Quercetin
[CAS# 117-39-5]

Identification

• Classification: API >> Respiratory medication >> Antitussive
• Name: Quercetin
• Synonyms: 3,3',4',5,7-Pentahydroxyflavone; 2-(3,4-Dihydroxyphenyl)-3,5,7-trihydroxy-4H-chromen-4-one
• Molecular Formula: C₁₅H₁₀O₇
• Molecular Weight: 302.24
• CAS Registry Number: 117-39-5
• EC Number: 204-187-1
• SMILES: C1=CC(=C(C=C1C2=C(C(=O)C3=C(C=C(C=C3O2)O)O)O)O)O

Properties

• Melting point: 314-317 °C
• Water solubility: <0.1 g/100 mL at 21 °C

Safety Data

• Hazard Symbols: GHS06 Danger
• Risk Statements: H301
• Safety Statements: P264-P270-P301+P316-P321-P330-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Acute toxicity	Acute Tox.	3	H301
Acute toxicity	Acute Tox.	4	H302

Discovery and Applications

Quercetin is a naturally occurring flavonoid that was first isolated in the 19th century from plant sources such as oak trees. It is one of the most abundant dietary flavonoids found in fruits, vegetables, and grains. The compound's chemical structure consists of a polyphenolic backbone with five hydroxyl groups, contributing to its antioxidant properties. Quercetin’s discovery laid the foundation for understanding the role of flavonoids in plant metabolism and human health.

The synthesis of quercetin can be achieved through the extraction from plant materials or by chemical synthesis. In nature, quercetin is typically extracted from sources like onions, apples, berries, and tea. A common laboratory method for synthesizing quercetin involves the oxidation of suitable precursors, such as flavanols, in the presence of acidic or basic catalysts. Advances in biotechnology have also enabled microbial synthesis of quercetin, offering a sustainable alternative for large-scale production.

Quercetin is widely recognized for its potent antioxidant and anti-inflammatory properties. It scavenges free radicals, thereby protecting cells from oxidative damage. This property has led to its use in dietary supplements and functional foods to promote general health and reduce the risk of chronic diseases. In addition to its antioxidant activity, quercetin has demonstrated potential in cardiovascular health by improving endothelial function and reducing blood pressure. It also exhibits antiviral and anticancer properties, making it a subject of ongoing research for therapeutic applications.

In the pharmaceutical industry, quercetin is explored for its ability to modulate signaling pathways related to inflammation and cell proliferation. It has shown promise in enhancing the efficacy of chemotherapeutic agents and protecting healthy cells during cancer treatment. Moreover, quercetin's potential neuroprotective effects are being studied for the prevention and treatment of neurodegenerative diseases such as Alzheimer's and Parkinson's disease.

The discovery and ongoing research into quercetin highlight its significance in nutrition, medicine, and pharmacology. Its broad range of biological activities and accessibility from natural sources ensure its continued relevance in health and therapeutic applications.

References

2024. Unraveling the phytochemical complexity and antimicrobial potency of introduced versus native Argania spinosa trees in Eastern Morocco. Chemical Papers.
DOI: 10.1007/s11696-024-03739-1

1994. Effects of Flavonoid Compounds on the Activity of NADPH Diaphorase Prepared from the Mouse Brain. Japanese Journal of Pharmacology.
DOI: 10.1254/jjp.65.371

1979. Antineoplastic Activity and Cytotoxicity of Flavones, Isoflavones, and Flavanones. Journal of Natural Products.
DOI: 10.1021/np50001a002