Abstract

• The present research is concerned with some phytochemical and biological investigation of crude extracts from Oroxylum. Indicum (L.) (Kyaung sha) fruits. Preliminary phytochemical investigations by test tube methods revealed the presence of alkaloids, α–amino acids, carbohydrates, flavonoids, glycosides, organic acids, phenolic compounds, reducing sugars, saponins, steroids, tannins, and terpenoids, and the absence of starch in the tested samples. The total phenol contents of watery extract of fruits were determined by the Folin-Ciocalteu reagent (FCR) method. Gallic acid (3,4,5- trihydroxy benzoic acid), was used to construct a standard calibration curve for total phenol. TPC contents (μg GAE/mg) were found to be the highest content (51.28  0.41). The total flavonoid contents of watery extract of fruits were determined by the aluminum chloride method. Quarcetin was used to construct a standard calibration curve for total flavonoid. TFC contents (mg QE/g) were found to be highest content (36.05  1.2). The watery and ethanol extracts of the fruits were observed to possess antioxidant capacity by the DPPH assay method, with the watery extract having more potent antioxidant activity (IC50 = 18.28 μg/mL) than other tested samples. Moreover, the watery extract also exhibits higher antidiabetic activity, expressed in terms of α-amylase inhibitory (IC50 = 106.85 μg/mL than other tested samples. In the antimicrobial screening by agar well diffusion method, petroleum ether and ethyl acetate extracts were found to possess high activity against all tested microorganism with the inhibition zone diameters ranging between 18 mm ~ 23 mm but other crude extracts of fruits had mild activity. According to the result, O. indicum (Kyaung sha) fruits contain the highest amount of phytochemical constituents, so these selected fruits have more portent antioxidant, antidiabetic, and antimicrobial effects.