Structural optimization affording 2-(R)-(1-(R)-3, 5-bis(trifluoromethyl)phenylethoxy)-3-(S)-(4-fluoro)phenyl-4- (3-oxo-1,2,4-triazol-5-yl)methylmorpholine, a potent, orally active, long-acting morpholine acetal human NK-1 receptor antagonist

Structural modifications requiring novel synthetic chemistry were made to the morpholine acetal human neurokinin-1 (hNK-1) receptor antagonist 4, and this resulted in the discovery of 2-(R)-(1-(R)-3, 5-bis(trifluoromethyl)phenylethoxy)-3-(S)-(4-fluoro)phenyl-4-(3-ox o-1 ,2,4-triazol-5-yl)methyl morpholine (17). This modified compound is a potent, long-acting hNK-1 receptor antagonist as evidenced by its ability to displace [125I]Substance P from hNK-1 receptors stably expressed in CHO cells (IC50 = 0.09 +/- 0.06 nM) and by the measurement of the rates of association (k1 = 2.8 +/- 1.1 x 10(8) M-1 min-1) and dissociation (k-1 = 0.0054 +/- 0.003 min-1) of 17 from hNK-1 expressed in Sf9 membranes which yields Kd = 19 +/- 12 pM and a t1/2 for receptor occupancy equal to 154 +/- 75 min. Inflammation in the guinea pig induced by a resiniferatoxin challenge (with NK-1 receptor activation mediating the subsequent increase in vascular permeability) is inhibited in a dose-dependent manner by the oral preadmininstration of 17 (IC50 (1 h) = 0.008 mg/kg; IC90 (24 h) = 1.8 mg/kg), indicating that this compound has good oral bioavailbility and peripheral duration of action. Central hNK-1 receptor stimulation is also inhibited by the systemic preadministration of 17 as shown by its ability to block an NK-1 agonist-induced foot tapping response in gerbils (IC50 (4 h) = 0.04 +/- 0.006 mg/kg; IC50 (24 h) = 0.33 +/- 0.017 mg/kg) and by its antiemetic actions in the ferret against cisplatin challenge. The activity of 17 at extended time points in these preclinical animal models sets it apart from earlier morpholine antagonists (such as 4), and the piperidine antagonists 2 and 3 and could prove to be an advantage in the treatment of chronic disorders related to the actions of Substance P. In part on the basis of these data, 17 has been identified as a potential clinical candidate for the treatment of peripheral pain, migraine, chemotherapy-induced emesis, and various psychiatric disorders.     

(R)-(-)- and (S)-(+)-Synadenol: synthesis, absolute configuration, and enantioselectivity of antiviral effect

Synthesis of (R)-(-)- and (S)-(+)-synadenol (1a and 2a, 95-96% ee) is described. Racemic synadenol (1a + 2a) was deaminated with adenosine deaminase to give (R)-(-)-synadenol (1a) and (S)-(+)-hypoxanthine derivative 5. Acetylation of the latter compound gave acetate 6. Reaction with N, N-dimethylchloromethyleneammonium chloride led to 6-chloropurine derivative 7. Ammonolysis furnished (S)-(+)-synadenol (2a). Absolute configuration of 1a was established by two methods: (i) synthesis from (R)-methylenecyclopropanecarboxylic acid (8) and (ii) X-ray diffraction of a single crystal of (-)-synadenol hydrochloride. Racemic methylenecyclopropanecarboxylic acid (10) was resolved by a modification of the described procedure. The R-enantiomer 8 was converted to ethyl ester 13 which was brominated to give vicinal dibromides 14. Reduction with diisobutylaluminum hydride then furnished alcohol 15 which was acetylated to the corresponding acetate 16. Alkylation-elimination procedure of adenine with 16 yielded acetates 17 and 18. Deprotection with ammonia afforded a mixture of Z- and E-isomers 1a and 19 of the R-configuration. Comparison with products 1a and 2a by chiral HPLC established the R-configuration of (-)-synadenol (1a). These results were confirmed by X-ray diffraction of a single crystal of (-)-synadenol hydrochloride. The latter forms a pseudosymmetric dimer with adenine-adenine base pairing in the lattice with the nucleobase in an anti-like conformation. Enantiomers 1a and 2a exhibit varied enantioselectivity toward different viruses. Both enantiomers are equipotent against human cytomegalovirus (HCMV) and varicella zoster virus (VZV). The S-enantiomer 2a is somewhat more effective than R-enantiomer 1a in herpes simplex virus 1 and 2 (HSV-1 and HSV-2) assays. By contrast, enantioselectivity of antiviral effect is reversed in Epstein-Barr virus (EBV) and human immunodeficiency virus type 1 (HIV-1) assays where the R-enantiomer 1a is preferred. In these assays, the S-enantiomer 2a is less effective (EBV) or devoid of activity (HIV-1).     

