Antioxidant and anti-nitric oxide components from Quercus glauca

Area of Science:

• Phytochemistry
• Natural Products Chemistry
• Pharmacology

Background:

• Quercus species are known sources of bioactive compounds.
• Ethnobotanical uses of Quercus glauca suggest potential medicinal properties.
• Investigating the chemical constituents of Quercus glauca can lead to the discovery of novel therapeutic agents.

Purpose of the Study:

• To isolate and characterize new and known chemical constituents from the ethanolic extract of Quercus glauca.
• To evaluate the isolated compounds for their potential to inhibit nitric oxide (NO) production.
• To assess the antioxidant activities of the isolated compounds.

Main Methods:

• Extraction of Quercus glauca using ethanol.
• Isolation of compounds using chromatographic techniques.
• Structure elucidation of new compounds via spectroscopic analysis (e.g., NMR, MS).
• In vitro assays to measure nitric oxide inhibition and antioxidant capacity.

Main Results:

• Two new lignans, (+)-5'-methoxyisolariciresinol-9'-O-α-L-rhamnopyranoside and (7R,8S)-dihydrodehydrodiconiferyl alcohol 4-β-D-xyloside, were identified.
• Fourteen known compounds, including lignanoids, triterpenoids, flavonoids, aromatics, and a steroid, were also isolated.
• Compounds 9 and 14 exhibited potent inhibition of nitric oxide production (IC50 values of 8.25 and 14.04 µM, respectively).
• Compounds 1, 4-6, 14, and 15 displayed moderate antioxidant activities.

Conclusions:

• The ethanolic extract of Quercus glauca is a rich source of diverse phytochemicals, including novel lignans.
• Certain isolated compounds, particularly 9 and 14, possess significant anti-inflammatory potential due to NO inhibition.
• The identified compounds, with their antioxidant properties, may offer protective effects against oxidative stress.
• Further research into these compounds could lead to the development of new therapeutic agents for inflammatory and oxidative stress-related diseases.