Abstract: To counteract the deleterious effects of high salinity on cell osmotic pressure,halotolerant or halophilic microorganisms,a particular class of organic compatible solutes ectoines(abbreviated to Ects) was accumulated.Ects mainly includes ectoine and its hydroxylated derivative 5-hydroxyectoine(5-HE).Ects not only can balance the intracellular osmotic pressure,but also provide anti-reverse assistance for proteins,nucleic acids,cell membrane and even whole cells under the extreme conditions of high temperature,cold,drought,high pH value,high pressure or high salt.In this review,the importance of current and potential applications of ectoines as protecting agents for macromolecules and cells,together with their potential as therapeutic agents for certain diseases were summarized.In addition,its current prospects of biological medicine and health care application were also discussed.

Key words: ectoine, 5-hydroxyectoine, compatible solute, bioengineering, medical applications