Catalytic DNA-and RNA-hydrolyzing antibodies from milk of healthy human mothers

Various catalytically active antibodies (Abs), or abzymes, have been detected recently in the sera of patients with autoimmune pathologies, in whom their presence is probably associated with autoimmunization. Normal humans are generally not considered to have abzymes, since no obvious immunizing factors are present. Here is shown by different methods that IgG from the milk of normal females possesses both DNase and RNase activities. The activities were also present in the IgG F(ab′)₂ and Fab fragments. Affinity modification of IgG by the chemically reactive derivative of an oligonucleotide led to preferential modification of the L chain of IgG. After separation of the subunits by sodium dodecyl sulfate electrophoresis in a gel containing DNA, an in-gel assay showed DNase activity in the L chain. The L chain separated by affinity chromatography on DNA-cellulose was catalytically active. These findings speak in favor of the generation of cat alytic Abs by the immune system of healthy mothers. It is known that the treatment of adults with DNases and RNases offers protection from viral and bacterial diseases. Since breast milk protects the infants from infec tions until the immune system is developed, this raises the possibility that catalytic Abs like nucleases, may possess a protective role.     

Hydrosilylation of non-1-ene with phenylsilane in the presence of yttrium and lutetium bisguanidinate hydride complexes

Some regularities of hydrosilylation of non-1-ene with phenylsilane catalyzed by yttrium and lutetium bisguanidinate hydride complexes {[(Me₃Si)₂NC(NR)₂]₂Ln(μ-H)}₂ (Ln = Y, Lu; R = Prⁱ, Cy (Cy is cyclohexyl)) have been studied. The addition of PhSiH₃ to the double bond of non-1-ene in the presence of a {[(Me₃Si)₂NC(NPrⁱ)₂]₂Y(μ-H)}₂ complex has the first order in olefin and zero order in phenylsilane. This indicates that the insertion of non-1-ene into the Ln-H bond is a rate determining stage of the process, whereas the metathesis of the Ln-C σ-bond upon the action of phenylsilane proceeds rapidly. The first example of successive double alkylation of phenylsilane with an olefin catalyzed by a rare-earth metal complex with the formation of tertiary silane has been discovered.     

Nickel(II) and cobalt(II) complexes with 4,5-dichloro-isothiazole-3-carboxylic acid and 1,10-phenanthroline: synthesis,crystal structures and cytotoxicity

Transition Metal Chemistry - In this study, Ni(II) and Co(II) complexes [Co(H2O)2L2] (1), [Ni(H2O)2L2] (2), [Co(phen)L2] (3), [Ni(phen)L2]·2H2O·EtOH (4·2H2O), and...     

Structural Inhomogeneity in Electrolyte Solutions: The Calcium Perchlorate–Water System

A new approach has been proposed to study the structure of aqueous electrolyte solutions. NIR, Raman and attenuated total reflectance, Fourier transform infra-red (ATR FTIR) spectra have been measured for aqueous calcium perchlorate solutions in the 0.22–4.3 mol·L^?1 (0.22–7.46 mol·kg^?1) concentration range at 25 °C. By the methods of principal component analysis (PCA) and multivariate curve resolution—alternating least squares (MCR-ALS) the number, spectra and concentration profiles have been determined for spectroscopically distinguishable forms of water and ClO ₄ ^? ion in solutions. The results have been analyzed using a phenomenological model, establishing thereby: concentration ranges for structural rearrangements of the solution, the nature of structural microirregularities and different states of the ClO ₄ ^? ion in the areas of domination of the natural water structure, and of cybotactic groups of calcium perchlorate hexa and tetra hydrates.     

Natural radioactivity in springs of Sverdlovsk region,Middle Urals,Russia

Journal of Radioanalytical and Nuclear Chemistry - Activity concentrations of natural radionuclides were determined in water from 31 springs of Sverdlovsk region, Middle Urals, Russia. Activity...     

New 3,4-bis(indol-1-yl)maleimides as protein kinase inhibitors

Chemistry of Heterocyclic Compounds - Several previously unknown derivatives of 3,4-bis(indol-1-yl)maleimide, as well as 3-(2,3-dihydroindol-1-yl)-4-(indol-1-yl)maleimide were synthesized as...     

