(Z)2-(5-(4-methoxybenzylidene)-2, 4-dioxothiazolidin-3-yl) acetic acid protects rats from CCl(4) -induced liver injury

Background and Aim: (Z)2‐(5‐(4‐methoxybenzylidene)‐2, 4‐dioxothiazolidin‐3‐yl) acetic acid (MDA) is an aldose reductase (AR) inhibitor. Recent studies suggest that AR contributes to the pathogenesis of inflammation by affecting the nuclear factor κB (NF‐κB)‐dependent expression of cytokines and chemokines and therefore could be a novel therapeutic target for inflammatory pathology. The current study evaluated the in vivo role of MDA in protecting the liver against injury and fibrogenesis caused by CCl₄ in rats, and the underlying mechanisms. Methods: A single injection of CCl₄ induced acute hepatitis, and repeated injections were used to induce hepatic fibrosis in rats. Therapeutic efficacy was assessed by comparison of the severity of hepatic injury and fibrosis in MDA ‐ treated rats versus untreated controls. Results: MDA significantly protected the liver from injury by reducing the activity of serum alanine aminotransferase, and improving the histological architecture of the liver. MDA modulated NF‐κB‐dependent activation of inflammatory cytokines by reducing hepatic mRNA levels of tumor necrosis factor‐α, interleukin‐1β, inducible nitric oxide (NO) synthase and transforming growth factor‐β. In addition, MDA attenuated oxidative stress by increasing the content of hepatic glutathione. These favorable changes were associated with suppressed hepatic NF‐κB activation by MDA. MDA treatment improved liver fibrosis in rats that received repeated CCl₄ injections. In vitro, MDA attenuated phosphorylation of IκB and activation of NF‐κB, and thus prevented biosynthesis of NO in lipopolysaccharide‐activated RAW264.7 cells. Conclusions: The present study suggests that AR is a novel therapeutic anti‐inflammatory target for the treatment of hepatitis and liver fibrosis.     

Asymmetric phosphorylation through catalytic P(III) phosphoramidite transfer: Enantioselective synthesis of d-myo-inositol-6-phosphate

Despite the ubiquitous use of phosphoramidite chemistry in the synthesis of biophosphates, catalytic asymmetric phosphoramidite transfer remains largely unexplored for phosphate ester synthesis. We have discovered that a tetrazole-functionalized peptide, in the presence of 10-Å molecular sieves, functions as an enantioselective catalyst for phosphite transfer. This chemistry in turn has been used as the key step in a streamlined synthesis of myo-inositol-6-phosphate. Mechanistic insights implicate phosphate as a directing group for a highly selective kinetic resolution of a protected inositol monophosphate. This work represents a distinct and efficient method for the selective catalytic phosphorylation of natural products.     

The inhibitory effect of 4-chloro-2-(2,6-dichloro-4-hydroxyphenyl)-1-ethyl-6-hydroxyindole (D 15413) on estrogen-dependent mammary tumors

Summary The antineoplastic activity of 4-chloro-2-(2,6-dichloro-4-hydroxyphenyl)-1-ethyl-6-hydroxyindole (D 15413) was determined in several estrogen-dependent mammary tumor models. The growth of DMBA-induced rat mammary carcinomas was inhibited by doses ranging from 2 to 18 mg/kg. A dose of 6×12 mg/kg per week p.o. reduced the tumor area by 82% (control+192%). D 15413 was also active against MNU-induced rat mammary tumors and transplanted MXT tumors of the mouse. In vitro, the growth of estrogen receptor positive MCF-7 breast cancer cells was inhibited by D 15413 (10^–8–10^–5 M). A mode of action considering endocrine and cytotoxic effects is discussed.Supported by the Deutsche Forschungsgemeinschaft, Sonderforschungsbereich 234, and by the Verband der Chemischen Industrie, Fonds der Chemischen IndustrieDedicated to Professor D. Schmähl on the occasion of his 60th birthday     

