Antihaemorrhagic potentials of Fagonia cretica against Naja naja karachiensis (black Pakistan cobra) venom

Plants have been extensively used as a remedy for the treatment of snake bites. The aim of this study was to determine the antivenom potentials of methanolic extract from the aerial parts (leaves and twigs) of Fagonia cretica L. on a haemorrhage induced by venom from Naja naja karachiensis. The haemorrhagic response of venom was dose dependent from 0.1 to 4.0?μg per 1.5?μL phosphate buffer saline (PBS) on vitelline veins of fertilised hens' eggs in their shells. The extract effectively eliminated and neutralised, in a dose-dependent manner, the haemorrhagic activity of snake venom. The minimum effective neutralising dose of F. cretica extract was found to be 15?μg per 1.5?μL PBS. The extract possesses potentials as haemorrhagic inhibitor against snake venom compared to the standard antiserum and various plants reported in the literature. This study also provides a scientific base for the use of F. cretica in traditional medicine for the treatment of snake bite.     

New dimeric and supramolecular organotin(IV) complexes with a tridentate schiff base as potential biocidal agents

The paper describes the synthesis and structural characterization of six new diorganotin(IV) compounds 1–6, [R₂SnL] and a monoorganotin(IV) derivative, C₄H₉SnClL (7). Here L = N′-(5-bromo-2-oxidobenzylidene)-N-(oxidomethylene)hydrazine ligand with ONO tridentate chelation capability and R = CH₃ (1), C₂H₅ (2), n-C₄H₉ (3), C₆H₅ (4), C₈H₁₇ (5), tert-C₄H₉ (6), The packing diagram offers a supramolecular structure for 1 and a dimeric structure for 4 with distorted square-pyramidal and distorted trigonal geometry, respectively. The different geometry of 1 than 4 can be attributed to the presence of intermolecular non-covalent Sn---O and Sn---H interactions in the former. The antifungal, antibacterial, antiurease and antileishmanial activities of these complexes proved them to be active biologically and may be formulated as new metal-based drugs in future.     

Intramolecular monomer-on-monomer (MoM) Mitsunobu cyclization for the synthesis of benzofused thiadiazepine-dioxides

The utilization of a monomer-on-monomer (MoM) intramolecular Mitsunobu cyclization reaction employing norbornenyl-tagged (Nb-tagged) reagents is reported for the synthesis of benzofused thiadiazepine-dioxides. Facile purification was achieved via ring-opening metathesis (ROM) polymerization initiated by one of three metathesis catalyst methods: (i) free metathesis catalyst, (ii) surface-initiated catalyst-armed silica, or (iii) surface-initiated catalyst-armed Co/C magnetic nanoparticles.     

New Supramolecular Triorganotin(IV) Dithiocarboxylates as Potential Antibacterial Agents

Four triorganotin derivatives of general formula C₁₀H₁₀NS₂SnR₃,_, where R = CH₃ ( 1 ), C₄H₉ ( 2 ), C₆H₁₁ ( 3 ), and C₆H₅ ( 4 ), have been synthesized by the metathesis reaction of 1,2,3,4‐tetrahydroisoquinolnium salt of ligand with triorganotin(IV) chloride in the 1:1 ratio. These complexes were characterized by elemental analysis, Raman, IR, multinuclear NMR (¹H, ¹³C, and ¹¹⁹Sn), and mass spectrometry. The crystal structure confirmed a supramolecular zig‐zag chain structure mediated by S–H (2.968 Å) for complex 4 with the central Sn atom exists in a distorted trigonal bipyramidal geometry. A subsequent antibacterial study indicates that the compounds are biologically active.     

Structural properties and antibacterial potency of new supramolecular organotin(IV) dithiocarboxylates

A series of new organotin(IV) derivatives; Me₃SnL (1), Bu₃SnL (2), Ph₃SnL (3), Me₂SnClL (4), Bu₂SnClL (5), Ph₂SnClL (6), Et₂SnClL (7) and Et₂SnL₂ (8) where L = N-(2,3-dimethylphenyl)piperazine-1-carbodithioate have been synthesized and characterized by various analytical techniques. Among these techniques, ¹H and ¹³C NMR were carried out to asses solution structures whereas the solid state structures were confirmed by FT-IR and X-ray single crystal analysis (3, 5 and 8). Crystal structure of complex (3) and (5) showed distorted trigonal bipyramidal geometry and square pyramidal geometry, respectively. The inclination of the structure 5 towards square-pyramidal may be due to the presence of the Sn-Cl?HN-piperazine hydrogen bonds between the adjacent molecules. A supramolecular structure is shown by compound (8), with central tin atom exists in a distorted octahedral geometry. The antibacterial results indicated the profound activity of the compounds against various strains of bacteria. In addition to this, the triorganotin(IV) derivatives were found more active than diorganotin(IV) compounds.     

