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.     

Promotional effects of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) on N-nitrosobis(2-oxopropyl)amine (BOP)-initiated carcinogenesis in hamsters

The effects of administration of low doses of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), a tobacco-specific nitrosamine, were investigated in hamsters treated with N-nitrosobis(2-oxopropyl)amine (BOP). Female Syrian golden hamsters were given a single sc injection of BOP at a dose of 10 mg/kg and then administered 2 or 5 ppm NNAL in their drinking water for 52 wk. Additional groups of animals received the BOP injection alone, or only the 2 or 5 ppm NNAL treatments as BOP-negative controls. At wk 53 of the experiment, all surviving animals were killed and the development of proliferative lesions was assessed histopathologically. The total incidence of combined carcinomatous and dysplastic lesions of the exocrine pancreas was significantly higher (P < 0.05) in the BOP/NNAL 5 ppm group than in the BOP alone group, although there was no statistically significant influence of NNAL on the development of either pancreatic adenocarcinomas or dysplastic lesions viewed singly. The treatments with NNAL alone did not induce any proliferative lesions of the exocrine pancreas. No significant intergroup differences were found in either incidence or multiplicity of islet cell proliferative lesions. Immunohistochemical examination of islet cell proliferative lesions (hyperplasias and adenomas) found in the BOP-treated animals showed no significant differences in pancreatic hormone production between NNAL-treated and -untreated groups. The NNAL treatment did not exert any influence on lung, liver or kidney tumorigenesis. Thus, the results suggest that NNAL enhances BOP-induced exocrine but not endocrine pancreatic tumorigenesis in hamsters when given in the post-initiation phase.     

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).     

Metabolism of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) in isolated rat lung and liver

PURPOSE: Assessment of sustained voluntary contraction of the external sphincter is helpful in evaluating the patient who has a defecation disorder on presentation. A new index of external sphincter function is described. METHOD: A prospective registry of patients referred for computerized anal manometry using standard protocols was reviewed. Patients were grouped by primary symptoms; those with overlapping complaints were excluded. The rate of fatigue, defined as the change in stationary squeeze over a 40-second period of voluntary contraction, was calculated by linear regression analysis. Fatigue rate index, a calculated measure of time necessary for the external sphincter to become completely fatigued, was determined to permit comparison of external sphincter fatigue in patients with different complaints. RESULTS: Twenty-six healthy volunteers (15 women; mean age, 45 years), 33 patients with a primary complaint of anal seepage (13 women; mean age, 53 years), 75 patients with gross incontinence (61 women; mean age, 53 years), and 49 patients with severe constipation (41 women; mean age, 45 years) were evaluated. Mean resting and squeeze pressures were 55 mmHg and 107 mmHg for volunteers, 37 mmHg and 97 mmHg for patients with seepage, 30 mmHg and 49 mmHg for incontinent patients, and 56 mmHg and 93 mmHg for constipated patients. Pudendal neuropathy, as evidenced by a prolonged pudendal nerve terminal motor latency (> 2.4 ms), was identified in 13 percent of volunteers, 32 percent of patients with seepage, 54 percent of incontinent patients, and 38 percent of constipated patients. Mean fatigue rate index was 3.3 minutes for volunteers, 2.3 minutes for seepage patients, 1.5 minutes for incontinent patients, and 2.8 minutes for constipated patients. Compared with volunteers and patients with seepage, the incontinent patients had a significantly shorter fatigue rate index (P < 0.05; Student's t-test), which was independent of the variations in resting pressure (P < 0.05; two-way analysis of variance). CONCLUSION: The external anal sphincter is normally subject to fatigue. Patients with worsening degrees of incontinence have a predictably lower fatigue rate index. Fatigue rate index is a simple measure of external sphincter integrity, which may be used in assessment of sphincter function and future treatment protocols.     

