A Spectroscopic Study of Interaction of Auricyanide with n-Acetylcysteine
Interaction of auricyanide, an important metabolite of anti-arthritic gold-based drug auranofin, was studied in vitro with a pharmacologically active ligand n-acetylcysteine with a view to understand reactivity of gold in vivo. Formation of reduction product aurocyanide occurred through mono- and di-n-acetylcysteine-substituted intermediates. The product and intermediates were identified and monitored spectrophotometrically and by electrospray ionization mass spectrometry. This study suggests successive substitution with n-acetylcysteine through trans effect. At equimolar concentrations of auricyanide and n-acetylcysteine, only mono-substituted mixed-ligand complex was formed. Substitution of the data obtained to various kinetic models suggested that the reaction orders are 0.6 in terms of n-acetylcysteine, 1.5 in terms of auricyanide, and 2 overall. The intermediates detected in this work may help to synthesize more effective and less toxic gold drugs.
KeywordsAuricyanide n-acetylcysteine Electrospray ionization mass spectroscopy (ESI-MS) Rheumatoid arthritis UV-vis spectroscopy
SGTK thanks Higher Education Commission of Pakistan for the award of indigenous PhD scholarship.
Compliance with Ethical Standards
No animals, humans, or their materials were used in this work.
Conflict of Interest
The authors declare that they have no conflict of interest.
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