Substituent Effects on the Coordination Chemistry of Metal-Binding Pharmacophores.

ABSTRACT: A combination of XAS, UV-vis, NMR, and EPR was used to examine the binding of a series of α-hydroxythiones to CoCA. All three appear to bind preferentially in their neutral, protonated forms. Two of the three clearly bind in a monodentate fashion, through the thione sulfur alone. Thiomaltol (TM) appears to show some orientational preference, on the basis of the NMR, while it appears that thiopyromeconic acid (TPMA) retains rotational freedom. In contrast, allothiomaltol (ATM), after initially binding in its neutral form, presumably through the thione sulfur, forms a final complex that is five-coordinate via bidentate coordination of ATM. On the basis of optical titrations, we speculate that this may be due to the lower initial pK_a of ATM (8.3) relative to those of TM (9.0) and T

SUBMITTER: Craig WR 

PROVIDER: S-EPMC6489498 | biostudies-literature | 2017 Oct

REPOSITORIES: biostudies-literature