2-Amino-2-hydroxymethyl-1,3-propanediol

Chemical Name 2-Amino-2-hydroxymethyl-1,3-propanediol Common Name Trometamol Structural Formula ... 

The blend is partially crosslinked with a vinyl monomer when dissolved in an organic aprotic solvent and has a pH of 5.0 or lower. The first block copolymer is prepared by polycondensing a bis-hydroxyalkyl ether, such as dipropylene glycol, diethylene glycol, and the like, with propylene oxide. Next, the resulting propoxylated diol is reacted with ethylene oxide to produce the block copolymer. The second copolymer is prepared by polycondensing 2-amino-2-hydroxymethyl-1,3-propanediol, commonly known as TRIS, with... 

Amino-2-hydroxybenzoic acid, 2 668-669 physical properties of, 2 666t 2-Amino-2-(hydroxymethyl)-1,3-propanediol... 

Figure 7.9. A possible metrological traceability chain for the result of a measurement of protein in a sample of grain. aTris = 2-amino-2-hydroxymethyl-1,3-propanediol b Dumas apparatus is calibrated using tris CRM and grain samples are certified in an interlaboratory study cthe master instruments measure grain samples to act as the grower s calibrator for field measurements.

Fia. 5A.—Formation and Disappearance of O-a-L-Arabinosyl-D-glucoses with 0-Galactosidase of E. coli, ML 309.(Donor o-nitrophenyl a-L-arabinopyranoside. Acceptor D-glucose. 0.06 M 2-amino-2-(hydroxymethyl)-1,3-propanediol hydrochloride buffer, pH 7.6 40°. I, 0-a-L-Arabinosyl-(l — 3)-D-glucose II, 0-a-L-arab-inosyl-(l —>4)-D-glucose III, 0-a-L-arabinosyl-(l — 6)-D-glucose. The disaccharides were estimated with triphenyltetrazolium chloride. The ordinate shows the extinction at 546 m. )... 

Fio. 9.—Dependence on pH of Maximal Velocity (Vm i) of the Hydrolysis of a-Lactose by /3-Galactosidase at 20°. (Buffers 0.05 M 2-amino-2-(hydroxymethyl)-1,3-propanediol-acetic acid. is expressed in micromoles of a-lactose hydrolyzed per min. per mg. of enzyme. X----X, in the absence of alkali salts.)... 

Because of the results found with p-(chloromercuri)benzoate and because /3-galactosidase is believed to be a sulfhydryl enzyme, it seemed advisable to investigate the effects of other sulfhydryl reagents. Virtually no inhibition of /3-galactosidase was found in the presence of iodoacetam-ide (9 X 10 M) over a period of 7 hours. A -Phenylmaleimide, at concentrations as high as 8.7 X 10 M, produced less than 10 % inhibition over a 20-hour period. However, when the concentration of V-phenyl-maleimide was raised to 9.1 X 10 M, assay of the incubation mixture revealed that 50% inhibition of /3-galactosidase occurred within a 2-hour period when the experiment was performed in 2-amino-2-(hydroxymethyl)-1,3-propanediol— acetic acid buffer, pH 8.0. Virtually no activity was lost when the latter experiment was repeated in phosphate buffer (Na salts) at the same pH. 

The branched-chain tetritol, 2-C-(hydroxymethyl)glycerol, was synthesized by diazotization of 2-amino-2-(hydroxymethyl)-1,3-propanediol [tris(hydroxymethyl)aminomethane Tris]. The total crude product that resulted from this synthesis gave, after per(trimethylsilyl)ation, the three peaks shown in Fig. 17. 2-C-(Hydroxymethyl)glycerol from the per(tri-methylsilyl)ated Tris corresponded identically in retention time to the peak for the compound in the tetritol region of formose, and a comparison of the mass spectra of these two species (see Fig. 17) showed that they are identical. 

However, at zero buffer concentration the maximum stability was shifted to a pH of 5.85. Ampicillin was stable in solutions at pH 3 - 9 when stored for 24 hours at 5°C and 25°C. Ampicillin was unstable in solutions at pH 10 when stored at above conditions. Bundgaard demonstrated a metastable intermediate in iso-meration of penicillin to penicillenic acid in aqueous solutions. The degradation of ampicillin trihydrate in solution is greatly influenced not only by pH, but also by the types of buffer salts used j. 2-Amino-2 (hydroxymethyl)-1,3-propanediol (Tris) buffer of pH 7 is highly deleterious to the stability of ampicillin, but not at pH 5.0. Citrate presents a converse pattern in that ampicillin is relatively stable at pH 7 but not so at pH 5. Phosphate is intermediate in action but tends to resemble the Tris pattern. Jacobson and Russo-Alesi prepared ampicillin trihydrate solutions at a concentration of 5 mg/ml by dissolving it in buffer solutions of pH 5.0 or pH 7.0 prepared from O.lM sodium acetate and acetic acid and in buffers of pH 8.0 or pH 8.8 prepared from O.lM 2-amino-2 (hydroxy methyl)- ,... 

Amino-2-(hydroxymethyl)-1,3 propanediol or tris(hydroxymethyl)aminomethane. 

CAS 77-86-1 25149-07-9 108195-86-4 EINECS/ELINCS 201-064-4 Synonyms 2-Amino-2-(hydroxymethyl)-1,3-propanediol Aminotrimethylol-methane Aminotris(hydroxymethyl) methane THAM Tris Trisamine Tris Buffer Tris (hydroxymethyl) methanamine Tris (hydroxymethyl) methylamine 1,1,1-Tris (hydroxymethyl) methylamine Trometamol ... 

Amino-2"hydroxymethyl-1.3-propanediol (tris(hydroxymethyl)aminomethane. THAM, TRIS) (Other references in Vol.2, p.20 and Vol.5, p.l35)... 

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