Resonance Raman spectra of iron(III)-, copper(II)-, cobalt(III)-, and manganese(III)-transferrins and of bis(2,4,6-trichlorophenolato)diimidazolecopper(II) monohydrate, a possible model for copper(II) binding to transferrins

Fe(III), Cu(II), Co(III), and Mn(III) complexes of ovo- and human serum transferrins show resonance enhanced Raman bands near 1600, 1500, 1270, and 1170 cm-1 upon excitation with laser frequencies which fall within the visible absorption bands of those metalloproteins. Comparison of the visible absorption and resonance Raman spectra of the Cu(II)-transferrin complexes with those for the Cu(II) model compound, bis(2,4,6-trichlorophenolato)diimidazolecopper(II) monohydrate, indicates that the resonance Raman bands are due to enhancement of phenolic vibrational modes. For the model (Cu(II) compound, a normal coordinate analysis was used to aid our assignment of the observed resonance bands at 1562, 1463, 1311, and 1122 cm-1 to A1 vibrational modes of the 2,4,6-trichlorophenolato moiety. These assignments are consistent with those made for Cu(II)-transferrins. The latter assignments were based upon calculated A1 frequencies for p-methylphenol (Cummings, D.L., and Wood, J.L. (1974), J. Mol. Struct. 20, 1). The wavelength shifts in the resonance bands for the model compound from those for Cu(II)-transferrins are due to the influence of the chloro substituents on the planar vibrations of phenol. These results clearly identify tyrosine as a ligand in copper binding to transferrins.     

(2Z,4E)-5-(5,6-dichloro-2-indolyl)-2-methoxy-N-(1,2,2,6,6- pentamethylpiperidin-4-yl)-2,4-pentadienamide, a novel, potent and selective inhibitor of the osteoclast V-ATPase

Optimisation of a novel series of osteoclast ATPase inhibitors led to (2Z,4E)-5-(5,6-dichloro-2-indolyl)-2-methoxy-N-(1,2,2,6,6- pentamethylpiperidin-4-yl)-2,4-pentadienamide (1) that was the most potent compound in an in vitro osteoclast ATPase assay and in human bone resorption assays. Two of the possible geometric isomers have also been prepared and shown to be significantly less potent than 1.     

Thermionic emission properties of cermets of eutectic compositions in Me(IV)-(C,B)-(Mo,Re, W) systems

Conclusions Sintered eutectic (Ti, Zr, Hf)C-(Mo, Re, W) and ZrB₂-(Mo, Re, W) cathode cermets having a quasieutectic coarse-conglomerate structure are characterized by high stability of emission, and their effective work function is lower than that of their most emission-active components. The rapid stabilization of the emission characteristics of the eutectic cathode cermet composites is linked with the specific character of electron exchange between their phases, which creates optimum conditions for the formation of a self-stabilized structure on the surface of an emitter. The relative fall in work function exhibited by the cathode cermets investigated compared with their metallike compound components grows with increasing work function of their pure metallic components. Composite emitters of the eutectic compositions of the MeC (MeB₂)-Me' (where Me' = Mo, Re, W) systems are film-type emitters, on whose surfaces thin layers of the metal Me' form during heat treatment (sintering) and actual operation. The metal surface layers adsorb atoms from the metallike compounds MeC and MeB₂, which are supplied to the surfaces of the emitters by diffusion.Translated from Poroshkovaya Metallurgiya, No. 1(205), pp. 81–87, January, 1980.     

