ASSESSMENT OF PHYSIOLOGICAL AND ELECTROCHEMICAL EFFECTS OF A REPURPOSED ZINC DITHIOCARBAMATE COMPLEX ON ACINETOBACTER BAUMANNII BIOFILMS

Acinetobacter baumannii is an infectious agent of global proportion and concern, partly due to its proficiency in development of antibiotic resistance phenotypes and biofilm formation. Dithiocarbamates (DTC) have been identified as possible alternatives to the current antimicrobials. We report here the evaluation of several DTC-metal complexes against A. baumannii planktonic cells and biofilms. Among the DTC-metal complexes and DTCs tested, ZnL1 (N-methyl-1-phenyldithiocarbamato-S,S′ Zn(II)), originally designed as an antitumor agent, is effective against biofilm forming A. baumannii. A MIC value of 12.5 µM, comparable to that of Gentamicin (5 µM) was measured for planktonic cells in tryptic soy broth. Spectroscopy, microscopy and biochemical analyses reveal cell membrane degradation and leakage after treatment with ZnL1. Bioelectrochemical analyses show that ZnL1 reduces biofilm formation and decreases extracellular respiration of pre-formed biofilms, as corroborated by microscopic analyses. Due to the affinity of Zn to cells and the metal chelating nature of L1 ligand, we hypothesize ZnL1 could alter metalloprotein functions in the membranes of A. baumannii cells, leading to altered redox balance. Results indicate that the DTC-Zn metal complex is an effective antimicrobial agent against early A. baumannii biofilms under laboratory conditions

4-(((4-Methoxyphenyl)amino)methyl)-N,N-dimethylaniline and 2-Methoxy-5-((phenylamino)methyl)phenol

Molecular structures of 4-(((4-methoxyphenyl)amino)methyl)-N,N-dimethylaniline and 2-methoxy-5-((phenylamino)methyl)phenol synthesized via Schiff bases reduction route are reported. The compounds consist of asymmetric units of C16H20N2O (1) and C14H15NO2 (2) in orthorhombic and monoclinic crystal systems, respectively. Compound 1 consist of intermolecular C11—H11···N2 hydrogen bonding with C11···N21 = 3.463(4) Å. The hydroxyl group in 2 is also involved in intermolecular O2—H2···O2 and O2—H2···O21 hydrogen bonding with O2···O11 = 2.8885(15) Å and O1···O21 = 2.9277(5) Å. The molecular structures of the compounds are stabilized by secondary intermolecular interactions of C1—H1B···O11 and C5—H···(C41, C51, C61, C71) for 1 and H···C, C—H···O and N—H···C for 2. The reported compounds are important starting material for the synthesis of many compounds such as azo dyes and dithiocarbamate

Synthesis, characterization and anticancer studies of bis-(N-methyl-1-phenyldithiocarbamato) Cu(II), Zn(II), and Pt(II) complexes: single crystal X-ray structure of the copper complex

<p>Cu(II), Pt(II), and Zn(II) complexes of N-methyl-1-phenyldithiocarbamate were synthesized and characterized by FTIR, NMR, UV-visible spectroscopy and elemental analysis. The complexes were formulated as [Cu(L)₂], [Zn(L)₂] and [Pt(L)₂] (where L = N-methyl-1-phenyldithio­carbamate) in which two molecules of the ligands coordinate to the metal ions in a bidentate chelating fashion. This is confirmed by elemental analysis and the presence of strong single bands at 952, 951, and 955 cm⁻¹ for Cu(II), Pt(II), and Zn(II) complexes, respectively, in the FTIR spectra. The electronic spectra of Pt(II) and Cu(II) complexes are consistent with four-coordinate square planar geometry. Single crystal X-ray of [Cu(N-mpDTC)₂] confirmed square planar structural arrangement (CuS₄) in which the ligands are asymmetrically bonded to the Cu(II) ion building a centrosymmetric monomer entity. The S-Cu-S bite angle is 77.95° (3) whereas the intramolecular N–C bond length is 1.318 Å and <i>trans</i> S1¹-Cu-S1 = S2¹-Cu-S2 is 180°, which are consistent with reported copper thiolates in square planar environment. In vitro antiproliferative activity of the complexes against three human cancer cell lines showed that the zinc complex has better activity compared to Cu and Pt complexes, with IC₅₀ values of 14.28, 22.74 and 20.10 μM against TK10, UACC62, and MC7 cell lines, respectively.</p