Some Classes of Multivariate Life Distributions in Discrete Time

New classes of multivariate survival distribution functions based on monotonic behaviour of a multivariate failure rate are developed in the discrete set up. Relationship among the classes along with multivariate geometric distributions that act as boundaries of the various classes are identified.     

Synthesis,electrochemical and anti-microbial study of 2,5-diamino benzoquinones

Fifteen symmetric and unsymmetric 2,5-diamino benzoquinones have been synthesized and their electrochemical activity was studied by cyclic voltammetry. Presence of electron donating substituent like amino group found to shift the half wave potential towards more negative value which is more prominent in benzyl amino substituted amino benzoquinones (ABQs). All the compounds were checked for their anti-bacterial and anti-fungal activity by agar well diffusion technique. The more negative E_1/2 values of benzyl amino substituted ABQs make them more active towards various bacterial and fungal speciesas is evident from MIC values.     

β-Cyclodextrin as a supramolecular catalyst for the synthesis of 2Hindazolo[2,1-b]phthalazine-trione derivatives in water and their antimicrobial activities

An efficient and green method has been developed for the synthesis of 2H-indazolo[2,1-b]phthalazinetriones derivatives by employing 15 mol%β-cyclodextrinvia a one-pot multicomponent reaction of aldehyde,dimedone,hydrazine hydrate with succinic anhydride/phthalic anhydride in water at 80 ℃ for first time.The catalyst could be recovered and reused for four consecutive cycles without appreciable loss in catalytic activity and evaluated for in vitro antimicrobial activity against different Gram-positive and Gram-negative bacterial strains.The outcome of the screening study showed that compound 6d,6f and7 n exhibited excellent activity against E.coil.Whereas,compound 6f and 6h exhibited excellent activity against P.aeurginosa,and compound 6c,and 6e displayed again excellent activity against Staphylococcus aureus whereas compound 7o shows excellent activity against S.aureus and B.subtilis when compared with Ampicillin(standard control).The results indicated that maximum compounds are moderately effective against bacterial growth and their effectiveness is highest against standard drugs.     

Benzothiazole and Chromone Derivatives as Potential ATR Kinase Inhibitors and Anticancer Agents

Despite extensive studies and the great variety of existing anticancer agents, cancer treatment remains an aggravating and challenging problem. Therefore, the development of novel anticancer drugs with a better therapeutic profile and fewer side effects to combat this persistent disease is still necessary. In this study, we report a novel series of benzothiazole and chromone derivatives that were synthesized and evaluated for their anticancer activity as an inhibitor of ATR kinase, a master regulator of the DDR pathway. The cell viability of a set of 25 compounds was performed using MTT assay in HCT116 and HeLa cell lines, involving 72 h incubation of the compounds at a final concentration of 10 µM. Cells incubated with compounds 2c, 7h and 7l were found to show viability ≤50%, and were taken forward for dose–response studies. Among the tested compounds, three of them (2c, 7h and 7l) showed higher potency, with compound 7l exhibiting the best IC₅₀ values in both the cell lines. Compounds 2c and 7l were found to be equally cytotoxic towards both the cell lines, namely, HCT116 and HeLa, while compound 7h showed better cytotoxicity towards HeLa cell line. For these three compounds, an immunoblot assay was carried out in order to analyze the inhibition of phosphorylation of Chk1 at Ser 317 in HeLa and HCT116 cells. Compound 7h showed inhibition of pChk1 at Ser 317 in HeLa cells at a concentration of 3.995 µM. Further analysis for Chk1 and pChk1 expression was carried out in Hela cells by treatment against all the three compounds at a range of concentrations of 2, 5 and 10 µM, wherein compound 7h showed Chk1 inhibition at 2 and 5 µM, while pChk1 expression was observed for compound 7l at a concentration of 5 µM. To support the results, the binding interactions of the compounds with the ATR kinase domain was studied through molecular docking, wherein compounds 2c, 7h and 7l showed binding interactions similar to those of Torin2, a known mTOR/ATR inhibitor. Further studies on this set of molecules is in progress for their specificity towards the ATR pathway.     

Synthesis,Characterization, Thermal,and Antibacterial Studies of Organotin(Iv) Complexes of Indole-3-Butyric Acid and Indole-3-Propionic Acid

Abstract

Six organotin(IV) complexes of type Me₂SnL₂, Bu₂SnL₂, and Ph₃SnL [where L = indole-3-butyric acid (1, 2 and 3) or indole-3-propionic acid (4, 5 and 6)] have been synthesized by the reactions of the corresponding diorganotin(IV) oxide and triphenyltin(IV) hydroxide with respective indole-3-butyric acid (IBH) or indole-3-propionic acid (IPH) in the desired molar ratios of 1:2/1:1. All of the compounds have been characterized by elemental analysis, IR, ¹H NMR, ¹³C NMR, and ¹¹⁹Sn NMR spectroscopy. Thermal studies of all synthesized complexes have been carried out using thermogravimetry (TG) technique under a nitrogen atmosphere. The thermal decompositions for compounds Me₂SnL₂ and Bu₂SnL₂ occurred in two steps, whereas in compounds Ph₃SnL, it exhibited as three steps decomposition and resulted into the formation of pure SnO₂. The complexes were also screened against three gram-positive (Staphylococcus aureus, Staphylococcus epidermidis, and Micrococcus luteus) and three gram-negative (Escherichia coli, Pseudomonas aeruginosa, and Enterobacter aerogenes) bacteria using minimum inhibition concentration (MIC) method, and all of these complexes showed significant antibacterial activity.

[Supplementary materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements for the following free supplemental files: Additional text, tables, and figures.]     

