Chelation of Lanthanum (La3+) by Various Thiols – an in vitro Study

International Journal of Pharmacology and Clinical Sciences, 2014, 3, 2, 34-38.
Published: June 2014
Type: Short Communication
Authors: Muhammad Yaqoob, Muhammad Farid Khan, Muhammad Tausif Chaudhry, and Izhar Ahmad Shaikh

Author(s) affiliations:
Muhammad Yaqoob1, Muhammad Farid Khan2, Muhammad Tausif Chaudhry3*, Izhar Ahmad Shaikh4

1Post Graduate, 2Professor, Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Gomal University, D. I. Khan, Pakistan
3Senior Scientific Officer, 4Junior Scientific Officer, Pakistan Council of Scientific and Industrial Research (PCSIR), Islamabad, Pakistan

Abstract

In the present study, the interaction of various thiols (L-glutathione, L-cysteine, N-acetyl cysteine, and D-penicillamine) with LaCl3 was studied in vitro by modified Ellman’s method. Experiments carried out at various concentrations inferred gradual decrease in thiol concentration with the increase in La3+ concentration in aqueous solutions. Maximum interaction between thiols and La3+ was observed at pH 7.5 and 35°C as indicated by the lowest values of residual thiol concentration. The order of reactivity was DPA>GSH>NAC>Cys, where reactivity increased with increasing pKa of their thiol group. The possible products of the reaction are proposed to be La(RS)3 complex or oxidized form with a disulfide bond (RSSR).

Keywords: Chelation, Ellman’s modified method, Lanthanum, Thiols

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