallic acid and ellagic acid from both extracts of all three plants. The method was validated for precision, robustness, accuracy, LOD and LOQ as per the International Conference on Harmonization guidelines.

Results: The TLC analysis revealed the presence of several metabolites, and the pattern of metabolites in the plants exhibited a certain degree of similarity. A highly precise and reliable quantification technique was created for gallic acid and ellagic acid, operating within a linear concentration range of 81.18-288.22 µg/mL and 3.83-13.66 µg/mL, respectively. The correlation coefficients for gallic acid and ellagic acid were 0.997 and 0.996, indicating good linear relationships. The gallic acid content in all three plants ranged from 3.74 to 10.16% w/w, while the ellagic acid content ranged from 0.10 to 1.24% w/w.

Conclusion: The study contributes to the scientific understanding of the metabolite profiles and comparative analysis of Q. infectoria, T. chebula, and P. integerrima. The findings provide valuable insights into the chemical composition of these plants and can be used for various applications in herbal medicine.

Highlights: This pioneering scientific approach highlights the phytochemical similarities between Q. infectoria, T. chebula and P. integerrima.