Chondroitin sulfate is a complex carbohydrate that helps cartilage retain water. 

The name "Chondroitin sulfate" describes the structure of the molecule:

• "Chondroitin" is a type of glycosaminoglycan, a long chain of sugar molecules that provides support and flexibility to joints. The term "chondroitin" comes from the Greek words "chondros" meaning cartilage and "ine" meaning a female chemical.
•  "Sulfate" means that the chondroitin molecule is linked to a sulfate group, which is a chemical compound formed by sulfur and oxygen atoms. The sulfate group is important for the function of chondroitin, as it gives the molecule a negative charge that attracts water molecules and helps to provide the cartilage its quality of shock absorption.

Chondroitin sulfate is a glycosaminoglycan sulfate composed of alternating sugar chains (D-glucuronic acid and N-acetylgalactosamine). It is usually found attached to proteins as part of a proteoglycan, a protein-polysaccharide complex that gives elasticity and fluidity to tissues. It is naturally found in the body, particularly in the cartilage that cushions the joints. Commercially it is often derived from animal sources, such as cow or shark cartilage, or it can be synthetically produced in the laboratory.

The extraction and purification process from animal sources generally involves different steps:

• Extraction: The raw material (usually cow or shark cartilage) is treated with a solution of enzymes or other substances to break down the tissue and release the chondroitin sulphate.
• Purification: The resulting solution is filtered and purified to remove proteins and other impurities. This may involve processes such as dialysis, precipitation and chromatography.
• Drying: The purified chondroitin sulphate is then dried to produce a powder that can be used in supplements.

The synthetic production of chondroitin sulphate is a complex process involving the enzymatic synthesis of the chondroitin backbone followed by the addition of sulphate groups. This process requires specialised knowledge and equipment and is typically performed in a laboratory or industrial environment.

What it is used for and where

It is commonly used in food supplements for the treatment of osteoarthritis.