Flavonoids in Rosmarinus officinalis leaves

Area of Science:

• Phytochemistry
• Natural Products Chemistry
• Pharmacognosy

Background:

• Rosemary (Rosmarinus officinalis) is a well-known medicinal herb with a rich history of traditional use.
• Flavonoids and their derivatives are widely studied for their diverse biological activities, including antioxidant properties.
• Isolation and characterization of novel compounds from medicinal plants contribute to understanding their therapeutic potential.

Purpose of the Study:

• To isolate and characterize new flavonoid glucuronides from rosemary leaves.
• To evaluate the antioxidant activities of the isolated compounds.
• To identify potential bioactive constituents in rosemary for further investigation.

Main Methods:

• Extraction of rosemary leaves using 50% aqueous methanol.
• Isolation of compounds using chromatographic techniques.
• Structure elucidation employing chemical and spectroscopic methods (e.g., NMR, Mass Spectrometry).
• Antioxidant activity assessment using the ferric thiocyanate method.

Main Results:

• Three novel flavonoid glucuronides were successfully isolated and identified: luteolin 3'-O-beta-D-glucuronide, luteolin 3'-O-(4"-O-acetyl)-beta-D-glucuronide, and luteolin 3'-O-(3"-O-acetyl)-beta-D-glucuronide.
• Hesperidin was also isolated from the rosemary extract.
• Hesperidin exhibited the most significant antioxidant activity compared to the other isolated compounds in the ferric thiocyanate assay.

Conclusions:

• The study successfully identified novel flavonoid glucuronides from rosemary, expanding the known phytochemical profile of the plant.
• Hesperidin is a potent antioxidant present in rosemary leaves.
• These findings highlight the potential of rosemary as a source of bioactive compounds with antioxidant properties.