Shahan Zeb Khan

Synthesis, spectroscopic characterization, crystal structure, DNA interaction study and invitro biological screenings of 4-(5-chloro-2-hydroxyphenylamino)-4-oxobut-2-enoic acid

The titled compound, 4-(5-chloro-2-hydroxyphenylamino)-4-oxobut-2-enoic acid was synthesized and characterized by various techniques like elemental analyses, FT-IR, NMR ((1)H, and (13)C) and single crystal X-ray structural analysis. The appearance of the OH peak of the carboxylic acid in the FT-IR and NMR spectra conform the formation of the compound. A good agreement was found between the calculated values of C, H, N and found values in elemental analysis that show the purity of the compound. Protons H2 and H3 are in cis conformation with each other as conformed both from (1)H NMR as well as from single crystal X-ray analysis. The molecular structure of the title compound, C₁₀H₁₀NO₃Cl, is stabilized by short intramolecular OH---O hydrogen bonds within the molecule. In the crystal structure, intermolecular NH---O hydrogen bonds link molecules into zigzag chains resulting in a dendrimer like structure. The title compound was screened for biological activities like interaction with DNA, cytotoxicity, antitumor and antioxidant activities. DNA interaction study reveals that the binding mode of interaction of the compound with SS-DNA is intercalative as it results in hypochromism along with significant red shift of 5 nm. It was also found to be effective antioxidant of 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) and show almost comparable antioxidant activity to that of the standard and known antioxidant, ascorbic acid, at higher concentration. The antitumor activity data of the compound shows that it can be used as potent antitumor agent.

Heteroleptic Pd(II) dithiocarbamates: synthesis, characterization, packing and in vitro anticancer activity against HeLa cell line

Two new heteroleptic Pd(II) dithiocarbamates (1 and 2) have been synthesized by reaction of equimolar quantities of palladium(II) chloride, sodium 4-(3-methoxyphenyl)piperazine-1-carbodithioate, and appropriate substituted triphenylphosphines. The synthesized complexes have been characterized by their physical, spectral (IR, 1H, 13C, and 31P NMR), and X-ray crystallographic data. Complexes 1 and 2 showed square-planar geometry both in solution and solid states. The crystal packing of both complexes revealed similar 3-D-supramolecular networks comprised of 1-D chains. However, the nature and strength of various non-covalent interactions of these networks were slightly different. The DNA interaction studies of the complexes have been carried out by UV–visible spectroscopy to evaluate their anticancer potential. The study suggested intercalative interaction with 2.402 × 104 and 2.713 × 103 M−1 binding constants, respectively. The complexes have also been evaluated for their anticancer activity against HeLa cell line. Both complexes showed higher activity with IC50 values much lower (22.176 and 26.166 μM for 1 and 2, respectively) than the standard cisplatin (78.075 μM). Furthermore, the complexes induced stronger DNA fragmentation as investigated by DNA ladder assay for apoptosis. Our findings suggested that the anticancer action of these compounds stems from their interaction with DNA leading to DNA damage and apoptosis. The excellent activity of 1 and 2 deserves to be a focus for further research and in vivo studies. Graphical abstract The paper presents two new heteroleptic Pd(II) dithiocarbamates (1 and 2) and their outstanding anticancer properties.

Monofunctional platinum(II) dithiocarbamate complexes: synthesis, characterization and anticancer activity

Heteroleptic platinum(II) dithiocarbamates, of general formula [Pt(DTC)LCl], where DTC = 4-(4-methoxyphenyl)piperazine-1-carbodithioate (1 and 2) and 4-(furan-2-carbonyl)piperazine-1-carbodithioate (3) and L = tri(4-flourophenylphosphine) (1 and 3) and tri(4-chlorophenylphosphine) (2) have been synthesized and characterized by different analytical techniques. These complexes are square planar with picoplatin or phenanthriplatin type steric hindrance from aromatic C–H groups of the phosphine ligand as shown by single-crystal analysis. In 1, the Pt square plane is hindered by two axially oriented hydrogens, whereas by only one in 2 and 3. DNA-binding studies by UV/visible spectroscopy revealed a stronger electrostatic interaction of 1 compared to 2 and 3, and the results are further supported by viscometry and cyclic voltammetric measurements. Their in vitro anticancer activity against five different cancer cell lines using a MTT assay revealed high potency of the complexes. The higher activity of 1 than both 2 and 3 is consistent with DNA binding strength and we speculate that it may be due to the relatively inert nature of platinum towards off-target biomolecules ensured by the hindrance caused by the two axially oriented hydrogens.