High-performance liquid chromatographic determination of erdosteine and its optical active metabolite utilizing a fluorescent chiral tagging reagent, R-(-)-4-(N,N-dimethylamiosulfonyl)-7-(3-aminopyrrolidin-1-yl)-2 ,1,3-benzoxadiazole

Chiral separation of racemic M1 metabolized from erdosteine was investigated by reversed-phase chromatography. The sensitive determination of M1 and erdosteine with UV detection was difficult because of their low absorptivity in the effective wavelength region. To improve the sensitivity and separatability, one thiol and two carboxyl groups in the M1 structure were labelled with DBD-F and R-(-)-DBD-APy, respectively. Non-fluorescent DBD-F quantitatively reacted with thiol in M1 at room temperature for 30 min in borate buffer (pH 9.3) to produce the fluorescent derivative. On the other hand, the labelling of two carboxyls was carried out with a chiral fluorescent reagent, R-(-)-DBD-APy, in acetonitrile containing DPPA. The derivatives corresponding to a pair of the enantiomers were completely separated with water-acetonitrile containing 0.1% TFA as the mobile phase by an ODS column. Erdosteine with a carboxyl group was also labelled with R-(-)-DBD-APy and separated together with M1 derivatives. The detection limits (S/N=3) of erdosteine and M1 were 0.37 and 0.22 pmol, respectively. The proposed derivatization and separation methods were applied to simultaneous determination of racemic M1 and erdosteine in rat plasma after administration of erdosteine. The amounts of both enantiomers of M1 were essentially the same in oral and intravenous administrations. In contrast, total amounts (reduced-form and oxidized-form) of S-(-)-M1 in rat plasma were higher than those of R(+)-M1 in both administrations.     

Pharmacokinetics and amoebicidal activity of (+-)-(E)-3-(4- methylsulphinylstyryl)-1,2,4-oxadiazole (BTI 2286E) and its sulphone metabolite (BTI 2571E) in the golden hamster, Mesocricetus auratus

We studied, clinically and experimentally, hypertrophy of the part of the liver not embolized after portal vein embolization (PVE). The subjects of the clinical study were 29 patients with hepatocellular carcinoma (HCC) who underwent embolization of the right first portal branch; 19 patients had cirrhosis, and 10 did not. The volume of the liver was calculated from computed tomograms obtained before PVE and 2 weeks after. In all patients, the volume of the nonembolized (left) lobe increased significantly. For the experimental study, we used male Wistar rats. Normal rats were untreated, and in the other rats cirrhosis was induced with carbon tetrachloride. The portal branch that supplies 70% of the total volume of the liver was embolized. The rats underwent one of four procedures: 70% PVE, 70% portal vein ligation, 70% hepatectomy, or laparotomy only. Rats wre killed at different times after surgery, and the livers were removed and weighed. The mitotic index and DNA synthesis were measured in the nonembolized lobe (PVE group), in the lobe not supplied by the ligated branch (ligation group), or in the remaining liver (hepatectomy group). The liver weight, mitotic index, and DNA synthesis were high in the PVE, ligation, and hepatectomy groups for both normal rats and rats with cirrhosis. PVE caused cell proliferation and hypertrophy in the nonembolized part of the liver in the normal rats and even in those with cirrhosis. We concluded that PVE can extend the surgical indications for patients with HCC and underlying cirrhosis.     

Novel, highly potent aldose reductase inhibitors: (R)-(-)-2-(4-bromo-2-fluorobenzyl)-1,2,3,4- tetrahydropyrrolo[1,2-a]pyrazine -4-spiro-3'-pyrrolidine-1,2',3,5'-tetrone (AS-3201) and its congeners

