Chemical Constituents of Alocasia odora Rhizomes and Their Biological Activities: Experimental and Molecular Docking Approaches

Chemical research of the ethyl acetate extract from rhizomes of Alocasia odora (Roxb.) K.Koch, Araceae, led to the isolation and NMR determination of alocasin A, hyrtiosin B, hyrtiosulawesine, beta-sitosterol, and daucosterol. The first three compounds showed moderate xanthine oxidase inhibitory activity. All five isolates compounds are promising agents for antidiabetic treatment since they are better than the positive control acarbose (IC50 280.62 mu M) in alpha-glucosidase inhibitory assay. In the anti-inflammatory model of LPS-stimulated RAW 264.7 cells, three alkaloids were differentially active against NO production. The ethyl acetate extract, which was non-toxic (LD50 > 0.5 g/kg b.w mice), was also active in xanthine oxidase and alpha-glucosidase inhibitory assays. Molecular docking studies were performed to investigate alpha-glucosidase inhibitory mechanism of three potential alkaloids, in which these molecules exhibited higher binding affinities to the C-terminal than to the N-terminal domain through interaction with key residues within the active site.