In Vitro Biological Evaluation and In Silico Studies of a New Anthraquinone From <i>Zingiber Cassumunar</i> Roxb. in Type 2 Diabetes Management

A novel diphenyl-anthraquinone compound, cassuquinone A (CA), was isolated from the rhizomes of Zingiber cassumunar. Structural elucidation was accomplished using detailed nuclear magnetic resonance and high-resolution mass spectroscopy-electrospray ionization techniques, revealing a symmetrical anthraquinone core with methoxylated aromatic rings. CA exhibited potent α-glucosidase (AR) inhibitory activity with an IC₅₀ of 11.72 µM, significantly more potent than the positive control, acarbose (IC₅₀ = 190.60 µM), highlighting its potential as an antidiabetic agent. Molecular docking studies indicated stable binding of CA to AR, with key interactions involving Arg315, Phe314, Glu411, Val232, and Ser240, contributing to its high docking score. Additionally, molecular dynamics simulations demonstrated that CA stabilizes the AR structure by reducing the enzyme's flexibility, especially within the active site, which may hinder substrate access and product release.