A series of novel tetrahydropyrrolo[1,2-a]pyrazine derivatives were synthesized and evaluated as aldose reductase inhibitors (ARIs) on the basis of their abilities to inhibit porcine lens aldose reductase (AR) in vitro and to inhibit sorbitol accumulation in the sciatic nerve of streptozotocin-induced diabetic rats in vivo. Of these compounds, spirosuccinimide-fused tetrahydropyrrolo[1, 2-a]pyrazine-1,3-dione derivatives showed significantly potent AR inhibitory activity. In the in vivo activity of these derivatives, 2-(4-bromo-2-fluorobenzyl)-1,2,3,4-tetrahydropyrrolo[1, 2-a]pyrazine-4-spiro-3'-pyrrolidine-1,2',3,5'-tetrone (23t) (SX-3030) showed the best oral activity. The enantiomers of 23t were synthesized, and the biological activities were evaluated. It was found that AR inhibitory activity resides in the (-)-enantiomer 43 (AS-3201), which was 10 times more potent in inhibition of the AR (IC50 = 1.5 x 10(-8) M) and 500 times more potent in the in vivo activity (ED50 = 0.18 mg/kg/day for 5 days) than the corresponding (+)-enantiomer 44 (SX-3202). From these results, AS-3201 was selected as the candidate for clinical development. The absolute configuration of AS-3201 was also established to be (R)-form by single-crystal X-ray analysis. In this article we report the preparation and structure-activity relationship (SAR) of tetrahydropyrrolopyrazine derivatives including a novel ARI, AS-3201.     

Pharmacodynamics of 2-(4-benzyl-piperidino)-1-(4-hydroxyphenyl)-1-propanol (Ifenprodil). (3) Effects on the autonomic, peripheral and central nervous systems

Effects of ifenprodil tartrate, a potent vasodilator, on the autonomic, peripheral and central nerve system were studied in experimental animals. In isolated vas deferens of guinea pigs, the contraction in response to noradrenaline and sympathetic nerve stimulation was competetively antagonized by ifenprodil 10(-7)--10(-5) M (pA2: 7.69 against noradrenaline). Ifenprodil (50 approximately 1,000 mug/kg i.v.) inhibited the contraction of cat nictitating membrane and dog urinary bladder induced by sympathetic nerve stimulation. Ifenprodil (250 approximately 1,000 mug/kg i.v.) lowered adrenaline-induced lethality (ED50: 360 mug/kg). The drug produced a hypermotility of guinea pig uterus, and showed a transient hypertonus of dog gut which was abolished by atropine. Ifenprodil (10 approximately 20 mg/kg i.v.) inhibited the propulsion of charcoal meal in mice. In Shay rats, more than 10 mg/kg i.m. of the drug inhibited the secretion of acid gastric juice and the ulceration. Ifenprodil showed a potent local anesthetic action in the guinea pig cornea and skin. The spontaneous EEG of rabbits showed a resting pattern (0.25 approximately 2 mg/kg i.v.) followed by an arousal pattern (5 approximately 10 mg/kg). Ifenprodil (20 approximately 100 mg/kg p.o.) potentiated a hypnosis induced by barbital, and potentiated pentylenetetrazol, strychnine and picrotoxin induced convulsion. The drug (20 and 100 mg/kg p.o.) lowered the body temperature of rats. From these results it is concluded that ifenprodil produces a blocking action of alpha-adrenoceptors in various smooth muscle preparations and a direct relaxation of the smooth muscle itself without affecting the motor and central nerve systems.     

Safety, pharmacokinetics, and antiretroviral activity of intravenous 9-[2-(R)-(Phosphonomethoxy)propyl]adenine, a novel anti-human immunodeficiency virus (HIV) therapy, in HIV-infected adults

9-[2-(R)-(Phosphonomethoxy)propyl]adenine (PMPA) is a nucleotide analogue with potent antiretroviral activity in vitro and in simian models. A randomized, double-blind, placebo-controlled, dose-escalation clinical trial of intravenous PMPA monotherapy was conducted in 20 human immunodeficiency virus (HIV)-infected adults with CD4 cell counts of >/=200 cells/mm3 and plasma HIV RNA levels of >/=10,000 copies/ml. Two dose levels were evaluated (1 and 3 mg/kg of body weight/day). Ten subjects were enrolled at each dose level (eight randomized to receive PMPA and two randomized to receive placebo). On day 1, a single dose of PMPA or placebo was administered by intravenous infusion. Beginning on study day 8, PMPA or placebo was administered once daily for an additional 7 consecutive days. All subjects tolerated dosing without significant adverse events. Mean peak serum PMPA concentrations were 2.7 +/- 0.9 and 9.1 +/- 2.1 microgram/ml in the 1- and 3-mg/kg cohorts, respectively. Serum concentrations declined in a biexponential fashion, with a terminal half-life of 4 to 8 h. At 3 mg/kg/day, a single infusion of PMPA resulted in a 0.4 log10 median decline in plasma HIV RNA by study day 8. Following 7 consecutive days of study drug administration thereafter, the median changes in plasma HIV RNA from baseline were -1.1, -0.6, and 0.1 log10 in the 3-mg/kg/day, 1-mg/kg/day, and placebo dose groups, respectively. Following the final dose in the 3-mg/kg/day cohort, the reduction in HIV RNA was sustained for 7 days before returning toward baseline. Further studies evaluating an oral prodrug of PMPA are under way.     

