Sudalaiandi Kumaresan

Synthesis, characterization, and biological evaluation of Schiff base-platinum(II) complexes.

The platinum complexes of Schiff base ligands derived from 4-aminoantipyrine and a few substituted aldehydes were synthesized and characterized by elemental analysis, mass, (1)H NMR, IR, electronic spectra, molar conductance, and powder XRD. The structure of one of the ligands L5 was confirmed by a single crystal XRD analysis. The Schiff base ligand crystallized in the triclinic, space group P-1 with a=7.032(2)Ǻ, b=9.479(3)Ǻ, c=12.425(4)Ǻ, α=101.636(3)°, β=99.633(3)°, γ=94.040(3)°, V=795.0(4)Ǻ(3), Z=2, F(000)=352, Dc=1.405 mg/m(3), μ=0.099 mm(-1), R=0.0378, and wR=0.0967. The spectral results show that the Schiff base ligand acts as a bidentate donor coordinating through the azomethine nitrogen and the carbonyl oxygen atoms. The geometrical structures of these complexes are found to be square planar. Antimicrobial studies indicate that these complexes exhibit better activity than the ligand. The anticancer activities of the complexes have also been studied towards human cervical cancer cell line (HeLa), Colon Cancer Cells (HCT116) and Epidermoid Carcinoma Cells (A431) and it was found that the [Pt(L3)Cl2] complex is more active.

Potash alum [KAl(SO 4 ) 2 .12H 2 O] catalysed esterification of formylphenoxyaliphatic acids

AbstractA convenient and clean procedure for esterification is reported. Direct condensation of formylphenoxyaliphatic acids with low to high boiling alcohols catalysed by potash alum gave moderate to good yields. This catalyst could be recovered and reused without substantial loss in its catalytic activity and the methodology could be used for a range of closely related substrates. Graphical AbstractDirect condensation of formylphenoxyaliphatic acids with low to high boiling alcohols catalysed by potash alum gave moderate to good yields. This methodology could be used for a range of closely related substrates.

Homodinuclear lanthanide complexes of phenylthiopropionic acid: synthesis, characterization, cytotoxicity, DNA cleavage, and antimicrobial activity.

Lanthanide complexes of La(III), Pr(III), Nd(III), Sm(III), and Ho(III) with phenylthiopropionic acid were synthesized and characterized by elemental analysis, mass, IR, electronic spectra, molar conductance, TGA, and powder XRD. The results show that the lanthanide complexes are homodinuclear in nature. The two lanthanide ions are bridged by eight oxygen atoms from four carboxylate groups. Thermal decomposition profiles are consistent with the proposed formulations. Powder XRD studies show that all the complexes are amorphous in nature. Antimicrobial studies indicate that these complexes exhibit more activity than the ligand itself. The DNA cleavage activity of the ligand and its complexes were assayed on Escherichia coli DNA using gel electrophoresis in the presence of H(2)O(2). The result shows that the Pr(III) and Nd(III) complexes have completely cleaved the DNA. The anticancer activities of the complexes have also been studied towards human cervical cancer cell line (HeLa) and colon cancer cells (HCT116) and it was found that the La(III) and Nd(III) complexes are more active than the corresponding Pr(III), Sm(III), Ho(III) complexes, and the free ligand on both the cancer cells.

Analogues of N,1-diphenyl-4,5-dihydro-1H-[1]benzothiepino[5,4-c]pyrazole-3-carboxamide and N,1-diphenyl-4,5-dihydro-1H-[1]benzothiepino[5,4-c]pyrazole-3-carboxamide-6,6-dioxide: syntheses, characterization, antimicrobial, antituberculosis, and antitumor activity

A series of N,1-diphenyl-4,5-dihydro-1H-[1]benzothiepino[5,4-c]pyrazole-3-carboxamides (11a–m) and N,1-diphenyl-4,5-dihydro-1H-[1]benzothiepino[5,4-c]pyrazole-3-carboxamide-6,6-dioxides (12a–m) were synthesized by varying the active part (carboxamide group) of the pyrazole and were characterized by IR, 1H-NMR, 13C-NMR, mass spectral data, and elemental analyses. All compounds were evaluated for their antibacterial and antifungal activity. Compounds 11k and 12k showed higher activity than chloroamphenicol against Klebsiella pneumonia and Escherichia coli. Compounds 11b, 11c, 11l, 12b, 12c, and 12l displayed higher activity towards amikacin in inhibiting the growth of Escherichia coli (MIC 3.125 mg mL−1). Compounds 11k and 12k were equipotent to clotrimazole in inhibiting the growth of Candida albicans (MIC 3.125 mg mL−1). All compounds were screened for their cytotoxic activity against two tumor cell lines, namely the human colon tumor cell line (HCT116) and human cervical cancer cell line (HeLa). Most of the test compounds exhibited potent antitumor activity, especially compounds 11k and 12k, which displayed the highest activity among the test compounds with an IC50 equal to 18 and 12 μM for HeLa cells, and 16 and 10 μM for HCT116 cells, respectively. All the synthesized compounds showed low to moderate inhibitory activities against M. tuberculosis (MTB) H37Rv, whereas 11k and 12k were found to be more active against M. tuberculosis, with MIC values of 8.2 and 7.8 μM, compared to other analogues.

Hydrothermal syntheses and single crystal structural characterization of M(H2O)6(OPTA)2 [M = Co(II), Ni(II), Zn(II); OPTA = 1-oxopyridinium-2-thioacetato]

A new class of compounds of the family M(H2O)6(OPTA)2 (where M = Co(II), Ni(II), and Zn(II); OPTA = 1-oxopyridinium-2-thioacetato) was prepared from the appropriate metal acetates, 1-oxo-pyridinium-2-thioacetic acid (OPTAH), and potassium hydroxide in hydrothermal media and structurally characterized. The structure is constructed from M(H2O)62+ and two anions of OPTAH (C7H6NO3S) linked through hydrogen bonding into an extended network.

catena -Poly[[[aqua[3-(2-pyridylsulfanyl)propionato N -oxide-κ O ^1^]copper(II)]-μ-[3-(2-pyridylsulfanyl)propionato N -oxide-κ^3^ O ^3^: O ^1^, O ^1'^] dihydrate]

In the title complex, {[Cu(C8H8NO3S)2(H2O)] x 2 H2O}n, the Cu(II) cation has a distorted square-pyramidal coordination environment consisting of five O atoms, one from a water molecule, one from an N-O group and the other three from the carboxylate groups of two 3-(2-pyridylsulfanyl)propionate N-oxide anions. The aqua[3-(2-pyridylsulfanyl)propionato N-oxide]copper(II) moieties are bridged by 3-(2-pyridylsulfanyl)propionate N-oxide anions to form an infinite three-dimensional coordination polymer with a zigzag chain structure. The crystal structure is stabilized by hydrogen bonds.