Effect of different solvents on bioactive phenolics and antioxidant, antimicrobial, and <i>α</i> -glucosidase inhibition activities of <i>Barringtonia acutangula</i> Gaertn. flower extracts

<i>Barringtonia acutangula</i> Gaertn. is a well-known vegetable and medicinal plant. This study assessed solvents' effect on phytochemical contents and bioactivities of flower extracts. High-polar extracts (ethanol, aqueous) demonstrated much higher phenolic contents (132.21, 240.83 mg gallic acid equivalent per gram of extract, respectively) than non-/medium-polar extracts, with more impressive flavonoid/saponin contents. Aqueous extract was highlighted for antioxidant activity and <i>α</i>-glucosidase inhibition (IC₅₀ = 35.01, 5.63 μg/mL, respectively) on which HPLC analysis revealed gallic acid (<b>1</b>), pyrogallol (<b>2</b>), ilexsaponin A1 (<b>3</b>) as major compounds for 1.83, 1.26, 0.15%, respectively. Phenolics <b>1</b> and <b>2</b> displayed strong <i>α</i>-glucosidase inhibition (IC₅₀ 6.6 - 18.7 μM), consolidated by molecular docking studies and molecular dynamics simulations, based on their stable complexes with <i>α</i>-glucosidase protein (MAL32) <i>via</i> H-bonds of hydroxy phenol moieties, which was more effective in <b>2</b>. The study suggested the potency of <i>B. acutangula</i> flower water extract and its phenolics, displaying the need for in-depth investigation.