Figure 1. Sequence alignment between α-glucosidase (MAL12) and oligo-1,6-glucosidase (O16GB). The identity and the similarity between the corresponding residues are indicated in red and green, respectively. The active site residues are indicated in a blue rectangular box.

Figure 2. Comparative view of (a) homology-modeled structure of α-glucosidase and (b) X-ray crystal structure of oligo-1,6-glucosidase.

Figure 3. Comparison of the ProSa energy profiles for the homology-modeled structure of α-glucosidase (red) and the X-ray structure of oligo-1,6-glucosidase (green).

Figure 4. Chemical structures of the newly identified α-glucosidase inhibitors.

Figure 5. Binding mode of 11 in the active site of α-glucosidase. Carbon atoms of the protein and the ligand are indicated in green and cyan, respectively. Each dotted line indicates a hydrogen bond.

Figure 6. Binding mode of 12 in the active site of α-glucosidase. Carbon atoms of the protein and the ligand are indicated in green and cyan, respectively. Each dotted line indicates a hydrogen bond.

Inhibitory activities of the newly identified compounds 1–13 against α-glucosidase

Physicochemical properties of the newly identified α-glucosidase inhibitors