Di-2-pyridylketone-N1-substituted thiosemicarbazone derivatives of copper(II): Biosafe antimicrobial potential and high anticancer activity against immortalized L6 rat skeletal muscle cells.

The basic aim of this study pertains to developing antimicrobial or anticancer agents based on N, S-donor organic ligands bonded to metals. In the present investigation, di-2-pyridylketone-N1-substituted thiosemicarbazone (py2tscH-N1HR2, Chart 2) thio-ligands were reacted with copper(I) halides in organic solvents yielding copper(II) complexes of stoichiometry, [Cu(N,N,S-py2tsc-N1HR2)X] (X = I, R2 = H, 1; Me, 2; Et, 3; Ph, 4; X = Br, R2 = H, 5; Me, 6; Et, 7; Ph, 8; X = Cl, R2 = H, 9; Me, 10; Et, 11; Ph, 12); the formation of CuII probably occurs through a proton coupled electron transfer (PCET) process. Electron spin resonance, ultraviolet-visible spectroscopy and X-ray crystallography (2, 3, 5, 7, 11) supported a distorted square planar geometry of these complexes. Moderate to high antimicrobial activities of these complexes against methicillin resistant Staphylococcus aureus, Gram positive bacteria, Staphylococcus aureus and Gram negative bacteria, Klebsiella pneumoniae 1, Salmonella typhimurium 2 and one yeast Candida albicans were recorded. Complexes were found to be biosafe with 88-91% cellular viability. All complexes have shown high anticancer activity against the immortalized L6 rat skeletal muscle cell line with very low IC50 values.

Rational modification of a lead molecule: Improving the antifungal activity of indole - triazole - amino acid conjugates.

The modification of a molecule that was identified as highly efficacious in the previous studies could considerably improve the biological activity of the resulting compounds. While targeting lanosterol 14-α demethylase, the molecular modelling studies convinced that the extension of the phenyl ring of compound 1 deep into the hydrophobic pocket of the enzyme may increase the enzyme - ligand interactions and hence improve the anti-fungal profile of the molecules. As a result, the newly designed compounds 2 were synthesized and screened for their anti-microbial properties and these compounds were found to exhibit considerably better activity than the previous molecule 1. Some of the compounds in this series exhibited MIC90 16 µg mL-1 and 32 µg mL-1 against Candida albicans and Aspergillus niger, respectively as against 312 µg mL-1 for compound 1.

Scaffolds of hydroxyl apatite nanoparticles disseminated in 1, 6-diisocyanatohexane-extended poly(1, 4-butylene succinate)/poly(methyl methacrylate) for bone tissue engineering.

Poly(1, 4-butyl succinate) extended 1, 6-diisocyanatohexane (PBSu-DCH) polymers and Polymethylmethacrylate (PMMA) scaffolds decorated with nano hydroxyl apatite have been prepared and characterized for regeneration of bone in cranio-maxillofacial region. Synthesized scaffolds revealed good response in bone regeneration and excellent cell viability in comparison to commercial available glass plate, which lead to better proliferation of MG-63 cell lines. Additionally, they demonstrate high porosity and excellent water retention ability. Moreover, controlled degradation (in pH=7.4) and sustained drug release in pH (4.5 and 7.4) are advantages of these scaffolds to serve as delivery vehicles for therapeutic drugs. Samples also provide the protection against Escherichia coli and Methicillin Resistant Staphylococcus aureus microorganisms which can be helpful for quick recovery of the patient. In-vitro inflammatory response has been assessed via adsorption of human plasma/serum proteins on the surface of the scaffolds. Results suggest that prepared scaffolds have good bone regeneration ability and provide friendly environment for the cell growth with the additional advantage of protection of the surrounding tissues from microbial infection. With all these features, it is speculated that these scaffolds will have wide utility in the area of tissue engineering and regenerative medicine.

Antimicrobial Potential of Callistemon lanceolatus Seed Extract and its Statistical Optimization.

Plants have always been eminent source of medicinal products. Screening of the aqueous seeds extract of Callistemon lanceolatus (bottle brush) revealed its broad spectrum antimicrobial potential with an inhibition zone ranging from 13 to 28 mm against various pathogenic microorganisms. While optimizing the different parameters the antimicrobial activity was better expressed at 15 % concentration, prepared by extracting the material at 60 °C for 20 min. The extract was filtered through muslin cloth and gave best results at its natural pH. Statistical optimization by Response surface methodology enhanced the antimicrobial activity up to 1.6-fold. Minimum inhibitory concentration values of the aqueous extract of seeds of C. lanceolatus against different organisms ranged from 1-5 mg/ml. The viable cell count studies indicated a bactericidal effect against most of the pathogens. The aqueous extract was found to be relatively thermostable at 100 °C. When treated for shelf life at ambient conditions and refrigeration temperature (2-8 °C), the latter only showed a 28 % loss in antimicrobial activity. The aqueous extract was found to be biosafe when evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide reagent (MTT toxicity) assay and Ames mutagenicity assay.