In vitro α-amylase and α-glucosidase inhibitory effects and antioxidant potential of new dihydrochalcones from Baphia massaiensis Taub

Two previously undescribed dihydrochalcones, 4,2′-dihydroxy- [2″, 2″-dimethylpyrano (3″, 4″: 4′, 5′]) dihydrochalcone ( 1 ) and 4, 2′, 4′, 2″-tetrahydroxy-5′-(3″-methylbut-3″-enyl) dihydrochalcone ( 2 ), along with six known compounds (3 - 8 ) were isolated from chloroform-methanol (1:1) extract of Baphia Massaiensis twigs. Their chemical structures were determined using NMR analysis, mass spectrometry, electronic circular dichroism (ECD), density functional theory (DFT) calculations, and a thorough comparison with reported data from the literature. All the isolated compounds (1−8) were assessed for their antioxidant activities, α-amylase and α-glucosidase inhibition effects. Dihydrochalcone 1 showed significant antioxidant activity with IC 50 value of 118.8 ± 2.95 µM, and a more potent antioxidant activity was exhibited by compounds 3 and 6 with IC 50 values of 84.3 ± 0.07 µM and 62.1 ± 1.59 µM, respectively, compared to the positive control, gallic acid with IC 50 value of 92.9 µM. Dihydrochalcone 2 showed moderate inhibition against α-amylase and α-glucosidase with IC 50 values of 44.0 ± 4.83 µM and 51.7 ± 9.72 µM compared to the standard acarbose with IC 50 values of 22.9 ± 0.92 µM and 31.5 ± 0.63 µM, respectively. Molecular docking studies of the new dihydrochalcones 1 and 2, revealed the active binding sites which support the observed α-amylase and α-glucosidase inhibitory effects.