Biliary excretion of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone in the rat

The tobacco-specific nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) is a potent pancreas carcinogen in rats. The biliary excretion of NNK was therefore studied in anesthetized female Sprague-Dawley rats following i.p. administration of 0.7 mumol/kg [carbonyl-14C]NNK. The concentration of radioactivity peaked within 30 min and decreased thereafter exponentially. Cumulative excretion of radioactivity reached a plateau at 6-9% of the total dose. HPLC analysis revealed the presence of 4-hydroxy-4-(3-pyridyl)butyric acid (hydroxy acid), 4-oxo-4-(3-pyridyl)-butyric acid (keto acid), 4-(methylnitrosamino)-1-(3-pyridyl)-1-butyl beta-D-glucopyranosiduronic acid (NNAL Glu), 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) and NNK. NNAL Glu was the major metabolite contributing 34 +/- 4% of total radioactivity in bile at 30 min and 58 +/- 4% at 5 h. The percentage of acidic metabolites remained constant at approximately 20%. In contrast, the percentage of NNK and NNAL decreased within the first 2 h to < 5% and < 10% respectively. The elimination kinetics of NNK and its metabolites fitted into a one-compartment model with a half-life of 37 min for NNK, 52 min for NNAL and 110 min for NNAL Glu and acidic metabolites. In three rats dosed with 240 mumol/kg NNK i.p., the concentration of radioactivity peaked after 1-2 h and decreased very slowly thereafter. After 5-8 h a total of 12-17% of the dose has been excreted in the bile with no indication of a plateau. At all time points NNAL Glu was the major metabolite contributing up to 95% of total radioactivity in bile. The percentage of acidic metabolites was < 5% throughout the experiment. Whereas NNK contributed one-third of the radioactivity at 30 min and decreased rapidly, the percentage of NNAL in bile remained rather constant at approximately 5-10%. In conclusion, the detection of NNK, NNAL and NNAL Glu gives support to the hypothesis that tobacco-specific carcinogens could reach the pancreas retrograde from the bile, especially at high NNK concentrations.     

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.     

Inhibition of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone-induced mouse lung tumor formation by FGN-1 (sulindac sulfone)

The sulfone derivative of the non-steroidal anti-inflammatory drug (NSAID), sulindac, has been reported to inhibit mammary and colon tumor formation in rodent models of chemically-induced carcinogenesis. Unlike its parent compound, this metabolite lacks cyclo-oxygenase inhibitory activity. A tumor induction protocol, consisting of NNK administration in the drinking water over several weeks to model chronic human exposure, was used to test whether the sulfone (called FGN-1) could inhibit the formation of primary lung tumors in mice. A total of 150 female, AIN76A-fed, A/J mice received 9 mg of NNK each. Concentrations of FGN-1 that had been previously determined not to affect body weight gain were added to the food at levels of 0, 250, 500 and 750 mg/kg of diet (30 mice/group) starting 2 weeks before NNK administration and continuing for 22 weeks. At that time pleural surface tumors were counted. Tumor incidence decreased significantly from 96 % in the control diet and 93% in the 250 FGN-1 mg/kg diet to 63 and 67% in the 500 and 750 mg FGN-1/kg diet groups, respectively (P < 0.001 by chi-square analysis). Lung tumor multiplicity decreased from 18.1+/-3 tumors/ mouse (mean+/-SEM, control diet) to 12.3+/-3 (250), 5.3+/-1 (500) and 2.1+/-1 (750) (P < 0.0005 by post hoc ANOVA). In previous studies using this carcinogenesis protocol, the maximum tolerated dose of sulindac inhibited lung tumor multiplicity by no more than 50% with no effect on incidence. This dose-dependent reduction in tumorigenesis by a non-toxic dose of FGN-1 indicates a strong chemopreventive activity against experimental induction of lung carcinogenesis. The greater potency of the sulfone over sulindac and its lack of toxic side effects because of its inability to affect cyclo-oxygenase activity suggests that clinical testing in individuals at high risk for lung cancer should be considered.     

