Synthesis, structures, anticancer activities and DNA-binding properties of new dicopper(II) complexes bridged by N-benzoato-N′-(2-amino-2-methylethyl)oxamide

Synthesis and crystal structure of a new dicopper(II) complex withN-benzoato-N′-(hydroxypropyl)oxamide as ligand: cytotoxic activities and reactivities towards DNA and BSA

“…This observation is often the characteristic of intercalation and coincides with other intercalators [52]. The quenching of EB bound to HS-DNA by the dicopper(II) complex is in agreement with the linear Stern-Volmer equation [53]: [24] [H 3 oxbm is N-benzoato-N′-(2-amino-2-methylethyl)oxamido], we find that the K b and K sv values of the former are both higher than those of the latter, implying that the different oxamidato-bridge ligands have significant effects on both molecular and electronic structure. The large methyl in H 3 oxbm of the previously reported dicopper(II) complex results in increasing steric hindrance, when the dicopper(II) complex intercalates into HS-DNA.…”

“…There are ν s (NO 2 ) at 1342 cm À1 and ν as (NO 2 ) at 1555 cm À1 in uncoordinated 2,4,6-trinitrophenol (Hpic). However, in the dicopper(II) complex, ν s (NO 2 ) of pic splits into two bands at 1332 and 1361 cm À1 , and ν as (NO 2 ) of pic emerges at 1519 cm À1 , suggesting that the nitryl oxygens of pic take no part in coordination [24], consistent with the molar conductance measurement and crystal structure of the dicopper(II) complex (vide infra).…”

“…The IC 50 values of the present dicopper(II) complex for the SMMC-7721 and A549 cell lines are 10.2 ± 0.7 and 13:5 AE 0:8 lg mL À1 , respectively, lower than those of an analogous dicopper(II) complex [Cu 2 (oxbm)(phen) (H 2 O)(CH 3 OH)](pic) (SMMC-7721, 13 AE 0:7 lg mL À1 ; A549, 16 AE 0:8 lg mL À1 ) [24], indicating that the present dicopper(II) complex has better activities than the previously reported dicopper(II) complex. The order of in vitro anticancer activities for the two dicopper (II) complexes is consistent with their DNA-binding abilities (vide infra).…”

“…Particularly, copper complexes containing heterocyclic bases have been extensively explored for strong interactions with DNA and cytotoxic activities [18][19][20][21] since Sigman et al first discovered that copper coordinated to 1,10-phenanthroline (phen) can cleave DNA [21]. Compared with the number of studies dealing with mononuclear complexes [21][22][23], relatively few studies on dinuclear complexes have been reported [24]. A number of proteins containing dinuclear metal centers play paramount roles in biology, including dioxygen transport or activation, electron transfer, reduction of nitrogen oxides, and hydrolytic chemistry, prompting us to design and synthesize new dinuclear complexes.…”

“…Taking into account the above facts, quite recently we reported the structures, anticancer activities, and DNA-binding properties of the dicopper(II) complex bridged by N-benzoato-N′-(2-amino-2-methylethyl)oxamide, and end-capping with phen [24]. As continuation of our ongoing program, in this paper, we describe the synthesis and structure of a new dicopper(II) complex, [Cu 2 (oxbpa)(phen)(H 2 O)](pic)·2H 2 O, using N-benzoato-N′(hydroxypropyl)oxamide (H 3 oxbpa) as a bridging ligand, and end-capped with phen.…”