What Is the CAS Number of Zeaxanthin?
If you work with nutritional ingredients or simply read supplement labels closely, you have probably come across zeaxanthin and wondered how to pin it down precisely. The direct answer is that the CAS number of zeaxanthin is 144-68-3. That single identifier is how chemists, manufacturers, and regulators around the world make sure they are all talking about the exact same molecule. In this article, we will explain what that number means, why it matters, and what else you should know about this well-known eye-health carotenoid.
What Exactly Is a CAS Number?
CAS numbers are unique numerical identifiers assigned to chemical substances by the Chemical Abstracts Service. They are not formulas or codes with hidden meaning—they are simply registry numbers that give every substance a single, unambiguous identity. When a buyer, a quality-control lab, or a customs official sees "144-68-3," they know immediately which compound is being referenced, regardless of the language on the label or the brand name of the product. That is why the CAS number is one of the first things a serious ingredient buyer checks before placing an order.
The Chemical Identity of Zeaxanthin
Zeaxanthin is a natural carotenoid pigment that belongs to the xanthophyll family, the same group of compounds that gives many plants their yellow and orange colors. Its key identifiers are:
- CAS number: 144-68-3
- Molecular formula: C40H56O2
- Molecular weight: 568.87 g/mol
- IUPAC name: (3R,3'R)-beta,beta-carotene-3,3'-diol
- Common synonyms: zeaxanthol, maize yellow, xanthophyll 3
This yellow-orange pigment is what gives corn kernels, paprika, and marigold petals their warm color. When you see "zeaxanthin" listed on an ingredient panel, the number 144-68-3 is the reference that confirms exactly which compound is present.
Where Does Zeaxanthin Come From?
In nature, zeaxanthin is found in green leafy vegetables such as spinach and kale, as well as in yellow corn, egg yolks, goji berries, and paprika. For commercial production, however, the most important source is the marigold flower (Tagetes erecta), which is naturally rich in zeaxanthin and its close relative lutein. Manufacturers extract the pigment from marigold petals and process it into standardized powders and beadlets that are used in dietary supplements, foods, and beverages. Because the extraction and standardization steps require careful control, most brands source this ingredient from an experienced botanical extracts manufacturer rather than trying to produce it in-house.
Why Zeaxanthin Matters for Eye Health
Zeaxanthin is one of only two carotenoids that accumulate in the macula—the central part of the retina responsible for sharp, detailed vision. Along with lutein, it forms the macular pigment, which acts like a pair of built-in sunglasses: it filters high-energy blue light and neutralizes free radicals before they can damage delicate retinal tissue. The human body cannot make zeaxanthin on its own, so it must come from food or supplements. That is why lutein and zeaxanthin are such popular ingredients in vision-support products and why so many supplement formulators include them in daily eye-care formulas.
Zeaxanthin vs. Lutein: Two Sides of the Same Coin
Lutein and zeaxanthin are almost always mentioned together, and for good reason—they are structural isomers, meaning they share the same molecular formula but differ slightly in the arrangement of their atoms. Both concentrate in the macula, and most vision supplements pair them because they complement each other. The practical difference is that zeaxanthin is less abundant in typical Western diets, so targeted supplementation can help bring levels closer to what research suggests is beneficial for long-term eye health.
Buying Zeaxanthin as an Ingredient: What to Check
If you are sourcing zeaxanthin for a supplement, food, or beverage product, the CAS number is only the starting point. A reliable supplier provides a certificate of analysis showing purity, heavy-metal content, and microbiological results, and each batch should be tested with methods such as HPLC to confirm the active compound. Working with a trusted botanical extracts manufacturer helps ensure you receive consistent, traceable material that meets the specifications your product requires. Cactus Botanics offers zeaxanthin and a full range of botanical extracts, with in-house and third-party analytical testing, GMP-compliant production, and global logistics support for customers in more than 190 countries.
Final Thoughts
The CAS number of zeaxanthin is 144-68-3—a short string of digits that carries real weight in the ingredient industry. Whether you are checking a certificate of analysis, comparing suppliers, or simply reading a label with more confidence, knowing this identifier helps you verify that you are getting the genuine, well-defined molecule. And when it comes time to choose a source, partnering with a manufacturer that combines rigorous testing with reliable supply makes all the difference.
