Multifaceted Biological Activity of Selected Flavone C-Monoglucosides

Area of Science:

• Biochemistry
• Pharmacology
• Natural Products Chemistry

Background:

• Flavonoids, particularly C-monoglucosides like orientin and vitexin, are plant-derived compounds with diverse biological activities.
• Understanding the structure-activity relationships of these compounds is crucial for their potential therapeutic applications.

Purpose of the Study:

• To determine the multifaceted biological activities of selected flavone C-monoglucosides (orientin, homoorientin, vitexin, isovitexin) and quercetin.
• To evaluate the relationship between their antioxidant properties and inhibitory activities against ACE, AChE, and AGE formation.

Main Methods:

• Differential pulse voltammetry (DPV) was used to measure antioxidant activity via peak oxidation potentials (Epa).
• Inhibitory activities against angiotensin-converting enzyme (ACE), acetylcholinesterase (AChE), and advanced glycation end-products (AGEs) formation were assessed in model systems.
• Correlation analyses were performed to link Epa values with inhibitory activities.

Main Results:

• Antioxidant activity ranking: Quercetin > homoorientin ≈ orientin > isovitexin ≈ vitexin.
• ACE inhibitory activity ranking: Quercetin > homoorientin > orientin > vitexin > isovitexin; a strong positive correlation (r=0.787) was found between ACE inhibition and Epa.
• AChE inhibitory activity: homoorientin > orientin > isovitexin > vitexin > quercetin. Anti-AGEs activity: homoorientin > orientin > isovitexin > quercetin > vitexin.

Conclusions:

• Flavone C-monoglucosides exhibit significant multifaceted biological activities, including antioxidant, ACE, AChE inhibition, and anti-AGE properties.
• A strong correlation exists between antioxidant potential (Epa) and ACE inhibitory activity, suggesting a common mechanism.
• Homoorientin and orientin demonstrate notable potential for further investigation in therapeutic contexts.