Bovine serum albumin interactive one dimensional hexanuclear manganese(III) complex: synthesis, structure, binding and molecular docking studies

The reaction of MeO-salox (4-methoxy salicylaldehyde-oxime) with Mn(OAc)(2)center dot 4H(2)O in a 1 : 1 molar ratio in methanol medium and in the presence of tetrabutylammonium hydroxide yields the hexanuclear complex [Mn6O2(4-MeO-salox)(6)(N-3)(2)(MeOH)(2)(H2O)(2)center dot 2H(2)O](n) (1). Single crystal X-ray diffraction reveals that complex 1 adopts a 1D chain network facilitated by two EE-azido bridges. BSA binding studies reveal that complex 1 causes fluorescence quenching of BSA through both static and dynamic mechanisms. A 1 : 1 binding mode is established through a Benesi-Hildebrand plot with an intrinsic binding constant of (3.40 +/- 0.01) x 10(4) M-1. The circular dichroism studies indicate variation of the secondary structure of BSA upon binding with complex 1. The site-selective binding and molecular docking studies reveal the probable binding site of complex 1 is at the mouth of site I in subdomain IIA of BSA.