5hydroxyectoine

5-Hydroxyectoine is a naturally occurring compatible solute, a hydroxylated derivative of ectoine, produced by certain bacteria such as halophiles and soil-dwelling species. Like ectoine, it accumulates in response to osmotic stress and helps cells cope with high salinity, desiccation, and temperature fluctuations. The hydroxylation step enlarges the pool of compatible solutes available to the cell and can influence protective properties in stress conditions.

Biosynthesis and occurrence: In bacteria that synthesize ectoine, the core pathway is catalyzed by the enzymes encoded by ectA, ectB, and ectC to form ectoine. The 5-hydroxylation of ectoine to give 5-hydroxyectoine is performed by the enzyme EctD, a non-heme iron(II)/2-oxoglutarate-dependent dioxygenase, using molecular oxygen and 2-oxoglutarate as cofactors. This modification expands the range of osmoprotectants produced under environmental stress.

Properties and function: 5-Hydroxyectoine is highly water-soluble and behaves as a compatible solute, stabilizing cellular proteins and membranes without disrupting cellular processes. It can contribute to the stabilization of enzymes and other biomolecules during drying, freezing, and thermal stress, and it often complements ectoine in stress-protection roles within microbial cells.

Applications and research: The compound is studied for its protective effects in biotechnology and cosmetics. It is used as a moisturizing and protective ingredient in skincare formulations and as a stabilizer in enzyme preparations and other biologics. Ongoing research explores its mechanisms of action, production optimization, and potential additional applications in formulation science.

Safety and regulation: 5-Hydroxyectoine is generally regarded as safe for cosmetic use in many jurisdictions, but regulatory status can vary by region and product category.