It is assumed that Ectoin has a cosmotropic, meaning structure-forming ability on the surrounding water. Due to this ability, changes in the water structure can be observed which provide the basis for Ectoin´s stabilizing function on biopolymers.

The basic idea of the testing done is that science makes a distinction between molecules which are “structure beakers” and "structure makers" (synonyms: chaotropic and kosmotropic). Furthermore, experts make a distinction between two different solvent states: undisturbed bulk water and water influenced by Ectoin (hydration water). These two types of water show differences in absorption maximum and band shape on the wavelength scale.

The test method used is NIR spectroscopy which is one of the few methods that allow direct observation of changes in water structure. It is used to analyze overtones of O-H vibrations near 1450 nm and 1900 nm, which display a characteristic shift towards higher wavelengths when hydrogen bonds are strong. These can be found particularly in frozen water where hydrogen bonds reach maximal strength. NIR spectroscopy is therefore a useful method for revealing the characteristic hydration spectrum of Ectoin and bioploymers.

In testing it was clearly seen that Ectoin strongly influences the surrounding water. The NIR data supported the view that Ectoin induces the formation of strong hydrogen bonding causing a big hydration shell (4 - 5 molecules of water surround one Ectoin molecule). These values are significantly higher than those of well-known moisturizers e.g. urea.

Literature:
Galinski, E.A., M. Stein, B. Amendt and M. Kinder, The Kosmotropic (Structure-Forming) Effect of Compensatory Solutes, Comp. Biochem. Physiol., Vol. 117A, No. 3, 357-365, 1997
Galinski, E.A., Compatible solutes of halophilic eubacteria: molecular principles, water-solute interaction, stress protection, Birkhäuser Verlag, 1993.