Capsaicin
[CAS# 404-86-4]

Identification

• Classification: Biochemical >> Natural biochemical product
• Name: Capsaicin
• Synonyms: (E)-N-[(4-Hydroxy-3-methoxyphenyl)methyl]-8-methyl-6-nonenamide; 8-Methyl-N-vanillyl-6-nonenamide; (E)-8-Methyl-N-vanillyl-6-nonenamide
• Molecular Formula: C₁₈H₂₇NO₃
• Molecular Weight: 305.42
• CAS Registry Number: 404-86-4
• EC Number: 206-969-8
• SMILES: CC(C)/C=C/CCCCC(=O)NCC1=CC(=C(C=C1)O)OC

Properties

• Solubility: insoluble (water), 50 mM (DMSO, ethanol)
• Density: 1.0±0.1 g/cm³, Calc.^*
• Melting point: 62-65 °C
• Index of Refraction: 1.508, Calc.^*
• Boiling Point: 469.7±55.0 °C (760 mmHg), Calc.^*
• Flash Point: 237.9±31.5 °C, Calc.^*, 113 °C

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

Safety Data

• Hazard Symbols: GHS05;GHS06;GHS07 Danger
• Risk Statements: H301-H302-H315-H318
• Safety Statements: P264-P264+P265-P270-P280-P301+P316-P301+P317-P302+P352-P305+P354+P338-P317-P321-P330-P332+P317-P362+P364-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Skin irritation	Skin Irrit.	2	H315
Serious eye damage	Eye Dam.	1	H318
Acute toxicity	Acute Tox.	4	H302
Acute toxicity	Acute Tox.	3	H301
Eye irritation	Eye Irrit.	2	H319
Specific target organ toxicity - single exposure	STOT SE	3	H335
Respiratory sensitization	Resp. Sens.	1	H334
Skin sensitization	Skin Sens.	1	H317
Acute toxicity	Acute Tox.	4	H312
Acute toxicity	Acute Tox.	4	H332
Specific target organ toxicity - single exposure	STOT SE	1	H335
Specific target organ toxicity - single exposure	STOT SE	3	H336
Acute toxicity	Acute Tox.	2	H300
Acute toxicity	Acute Tox.	3	H311

• Transport Information: UN 2811

Discovery and Applications

Capsaicin is a bioactive compound primarily found in chili peppers (Capsicum species) that is responsible for their characteristic pungency. This compound has been extensively studied since its discovery in the 19th century, when chemists began isolating and identifying the components responsible for the heat in peppers. Capsaicin was first extracted in its pure form in 1816 by the French chemist Henri Louis Duhamel du Monceau. The structure of capsaicin was subsequently elucidated in the late 19th century, revealing it to be an alkaloid with the molecular formula C18H27NO3.

The biosynthesis of capsaicin in peppers involves a series of enzymatic reactions that convert precursor compounds into the pungent alkaloid. The main pathway involves the condensation of vanillylamine and fatty acid derivatives, which are essential for the development of the spicy flavor characteristic of many chili varieties. Capsaicin is typically concentrated in the placental tissue of the fruit, where it serves as a defense mechanism against herbivores and fungi, making the fruit less palatable to potential threats.

One of the most notable applications of capsaicin is in the food industry, where it is used as a flavoring agent and food preservative. Its ability to enhance flavor and provide a sense of heat makes it a popular ingredient in various cuisines worldwide. Beyond its culinary uses, capsaicin has been extensively researched for its potential health benefits. Studies have suggested that capsaicin possesses analgesic properties, making it a valuable component in topical pain relief formulations. Creams and patches containing capsaicin are commonly used to alleviate pain associated with conditions such as arthritis, neuropathy, and muscle soreness.

In addition to its analgesic effects, capsaicin has been investigated for its potential anti-inflammatory and antioxidant properties. Research indicates that capsaicin may help modulate inflammatory pathways, which could benefit conditions like obesity and metabolic syndrome. Some studies have also linked capsaicin to potential weight management benefits, as it may enhance metabolism and promote fat oxidation, making it a popular ingredient in dietary supplements and weight loss products.

Furthermore, capsaicin has attracted attention in the realm of cancer research. Preliminary studies have suggested that capsaicin may exhibit anti-cancer properties by inducing apoptosis in certain cancer cell lines and inhibiting tumor growth. These findings have opened up new avenues for exploring capsaicin as a potential adjunct therapy in cancer treatment, although further research is needed to confirm these effects in clinical settings.

In summary, capsaicin is a significant bioactive compound with a rich history and diverse applications. Its discovery marked a pivotal moment in the study of natural products and their effects on human health. Today, capsaicin continues to be a focus of research, exploring its potential benefits in pain relief, inflammation modulation, weight management, and cancer therapy.

References

2025. Cocktail enzyme-assisted natural deep eutectic solvent for enhanced extraction of capsaicin from chili peppers: Mechanism exploration based on multi-experiments and molecular dynamic simulation. Food Chemistry.
DOI: 10.1016/j.foodchem.2024.141959

2025. Extraction mechanism and bio-activities of capsaicinoids from lantern peppers placenta using deep eutectic solvents. Food Chemistry.
DOI: 10.1016/j.foodchem.2024.141773

2005. Analysis of Eight Capsaicinoids in Peppers and Pepper-Containing Foods by High-Performance Liquid Chromatography and Liquid Chromatography−Mass Spectrometry. Journal of Agricultural and Food Chemistry, 53(23).
DOI: 10.1021/jf050469j