Abstract

• This research focuses on the chemical and biological aspect of crude extracts of endophytic fungi isolated from Oroxylum indicum (L.) Benth (Kyaung sha) fruits. The endophytic fungi have been isolated from O. indicum (Kyaung sha) fruit by the direct method, followed by cultured in potato agar medium (PGA). Four endophytic fungi (EFK1, EFK2, EFK3, and EFK4) have been isolated from O. indicum (Kyaung sha) fruit. Preliminary phytochemicals, total phenolic contents (TPC) and total flavonoid content (TFC) have been carried out as chemical investigations. Showing 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 all tested samples. The total phenol contents of isolated fungi 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 were expressed as a microgram of gallic acid equivalent per milligram of crude extract (μg GAE/mg). TPC (μg GAE/mg) were found to be highest in EFK2 (216.86  0.66). The total flavonoids content (TFC) of isolated fungi were determined by using spectrophotometric method with aluminum chloride. The content of flavonoids was expressed in term of quercetin equivalent, mg of QE/g of extract. TFC (mg QE/g) was found to be highest in EFK3 (67.47 ± 1.40). The four isolated fungi were observed to possess antioxidant capacity by the DPPH assay method. Among them, EFK 2 has more potent antioxidant activity (IC50 = 12.15 μg/mL) than other tested samples. Moreover, anti-diabetic activity (expressed in terms of α-amylase inhibitory) indicated that EFK 3 and EFK 4 possessed higher anti-diabetic activity (IC50 = 4.94 μg/mL) than other tested samples. The four endophytic fungi were found to possess high activity against all tested microorganisms with the inhibition zone diameters ranging between 20 mm ~ 30 mm. All endophytic fungi have more portent antioxidant, antidiabetic and antimicrobial effects.