Synthesis,nematicidal activity and docking study of novel chromone derivatives containing substituted pyrazole

A series of chromone derivatives containing substituted pyrazole were designed and synthesized. Preliminary bioassays showed that most of the synthesized compounds exhibited good nematicidal activity in vivo against Meloidogyne incognita at 10 mg/L.     

Some transition metal ions complexes of tricine (Tn) and amino acids: pH-titration,synthesis and antimicrobial activity

Equilibrium studies have been carried out on complex formation of M(II) (M = Co(II), Cu(II) and Zn(II)) with tricine (Tn) and L = amino acids in aqueous solution, at 25 °C and ionic strength of I = 0.1 M (NaNO₃). The ternary complexes of amino acids are formed by simultaneous reactions. The concentration distribution of the complexes is evaluated. The solid complexes of [M(II)–Tn–Histidine (Hist)] have been synthesized and characterized by elemental analysis, infrared, magnetic and conductance measurements. The synthesized complexes have been screened for their antibacterial activities and the complexes show a significant antibacterial activity against four bacterial species: Staphylococcus aureus (Gram +ve), Streptococcus pyogenesr (Gram +ve), Serratia marcescens (Gram −ve) and Escherichia coli (Gram −ve). The activity increases by increasing the concentration of the complexes.     

Volatile Organic Compounds from Bacillus aryabhattai MCCC 1K02966 with Multiple Modes against Meloidogyne incognita

Plant-parasitic nematodes cause severe losses to crop production and economies all over the world. Bacillus aryabhattai MCCC 1K02966, a deep-sea bacterium, was obtained from the Southwest Indian Ocean and showed nematicidal and fumigant activities against Meloidogyne incognita in vitro. The nematicidal volatile organic compounds (VOCs) from the fermentation broth of B. aryabhattai MCCC 1K02966 were investigated further using solid-phase microextraction gas chromatography-mass spectrometry. Four VOCs, namely, pentane, 1-butanol, methyl thioacetate, and dimethyl disulfide, were identified in the fermentation broth. Among these VOCs, methyl thioacetate exhibited multiple nematicidal activities, including contact nematicidal, fumigant, and repellent activities against M. incognita. Methyl thioacetate showed a significant contact nematicidal activity with 87.90% mortality at 0.01 mg/mL by 72 h, fumigant activity in mortality 91.10% at 1 mg/mL by 48 h, and repellent activity at 0.01–10 mg/mL. In addition, methyl thioacetate exhibited 80–100% egg-hatching inhibition on the 7th day over the range of 0.5 mg/mL to 5 mg/mL. These results showed that methyl thioacetate from MCCC 1K02966 control M. incognita with multiple nematicidal modes and can be used as a potential biological control agent.     

Diazenyl schiff bases: Synthesis,spectral analysis,antimicrobial studies and cytotoxic activity on human colorectal carcinoma cell line (HCT-116)

A series of diazenyl schiff bases have been synthesized by reaction of salicylaldehyde containing azo dyes with various substituted aniline derivatives in the presence of acetic acid as catalyst. The structures of diazenyl derivatives were determined by FTIR, UV–vis, ¹H NMR, ¹³C NMR, CHN analysis, fluorimetric and mass spectroscopic studies. The synthesized derivatives were screened for their in vitro antimicrobial activity against various Gram-positive (S. aureus, B. subtilis, B. cereus), Gram-negative (S. typhi, S. enterica, E. coli, P. aeruginosa) bacterial and fungal (C. albicans, A. niger and A. fumigatus) strains, using cefadroxil (antibacterial) and fluconazole (antifungal) as standard drugs. The diazenyl schiff bases were also screened for their cytotoxicity against human colorectal carcinoma cell line (HCT-116) using 5-fluorouracil as standard drug by Sulforhodamine-B Stain (SRB) assay. The schiff bases exhibited significant activity toward both Gram-positive, Gram-negative bacterial and fungal strains. Most of the synthesized derivatives showed high activity against S. enterica. 4-((2,5-Dichlorophenyl)diazenyl)-2-((3-bromophenylimino)methyl)phenol (SBN-40) was found to be very active against S. aureus, B. cereus and E. coli, with MIC = 0.69 (µM/ml × 10²). The compound 4-((2-bromophenyl)diazenyl)-2-((4-nitrophenylimino)methyl)phenol (SBN-13) possessed comparable activity (IC₅₀ = 7.5 µg/ml) to the standard drug 5-fluorouracil (IC₅₀ = 3.0 µg/ml) against human colorectal carcinoma cell line (HCT-116).     