Synthesis,Characterization and Crystal Structure of Tetrabutylbis(4,5-dimethoxy-2-nitro benzoato)Distannoxane Dimer

Abstract  

Reaction of di-n-butyltin oxide with 4,5-dimethoxy-2-nitrobenzoic acid yields the title compound which crystallizes as the usual dicarboxylatotetraorganodistannoxane dimer. Experimental details for the preparation and the structural characterization (by FTIR, NMR and single crystal XRD) are provided. The IR data shows that ligand acts in the bidentate manner. The crystal structure analysis of the compound reveals the presence of a centrosymmetric planar Sn₂O₂ unit connected to exocyclic Sn atom via two bidentate bridging carboxylate ligands. The remaining two carboxylate ligands are coordinated to the exocyclic Sn atom in the monodentate manner.     

New dimeric, trimeric and supramolecular organotin(IV) dithiocarboxylates: Synthesis, structural characterization and biocidal activities

Some new tri-, chlorodi- and diorganotin(IV) dithiocarboxylates (1–10) of 4-benzylpiperidine-1-carbodithioate ligand (L), with general formulae R₃SnL {R = n-C₄H₉ (1), C₆H₁₁ (2), CH₃ (3) and C₆H₅ (4)}, R₂SnClL {R = n-C₄H₉ (5), C₂H₅ (7), CH₃ (9)} and R₂SnL₂ {R = n-C₄H₉ (6), C₂H₅ (8), CH₃ (10)}, have been synthesized by the reaction of organotin(IV) chlorides with the ligand-salt in the appropriate molar ratio. Elemental analysis, Raman, IR, multinuclear NMR (¹H, ¹³C and ¹¹⁹Sn) and X-ray crystallographic studies have been undertaken to elucidate the structures of the complexes, both in solution and in solid state. Single-crystal X-ray diffraction study indicate trimeric, dimeric, supramolecular cyclic and supramolecular zig–zag chain structures for complexes 2, 4, 6 and 9, respectively. Square-pyramidal geometry is attributed to complex 9 on the basis of the τ value (0.4). A subsequent antimicrobial study indicates that the compounds are biologically active.     

Synthesis of core‐shell magnetic molecularly imprinted polymer for the selective determination of imidacloprid in apple samples

This work demonstrates the synthesis and characterization of core‐shell magnetic molecularly imprinted polymers based on surface imprinting using methacryloyl chloride as a functional monomer for the selective extraction of imidacloprid (template) from apple fruit. The characterization analysis results ensured the successful synthesis of the magnetic molecularly imprinted polymers owing to their heterogeneous structure and good magnetic properties. An isothermal binding test was assessed with a pseudo‐second‐order kinetic model, and the kinetic results fit well to the Freundlich isothermal model. The polymers exhibited an adsorption capacity of 5.75 mg/g for the target analyte with a good selective extraction ability. In addition, the polymers can be reused several times without significant performance loss. The molecularly imprinted polymers showed good performance in the analysis of spiked apple sample with a linear range of 0.05–1.0 mg/L, a limit of detection of 0.048 mg/L and a limit of quantification of 0.146 mg/L (S/N = 3/10). The recoveries of the samples were 77.66–96.57% and their respective relative standard deviations were 3.36–0.45%. All the results indicated that the proposed method provided good selective extraction, as qualifying the analytical standards.     

A Laser Reduced Graphene Oxide Grid Electrode for the Voltammetric Determination of Carbaryl

Laser-reduced graphene oxide (LRGO) on a polyethylene terephthalate (PET) substrate was prepared in one step to obtain the LRGO grid electrode for sensitive carbaryl determination. The grid form results in a grid distribution of different electrochemically active zones affecting the electroactive substance diffusion towards the electrode surface and increasing the electrochemical sensitivity for carbaryl determination. Carbaryl is electrochemically irreversibly oxidized at the secondary amine moiety of the molecule with the loss of one proton and one electron in the pH range from 5 to 7 by linear scan voltammetry (LSV) on the LRGO grid electrode with a scan rate of 300 mV/s. Some interference of the juice matrix molecules does not significantly affect the LSV oxidation current of carbaryl on the LRGO grid electrode after adsorptive accumulation without applied potential. The LRGO grid electrode can be used for LSV determination of carbaryl in fruit juices in the concentration range from 0.25 to 128 mg/L with LOD of 0.1 mg/L. The fabrication of the LRGO grid electrode opens up possibilities for further inexpensive monitoring of carbaryl in other fruit juices and fruits