The Metabolic Advantage of Choline Lactate in Growth Media: An Experimental Analysis with Staphylococcus lentus

The metabolic effectiveness of choline lactate in the growth media was investigated relative to conventional carbon source for growing Staphylococcus lentus, a bacterial strain commonly used in bioremediation of industrial effluents and xenobiotic detoxification. Bacterial growth thermodynamics was determined by biocalorimetry. ¹³C NMR and FTIR spectroscopic analyses traced the consumption of choline lactate at specific time intervals of bacterial growth. Under aerobic conditions, it is apparent that S. lentus initially metabolized lactate for its energy needs, while the choline cation of the ionic salt seemed to provide its C and N for biosynthetic intermediates for cell structure/function, in the growing bacterial colony. Urea accumulation after 40 h of bacterial growth was recorded. Possible metabolic trajectory of choline lactate consumed during S. lentus growth is suggested here. The theoretical estimation of heats of reaction for the proposed metabolic pathway (455 kJ/mol) was comparable with the experimentally obtained reaction enthalpy (435 kJ/mol), which further validated the proposed metabolic pathway. The biomass and energy profile of bacteria growth in choline media was found to be more favorable than in glucose media. The ionic liquid, choline lactate, offers a metabolically and energetically efficient carbon (and nitrogen) source for growing S. lentus.     

Synthesis and characterization of Pd complexes of a carbazolyl/bis(imine) NNN pincer ligand

A serendipitously discovered construction of a carbazole nucleus by lithiation of N-methylated bis(4-methyl-2,6-dibromophenyl)amine is described. It was used to synthesize an NNN pincer-type ligand that combines a central carbazole site (N-methylated in the precursor ligand) with two flanking aldimine donors bearing mesityl substituents. The installation of this ligand on Pd was accomplished via an N-Me cleaving reaction with (COD)PdCl(2) producing MeCl and (NNN)PdCl (where NNN is an anionic carbazolyl/bis(imine) pincer ligand). Several (NNN)PdX complexes were characterized spectroscopically. (NNN)PdOTf ((-)OTf = triflate or (-)O(3)SCF(3)) readily reacted with stoichiometric amounts of water in benzene or dichloromethane to give a cationic water adduct [(NNN)Pd(OH(2))]OTf. An X-ray diffraction study on a single crystal of (NNN)PdCl revealed an almost perfectly square planar environment about Pd and an almost perfectly planar carbazole/bis(imine) conjugated system. Cyclic voltammetry of (NNN)PdCl showed quasi-reversible oxidation at E(1/2) = 0.72 V vs Fc/Fc(+) which is most likely ligand-based.     

Synthesis of novel N-hydroxy heterocycles via intramolecular reductive cyclization of diketoximes by NaBH3CN

A simple and efficient protocol for the construction of substituted piperazines, piperidines, thiomorpholines, decahydroquinolines, perhydrocyclopenta[b]pyridine, and pyrrolidines bearing N-hydroxy substituents through intramolecular reductive cyclization of diketoximes using sodium cyanoborohydride is described.     

Atomically Precise Crystalline Materials Based on Kinetically Inert Metal Ions via Reticular Mechanopolymerization

Atomistic control of the coordination environment of lattice ions and the distribution of metal sites within crystalline mixed‐metal coordination polymers remain significant synthetic challenges. Herein is reported the mechanochemical synthesis of a reticular family of crystalline heterobimetallic metal–organic frameworks (MOFs) is now achieved by polymerization of molecular Ru₂[II,III] complexes, featuring unprotected carboxylic acid substituents, with Cu(OAc)₂. The resulting crystalline heterobimetallic MOFs are solid solutions of Ru₂ and Cu₂ sites housed within [M₃L₂] phases. The developed mechanochemical strategy is modular and allows for systematic control of the primary coordination sphere of the Ru₂ sites within an isoreticular family of materials. This strategy is anticipated to provide a rational approach to atomically precise mixed‐metal materials.     

Structures and Unexpected Dynamic Properties of Phosphine Oxides Adsorbed on Silica Surfaces

Solid‐state NMR spectroscopy of selected phosphine oxides adsorbed on silica surfaces establishes the surface mobilities, even of phosphine oxides with high melting points. Crystal structures of the adducts Ph₃PO ? HOSiPh₃ and Cy₃PO ? H₂O indicate that the interactions with silica involve hydrogen bonding of the P?O group to adsorbed water and surface silanol groups.     