Design,synthesis and molecular modeling studies of few chalcone analogues of benzimidazole for epidermal growth factor receptor inhibitor in search of useful anticancer agent

In the present investigation, few 3-(substitutedphenyl)-1-[2-(1-hydroxy-ethyl)]-1H-benzimidazol-1-yl)prop-2-en-1-ones are EGFR antagonist are designed, by molecular docking analysis. The synthesized compounds were tested for their in vitro anticancer activity by propidium iodide fluorescent assay and Trypan blue viability assay against colorectal cancer cell lines (HCT116) and non-small cell lung cancer cell lines (H460). Human Epithelial Kidney cell lines (HEK) are used as normal cell lines for studying effect of drug on non-cancerous cells within human body. Evaluation of cytotoxic studies of synthesized compounds CHL(1–8) reveal that compound CHL1 [IC₅₀ = 7.31 and 10.16 μM against HCT116 and H460 cell lines respectively, by PI assay] and CHL8 [IC₅₀ = 12.52 and 6.83 against HCT116 and H460 μM cell lines respectively] possess promising cytotoxic activity.     

Synthesis and characterization of nanoparticles of α-Bi2Mo3O12 prepared by co-precipitation method: Langmuir adsorption parameters and photocatalytic properties with rhodamine B

Nanoparticles of α-Bi₂Mo₃O₁₂ were prepared by co-precipitation method at calcination temperatures of 250, 300, 400 and 480 °C. The characterization of α-Bi₂Mo₃O₁₂ synthesized at different temperatures was carried out by X-ray diffraction (XRD), thermal analysis (TGA/DTA), transmission electron microscopy (TEM), and diffuse reflectance spectroscopy (DRS). Adsorption parameters and photocatalytical activity under visible light irradiation of α-Bi₂Mo₃O₁₂ were evaluated using the rhodamine B (rhB) dye as model. The adsorption constant (K) and maximum amount of dye adsorbed (q_max) on the surface of the samples synthesized were evaluated following the Langmuir isotherm. The sample calcinated at 250 °C showed the maximum adsorption percentage of dye, which ranged between 20 and 46% for initial concentrations of rhB from 5 to 15 mg L^?1, with a K = 6.96 × 10⁵ L mol^?1 and q_max = 2.73 mg g^?1. All samples were able to induce the oxidative photodegradation of rhB, however, the bleaching of dye solution was reached more quickly for the sample calcinated at 250 °C.     

Synthesis of 99mTc-gemifloxacin freeze dried kits and their biodistribution in Salmonella typhi,Pseudomonas aeruginosa and Klebsiella pneumoniae

Gemifloxacin, a novel, 4th generation fluoroquinolone derivative, was labeled with^99mTc; its freeze dried kits were prepared and used for infection imaging. Kits showed great stability with higher labeling efficiency. Kits were synthesized through a simple method; developed at room temperature without HCl and heating with low colloidal content. Reaction conditions were optimized in order to get maximum radiochemical purity. Highest labeling efficiency (99 ± 0.05)% was achieved when 1.0 mg gemifloxacin was labeled with 10 mCi sodium pertechnetate in the presence of 50 μg SnCl₂ and 300 μg D-penicillamine at room temperature. Radiolabeled antibiotic kits were preclinically assessed such as in-vitro stability, lipophilicity, protein binding, in-vitro binding with bacterial strains and pharmacokinetic investigations in animals. Kits were found highly stable for 6 h both at room temperature and at 37 °C in serum. Biodistribution showed excellent uptake of activity at infection site (in Pseudomonas aeruginosa, Salmonella typhi and Klebsiella pneumoniae). Biodistribution data showed that ^99mTc-gemifloxacin has the potential and may be used for infection imaging.     

