Investigation on Photodecomposition of Standardised Ethyl Acetate Fraction of Katha

Objective: The present study delves into photodecomposition of a standardised ethyl acetate fraction of Katha and manifest how the antioxidant potential degrades exponentially with time. Methods: Coarsely dried heart wood of Acacia catechu (L.f.) Willd. was treated with 10 % hydro-alcoholic solution to obtain Katha as final product. The powdered Katha was standardised via pharmacognostic parameters and further subjected to soxhlet extraction using ether, ethyl acetate and ethanol to obtain different extracts/fractions. Phytochemical investigations were carried out to screen polyphenols (tannins) of interest which later were confirmed by thin layer chromatography (TLC). Photodecomposition of ethyl acetate fraction with respect to its in-vitro antioxidant potential using DPPH and nitric oxide scavenging assay was determined at 0 h, 4 h, 8 h, 12 h, 16 h, 20 h and 24 h of 250, 500, 750 and 1000 μg/ml concentrations respectively. Ethyl acetate fraction conceded the highest amount of polyphenols. Results: The extract was found to be unstable at room temperature and displayed a quick change in colour from light orange to deep dark orange within few hours, which also abide by its decreasing antioxidant activity exponentially with time. Antioxidant potential was observed in the following order in dose dependant manner: 0 h > 4 h > 8 h > 12 h > 16 h > 20 h > 24 h. Conclusion: Moreover, published literature should have not mentioned the age of extract they have used for their study, which may explain the wide differences in the observations reported with this plant.