Acteoside and Acyl-Migrated Acteoside, Compounds in Chinese Kudingcha Tea, Inhibit α-Amylase In Vitro.

Area of Science:

• Biochemistry
• Pharmacology
• Food Science

Background:

• Acteoside is a key polyphenol in small-leaved kudingcha (Chinese tea) with known biological activities.
• Polyphenols are widely studied for their health benefits and interactions with enzymes.
• Understanding the behavior of acteoside under different conditions is crucial for its application.

Purpose of the Study:

• To investigate the acyl migration of acteoside to isoacteoside under high-temperature treatment.
• To evaluate the α-amylase inhibitory effects of acteoside and isoacteoside.
• To explore the binding interactions between acteoside/isoacteoside and α-amylase.

Main Methods:

• High-temperature treatment to induce acyl migration.
• Enzyme inhibition assays to measure α-amylase activity.
• Spectroscopic techniques (fluorescence spectra, circular dichroism) for binding studies.
• Computational protein-ligand docking.

Main Results:

• High-temperature treatment of acteoside resulted in acyl migration to isoacteoside.
• Acteoside demonstrated superior inhibition of α-amylase compared to isoacteoside.
• Both compounds induced conformational changes in α-amylase, with binding sites near the active pocket.
• Differences in binding affinity and site explained the varying inhibition rates.

Conclusions:

• Acteoside is a potent inhibitor of α-amylase, more so than isoacteoside.
• The binding of acteoside and isoacteoside to α-amylase leads to reduced enzyme activity.
• Structural differences between acteoside and isoacteoside account for their distinct inhibitory potencies and binding characteristics.