New acylated iridoid glucosides from Vitex altissima

Area of Science:

• Phytochemistry
• Natural Products Chemistry
• Pharmacology

Background:

• Vitex altissima is a plant species with potential medicinal properties.
• Iridoid glucosides are a class of natural compounds known for diverse biological activities.

Purpose of the Study:

• To isolate and characterize new iridoid glucosides from Vitex altissima leaves.
• To evaluate the isolated compounds for 5-lipoxygenase inhibitory and antioxidant activities.
• To assess the anti-inflammatory potential of selected compounds.

Main Methods:

• Isolation of compounds using ethyl acetate extraction.
• Structure elucidation through spectral data interpretation (e.g., NMR, MS).
• In vitro antioxidant assays: superoxide free-radical scavenging (NBT riboflavin photoreduction) and DPPH-radical scavenging.
• In vivo anti-inflammatory assay: rat paw edema.

Main Results:

• Six new iridoid glucosides (1-6) were isolated and identified, along with two known iridoids (agnuside, negundoside).
• Compounds 2, 3, and 4 exhibited significant antioxidant activity in both tested assays.
• Compounds 1, 2, and negundoside showed no significant 5-lipoxygenase inhibitory activity and were evaluated for anti-inflammatory effects.

Conclusions:

• Vitex altissima leaves are a rich source of diverse iridoid glucosides.
• Specific iridoid glucosides from this plant possess notable antioxidant properties.
• Further investigation into the anti-inflammatory mechanisms of these compounds is warranted.