Visual spatial memory is enhanced in female rats (but inhibited in males) by dietary soy phytoestrogens

Background  

In learning and memory tasks, requiring visual spatial memory (VSM), males exhibit superior performance to females (a difference attributed to the hormonal influence of estrogen). This study examined the influence of phytoestrogens (estrogen-like plant compounds) on VSM, utilizing radial arm-maze methods to examine varying aspects of memory. Additionally, brain phytoestrogen, calbindin (CALB), and cyclooxygenase-2 (COX-2) levels were determined.     

Solid-state supramolecular structures of resorcinol-arylboronic acid compounds

[structure: see text] An X-ray crystallographic study of unique hydrogen-bonded supramolecular solid-state networks comprised of a tetraarylboronic acid resorcinarene is described. When 1 is recrystallized from 9:1 MeOH:EtOH, partial esterification takes place to give compound 2, the corresponding half methyl ester, which forms an infinite two-dimensional array. Each molecule participates in 12 hydrogen bonds with other macrocycles. These hydrogen bonds are both B-OH- - - OH (phenolic) and OH (phenolic)- - -OH (phenolic).     

Endo and Exo Coordination to Cofacial Binuclear Copper(II) Complexes

A structural study of internal (endo) and external (exo) coordination to cofacial binuclear complexes is reported.Cu₂(NBA)₂(NBAH₂=3,3'-[2,7-naphthalenediylbis(methylene)]-bis(2,4-pentanedione)) is large enough to accommodate 2-methylpyrazine as an intramolecularly coordinated guest molecule Cu₂(NBA)₂((2Mepyz))4CH₂Cl₂Cu₂C₅₃H₅₈N₂O₈Cl₈, orthorhombic, space group Pnma (No. 62); a = 22.4674(11); b = 22.230(2); c = 11.4520(6) Å V = 5719.6(6) ų (at 100 K); Z = 4; R = 0.058; R _w = 0.167 for 344 parameters and 5339 reflections with I > 2(I). The Cu₂(NBA)₂(-(2-Mepyz)) molecules possess crystallographic m symmetry, with the CuCu vector (CuCu' 7.4801(8) Å) perpendicular to the mirror plane; this requires disorder in the 2-Mepyz guests. The two ``Cu(acac)₂' moieties (acacH = 2,4-pentanedione) are not quite parallel (dihedral angle between (acac)₂ planes = 3.93(7)^circ), forming a slightly wider opening on the side of the methyl group in the 2-Mepyz guest. On the other hand, the cavity in Cu₂(XBA)₂ (XBAH₂ = 3,3'-[1,3-phenylenebis(methylene)]-bis(2,4-pentanedione)) is smaller, so that CH₃CN must bind externally.Cu₂(XBA)₂(CH₃CN)₂1.5CH₃CNH₂O,Cu₂C₄₃H_52.5N_3.5O₉, monoclinic, space group P2₁/c (No. 14); a = 11.7361(16); b = 14.197(3); c = 13.299(3) Å; = 92.22(2)^{^}; V = 2214.3(7) ų (at 100 K); Z = 2; R = 0.044; R _w = 0.124 for 275 parameters and 4983 reflections with I > 2 (I). This structure contains centrosymmetric Cu₂(XBA)₂ units (CuCu' 4.8302(12) Å) with externally coordinated CH₃CN ligands. The crystal packing in Cu₂(NBA)₂((2Mepyz))4CH₂Cl₂,which contains close contacts between layers of Cu₂(NBA)₂(-(2-Mepyz)) moieties, is also similar to that in three other crystalline host–guest adducts M₂(NBA)₂(-G). Cu₂(XBA)₂(CH₃CN)₂1.5CH₃-CNH₂O does not contain similar layers of molecules, presumably because the adduct molecules do not have the same type of exposed flat surfaces.     

Zwitterionic and neutral binuclear complexes formed from copper(II) hexafluoroacetylacetonate and an amino alcohol

Reaction of anhydrous Cu(hfac)₂ (hfacH = 1,1,1,5,5,5-hexafluoro-2,4-pentanedione) with 2-(diisopropylamino)ethanol yields two different binuclear copper(II) complexes. Compound 1, [Cu(hfac)₂(-OCH₂CH₂NH(i-Pr)₂)]₂, Cu₂C₃₆H₄₂O₁₀N₂F₂₄, consists of centrosymmetric dimers containing two cis-Cu(hfac)₂ moieties that are bridged by two zwitterionic 2-(diisopropylammonio)ethoxide ions. Cell parameters are a = 11.6516(13); b = 14.0117(17); c = 15.3258(17) Å = 105.75(9)° in space group P2₁/n. The copper ions exhibit tetragonally distorted octahedral coordination, with two of the Cu—O(hfac) distances showing characteristic elongation (2.2858(16) and 2.3192(17) Å). Compound 2, [Cu(hfac)((i-Pr)₂NCH₂CH₂O)]₂, Cu₂C₂₆H₃₈O₆N₂F₁₂, also contains centrosymmetric dimers; these are formed by two square-pyramidal moieties joined at their bases. Cell parameters are a = 7.7353(5); b = 13.6166(17); c = 15.683(2) Å = 98.23(1)° in space group P2₁/n. In this structure the apical Cu—O(hfac) distance is elongated (2.254(4) Å), and the O atoms of the 2-(diisopropylamino)ethoxide ions are bridging.     

Cyclohexene oxide/CO2 copolymerization catalyzed by chromium(III) salen complexes and N-methylimidazole: effects of varying salen ligand substituents and relative cocatalyst loading

A detailed mechanistic study into the copolymerization of CO2 and cyclohexene oxide utilizing CrIII(salen)X complexes and N-methylimidazole, where H2salen = N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-ethylenediimine and other salen derivatives and X = Cl or N3, has been conducted. By studying salen ligands with various groups on the diimine backbone, we have observed that bulky groups oriented perpendicular to the salen plane reduce the activity of the catalyst significantly, while such groups oriented parallel to the salen plane do not retard copolymer formation. This is not surprising in that the mechanism for asymmetric ring opening of epoxides was found to occur in a bimetallic fashion, whereas these perpendicularly oriented groups along with the tert-butyl groups on the phenolate rings produce considerable steric requirements for the two metal centers to communicate and thus initiate the copolymerization process. It was also observed that altering the substituents on the phenolate rings of the salen ligand had a 2-fold effect, controlling both catalyst solubility as well as electron density around the metal center, producing significant effects on the rate of copolymer formation. This and other data discussed herein have led us to propose a more detailed mechanistic delineation, wherein the rate of copolymerization is dictated by two separate equilibria. The first equilibrium involves the initial second-order epoxide ring opening and is inhibited by excess amounts of cocatalyst. The second equilibrium involves the propagation step and is enhanced by excess cocatalyst. This gives the [cocatalyst] both a positive and negative effect on the overall rate of copolymerization.     

The application of homotopy analysis method to solve nonlinear differential equation governing Jeffery–Hamel flow

In this paper Jeffery–Hamel flow has been studied and its nonlinear ordinary differential equation has been solved through homotopy analysis method (HAM). The obtained solution in comparison with the numerical ones represents a remarkable accuracy. The results also indicate that HAM can provide us with a convenient way to control and adjust the convergence region.