Density and activity of pertechnetic acid aqueous solutions at T = 298.15 K

The previous isopiestic investigations of HTcO₄ aqueous solutions at T = 298.15 K are believed to be unreliable, because of the formation of a ternary mixture at high molality. Consequently, published isopiestic molalities for aqueous HTcO₄ solutions at T = 298.15 K were completed and corrected. Binary data (variation of the osmotic coefficient and activity coefficient of the electrolyte in solution in the water) at T = 298.15 K for pertechnetic acid HTcO₄ were determined by direct water activity measurements. These measurements extend from molality m = 1.4 mol · kg⁻¹ to m = 8.32 mol · kg⁻¹. The variation of the osmotic coefficient of this acid in water is represented mathematically. Density variations at T = 298.15 K are also established and used to express the activity coefficient values on both the molar and molal concentration scale. The density law leads to the partial molar volume variations for aqueous HTcO₄ solutions at T = 298.15 K, which are compared with published data.     

Synthesis,biological evaluation and Structure Activity Relationships (SARs) study of 8-(substituted)aryloxycaffeine

A series of 8-(substituted)aryloxycaffeine were prepared from 8-bromocaffeine and (substituted)phenols by modified Ullmann reaction. In vitro antibacterial activity, inhibitory activity on topoisomerase II and pharmacological activities were evaluated for the synthesized 8-(substituted)aryloxycaffeine. Among the synthesized compounds, 8-(5-chloropyridin-3-yloxy)caffeine (3k) showed strong inhibitory activity (MIC = 15.6 μg/mL) against the tested gram negative (−) bacteria Salmonella enteritidis. 8-(quinolin-8-yloxy)caffeine (3g) showed the strongest inhibitory activity against topoisomerase II. And the compounds 8-(6-methylpyridin-2-yloxy)caffeine (3j) and 8-(3-chloro-6-(trifluoromethyl)pyridin-2-yloxy)caffeine (3m) showed analgesic effect without the central nervous system stimulation.     

Surface modified Pt/C as a methanol tolerant oxygen reduction catalyst for direct methanol fuel cells

A new procedure has been successfully developed by which PtN_x/C is synthesized to enhance methanol tolerance while maintaining a high catalytic activity for the oxygen-reduction reaction (ORR). The nitrogen-modified Pt surface, which is prepared using a chelating agent followed by heat treatment, exhibits considerable selectivity toward the ORR in the presence of methanol. The high methanol tolerance could be attributed to the suppression of methanol adsorption resulting from the modification of the Pt surface with nitrogen. A direct methanol fuel-cell (DMFC) test showed that a power density of up to 120 m W cm⁻² was generated when PtN_x/C was used as the cathode catalyst (1 mg cm⁻²) in 6 M methanol and oxygen at 70 °C.     

Electrochemical synthesis of a ferrocenecarboxylic acid–C60 composite and its electrocatalysis to hydrogen peroxide

A new ferrocenecarboxylic acid–C₆₀ composite (Fc–C₆₀) has been synthesized by controlled potential electrolysis. A composite modified glassy carbon electrode has been prepared based on its good electrochemical activity. The modified electrode in 0.1 M NaClO₄ solution shows a reversible oxidation wave at E_1/2 = 0.32 V (vs. SCE) attributed to the oxidation of the ferrocene entity and a quasi-reversible reduction wave of C₆₀ entity at E_1/2 = ?0.54 V (vs. SCE). Electrocatalytic studies show that Fc–C₆₀ at the modified electrode can mediate the reduction of hydrogen peroxide (H₂O₂), and a broad linear range from 1.2 μM to 21.9 mM for H₂O₂ were obtained with a determination limit of 2.5 × 10^?7 M by amperometry.     