Lignin-degrading enzyme from Phanerochaete chrysosporium: Purification, characterization, and catalytic properties of a unique H(2)O(2)-requiring oxygenase

An extracellular lignin-degrading enzyme from the basidiomycete Phanerochaete chrysosporium Burdsall was purified to homogeneity by ion-exchange chromatography. The 42,000-dalton ligninase contains one protoheme IX per molecule. It catalyzes, nonstereospecifically, several oxidations in the alkyl side chains of lignin-related compounds: C_α—C_β cleavage in lignin-related compounds of the type aryl—C_αHOH—C_βHR—C_γH₂OH (R = -aryl or -O-aryl), oxidation of benzyl alcohols to aldehydes or ketones, intradiol cleavage in phenylglycol structures, and hydroxylation of benzylic methylene groups. It also catalyzes oxidative coupling of phenols, perhaps explaining the long-recognized association between phenol oxidation and lignin degradation. All reactions require H₂O₂. The C_α—C_β cleavage and methylene hydroxylation reactions involve substrate oxygenation; the oxygen atom is from O₂ and not H₂O₂. Thus the enzyme is an oxygenase, unique in its requirement for H₂O₂.     

An efficient, palladium-catalyzed, enantioselective synthesis of (2R)-3-butene-1,2-diol and its use in highly selective Heck reactions

A robust and scalable procedure for the palladium-catalyzed dynamic kinetic asymmetric transformation of 3,4-epoxy-1-butene into (2R)-3-butene-1,2-diol with water as the cosolvent is reported. Examination of the effects of solvent and temperature led to the identification of conditions that permitted use of 0.025 mol % catalyst, providing (2R)-3-butene-1,2-diol in 84% isolated yield and 85% enantiomeric excess. Subsequent Heck reactions with a diverse range of coupling partners are described and the influence of their electronic nature on maintaining the enantiopurity of the diol is discussed.     

Preclinical characterization of a (S)-N-(4-cyano-3-trifluoromethyl-phenyl)-3-(3-fluoro, 4-chlorophenoxy)-2-hydroxy-2-methyl-propanamide: a selective androgen receptor modulator for hormonal male contraception

The pharmacologic effects of (S)-N-(4-cyano-3-trifluoromethyl-phenyl)-3-(3-fluoro, 4-chlorophenoxy)-2-hydroxy-2-methyl-propanamide (S-23) were characterized in male rats as an animal model of hormonal male contraception. S-23 showed high binding affinity (inhibitory constant = 1.7 +/- 0.2 nm) and was identified as a full agonist in vitro. In castrated male rats, the ED50 of S-23 in the prostate and levator ani muscle was 0.43 and 0.079 mg/d, respectively. In intact male rats treated for 14 d, S-23 alone suppressed LH levels by greater than 50% at doses greater than 0.1 mg/d, with corresponding decreases in the size of the prostate but increases in the size of levator ani muscle. In intact male rats treated for up to 10 wk with S-23 and estradiol benzoate (EB; necessary to maintain sexual behavior in rats), S-23 showed biphasic effects on androgenic tissues and spermatogenesis by suppressing serum concentrations of LH and FSH. EB alone showed no effect on spermatogenesis. In the EB + S-23 (0.1 mg/d) group, four of six animals showed no sperm in the testis and zero pregnancies (none of six) in mating trials. After termination of treatment, infertility was fully reversible, with a 100% pregnancy rate observed after 100 d of recovery. S-23 increased bone mineral density and lean mass but reduced fat mass in a dose-dependent manner. This is the first study to show that a selective androgen receptor modulator combined with EB is an effective and reversible regimen for hormonal male contraception in rats. The beneficial effects of S-23 on the muscle, tissue selectivity, and favorable pharmacokinetic properties make it a strong candidate for use in oral male contraception.     

