In vitro biological evaluation and consideration about structure-activity relationship of silver(I) aminoacidate complexes

Antimicrobial and Anticancer Application of Silver(I) Dipeptide Complexes

“…The values of the quenching constants (Ksv), obtained from the fluorescence emission spectra of the CT DNA-HO system in the absence or in the presence of increasing amounts of Ag(I) complexes, are given in Table 6 and imply that complex AgGlyAsp shows a moderately greater ability to release the groove binder Hoechst 33258 from DNA than AgGlyGly and AgGlyAla. The calculated Stern-Volmer constants (Ksv) are slightly higher than for earlier researched silver(I) glycinate and aminoacidate complexes [16,17].…”

“…This bond distance is shorter than the van der Walls radii (3.44 Å), which indicates the presence of argentophilic interactions [41]. Similar argentophilic interactions were observed in complex AgAla, with Ag-Ag bond distances from 2.8722(3) Å to 3.3011(4) Å [17]. Each HGlyGly ligand in zwitterion form is coordinated to silver (I) ions through the terminal carboxylate group from one glycine residue in syn-syn-anti coordination mode and one molecule of ligand has tridentate properties and bridges three silver ions.…”

“…This result indicates the groove-binding nature of the investigated silver(I) dipeptide complexes. Previously, we recorded a similar course of the CD spectrum for the bioactive glycinate [16] and aminoacidate complexes [17].…”

“…CT DNA, a model of right-handed DNA-duplex structure (B-form), shows two characteristic bands consisting of a positive one at 275 nm due to base stacking and a negative one at 245 nm due to the right-handed helicity of DNA [56]. In general, intercalation of the classical DNA intercalator increases the intensities of both CD bands due to stabilization of the double helical conformation of B-DNA, whereas non-intercalation modes such as electrostatic interactions and groove bindings of small molecules show a decrease or no perturbation in base stacking and helicity bands [17]. The circular dichroic spectra of CT DNA in the absence and presence of the Ag(I) complexes are given in Figure 12.…”

“…The aim of this selection was to prepare compounds with suitable physicochemical properties and minimal toxic effects, so that the organism would degrade the compound using natural metabolic pathways. We found that the silver(I) complexes AgGly, AgAla, and AgNam with ionic structure show significantly higher AMB (antimicrobial) activity than the neutral AgPhe complex, indicating that the cationic part of the structure may interact with negatively charged components of the cell membrane [16,17].…”