Three novel complexes of copper: synthesis, characterization, crystal structure, HSA-binding and docking studies, and antiproliferative activity

Synthesis, structural studies, interaction with DNA/HSA and antitumor evaluation of new Cu(ii) complexes containing 2-(1H-imidazol-2-yl)pyridine and amino acids

“…The endogenous fluorescence of HSA was produced by amino acid residues (including Trp, Tyr and Phe), and the interaction of Cu( ii ) complexes with HSA would result in fluorescence quenching. 28,29 As depicted in Fig. 6b, with the increasing concentration of the complexes, the fluorescence intensity of HSA around 341 nm decreased significantly and a weak red shift was observed ( CuI1 : 341 → 359 nm, CuI2 : 341 → 345 nm, and CuI3 : 341 → 346 nm), indicating that the complexes could interact with HSA, resulting in varying degrees of changes in the secondary and even tertiary structures of HSA.…”

“…The K q value of the combination of the complexes and HSA exceeded the maximum diffusion collision constant 2.0 × 10 10 M −1 S −1 , which further proved that the attenuation of fluorescence was caused by the static quenching mechanism. 28,31 For static quenching, the Scatchard formula can be used to calculate the binding constant K b and the number of binding sites n (Fig. 6c).…”

Synthesis, characterization and biological activity of novel copper complexes containing a β-carboline derivative and amino acids

“…33 Tryptophan (Trp), tyrosine (Tyr), and phenylalanine (Phe) are the primary contributors to the endogenous fluorescence of HSA, most of which are caused by Trp residues. 34 Among them, the quenching rates of Cu1 and Cu2 are 57.92% and 83.09%, respectively, showing that Cu2 > Cu1 in terms of the degree of fluorescence quench. Trp214, the only tryptophan in HSA, is located in the hydrophobic cavity of HSA subdomain II.…”