Hydrogen Peroxide and Di(hydroperoxy)propane Adducts of Phosphine Oxides as Stoichiometric and Soluble Oxidizing Agents

Aqueous hydrogen peroxide is widely used as an oxidizing agent in industry and academia. Herein, the hydrogen peroxide adducts of phosphine oxides, [tBu₃PO ? H₂O₂]₂ and [Ph₃PO ? H₂O₂]₂ ? H₂O₂, are described. Additionally, the corresponding di(hydroperoxy)propane adducts R₃PO ? (HOO)₂CMe₂ (R=Cy, Ph) were synthesized and characterized. All adducts could be obtained as large single crystals suitable for structural characterization by X‐ray crystallography and solid‐state NMR spectroscopy. The di(hydroperoxy)propane adducts are soluble in organic solvents which enables oxidation reactions in one phase. As the adducts are solid and molecular, they can easily be applied stoichiometrically. No loss of oxidizing power occurs upon long‐term storage of the single crystals at room temperature or the powders at ?20 °C.     

Laryngeal Chondroma

Cartilaginous tumors of the larynx represent less than 1% of laryngeal tumors. Chondroma and "low-grade" chondrosarcoma are the most common; 70%-75% of these tumors arise on the endolaryngeal surface of the posterior lamina of the cricoid cartilage. The clinical presentation is varied and directly dependent on the size and location of the tumor; stridor, hoarseness, dyspnea, or a neck mass are common presenting signs. CT scanning in the axial plane is the mainstay of radiographic imaging due to its ability to show size, extent of the tumor, and invasion into surrounding structures. Surgical extirpation is the standard therapy with no role for radiation therapy or chemotherapy. Although significant recurrence rates have been reported, there is not a significant difference between initial conservative therapy followed by salvage therapy versus initial radical therapy.     

Characterization of N-isopropyl acrylamide/acrylic acid grafted polypropylene nonwoven fabric developed by radiation-induced graft polymerization

Radiation-induced graft copolymerization of N-isopropylacrylamide (NIPAAm) and acrylic acid (AA) mixture was carried out on polypropylene nonwoven fabric to develop a thermosensitive material and has been found to affect the thermal and physical characteristics of fabric. The grafted fabrics with different monomer ratios were characterized by thermal gravimetric analysis (TGA), fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), X-ray diffraction (XRD), contact angle and atomic force microscopy (AFM). Results of FTIR clearly indicated that poly(acrylic acid) and poly(N-isopropyl acrylamide) were successfully grafted onto the membrane surface. TGA results showed that the thermal stability of PP fabric increased after grafting of NIPAAm/AA. The crystallinity values from DSC and XRD were found to decrease with increase in degree of grafting because of the addition of grafted chains within the noncrystalline region. The decrease in contact angles of the grafted fabric with an increase of the degree of grafting shows that PNIPAAm/PAA exists as the hydrophilic component. The increase in surface roughness after grafting was observed by AFM.     

Variation in the biomolecular interactions of nickel(II) hydrazone complexes upon tuning the hydrazide fragment

Three new bivalent nickel hydrazone complexes have been synthesised from the reactions of [NiCl(2)(PPh(3))(2)] with H(2)L {L = dianion of the hydrazones derived from the condensation of o-hydroxynaphthaldehyde with furoic acid hydrazide (H(2)L(1)) (1)/thiophene-2-acid hydrazide (H(2)L(2)) (2)/isonicotinic acid hydrazide (H(2)L(3)) (3)} and formulated as [Ni(L(1))(PPh(3))] (4), [Ni(L(2))(PPh(3))] (5) and [Ni(L(3))(PPh(3))] (6). Structural characterization of these compounds 4-6 were accomplished by using various physico-chemical techniques. Single crystal X-ray diffraction data of complexes 4 and 5 proved their distorted square planar geometry. In order to ascertain the potential of the above synthesised compounds towards biomolecular interactions, additional experiments involving interaction with calf thymus DNA (CT DNA) and bovine serum albumin (BSA) were carried out. All the ligands and corresponding nickel(ii) chelates have been screened for their scavenging effect towards O(2)(-), OH and NO radicals. The efficiency of complexes 4-6 to arrest the growth of HeLa, HepG-2 and A431 tumour cell lines has been studied along with the cell viability test against the non-cancerous NIH 3T3 cells under in vitro conditions.