In vitro evaluation of 11C-labeled (S)-nicotine, (S)-3-methyl-5-(1-methyl-2-pyrrolidinyl)isoxazole, and (R,S)-1-methyl-2-(3-pyridyl)azetidine as nicotinic receptor ligands for positron emission tomography studies

The binding characteristics of the novel 11C-labeled nicotinic ligands (R,S)-1-methyl-2-(3-pyridyl) azetidine (MPA) and (S)-3-methyl-5-(1-methyl-2-pyrrolidinyl)isoxazole (ABT-418) were investigated in comparison with those of (S)-[11C]nicotine in vitro in the rat brain to be able to predict the binding properties of the new ligands for positron emission tomography studies in vivo. The data from time-resolved experiments for all ligands indicated fast binding kinetics, with the exception of a slower dissociation of [11C]MPA in comparison with (S)-[11C]nicotine and [11C]ABT-418. Saturation experiments revealed for all ligands two nicotinic receptor binding sites with affinity constants (K(D) values) of 2.4 and 560 nM and binding site densities (Bmax values) of 65.5 and 223 fmol/mg of protein for (S)-[11C]nicotine, K(D) values of 0.011 and 2.2 nM and Bmax values of 4.4 and 70.7 fmol/mg of protein for [11C]MPA, and K(D) values of 1.3 and 33.4 nM and Bmax values of 8.8 and 69.2 fmol/mg of protein for [11C]ABT-418. In competing with the 11C-ligands, epibatidine was most potent, followed by cytisine. A different rank order of potencies was found for (-)-nicotine, (+)-nicotine, MPA, and ABT-418 displacing each of the 11C-ligands. Autoradiograms displayed a similar pattern of receptor binding for all ligands, whereby [11C]MPA showed the most distinct binding pattern and the lowest nonspecific binding. We conclude that the three 11C-labeled nicotinic ligands were suitable for characterizing nicotinic receptors in vitro. The very high affinity of [11C]MPA to nicotinic acetylcholine receptors, its low nonspecific binding, and especially the slower dissociation kinetics of the [11C] MPA from the putative high-affinity nicotinic acetylcholine receptor binding site compared with (S)-[11C]nicotine and [11C]ABT-418 raise the level of interest in [11C]MPAfor application in positron emission tomography.     

Design, synthesis and conformational analysis of hGM-CSF(13-31)-Gly-Pro-Gly-(103-116)

On the basis of the X-ray structure and results from structure-activity relationship studies, the following GM-CSF analogue was designed and synthesized by solid-phase methodology: hGM-CSF[13-31]-Gly-Pro-Gly-[103-116]-NH2. This analogue was constructed to comprise helices A and D of the native hGM-CSF, covalently linked in an antiparallel orientation by the tripeptide spacer Gly-Pro-Gly, which is known as a turn-inducing sequence. The conformational analysis of the analogue by CD spectroscopy revealed an essentially random structure in water, while alpha-helix formation was observed upon addition of TFE. In 40% TFE the helix content was approximately 45%. By two-dimensional NMR experiments in 1:1 water/trifluoroethanol mixture two helical sequences were identified comprising the segments corresponding to helix A and helix D. In addition to medium-range NOESY connectivities, a long-range cross-peak was found involving the leucine residues at positions 13 and 35. Based on the experimentally derived data (54 NOEs), the structure was refined by restrained molecular dynamics simulations over 120 ps at various temperatures. A representative conformation derived from the computer simulation is mainly characterized by two helical segments connected by a loop region. The overall three-dimensional structure of the analogue is comparable to the X-ray structure of hGM-CSF in that helices A and D are oriented in an antiparallel fashion, forming a two alpha-helix bundle. Nevertheless, there are small differences in the topology of the helices between the solution structure of the designed analogue and the X-ray structure of hGM-CSF. The possible implications of these conformational features at the effects of biological activity are discussed.     