Incorporation of Titanium(IV) into Sterically Hindered Schiff Bases of Heterocyclic β -Diketones Involving Ketooximes and Glycol as Coligands: Preparation and Structural Considerations

Titanium(IV) complexes of the general formula TiL(OPr ⁱ )₂ [where LH₂ = R CH₃ where R = ─C₆H₅, ─C₆H₄Cl(p)] were prepared by the interaction of titanium isopropoxide with sterically hindered Schiff bases derived from heterocyclic β -diketones in 1:1 molar ratio in dry benzene. The complexes TiL(OPr ⁱ )₂ were used as versatile precursors for the synthesis of other titanium(IV) complexes. Titanium(IV) complexes of the type TiLL'(OPr ⁱ ) (where L'H═R¹R²C═NOH, R¹ = R² = ─CH₃; R¹ = ─CH₃,R² = ─C₆H₅; R¹ = ─COC₆H₅, R² = ─C₆H₅) were synthesized by the reaction of TiL(OPr ⁱ )₂ with ketooximes (L'H) in equimolar ratio in dry benzene. Another type of titanium(IV) complexes having the general formula TiLGH(OPr ⁱ ) (where GH₂═HO─G─OH, G = ─CH₂─CH₂─) have been prepared by the reaction of TiL(OPr ⁱ )₂ with glycol in 1:1 molar ratio in dry benzene. Plausible structures of these new titanium(IV) complexes have been proposed on the basis of analytical data, molecular weight measurements, and spectral studies.     

Thermal analysis of new dimethyl/dibutyl tin(IV) compounds with amino acids

Six diorganotin(IV) compounds with amino acids of general formula [(CH₃)₂SnAACl]₂ and [(CH₃CH₂CH₂CH₂)₂SnAACl]₂ (where AA = l-methioninate, l-cysteinate, and l-tryptophanate) were synthesized by reacting dimethyltin(IV) dichloride (M) and dibutyltin(IV) dichloride (B) with l-methionine (M₁) or l-cysteine (C) or l-tryptophan (T) using acetonitrile as solvent and designated as MM₁, MC, MT, BM₁, BC, and BT. The structural characterization of dimethyltin(IV) and dibutyltin(IV) compounds were done using elemental analysis, FT-IR, ¹H-NMR, ¹³C-NMR, and ¹¹⁹Sn-NMR spectroscopy. The thermal properties of the synthesized compounds were studied by thermogravimetric analysis and differential scanning calorimetry techniques in a dynamic atmosphere of nitrogen. The thermal decomposition mechanisms were similar for compounds MM₁, BM₁, MC, BC, and occurred in one step, while in compounds MT and BT it occurred in two consecutive steps. The TG curves of the MT and BT compounds suggest the loss of the ligand (AA) in the first step, with probable formation of a tin oxide R₂SnO intermediate. At the end of the second step free tin is obtained similar to the MM₁, BM₁, MC, BC in accordance with the stoichiometry of the related compounds.     

Some Zirconium(IV) Complexes of Sterically Constrained Sulfur-Containing Schiff Bases of Heterocyclic β -Diketones: Synthetic Strategy and Structural Investigation Based Upon Spectroscopic Studies

Zirconium(IV) Schiff base chelates having the general formula ZrL(OPr ⁱ )₂ [where LH ₂ = R CH ₃ , R = –C ₆ H ₅ , –C ₆ H ₄ Cl(p)] were synthesized by the reaction of Zr(OPr ⁱ )₄.Pr ⁱ OH with sterically constrained sulfur-containing Schiff bases of heterocyclic β -diketones in a 1:1 molar ratio in dry refluxing benzene. The complexes ZrL(OPr ⁱ ) ₂ were used as important precursors for the synthesis of the complexes of the type Zr(L) ₂ . The complexes, Zr(L) ₂ , were prepared by the interaction of precursor ZrL(OPr ⁱ ) ₂ with sterically constrained sulfur-containing Schiff bases of heterocyclic β -diketones in a 1:1 molar ratio in dry benzene. The structures of these zirconium(IV) chelates have been discerned with the help of elemental analyses, physicochemical studies, and spectral [IR and NMR ( ¹ H and ¹³ C)] data. A distorted trigonal bipyramidal and a distorted octahedral geometry may be assigned to zirconium(IV) chelates of the types ZrL(OPr ⁱ ) ₂ and Zr(L) ₂ , respectively.     

Isolation and Characterization of Dimethyl Sulfide (DMS)-Degrading Bacteria from Soil and Biofilter Treating Waste Gas Containing DMS from the Laboratory and Pulp and Paper Industry

Dimethyl sulfide (DMS) is one of the sulfurous pollutants present in the waste gas generated from the pulp and paper industry. DMS has environmental health implications; therefore, it is necessary to treat the waste gas containing DMS prior to discharge into the environment. A bench-scale biofilter was operated in the laboratory as well as in a pulp and paper industry for the treatment of DMS. Both the biofilters were packed with pre-sterilized wood chips and cow dung/compost of the same origin seeded with biomass developed from garden soil enriched with DMS. The biofilters were operated for the generation of process parameters, and the potential microorganisms isolated from both the biofilters have been purified and characterized for degradation of DMS. Further, these cultures were purified on a basal medium using DMS as a sole carbon source for the growth. Further, the purified cultures were characterized through standard fatty acid methyl esters (FAME)-gas chromatography method, and the isolates were found to be mesophilic, aerobic microbes. These microbes were identified as Bacillus sphaericus-GC subgroup F, Paenibacillus polymyxa, B. sphaericus-GC subgroup F, B. sphaericus-GC subgroup F, and Bacillus megaterium-GC subgroup A, respectively. The potential culture for degradation of DMS was identified as B. sphaericus by 16s rRNA molecular analysis.