Canthaxanthin
[CAS# 514-78-3]

Identification

• Classification: Food additive >> Color protection agent
• Name: Canthaxanthin
• Synonyms: 2,4,4-Trimethyl-3-[3,7,12,16-tetramethyl-18-(2,6,6-trimethyl-3-oxo-1-cyclohexenyl)octadeca-1,3,5,7,9,11,13,15,17-nonaenyl]cyclohex-2-en-1-one
• Molecular Formula: C₄₀H₅₂O₂
• Molecular Weight: 564.84
• CAS Registry Number: 514-78-3
• EC Number: 208-187-2
• SMILES: CC1=C(C(CCC1=O)(C)C)/C=C/C(=C/C=C/C(=C/C=C/C=C(/C=C/C=C(/C=C/C2=C(C(=O)CCC2(C)C)C)\C)\C)/C)/C

Properties

• Density: 1.0±0.1 g/cm³, Calc.^*
• Index of Refraction: 1.575, Calc.^*
• Boiling Point: 717.0±40.0 ºC (760 mmHg), Calc.^*
• Flash Point: 253.9±24.3 ºC, Calc.^*

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

Safety Data

• Hazard Symbols: GHS07 Warning
• Hazard Statements: H302-H315-H319-H335
• Precautionary Statements: P280-P305+P351+P338

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Chronic hazardous to the aquatic environment	Aquatic Chronic	3	H412

Discovory and Applicatios

Canthaxanthin, a naturally occurring carotenoid, has the molecular formula C40H52O2 and is classified as a xanthophyll due to the presence of hydroxyl groups. This orange-red pigment was first identified in edible mushrooms by Austrian chemist Richard Kuhn in the 1930s during his research on carotenoids. Since then, canthaxanthin has been found in a wide range of natural sources, including crustaceans, flamingo feathers, and certain algae. Its distinctive color and antioxidant properties have made it a valuable compound in various industries, particularly food, cosmetics, and health.

The structure of canthaxanthin features a long polyene chain with alternating double bonds, characteristic of carotenoids, which allows it to absorb light in the visible spectrum. This conjugated system provides its vibrant color and ability to quench singlet oxygen, contributing to its antioxidant activity. Early studies on canthaxanthin revealed its potential for protecting cells from oxidative stress and enhancing pigmentation in living organisms.

One of the primary applications of canthaxanthin is as a food colorant, designated as E161g in the European Union. It is widely used in the aquaculture industry to enhance the coloration of farmed salmon, trout, and shrimp, as the natural diet of these species contains carotenoids that influence their pink or red hues. Canthaxanthin is also added to poultry feed to intensify the yellow color of egg yolks, making them more visually appealing to consumers. In addition to food, canthaxanthin is used as a pigment in cosmetics, such as self-tanning products, due to its ability to impart a bronzed appearance when deposited in the skin.

In the health and nutrition sectors, canthaxanthin has garnered interest for its potential benefits as a dietary supplement. As a potent antioxidant, it helps neutralize free radicals and protect cells from oxidative damage. Some studies have explored its role in boosting the immune system and maintaining eye health, similar to other carotenoids like beta-carotene and lutein. However, excessive intake of canthaxanthin has been associated with adverse effects, such as canthaxanthin retinopathy, a condition where crystalline deposits form in the retina.

The pharmaceutical industry has also investigated the potential of canthaxanthin for photoprotection. Its ability to absorb harmful ultraviolet (UV) radiation may help protect the skin from UV-induced damage, which is relevant for preventing skin cancer and premature aging. Furthermore, research is ongoing into its role in reducing inflammation and supporting overall skin health.

Synthetic production of canthaxanthin has been optimized to meet commercial demand. While natural extraction remains an option, chemical synthesis offers a more consistent and cost-effective supply. The synthetic process typically involves Wittig reactions or aldol condensation to build the polyene chain, followed by functionalization to introduce the terminal keto groups.

Canthaxanthin remains a valuable compound in numerous fields due to its vibrant color, antioxidant properties, and potential health benefits. Continued research is likely to expand its applications and address concerns regarding its safety and dosage in dietary and cosmetic products.

References

2001. Carotenoid incorporation into natural membranes from artificial carriers: liposomes and beta-cyclodextrins. Chemistry and Physics of Lipids, 112(1).
DOI: 10.1016/s0009-3084(01)00138-4

1985. Canthaxanthin--the ""tanning"" pill. Journal of the American Academy of Dermatology, 13(4).
DOI: 10.1016/s0190-9622(85)80442-4

2021. Eustigmatophyte strains with potential interest in cancer prevention and treatment: partial chemical characterization and evaluation of cytotoxic and antioxidant activity. Biotechnology Letters, 43(7).
DOI: 10.1007/s10529-021-03122-0