Trihexyphenidyl hydro­chloride: a powder diffraction study

In the cation of the title compound [systematic name: 1-(3-cyclo­hexyl-3-hy­droxy-3-phenyl­prop­yl)piperidinium chloride], C20H32NO+·Cl−, the cyclo­hexyl and piperidine rings are in chair conformations. In the crystal structure, cations and anions are linked into chains along the c-axis direction via O—H⋯Cl and N—H⋯Cl hydrogen bonds. Weak inter­molecular C—H⋯Cl inter­actions link further these chains into layers parallel to the bc plane. The salt, obtained from a racemic solution, was found to crystallize in the chiral P21212 space group, indicating that, in the absence of any evident chirality-inducing process, the polycrystalline powders consist of an equivalent mixture of R and S enanti­omers, forming a racemic conglomerate

How Big are the Big Multinational Companies?

Multinational corporations are increasingly seen as excessively big and powerful, and as having dramatically increased in size and power. This perception has led to the view that the big corporations are threatening democratic institutions of the nation-states and that they pervert the cultural and social fabric of countries. In this paper we analyse the size of large corporations and the recent trends in this size. Using value-added data (instead of sales) we find that multinationals are surprisingly small compared to the GDP of many nation-states. In addition, if anything, the size of multinationals relative to the size of nations has tended to decline somewhat during the last 20 years. Finally, we argue that there is little evidence that the economic and political power of multinationals has increased in the last few decades.

1-(Hydroxymethyl)pyrene

The asymmetric unit of the title compound, C17H12O, contains two molecules, in which the fused aromatic ring systems are almost planar [maximum deviations = 0.0529 (9) and 0.0256 (9) Å]. In the crystal, aromatic π–π stacking interactions (perpendicular distance of centroids of about 3.4 Å) and strong O—H...O hydrogen bonds result in a helical arrangement of pyrenyl dimers

A minimalist chemical model of matrix metalloproteinases- Can small peptides mimic the more rigid metal binding sites of proteins?

In order to develop a minimalist chemical model of matrix metalloproteinases (MMPs), we synthesized a pentadecapeptide (Ac-KAHEFGHSLGLDHSK-NH2) corresponding to the catalytic zinc(II) binding site of human MMP-13. The multi-domain structural organization of MMPs fundamentally determines their metal binding affinity, catalytic activity and selectivity. Our potentiometric, UV-VIS, CD, EPR, NMR, ESI-MS and kinetic study are aimed to explore the usefulness of flexible peptides to mimic the more rigid metal binding sites of proteins, to examine the intrinsic metal binding properties of this naked sequence, as well as to contribute the development of a minimalist, peptide-based chemical model of MMPs, including the catalytic properties. Since multiimidazole environment is also characteristic for copper(II), and recently copper(II) containing variants of MMPs have been identified, we also studied the copper(II) complexes of the above peptide. Around pH 6-7 the peptide, similarly to MMPs, offers {3Nim} coordinated binding site for both zinc(II) and copper(II). In the case of copper(II), the formation of amide coordinated species at higher pH ceased the analogy with the copper(II) containing MMP variant. On the other hand, the zinc(II)-peptide system mimics some basic features of the MMP active sites: the main species around pH 7 (ZnH2L) possesses {3Nim,H2O} coordination environment, the deprotonation of the zinc-bound water takes place near to the physiological pH, it forms relatively stable ternary complexes with hydroxamic acids, and the species ZnH2L(OH) and ZnH2L(OH)2 have notable hydrolytic activity between pH 7-9

4-Hy­droxy-3,5-dimeth­oxy-N-{4-[(5-methyl-1,2-oxazol-3-yl)sulfamo­yl]phen­yl}benzamide methanol monosolvate

The title compound, C19H19N3O7S·CH3OH, was synthesized from syringic acid and sulfamethoxazole. The benzene rings make a dihedral angle of 41.8 (1)° and the isoxazole ring is twisted by 74.3 (1)° from the central benzene ring. The crystal packing features O—H⋯O and O—H⋯N hydrogen bonds in which the hy­droxy groups from the main mol­ecule and methanol solvent mol­ecules serve as donor groups