A small-molecule therapeutic lead for Huntington's disease: preclinical pharmacology and efficacy of C2-8 in the R6/2 transgenic mouse

Huntington's disease (HD) is a progressive neurodegenerative disease caused by a glutamine expansion within huntingtin protein. The exact pathological mechanisms determining disease onset and progression remain unclear. However, aggregates of insoluble mutant huntingtin (mhtt), a hallmark of HD, are readily detected within neurons in HD brain. Although aggregated polyglutamines may not be inherently toxic, they constitute a biomarker for mutant huntingtin useful for developing therapeutics. We previously reported that the small molecule, C2-8, inhibits polyglutamine aggregation in cell culture and brain slices and rescues degeneration of photoreceptors in a Drosophila model of HD. In this study, we assessed the therapeutic potential of C2-8 in the R6/2 mouse model of HD, which has been used to provide proof-of-concept data in considering whether to advance therapies to human HD. We show that, at nontoxic doses, C2-8 penetrates the blood-brain barrier and is present in brain at a high concentration. C2-8-treated mice showed improved motor performance and reduced neuronal atrophy and had smaller huntingtin aggregates. There have been no prior drug-like, non-toxic, brain-penetrable aggregation inhibitors to arise from cell-based high-throughput screens for reducing huntingtin aggregation that is efficacious in preclinical in vivo models. C2-8 provides an essential tool to help elucidate mechanisms of neurodegeneration in HD and a therapeutic lead for further optimization and development.     

Determination of the absolute configuration of (-)-(2R)-succinic-2-d acid by neutron diffraction study: unambiguous proof of the absolute stereochemistry of the NAD+/NADH interconversion.

The absolute configuration of the CHD group (D = deuterium) in (-)-(2R)-succinic-2-d acid, as prepared from (-)-(2S,3R)-malic-3-d acid, has been shown unambiguously to be R by the technique of single-crystal neutron diffraction. The optically active cation (+)-phenylethylammonium was used as the chiral reference. The structure of [C6H5CH3CHNH3]+[HOOCCH2CHDCOO]- has been studied with x-ray diffraction at room temperature and neutron diffraction at 100 K. Crystal data from the neutron diffraction analysis of the phenylethylammonium salt of the title compound at 100 K: space group P21; a = 8.407(2) A, b = 8.300(4) A, c = 8.614(2) A, beta = 91.20(3) degrees; unit cell volume = 600.9(3) A3, zeta = 2 (numbers in parentheses are the estimated standard deviations). Final agreement factors are R(F2) = 0.0355 and R(wF2) = 0.0457 for 1690 independent neutron reflections and 297 parameters varied. The result confirms the stereochemistry of the malate/succinate transformation, as well as the NAD+/NADH interconversion, and demonstrates the usefulness of the single-crystal neutron diffraction method for determining the absolute configuration of molecules having a chiral monodeuteriomethylene group.     

Inhibition of human natural killer cell activity by (14R,15S)-14,15-dihydroxy-5Z,8Z,10E,12E- icosatetraenoic acid.

The interactions between products of the 15-lipoxygenase cascade and human natural killer (NK) cell activity have been studied. Addition of human leukocyte-derived (14R,15S)-14,15-dihydroxy-5Z,8Z,10E,12E-ic osatetraenoic acid (14,15-DiHETE) to the NK cytotoxicity assay against K562 target cells resulted in inhibition of NK cell activity, whereas addition of other 15-lipoxygenase-associated metabolites [i.e., (15S)-15-hydroperoxy-5Z,8Z,11Z,13E-icosatetra eno ic acid, (15S)-15-hydroxy-5Z,8Z,11Z,13E-icosatetraenoic acid, and (8R,15S)- and (8S,15S)-8,15-dihydroxy-5Z,9E,-11E,13E-icosat etr aenoic acid isomers] resulted in little or no inhibition of NK function. Dose-response studies indicate that leukocyte-derived 14,15-DiHETE and 14,15-DiHETE methyl ester, at micromolar concentrations, inhibit NK function even in the presence of 2.5% fetal calf serum. Synthetic 14,15-DiHETE prepared by total organic synthesis displayed similar biological activities over identical dose ranges. These icosanoids do not inhibit NK target cell binding and they exert only a variable effect in either antibody-dependent cytotoxicity or cytotoxic T-lymphocyte assays. These results demonstrate that the 14,15-DiHETE inhibits NK cell function in vitro. Moreover, they suggest that activation of the 15-lipoxygenase cascade and formation of 14,15-DiHETE in vivo may provide a mode of immune regulation.     