Electrochemical properties of Li(Li(1−x)/3CoxMn(2−2x)/3)O2 (0 ⩽ x ⩽ 1) solid solutions prepared by poly-vinyl alcohol (PVA) method

The whole range of solid solutions Li(Li_(1−x)/3Co_xMn_(2−2x)/3)O₂ (0 ⩽ x ⩽ 1) was firstly synthesized by an aqueous solution method using poly-vinyl alcohol as a synthetic agent to investigate their structure and electrochemical properties. X-ray diffraction results indicated that the synthesized solid solutions showed a single phase without any detectable impurity phase and have a hexagonal structure with some additional peaks caused by monoclinic distortion, especially in the solid solutions with a low Co amount. In the electrochemical examination, the solid solutions in the range between 0.2 ⩽ x ⩽ 0.9 showed higher discharge capacity and better cyclability than LiCoO₂ (x = 1) on cycling between 2.0 and 4.6 V with 100 mA g⁻¹ at 25 °C. For example, Li(Li_0.2Co_0.4Mn_0.4)O₂ (x = 0.4) exhibited a high discharge capacity of 180 mA h g⁻¹ at the 50th cycle. By synthesizing the solid solution between Li₂MnO₃ and LiCoO₂, the electrochemical properties of the end members were improved.     

Synthesis,characterization, single crystal XRD,in vitro antimicrobial and cytotoxicity study of tris(ethylenediamine)cobalt(III)chloride oxalate trihydrate

The complex tris(ethylenediamine)cobalt(III)chloride oxalate trihydrate [Co(en)₃]Cl(C₂O₄)·3H₂O crystallizes in the monoclinic space group C₂/c with the following unit cell parameters a = 19.9318 (13), b = 9.3344 (4), c = 19.0881 (13) Å β = 96.846(3)°, Z = 8. The crystal structure was solved by direct methods and refined by full matrix least squares procedures to a final R value of 0.0314 for 4330 observed reflections. The reported cobalt complex is six co-ordinated through amine nitrogen with distorted octahedral geometry. There are uncoordinated chloride and oxalate ions along with the water molecules. In-vitro antimicrobial activity was studied against various test organisms and found to be good. From in-vitro cytotoxic activity of the synthesized complex, the IC₅₀ value was found to be 55.85 μg/ml.     

Synthesis and biological evaluation of novel 1,2,4-triazole containing 1,2,3-thiadiazole derivatives

A series of novel 1,2,4-triazoles containing 1,2,3-thiadiazole derivatives were designed and synthesized. Their structures were confirmed by melting points, IR, 1H NMR, and elemental analysis and ESI-MS or HRMS. Preliminary bioassays indicated that these compounds exhibited very good insecticidal activity against Aphis laburni at 100 μg/mL, with mortality no less than 95%. Compounds 6a, 6c, 6f, 61 showed higher curative activity against TMV and compound 6h showed a higher induction effects against TMV in vivo at 100 μg/mL. Collectively, our data demonstrate a new strategy for control of insects and viruses.     

Influence of molar mass of polymer on the solvent activity for binary system of poly N-vinylcaprolactam and water

The water activity in aqueous solution of poly N-vinyl caprolactam with different molecular weights is measured by isopiestic method at T = 308.15 K. The results show that water activity and vapour pressure of poly N-vinylcaprolactam solution increases with increasing the molecular weight. The Flory-Huggins model, the modified Flory-Huggins model and Freed Flory-Huggins equation + NRTL model are used for correlation of the experimental solvent activity. It is found that the Freed Flory-Huggins + NRTL model is better than the others.     

Synthesis and anti-inflammatory activity of gold-nanoparticle bearing a dermatan sulfate disaccharide analog

A novel gold glyconanoparticle coating with DS disaccharide analog has been synthesized, and the potential anti-inflammatory activity was studied using carrageenan-induced paw edema model.     

Synthesis,bioactivity, action mode and 3D-QSAR of novel anthranilic diamide derivatives

Several newly synthesized anthranilic diamide derivatives were found to exhibit excellent bioactivity. The action mode test and 3D-QSAR analysis provided valuable information for evaluation and future design of anthranilic diamide insecticides.     

