Ligation modes for nicotinic acid binding to the chromium(III) salen complex

Elucidating a Biological Role for Chromium at a Molecular Level

“…The proposed identification of nicotinate (3-carboxypyridine) in “GTF” stimulated an interest in the synthesis of chromic nicotinate complexes. − The products of reaction of chromium(III) sources and the related pyridinecarboxylic acids picolinic acid (2-carboxypyridine) and isonicotinic acid (4-carboxypyridine) have also been studied in some detail. − Chromium(III) picolinate, Cr(pic) 3 , has been the most thoroughly studied of these synthetic products and has become a very popular nutritional supplement; products containing Cr(pic) 3 generate over $100 million in sales annually as the supplement is available over-the-counter in numerous forms, including pills, chewing gums, sports drinks, and nutrition bars. Cr(pic) 3 is a relatively well absorbed form of chromium (2−5% efficiency compared to dietary chromium, which is only absorbed with approximately 0.5% efficiency) and has been proposed to be the biologically active form of chromium .…”

Mechanism of anation of chromium (III) by L-lysine

“…Following the demonstration of GTF's (Glucose Tolerance Factor: a low-molecularweight chromium(Ill) complex) insulin potentiating activity (Mertz and Schwarz 1959;Mertz et al 1974;Mertz 1983), reports on various aspects of Cr(III) complexation with ligands of biological importance. (especially amino acids) have appeared (Khan and Kabir-ud-Din 1981;Gerdom and Goff 1982;Gonzalez-Vergara et Kabir-ud-Din and Khan 1985, 1992Khan 1985;Mitra-Mustofy and De 1986;Govindaraju et al 1989;Shahid et al 1990;Khan et al 1991). With the view that not only composition but other aspects may be helpful in understanding the nature of GTF, we present herein our results on the anation kinetics of aquachromium(III) by L-lysine.…”

Raman spectra of copper, cobalt, and nickel complexes of nicotinic acid: Equilibrium studies

“…The authors identified that the interaction between nicotinic acid-Ni [13] is a weak interaction with the stability constant values of log β 1 = 2.66 and 3.05 for pH-potentiometric and polarographic measurement, respectively. Also, nicotinic acid complexes of several metal ions [14][15][16][17][18] were investigated using various techniques such as pH-potentiometric titration, polarography, and UV-visible spectrophotometry. The complex formation of divalent transition metal ions (copper(II), cobalt(II) and nickel(II)), and nicotinic acid were recently studied in our laboratory in aqueous solutions using pH-potentiometric technique in the absence and in the presence of glycine peptides and their overall stability constants in aqueous solutions were obtained and explained by the HYPERQUAD 2008 program using the potentiometric data [19][20][21][22][23][24][25][26][27][28][29].…”