Cysteine | An-Najah Staff

Spectrophotometric Determination of ‎Cysteine and N-acetylcysteine in ‎Pharmaceutical Preparations

Thu, 2014-03-27 12:29 — Maher An-Natsheh

Journal Title, Volume, Page:

Microchimica Acta, Volume 129, Issue 1-2, pp 91-95

Year of Publication:

1998

Link:

http://link.springer.com/article/10.1007%2FBF01246854

Authors:

Maher Abu Eid

Chemistry Department , An-Najah National University , Nablus, Palestine

Current Affiliation:

Department of Chemistry, Faculty of Science, An-Najah National University, Nablus, Palestine

[email protected]

Preferred Abstract (Original):

An accurate fast spectrophotometric method for the determination of cysteine andN-acetyl-cysteine is presented, based on the oxidation of these amino acids by ferric ions in the presence of ferrozine, whereby a violet-coloured complex is formed which absorbs at 562 nm. The method was satisfactory for the determination of cysteine andN-acetylcysteine in samples within the range 0.02–6.00 μgml−1. Effects of time, acidity, ferric ions, ferrozine, sodium perchlorate concentrations and the tolerance limit for other amino acids have been reported. The method was applied to the determination of cysteine in amino acids mixtures andN-acetylcysteine in pharmaceutical preparations.

Substitution of Aquo-Ligands from Hexaaquochromoium(III) Ion by Cysteine. A Kinetic and Mechanistic Study

Mon, 2014-01-06 09:45 — Mohammed Al-Subu'

Journal Title, Volume, Page:

Journal of Applied Sciences, 2003, Volume: 3, Issue: 2, Page No.: 110-112

Link:

http://scialert.net/abstract/?doi=jas.2003.110.112

Authors:

Mohammed M. Al Subu

Department of Chemistry, Faculty of Science, An-Najah National University, Nablus, Palestine

Current Affiliation:

Department of Chemistry, Faculty of Science, An-Najah National University, Nablus, Palestine

[email protected]

Preferred Abstract (Original):

Substitution of aquo – lingands from hexaaqouchromolum (III) ion by Cysteine (Hcys) has been studied Kinetically at [H⁺] of 1.0 x 10^-2mol dm^-3.The calculated activation parameters ( H* and S*) have been compared with those of water – exchange and related anation reactions of haxaaquochromium (III) ion. The obtained results support an associated path S_N2).