Bioinspired synthesis of pure massicot phase lead oxide nanoparticles and assessment of their biocompatibility,cytotoxicity and in-vitro biological properties

Green and ecofriendly route for biosynthesis of lead oxide nanoparticles has been successfully demonstrated using aqueous leaf extracts of Sageretia thea (Osbeck.). Biosynthesized PbO (∼27 nm) nanoparticles were extensively characterized using XRD, FTIR, Raman, EDS etc. Morphology was studied through HR-TEM/SEM. As synthesized nanoparticles were investigated for their iv-vitro biological properties. Antibacterial activities revealed enhancement upon modulation by UV in a concentration dependent manner. Pseudomonas aeruginosa was found to be the most resistant strain (MIC = 250 µg/mL and MIC^uv = 31.25 µg/ml). MTT cytotoxicity on leishmania promastigotes and amastigotes revealed significant inhibition as indicated by their IC₅₀ values of 14.7 µg/mL and 11.95 µg/m respectively. Cytotoxicity was also confirmed using brine shrimp lethality (IC₅₀ = 27.7 µg/mL). Bio-compatibility evaluation indicated cytotoxicity to freshly isolated human macrophages (IC₅₀ = 57.1 µg/mL). Insignificant alpha-amylase inhibition and moderate protein kinase inhibition was revealed. Antioxidant activities indicated free radical scavenging activity (58 ± 2.45) at 200 µg/mL. Moderate total reducing power and total antioxidant activity was also indicated. Overall, we conclude lead oxide as a potential candidate for biological applications, however further studies are recommended on their in vitro and in vivo cytotoxicity.     

Biosynthesis of Bixa orellana seed extract mediated silver nanoparticles with moderate antioxidant,antibacterial and antiproliferative activity

Biosynthesis of metallic silver nanoparticles (AgNPs) has gained much interest and offers an attractive alternate to physical and chemical approaches. In recent year several safe, easy, cost-effective, reproducible, and environmentally friendly synthesis approaches for silver nanoparticles have been developed. In this research work, a simple, cheap, and unexplored method was applied on green synthesis of AgNPs using secondary metabolites extracted from Bixa orellana seeds. The seeds are rich of flavonoids and phenolic compounds which presumably responsible for the fast reduction and stabilization of silver ion into silver nanoparticles. The biosynthesis process is very likely to be able to reduce silver ions under simple physiological conditions. The surface plasmon resonance (SPR) that was appeared at 420 nm in UV–vis spectrum, had confirmed the formation of AgNPs. Moreover, the functional groups in secondary metabolite that act as reducing, capping and stabilizing agents for silver nanoparticles, are identified by Fourier transform infrared (FTIR) spectra. An X-ray diffraction analysis generated four peaks for Bixa orellana seed extract mediated AgNPs positioned at 2θ angles of 38.1°, 44.2°, 64.6°, and 77.5° corresponding to crystal planes (1 1 1), (2 0 0), (2 2 0), and (3 1 1). Field emission scanning electron microscope (FESEM) and transmission electron microscopy (TEM) images confirmed the formation of nanosized silver particles. The z-average of the synthesized particles measured by dynamic light scattering (DLS) was found to be 92.9 nm. AgNPs synthesized exhibited remarkable antioxidant activity, antibacterial and antiproliferative activity against human breast (MCF-7) cell line. On the basis of our results, we conclude that biologically synthesized AgNPs exhibited favorable characteristics and have the potential to be used in biomedical fields.     

Evaluation of the safety and antioxidant activities of Crocus sativus and Propolis ethanolic extracts

The possible toxicological effects and in vitro antioxidant activity of the ethanolic extracts of Crocus sativus and Propolis were investigated. Both extracts did not cause any mortalities or signs of toxicity in mice when administered orally at doses up to 5 g/kg b.wt. In the sub-chronic study; the tested extracts did not produce any significant change in liver and kidney functions of rats, following oral administration for 8 successive weeks at doses of 500 mg/kg b.wt. of each. Propolis showed remarkable in vitro antioxidant activity at concentrations of (40–100 mg/ml). In contrast, the ethanolic extract of C. sativus ethanolic extract showed weak antioxidant activity in concentrations of (1–10 mg/ml) while at concentrations of (20–100 mg/ml) failed to exhibit any antioxidant activity. It was concluded that: both extracts were non-toxic, as they did not cause any mortalities or signs of toxicity in mice when administered orally at doses up to 5 g/kg b.wt. Daily oral administration of C. sativus, Propolis ethanolic extracts alone or in combination for 8 successive weeks to rats was quiet safe and didn't cause any toxic changes in liver and kidney. Antioxidant study showed that Propolis ethanolic extract was a more potent antioxidant than C. sativus extract.