Targeting DNA junction sites by bis-intercalators induces topological changes with potent antitumor effects.

Targeting inter-duplex junctions in catenated DNA with bidirectional bis-intercalators is a potential strategy for enhancing anticancer effects. In this study, we used d(CGTATACG)2, which forms a tetraplex base-pair junction that resembles the DNA-DNA contact structure, as a model target for two alkyl-linked diaminoacridine bis-intercalators, DA4 and DA5. Cross-linking of the junction site by the bis-intercalators induced substantial structural changes in the DNA, transforming it from a B-form helical end-to-end junction to an over-wounded side-by-side inter-duplex conformation with A-DNA characteristics and curvature.

The effect of anions in the synthesis and structure of pyrazolylamidino copper(II) complexes.

Six new pyrazolylamidino Cu(II) complexes are synthesized directly from the reactions of Cu(X) salts (X = ClO, BF, or Cl) and pyrazole (pzH) in nitrile solution (RCN, R = Me or Et) at 298 K the metal-mediated coupling of RCN with pzH: [Cu(HNC(R)pz)(X)] (X = ClO or BF, R = Me, 1 or 7 and Et, 2 or 8, respectively) and dichloro Cu(II) complexes [CuCl(μ-Cl)(HNC(Me)pz)] (3) and [CuCl(HNC(Et)pz)] (4). Four more new complexes, [Cu(μ-Cl)(HNC(Me)pz)(pzH)][X] (X = ClO, 5 and BF, 9) and [Cu(μ-Cl)(HNC(Et)pz)(pzH)(X)] (X = ClO, 6 and BF, 10), are obtained indirectly from the anion substitution reaction with Cl ions in 1 and 7, and 2 and 8, respectively. All complexes are characterized by EA, FTIR, UV-vis and EPR spectroscopy and X-ray crystallographic analyses.

Catalytic O activation toward oxidative N-S bond formation by a thiolato Fe(III) complex.

Compounds with the benzisothiazol-3-one (BIT) skeleton perform excellently in the pharmaceutical field, although current synthetic methods remain limited in terms of synthetic efficiency. Herein, we report the catalytic intramolecular N-S bond formation for BITs from easily prepared disulfide precursors by an Fe(III) dithiolate through O activation at 298 K. Interestingly, the catalytic performance is enhanced by substituting O with a milder O-donor oxidant, ONMe.

Demethylation of an artificial hydrogenase agent for prolonged CO release and enhanced anti-tau aggregation activity.

Carbon monoxide (CO) plays an important role in signaling in cells, making its use as a therapeutic tool highly intriguing. Reduced burst emissions are important to avoid the cytotoxicity and tissue damage caused by CO. Here, we developed a stable diiron carbonyl [FeFe] hydrogenase agent that enables prolonged CO release activity (half-life of over 9 h) in cells.

Genome-wide analysis of cervical secretions obtained during embryo transfer reveals the association between deoxyribonucleic acid methylation and pregnancy outcomes.

Objective: To study whether the methylation status of cervical secretions can reflect the ability of the endometrium to allow embryo implantation.

Design: Case-control study.

Setting: In vitro fertilization centers.

High-Frequency Fe-H and Fe-H Modes in a -Fe(η-H)(H) Complex: A Speed Record for Nuclear Resonance Vibrational Spectroscopy.

Nuclear resonance vibrational spectroscopy (NRVS) and density functional theory (DFT) are complementary tools for studying the vibrational and geometric structures of specific isotopically labeled molecular systems. Here we apply NRVS and DFT to characterize the -[Fe(η-H)(H)(dppe)][BPh] [dppe = 1,2-bis(diphenylphosphino)ethane] complex. Heretofore, most NRVS observations have centered on the spectral region below 1000 cm, where the Fe signal is strongest.

Dioxygen activation by a dinuclear thiolate-ligated Fe(ii) complex.