Hydrogenation of C=C and C=N Bonds of the Amide-Imine Ligand in the Metal Coordination Sphere in the Reaction of Yttrium Bis(alkyl) Complex [2,6-iso-Pr2C6H3NC(=CH2)C(Me)=NC6H3-iso-Pr2-2,6]Y(CH2SiMe3)2(THF) with Molecular Hydrogen

Russian Journal of Coordination Chemistry - On treatment of the yttrium bis(alkyl) complex [ArNC(=CH2)C(Me)=NAr]Y(CH2SiMe3)2(THF) (I, Ar = C6H3-iso-Pr2-2.6) containing an amide-imine ligand, with...     

Mixed-ligand guanidinate derivatives of rare-earth metals. Molecular structures of { (Me3Si)2NC(N-cyclo-Hex)2}Y[N(SiMe3)2]2, [{ (Me3Si)2NC(N-cyclo-Hex)2}YbI(THF)2]2, and [{(Me3Si)2N} Y(THF)(µ-Cl)]2 complexes

The insertion of N,N′-dicyclohexylcarbodiimide at one of the Y-N bonds of the [(Me₃Si)₂N]₃Y complex in toluene at 70 °C afforded the monoguanidinate diamide derivative { (Me₃Si)₂NC(N-cyclo-Hex)₂}Y[N(SiMe)₃]₂ (1) (cyclo-Hex is cyclohexyl) in 72% yield. The reaction of equimolar amounts of sodium N,N′-dicyclohexyl-N″-bis(trimethylsilyl)guanidinate, which was prepared in situ from {(Me₃Si)₂N}Na and N,N′-dicyclohexylcarbodiimide, and YbI₂(THF)₂ in THF gave the [{(Me₃Si)₂NC(N-cyclo-Hex)₂}YbI(THF)₂]₂ complex (2). An attempt to use this procedure for the synthesis of the yttrium compound { (Me₃Si)₂NC(NSiMe₃)₂}₂YCl containing the sterically more hindered guanidinate ligand unexpectedly led to the formation of the diamide chloride complex [{(Me₃Si)₂N}₂Y(THF)(µ-Cl)]₂ (3). The structures of complexes 1–3 were established by X-ray diffraction. Compound 1 is mononuclear. Complexes 2 and 3 are dinuclear and contain two µ²-bridging halide ligands.     

Expedient Strategy for the Synthesis of 5-Acylethynylpyrrole-2-carbaldehydes

5-Acylethynylpyrrole-2-carbaldehydes have been synthesized from the protected pyrrole-2-carbaldehydes by their transition-metal-free topochemical mechanoactivated ethynylation with acylbromoacetylenes in a solid Al₂O₃ medium (room temperature, 6 h, 41–54% yields).     

Guanidinate derivatives of rare-earth metals. The synthesis, properties, and molecular structures of the complexes {(Me3Si)2NC(NPri)2}3Nd, {(Me3Si)2NC(NCy)2}3Lu, and {(Me3Si)2NC(NPri)2}2HC(NPri)2}Nd

The reactions of anhydrous LnCl₃ (Ln = Nd or Lu) with three equivalents of {(Me₃Si)₂NC(NR)₂}Li (R = Prⁱ or Cy; Cy is cyclohexyl) in THF afforded the corresponding tris(guanidinate) derivatives of lanthanides {(Me₃Si)₂NC(NR)₂}₃Ln (Ln = Nd, R = Prⁱ, (1); Ln = Lu, R = Cy (2)), which were isolated after the recrystallization from hexane in 82 and 88% yields, respectively. The complex {(Me₃Si)₂NC(NCy)₂}₂{HC(NCy)₂}Nd (3) containing two guanidinate ligands and one formamidinate ligand was isolated in attempting to synthesize the bis(guanidinate) borohydride derivative by the reaction of {(Me₃Si)₂NC(N-Cy)₂}Na with Nd(BH₄)₃(THF)₂ (in a molar ratio of 2: 1) in THF. This complex is apparently formed as a result of the fragmentation and redistribution of the guanidinate ligands. The X-ray diffraction study showed that in the crystalline state compounds 1–3 are mononuclear complexes containing no coordinated Lewis bases.