New 3D and 2D supramolecular heteroleptic palladium(II) dithiocarbamates as potent anticancer agents

Abstract Three new heteroleptic palladium(II) dithiocarbamates with better in vitro anticancer activity than cisplatin were synthesized and characterized by different analytical techniques, elemental analysis, FTIR, NMR, and single crystal X-ray diffraction analysis. The Pd center is chelated by dithiocarbamate ligand {4-benzylpiperazine-1-carbodithioate (1) and (3) or (4-(2-methoxyphenyl)piperazine-1-carbodithioate (2)}, triorganophosphine {tris-(4-flourophenyl)-phosphine (1) and (2) or tris-(4-chlorophenyl)phosphine (3)}, and a chloro-group, resulting in a square planar geometry. The packing diagram reveals a 3D network (1 and 2) and a 2D network (3) composed of various 1D chains in which the molecules are linked via hydrogen bonds (1–3) and halide⋯π (1, 3) interactions. The anticancer activities of complexes against HeLa cell line varies in the sequence 2 (23.438 μM) > 1 (38.293 μM) > 3 (47.554 μM) > cisplatin (78.075 μM). The cytotoxicity of these complexes is due to their strong induction of oxidative stress and DNA-damage ability leading to apoptosis.

Synthesis and Spectrophotometric Study of Toxic Metals Extraction by Novel Thio-Based Non-Ionic Surfactant

Abstract A new thio-based non-ionic surfactant 1-(3-chlorophenyl)-3-te-tradecanoylthiourea has been synthesized from potassium thiocyanate, tetradecanoyl chloride and 3-chloroanaline. The purity of the compound was characterized by techniques like 1H NMR, 13C NMR, and FT-IR. The compound was used to detect the toxic metals like copper, mercury and manganese by using UV-Visible spectrophotometric technique. The compound is able to act as a ligand as well to form micelles. Due to this the compound extracts these toxic metals in form of solubilization and complexation. The extracted metals settle down to the bottom in a water tank. The visible change in color with time proves the interaction of the compound with the metals. The compound having carbonyl as well as sulfur groups have soft corner to metal for complexation. This will be used to remove toxic metals from polluted soil and soft drinking surface and underground water. The surfactant is easily synthesized, very economical and environmentally acceptable. The CMC of the surfactant is also determined.

Synthesis, Characterizations and Multifunctional Activities of New Thiourea-Based Non-Ionic Surfactants

Abstract Six new thiourea-based non-ionic surfactants were prepared from easily existing raw resources in good yield name 1-sec-butyl-3-dodecanoylthiourea, 1-dodecanoyl-3-phenylthiourea, 1,1-dibutyl-3-dodecanoylthiourea, 3-dodecanoyl-1, 1-diphenylthiourea, 1-cyclohexyl-3-dodecanoylthiourea and 1-butyl-3-dodecanoylthiourea. The structural chemistry of these compounds was studied by multinuclear magnetic resonance (1H, 13C), Infrared spectroscopy and UV-Visible spectrophotometry techniques. Their solubility varies according to temperature. They show a low solubility, which increases with the temperature of the water. However, they are not stable. The are soluble in organic solvent like ethanol. These molecules possess a low critical micelle concentration and due to this it shows that they are moderately hydrophobic. These molecules were studied regarding their antimicrobial activities and their antifungal and antibacterial efficiency was tested against five microoganism strains. In all cases, the new compounds show a significant inhibition growth against the tested five bacterial and fungal strains. Due to these behaviors they can be used as future candidates in cleaning as well as in agriculture features. The corrosion inhibition behavior was also studied using chromium and aluminum metals.