Effect of 2-（8-hydroxy-6-methoxy- 1-oxo- 1H-2-benzopyran-3yl） propionic acid in combination with carboplatin on gastric carcinoma growth in vivo

AIM： To investigate the effects of 2-（8-hydroxy-6- methoxy-l-oxo-lH-2-benzopyran-3-yl） propionic acid （NM-3） alone and in combination with carboplatin on tumor growth and apoptosis in mouse models of human gastric cancer constructed by subcutaneous implantation of histologically intact tumor tissue.
METHODS： Human gastric cancer SGC-7901 tissues were implanted into the dorsal subcutis of nude mice. One week after tumors reached to a volume of 50-100 mm3 for around 1 wk, these mice were randomly divided into 8 groups （n = 10）. NM-3 was injected peritoneally at the dose of 10 mg/kg, 20 mg/kg or 40 mg/kg every other day for 5 wk, combined with carboplatin （5 mg/kg） every third day for 4 wk. As controls of combined treatment, another 4 groups of mice were injected with either NM-3 at 10 mg/kg, 20 mg/kg or 40 mg/kg, or with carboplatin alone （5 mg/kg）. The control mice received normal saline. Tumor weight, tumor growth inhibition （TGI）, and intratumoral microvessel density （MVD） were evaluated. Apoptosis of human gastric cancer was detected by TUNEL method and flow o/tometry analysis, respectively.
RESULTS： The mean tumor volume （692.40 ± 58.43 mm3, 548.30 ± 66.02 mm3, 382.13 ± 43.52 mm3） after treatment with carboplatin combined NM-3 at the dose of 10 mg/kg, 20 mg/kg or 40 mg/kg was lower than that after treatment with either NM-3 at the dose of 10 mg/kg, 20 mg/kg or 40 mg/kg or with carboplatin alone. Compared with the normal saline group, NM-3 administered at 10 mg/kg, 20 mg/kg or 40 mg/kg significantly reduced the tumor weight in these groups （P 〈 0.05）. Carboplatin used alone at 5 mg/kg showed minimal effects. But NM-3 in combination with carboplatin had greater effects of tumor weight than either NM-3 or carboplatin alone. NM-3 alone at the dose 10 mg/kg or in combination with carboplatin had no obvious effects on body changes. Two mice died of diarrhea in each of the two groups treated with 40 mg/kg NM-3 or with 40 mg/kg NM-3 in combination with carboplatin. A     

Plasma Parameters and Etching Characteristics of SiOxNy Films in CF4 + O2 + X (X = C4F8 or CF2Br2) Gas Mixtures

In this work, we carried out the study of CF₄ + O₂ + X (X = C₄F₈ or CF₂Br₂) gas chemistries in respect to the SiO_xN_y reactive-ion etching process in a low power regime. The interest in the liquid CF₂Br₂ as an additive component is motivated by its generally unknown plasma etching performance. The combination of various diagnostic tools (double Langmuir probe, quadrupole mass-spectrometry, X-ray photoelectron spectroscopy) allowed us to compare the effects of CF₄/X mixing ratio, input power and gas pressure on gas-phase plasma characteristics as well as to analyze the SiO_xN_y etching kinetics in terms of process-condition-dependent effective reaction probability. It was found that the given gas systems are characterized by: (1) similar changes in plasma parameters (electron temperature, ion current density) and fluxes of active species with variations in processing conditions; (2) identical behaviors of SiO_xN_y etching rates, as determined by the neutral-flux-limited process regime; and (3) non-constant SiO_xN_y + F reaction probabilities due to changes in the polymer deposition/removal balance. The features of CF₄ + CF₂Br₂ + O₂ plasma are lower polymerization ability (due to the lower flux of CF_x radicals) and a bit more vertical etching profile (due to the lower neutral/charged ratio).     