(3R,4S)-3-[4-(4-fluorophenyl)-4-hydroxypiperidin-1-yl]chroman-4,7-diol: a conformationally restricted analogue of the NR2B subtype-selective NMDA antagonist (1S,2S)-1-(4-hydroxyphenyl)-2-(4-hydroxy-4-phenylpiperidino)- 1-propanol

(1S,2S)-1-(4-Hydroxyphenyl)-2-(4-hydroxy-4-phenylpiperidino)-1-propanol (CP-101,606, 1) is a recently described antagonist of N-methyl-D-aspartate (NMDA) receptors containing the NR2B subunit. In the present study, the optimal orientation of compounds of this structural type for their receptor was explored. Tethering of the pendent methyl group of 1 to the phenolic aromatic ring via an oxygen atom prevents rotation about the central portion of the molecule. Several of the new chromanol compounds have high affinity for the racemic [3H]CP-101,606 binding site on the NMDA receptor and protect against glutamate toxicity in cultured hippocampal neurons. The new ring caused a change in the stereochemical preference of the receptor-cis (erythro) compounds had better affinity for the receptor than the trans isomers. Computational studies suggest that steric interactions between the pendent methyl group and the phenol ring in the acyclic series determine which structures can best fit the receptor. The chromanol analogue, (3R,4S)-3-[4-(4-fluorophenyl)-4-hydroxypiperidin-1- yl]chroman-4,7-diol (12a, CP-283,097), was found to possess potency and selectivity comparable to CP-101,606. Thus 12a is a new tool to explore the function of the NR2B-containing NMDA receptors.     

Absence of metabolism of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) by flavin-containing monooxygenase (FMO)

The N-nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) is a potent lung carcinogen present in tobacco and tobacco smoke. Carbonyl reduction, alpha-carbon hydroxylation (activation) and N-oxidation of the pyridyl ring (detoxification) are the three main pathways of metabolism of NNK. In this study, metabolism of NNK was studied with lung and liver microsomes from F344 rats, Syrian golden hamsters and pigs and cloned flavin-containing monooxygenases (FMOs) from human and rabbit liver. Thermal inactivation at 45 degrees C for 2 min reduced FMO S-oxygenating activity but did not affect N-oxidation of NNK, leading to the conclusion that FMOs are not implicated in the detoxification of NNK. Detoxification of NNK was not increased by n-octylamine or by incubation at pH 8.4, supporting the conclusion that FMOs are not involved in the metabolism of NNK. SKF-525A (1 mM) significantly reduced N-oxidation and alpha-carbon hydroxylation, suggesting that these two pathways were catalyzed by cytochromes P450. Metabolism of NNK was lower with lung microsomes than with liver microsomes. Inhibition of metabolism of NNK by SKF-525A was also observed with rat lung microsomes, leading to the conclusion that cytochromes P450 are involved in pulmonary metabolism of NNK. Cloned FMOs did not metabolize NNK. In conclusion, cytochromes P450 rather than FMOs are involved in N-oxidation of NNK. The high capacity of hamster liver microsomes to activate NNK does not correlate with the resistance of this tissue to NNK-induced hepatocarcinogenesis.     

1-(2-苯并噻唑)-3-(3,5-二溴吡啶)-三氮烯与铜的荧光反应及应用

合成并鉴定了一种新的三氮烯试剂1-(2-苯并噻唑) -3-(3,5-二溴吡啶)-三氮烯(BTPyBT),考察了酸度、缓冲溶液用量、铜离子浓度、试剂用量、反应温度及反应时间等影响该试剂与铜发生荧光反应的条件,建立了一个测定铜的荧光分析方法。实验表明,在pH 9.16的硼砂-氢氧化钠缓冲液中,BTPyBT与铜离子在室温下反应20 min后可形成组成比为3∶1的稳定络合物。所建立铜的荧光分析方法的线性范围为0.5~80.0 μg/L,检出限为0.2 μg/L。方法应用于矿泉水、纯净水及河水等水样品中痕量铜的测定,测定结果与原子吸收光谱法一致,相对标准偏差(n=6)为1.2%～4.7%。