Фрагменти до біографії І. Мазепи

Мета цієї статті увести до наукового обігу три документи, які стосуються життя й діяльності І. Мазепи. Перший з них нами було виявлено у польських архівосховищах. Автором цього листа, адресованого, очевидно, королеві Яну III Собеському, був учасник посольства Речі Посполитої до Москви, яке очолював вармінський біскуп і коронний канцлер Августин Міхал Радзейовський. Лист важливий тим, що проливає світло на малознаний період біографії Івана Мазепи, коли той був генеральним осавулом на лівобічній Гетьманщині. Другий і третій документи мають меншу цінність. Один з них - це типова рукописна газета - “новина”, у якій повідомляється про польсько-російські переговори у Варшаві у 1695 р. у зв’язку з азово-дніпровськими походами, у котрих визначну роль відіграли українські війська на чолі з гетьманом Іваном Мазепою. Автором наступного документа був Лаврентій Крщонович, визначний церковний діяч, ігумен деяких православних монастирів Гетьманщини, зокрема Свято-Троїцького Іллінського у Чернігові

Thermodynamics of polymolecular duplexes between phosphate-methylated DNA and natural DNA

Phosphate-methylated (P.M.) DNA possesses a very high affinity for complementary natural DNA, as a result of the absence of interstrand electrostatic repulsions. In this study, a model system phosphate-methylated d[Cn] with natural d(Gk) (n <k)is chosen for an investigation of the thermodynamic properties that determine duplex stability. The enthalpy change of a melting transition is shown to be considerably larger than is observed for corresponding natural DNA duplexes. It is found that H of GG/CC nearest neighbor pairwise interaction equals -15.6 kcal/mol, compared to -11.0 kcal/mol for the natural analog. The entropy change is strongly dependent on the length of the natural DNA strand and the number of phosphate-methylated DNA oligomers hybridized. The results are explained by means of a model in which a cooperative effect for subsequent hybridizations of phosphate-methylated DNA oligomers is assumed, thus giving additional stability

The A and B conformations of DNA and RNA subunits. Potential energy calculations for dGpdC

In order to obtain a molecular picture of the A and B forms of a DNA subunit, potential energy calculations have been made for dGpdC with C(3′)-endo and C(2′)-endo [or C(3′)-exo] sugar puckerings. These are compared with results for GpC. The global minima for dGpdC and GpC are almost identical. They are like A-form duplex DNA and RNA, respectively, with bases anti, the ω′, ω angle pair near 300°, 280°, and sugar pucker C(3′)-endo. For dGpdC, a B-form helical conformer, with sugar pucker C(2′)-endo and ω′ = 257°, ω = 298°, is found only 0.4 kcal/mol above the global minimum. A second low-energy conformation (2.3 kcal/mol) has ω′ = 263°, ω = 158° and ψ near 180°. This has dihedral angles like the original Watson–Crick model of the double helix. In contrast, for GpC, the C(2′)-endo B form is 6.9 kcal/mol above the global minimum. These theoretical results are consistent with experimental studies on DNA and RNA fibers. DNA fibers exist in both A and B forms, while RNA fibers generally assume only the A form. A low-energy conformation unlike the A or B forms was found for both dGpdC and GpC when the sugars were C(3′)-endo. This conformation—ω′,ω near 20°,80°—was not observed for C(2′)-endo dGpdC. Energy surface maps in the ω′,ω plane showed that C(2′)-endo dGpdC has one low-energy valley. It is in the B-form helical region (ω′ ∼ 260°, ω ∼ 300). When the sugar pucker is C(3′)-endo, dGpdC has two low-energy regions: the A-form helical region and the region with the minimum at ω′ = 16°, ω = 85°

Binary and ternary mixed metal complexes of terminally free peptides containing two different histidyl binding sites

Copper(II), nickel(II) and zinc(II) complexes of the terminally free peptides AHAAAHG and AAHAAAHG have been studied by combined applications of potentiometric and various spectroscopic techniques, including UV-visible, CD and EPR for copper(II) and UV-visible, CD and NMR for nickel(II). It was found that the octapeptide AAHAAAHG can easily bind two equivalents of copper(II) or nickel(II) ions and the amino terminus was identified as the primary ligating site of the molecule. On the other hand, this peptide has a relatively low zinc(II) binding affinity. Mono- and di-nuclear copper(II) and nickel(II) complexes were also formed with the heptapeptide AHAAAHG but this peptide can effectively bind one equivalent of zinc(II) ions, too, with the involvement of the deprotonated amide nitrogen in zinc(II) binding. The enhanced stability of the [MH-1L] species of AHAAAHG was explained by the tridentate (NH2,N-,Nim) coordination of the amino terminus supported by the macrochelation of the internal histidyl residue. Mixed metal copper(II)-nickel(II) complexes were also formed with both peptides and copper(II) ions were coordinated to the amino terminal, while nickel(II) ions to the internal histidyl sites. © 2013 Elsevier Inc