Clinical implications of ELA2-, HAX1-, and G-CSF-receptor (CSF3R) mutations in severe congenital neutropenia

Congenital Neutropenia (CN) is a heterogeneous bone marrow failure syndrome characterized by a maturation arrest of myelopoiesis at the level of the promyelocyte/myelocyte stage with peripheral blood absolute neutrophil counts below 0·5 × 10⁹/l. There are two major subtypes of CN as judged by inheritance: an autosomal dominant subtype, e.g. defined by neutrophil elastase mutations (approximately 60% of patients) and an autosomal recessive subtype (approximately 30% of patients), both presenting with the same clinical and morphological phenotype. Different mutations have been described (e.g. HAX1 , p14 etc) in autosomal recessive CN, with HAX1 mutations in the majority of these patients. CN in common is considered as a preleukemic syndrome, since the cumulative incidence for leukemia is more than 25% after 20 years of observation. Leukemias occur in both, the autosomal dominant and recessive subtypes of CN. The individual risk for each genetic subtype needs to be further evaluated. Numbers of patients tested for the underlying genetic defect are still limited. Acquired G-CSFR ( CSF3R ) mutations are detected in approximately 80% of CN patients who developed acute myeloid leukemia independent of the ELA2 or HAX1 genetic subtype, suggesting that these mutations are involved in leukemogenesis. As the majority of patients benefit from G-CSF administration, HSCT should be restricted to non-responders and patients with leukaemic transformation.     

Dose response inhibition in man of meal-stimulated gastric acid secretion by 15(R)-15-methyl prostaglandin E2, given orally.

15(R)-15-methyl prostaglandin E2 was given orally to healthy male volunteers. Thirty minutes later a 10% peptone meal was introduced into the stomach, and the acid response was measured by continuous intragastric titration with 0.5 N NaOH for the next two hours. The prostaglandin inhibited acid output in a dose dependent manner; the ED50 (dose inhibiting acid output by 50%) was as little as 10 micrograms per subject (or approximately 140 ng/kg). This compound is the most potent orally active inhibitor of gastric acid secretion in man that is known. It is likely that the antisecretory and cytoprotective properties shared by 15(R)-15-methyl prostaglandin E2 would be beneficial in the treatment of peptic ulcer and in preventing recurrences.     

The influence of 15(R)-15 methyl PGE2, methyl ester, on Nd:YAG laser-induced gastric ulcers

The effect of 15(R)-15 methyl PGE2 on the evolution of gastric ulcers induced by endoscopic Nd:YAG laser photocoagulation was studied. By continuous application of 50 to 70 watt power for 4 sec at a distance of 15 mm from the gastric mucosa, reproducible ulcers can be induced. The effect of the drug in nonantisecretory doses (10 micrograms/kg) on the acute ulcer formation and on the healing rate was evaluated in mongrel dogs by light microscopy. Local administration or oral pretreatment did not influence the size or depth of acute ulcers (7.4 mm in diameter) as compared to a control series (7.2 mm). Pretreatment for several days, however, had a marked beneficial effect on the healing rate of the ulcers (1.71 mm after 7 days compared to 2.76 mm for the control series). From these data it may be concluded that 15(R)-15 methyl PGE2 has a beneficial effect on ulcer healing, even in nonantisecretory doses.