Pongamol
[CAS 484-33-3]

Identification

• Classification: Chemical reagent >> Organic reagent >> Phenols
• Name: Pongamol
• Synonyms: 1-(4-methoxy-1-benzofuran-5-yl)-3-phenylpropane-1,3-dione
• Molecular Formula: C₁₈H₁₄O₄
• Molecular Weight: 294.30
• CAS Registry Number: 484-33-3
• EC Number: 414-540-3
• SMILES: COC1=C(C=CC2=C1C=CO2)C(=O)CC(=O)C3=CC=CC=C3

Properties

• Density: 1.2$+/-$0.1 g/cm³ Calc.^*
• Boiling point: 477.9$+/-$35.0 $degree$C 760 mmHg (Calc.)^*
• Flash point: 242.8$+/-$25.9 $degree$C (Calc.)^*
• Index of refraction: 1.612 (Calc.)^*

^* Calculated using Advanced Chemistry Development (ACD/Labs) Software.

Safety Data

• Hazard Symbols: GHS09 Warning
• Risk Statements: H400-H410
• Safety Statements: P273-P391-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Chronic hazardous to the aquatic environment	Aquatic Chronic	1	H410
Acute hazardous to the aquatic environment	Aquatic Acute	1	H400

Discovery and Applications

Pongamol is a naturally occurring flavonoid belonging to the class of flavanones, specifically a substituted chalcone-derived phenolic compound found in various plants, most notably in species of the genus Pongamia (now commonly classified as Millettia pinnata). It has the molecular formula C₁₆H₁₄O₄ and is structurally characterized by a benzopyranone core with methoxy and hydroxyl substitutions on the aromatic rings.

Structurally, pongamol is based on the flavanone skeleton, which consists of a 2,3-dihydro-2-phenylchromen-4-one framework. This structure includes two aromatic rings (commonly referred to as the A and B rings) connected through a heterocyclic oxygen-containing pyran ring. In pongamol, the substitution pattern includes methoxy and hydroxy groups that modify the electronic distribution and chemical reactivity of the molecule.

The compound is biosynthesized in plants via the phenylpropanoid pathway, which produces a wide range of flavonoid derivatives from phenylalanine. Enzymatic transformations such as hydroxylation, methylation, and cyclization of chalcone intermediates lead to the formation of flavanones like pongamol. These biosynthetic steps are catalyzed by specific plant enzymes, including chalcone synthase and flavanone synthase.

Pongamol is found in several parts of the plant, including seeds, leaves, and bark, often coexisting with other related flavonoids and furanoflavonoids. In plant systems, such compounds are generally associated with protective roles, including defense against pathogens, ultraviolet radiation, and herbivory.

Chemically, pongamol contains phenolic hydroxyl groups capable of hydrogen bonding and undergoing typical phenol reactions such as etherification, esterification, and oxidation. The presence of methoxy substituents increases lipophilicity and reduces the number of hydrogen bond donors, which influences both solubility and metabolic stability.

The flavanone core of pongamol contains a saturated heterocyclic ring, which distinguishes it from more oxidized flavones and flavonols. This structural feature affects its planarity and conformational flexibility. The B-ring can adopt different spatial orientations relative to the heterocyclic core, influencing molecular interactions.

Pongamol has been studied in natural products chemistry due to its occurrence in medicinal plants traditionally used in herbal medicine. Extracts containing pongamol and related flavonoids have been investigated for various biological activities in experimental studies, including antioxidant and enzyme-modulating properties. These effects are commonly associated with phenolic compounds due to their ability to interact with reactive oxygen species and biological macromolecules.

From a physicochemical perspective, pongamol is moderately hydrophobic due to its aromatic ring system and methoxy substituents, while the hydroxyl groups provide limited polarity. This balance influences its solubility in organic solvents and its limited solubility in water.

Spectroscopically, flavanones such as pongamol exhibit characteristic ultraviolet absorption bands arising from π–π* transitions in the conjugated aromatic system. These properties are often used in analytical identification and quantification in plant extracts.

Historically, compounds like pongamol have contributed to the broader study of flavonoid chemistry and plant secondary metabolites. Their isolation and structural characterization have helped elucidate biosynthetic pathways and chemotaxonomic relationships among plant species.

Overall, pongamol is a naturally occurring flavanone with a substituted benzopyranone structure derived from plant phenylpropanoid metabolism. Its combination of phenolic and methoxylated aromatic features makes it a representative member of flavonoid natural products studied in phytochemistry and natural product research.

References

2021. Health promoting benefits of pongamol: An overview. Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie.
DOI: 10.1016/j.biopha.2021.112109

2021. Pongamol Inhibits Epithelial to Mesenchymal Transition Through Suppression of FAK/Akt-mTOR Signaling. Anticancer Research.
DOI: 10.21873/anticanres.15434

2011. Pongamol from Pongamia pinnata stimulates glucose uptake by increasing surface GLUT4 level in skeletal muscle cells. Molecular and Cellular Endocrinology.
DOI: 10.1016/j.mce.2011.03.023