TRIS hydrochloride

Semipreparative enantiomer separation of propranolol hydrochloride by high-performance liquid chromatography using cellulose tris(3,5-Dimethylphenylcarbamate) chiral stationary phase.[Pubmed:19007476]

J Chromatogr Sci. 2008 Oct;46(9):767-71.

In this paper, we describe the direct semipreparative resolution of racemic (rac)-propranolol hydrochloride by high-performance liquid chromatography using cellulose tris(3,5-dimethylphenylcarbamate) as chiral stationary phase and mobile phase systems containing petroleum ether and 2-propanol with the use of basic additives. At analytical scale, the retention factor of both enantiomers is less than 5 with the separation factor 1.95 and the resolution 2.4. Then, the analytical method is scaled up to semipreparative loading to obtain small amounts of both propranolol hydrochloride enantiomers. Petroleum ether, rather than n-hexane, is used to effectively reduce the production cost of (R)- and (S)-propranolol. To increase the throughput, overlapping injections are used, allowing an injection to be made every 6.5 min instead of every 12 min. At semipreparative scale, approximately 19 mg/h enantiomers are isolated. The first fraction [(R)-(+)-propranolol hydrochloride] is isolated with a purity of > 99.6% (e.e.) and > 97.0% yield, and the second [(S)-(-)-propranolol hydrochloride] is isolated with a purity of > 99.3% (e.e.) and > 95.0% yield. In addition, optical rotations of both propranolol hydrochloride enantiomers isolated are investigated.

Determination of dehydroascorbic acid in mouse tissues and plasma by using tris(2-carboxyethyl)phosphine hydrochloride as reductant in metaphosphoric acid/ethylenediaminetetraacetic acid solution.[Pubmed:20190394]

Biol Pharm Bull. 2010;33(3):364-9.

Ascorbic acid (AA) has a strong anti-oxidant function evident as its ability to scavenge superoxide radicals in vitro. Moreover, AA is an essential ingredient for post-translational proline hydroxylation of collagen molecules. Dehydroascorbic acid (DHA), the oxidized form of AA, is generated from these reactions. In this study, we describe an improved method for assessing DHA in biological samples. The use of 35 mM tris(2-carboxyethyl)phosphine hydrochloride (TCEP) as a reductant completely reduced DHA to AA after 2 h on ice in a 5% solution of metaphosphoric acid containing 1 mM ethylenediaminetetraacetic acid (EDTA) at pH 1.5. This method enabled us to measure the DHA content in multiple tissues and plasma of 6-weeks-old mice. The percentages of DHA per total AA differed markedly among these tissues, i.e., from 0.8 to 19.5%. The lung, heart, spleen and plasma had the highest levels at more than 10% of DHA per total AA content, whereas the cerebrum, cerebellum, liver, kidney and small intestine had less than 5% of DHA per total AA content. This difference in DHA content may indicate an important disparity of oxidative stress levels among physiologic sites. Therefore, this improved method provides a useful standard for all DHA determinations.

High throughput method for the analysis of cetrizine hydrochloride in pharmaceutical formulations and in biological fluids using a tris(2,2'-bipyridyl)ruthenium(II)-peroxydisulphate chemiluminescence system in a two-chip device.[Pubmed:21726717]

Talanta. 2011 Aug 15;85(2):906-12.

A fast, economic and sensitive chemiluminescence (CL) method has been developed for the analysis of cetrizine hydrochloride (CET) in pharmaceutical formulations and in biological fluids. The CL method is based on the oxidation of tris(2,2'-bipyridyl)ruthenium(II) (Ru (bipy)(3)(2+)) by peroxydisulphate in a two-chip device. Up to 180 samples can be analysed per hour, consuming only minute quantities of reagents. Three instrumental setups were tested to find the most economical, sensitive and high throughput setup. In the first setup, a continuous flow of sample and CL reagents was used, whereas in the second setup, a fixed volume (2 muL) of (Ru (bipy)(3)(2+)) was introduced into a continuous infusion of peroxydisulphate and the sample. In the third design, a fixed volume of sample (2 muL) was injected while the CL reagents were continuously infused. Compared to the first setup, a 200% signal enhancement was observed in the third setup. Various parameters that influence the CL signal intensity, including pH, flow rates and reagent concentrations, were optimized. A linear response was observed over the range of 50 mug L(-1) to 6400 mug L(-1) (R(2)=0.9959) with RSD values of 1.1% (n=15) for 1000 mug L(-1). The detection limit was found to be 15 mug L(-1) (S/N=3). The amount of consumed sample was only 2 muL, from which the detected amount of CET was found to be 6.5 x 10(-14)mol. This procedure was successfully applied to the analysis of CET in pharmaceutical formulations and biological fluids.

Tris(azidoethyl)amine hydrochloride; a versatile reagent for synthesis of functionalized dumbbell oligodeoxynucleotides.[Pubmed:23339424]

Org Lett. 2013 Feb 1;15(3):694-7.

Triazole-cross-linked oligodeoxynucleotides were synthesized using the Cu(I) catalyzed alkyne-azide cycloaddition with tris(azidoethyl)amine hydrochloride and oligodeoxynucleotides possessing N-3-(propargyl)thymidine at both the 3'- and 5'-termini. Further installation of a functional molecule to the dumbbell oligodeoxynucleotides was achieved by utilizing the remaining azide group.