9176. TES

Nomenclature

CAS number: 7365-44-8
2-[[2-Hydroxy-1,1-bis(hydroxymethyl)ethyl]amino]ethanesulfonic acid; N-[2-hydroxy-1,1-bis(hydroxymethyl)ethyl]taurine; N-tris(hydroxymethyl)methyl-2-aminoethanesulfonic acid.
C6H15NO6S; mol wt 229.25.
C 31.43%, H 6.60%, N 6.11%, O 41.87%, S 13.99%.

Description and references

One of the zwitterionic amino acids known as “Good” buffers; active in the pH range 6.5 to 8.0. Prepn: N. E. Good et al., Biochemistry 5, 467 (1966). Thermodynamic constants: C. A. Vega, R. G. Bates, Anal. Chem. 48, 1293 (1976). Effect of temperature and solvent systems on pK2: H. A. Azab et al., Monatsh. Chem. 125, 233 (1994). Use as buffer: F. C. Molinia et al., Reprod. Nutr. Dev. 34, 491 (1994); K. Isobe, H. Nishise, J. Biotechnol. 75, 265 (1999).

Chemical structure

Properties

Crystals from alcohol/water, mp 226-228°, dec 231°. pKa of 0.1M soln: (0°) 7.92; (20°) 7.5; (37°) 7.14. Δ pKa/°C -0.020.

Use

Biological buffer.