Caffeoylquinic Acids: Separation Method, Antiradical Properties and Cytotoxicity.

Area of Science:

• Phytochemistry
• Natural Products Chemistry
• Pharmacognosy

Background:

• Moquiniastrum floribundum (Asteraceae) is a plant species with potential medicinal properties.
• Natural products, particularly those from the Asteraceae family, are a rich source of bioactive compounds.
• Understanding the antioxidant properties of plant-derived compounds is crucial for developing new therapeutic agents.

Purpose of the Study:

• To isolate and identify compounds from Moquiniastrum floribundum.
• To evaluate the isolated compounds for their cytotoxicity and antiradical (antioxidant) properties.
• To determine the structure-activity relationship concerning the antiradical activity of chlorogenic acid derivatives.

Main Methods:

• Phytochemical analysis involving isolation and structural elucidation of compounds.
• In vitro assays to assess cytotoxicity against selected cell lines.
• Antiradical activity evaluation using established antioxidant assays, comparing against a Trolox standard.

Main Results:

• Twelve chlorogenic acid derivatives and two flavones were successfully isolated.
• No significant cytotoxicity was observed for any of the isolated compounds.
• Chlorogenic acid derivatives demonstrated notable antiradical activity, surpassing that of the Trolox standard.
• Esterification with a caffeoyl group at the C-4 position of quinic acid resulted in higher antiradical activity compared to C-3 or C-5 positions.
• Additional caffeoyl groups enhanced antiradical activity, with methyl ester derivatives generally showing higher radical-scavenging capacity than their corresponding acids.

Conclusions:

• Moquiniastrum floribundum is a source of compounds with significant antiradical properties.
• Chlorogenic acid derivatives are the primary contributors to the observed antioxidant activity.
• The presence of a caffeoyl group at the C-4 position of quinic acid is critical for maximizing antiradical efficacy.
• Structural modifications, such as the addition of caffeoyl groups and esterification, can modulate the antioxidant potential of these compounds.