Dioxygen activation by FeII thiolate complexes is relatively rare in biological and chemical systems because the sulfur site is at least as vulnerable as the iron site to oxidative modification. O2 activation by FeII-SR complexes with thiolate bound trans to the O2 binding site generally affords the FeIV[double bond, length as m-dash]O intermediate and oxidized thiolate. On the other hand, O2 activation by Fe(ii)-SR complexes with thiolate bound cis to the O2 binding site generates FeIII-O-FeIII or S-oxygenated complexes.

Crystal Structure Analysis of the Repair of Iron Centers Protein YtfE and Its Interaction with NO.

Molecular mechanisms underlying the repair of nitrosylated [Fe-S] clusters by the microbial protein YtfE remain poorly understood. The X-ray crystal structure of YtfE, in combination with EPR, magnetic circular dichroism (MCD), UV, and (17) O-labeling electron spin echo envelope modulation measurements, show that each iron of the oxo-bridged Fe(II) -Fe(III) diiron core is coordinatively unsaturated with each iron bound to two bridging carboxylates and two terminal histidines in addition to an oxo-bridge. Structural analysis reveals that there are two solvent-accessible tunnels, both of which converge to the diiron center and are critical for capturing substrates.

A dinitrosyliron complex within the homoleptic Fe(NO)4 anion: NO as nitroxyl and nitrosyl ligands within a single structure.

Nitrosylation of the chelate-thiolate-containing dinitrosyliron complex (DNIC) [(S(CH(2))(3)S)Fe(NO)(2)](-) triggers nitric oxide (NO) activation to generate the homoleptic nitrosyl {Fe(NO)(2)}(9) DNIC [Fe(NO)(4)](-) (1) made up of two nitroxyls (or two NO anions) attached to a delocalized {Fe(NO)(2)}(9) motif. The significantly longer N3-O3/N4-O4 [1.380(12) and 1.

N-[2-(Methyl-sulfan-yl)phen-yl]-2-sulfanylbenzamide.

In the title compound, C(14)H(13)NOS(2), the S atom with the methyl group is involved in an intra-molecular hydrogen bond with the amido H atom. In the crystal, the sulfanyl H atoms form inter-molecular hydrogen bonds with the O atoms, connecting the mol-ecules into zigzag chains along the c axis. The two aromatic rings exhibit a small interplanar angle of 16.

Selective encapsulation of volatile and reactive methyl iodide.

A simple organic molecular container can selectively encapsulate the volatile and highly reactive MeI through hydrogen-bonding interactions in solution. The remarkable encapsulation of MeI without self-methylation of the container appears to be determined by the complementary binding sites and the rigidity of the hydrogen-bonding array constrained by the molecular framework.

N,N'-Bis[(1H-imidazol-1-yl)meth-yl]-2,2'-(disulfanedi-yl)dianiline.

The symmetrical title compound, C(20)H(20)N(6)S(2), contains a disulfide bond of 2.0884 (6) Å. The C-S-S-C torsion angle is -59.

Assembly and disassembly of a Zn10 high-nuclearity circular helicate.

A nano-scale decanuclear Zn(II) circular helicate is synthesized without the aid of counteranions during the assembly process, and can be totally disassembled into its reactants by specific anions.

Selective capture of volatile iodine using amorphous molecular organic solids.

A simple shape-persistent organic molecular container is capable of selective absorption and storage of I(2(g)) over water vapor and NO gas even in its amorphous solid state. In addition, the strongly associated I(2) can be efficiently released from the charged container in organic solvents under ambient conditions.

trans-Diacetonitrile-tetra-kis(1H-pyrazole-κN)nickel(II) dinitrate.

In the title complex, [Ni(CH(3)CN)(2)(C(3)H(4)N(2))(4)](NO(3))(2), the cation lies on an inversion center and adopts an octa-hedral coordination geometry about the Ni atom. The two acetonitrile ligands are in a trans conformation. N-H⋯O hydrogen bonds between cations and anions link the complex mol-ecules into one-dimensional chains running parallel to [100].