1-(4-安替比林)-3-(2-苯并噻唑)-三氮烯的合成及其与汞(Ⅱ)的显色反应

合成并鉴定了一种新三氮烯试剂1-(4-安替比林)-3-(2-苯并噻唑)-三氮烯(ABTTA),研究了该试剂与Hg2 的显色反应条件,并建立了一个测定汞的光度分析新方法。在溴化十六烷基三甲铵(CTMAB)存在下,试剂与汞在pH11.0Na2B4O7-NaOH缓冲溶液中迅速生成褐色络合物,其最大吸收波长为480nm。在最佳实验条件下,体系在480nm处的表观摩尔吸光系数为5.46×104L.mol-1.cm-1,25mL溶液中Hg2 的质量在5.0~70.0μg范围内符合比尔定律。对20多种共存离子的影响进行试验,结果表明,大多数常见离子不干扰测定。本方法虽然灵敏度不高,但线性范围宽、选择性较好,用于环境水样中汞的测定,结果满意。     

Myocardosis - myocardia - cardiomyopathy (author's transl)

"Cardiomyopathy", a term formerly used for heart muscle disease of unknown aetiology, is at present applied to all myocardial diseases other than coronary-heart disease. This definition includes many different forms of metabolic disorders of heart muscle. Four manifestations of metabolic myocardial disease, differing in their aetiology and pathogenesis are distinguished: (1) "transport" myocardosis, (2) "arthrocytotic" myocardosis, (3) myocardia, and (4) idiopathic cardiomyopathy. They are differentiated by combined morphological and quantitative mineral examination. "Transport" myocardosis is the most common form and its particular aetiology can be further specified. Cause of death in patients with metabolic disorders often remains undiscovered even at autopsy. Combination of histological and quantitative mineral analysis of myocardium can further define the particular form.     

Comparison of the effects of R-(-)-2-amino-1-(2,5-dimethoxy-4-methylphenyl) propane (DOM), r-(-)-2-amino-1-(2,5-dimethoxy-4-methylphenyl) butane (BL-3912A) and 5-hydroxytryptamine on non-innervated vascular smooth muscle

Human growth hormone (HGH) and somatomedin (Sm) concentrations have been studied in a group of newborns. Plasma HGH values were 41.17 +/- 24.26 (SD) ng/ml (14.00-90.00 ng/ml) and the Sm value was 0.59 +/- 0.43 (SD) U/ml (0.18-1.8 U/ml); the difference between these values and the ones observed in normal adults (2.45 +/- 2.53 (SD) ng/ml and 1.16 +/- 0.28 (SD) U/ml respectively) were statistically significant. While growth hormone values were higher than in normal adult controls, somatomedin was significantly decreased. It is possible that the dissociation between human growth hormone and somatomedin in newborn could reflect a reduced biosynthesis of the somatomedin-generating system and consequently a lack of a feed-back control on GH exerted by somatomedin.     

5-Br-PADAT和3,5-Br_2-PADAT作为络合滴定指示剂的应用

研究了 5 [(5 溴 2 吡啶 )偶氮 ] 2 ,4 二氨基甲苯和 5 [(3,5 二溴 2 吡啶 )偶氮 ] 2 ,4 二氨基甲苯作为直接滴定铜和以铜为回滴剂的指示剂的应用 ,以及以前者为指示剂滴定铜与锌等离子总量 ,并借助掩蔽剂以提高选择性 ,成功应用于铜合金等样品的分析。     

5—Br—PADAT和3,5—Br2—PTDAT作为络合滴定指示剂的应用

研究了５－「（５－溴－２－吡啶）偶氮」－２,４－二氨基甲苯和５－「（３,５－二溴－２－吡啶）偶氮」－２,４－二氨基甲苯作为直接滴定铜和以铜为回滴剂的批示剂的应用,以及以前者为指示剂滴定铜与锌等离子总量,并借助掩蔽剂以提高选择性,成功应用于铜合金等样品的分析。     

Synthesis and biological investigations of 1-(tetrahydropyran-2'-yl)- and 1-(tetrahydrofuran-2'-yl)benzimidazoles and 1/2-(tetrahydropyran-2'-yl)- and 1/2-(tetrahydrofuran-2'-yl)benzotriazoles

Sets of benzimidazole and benzotriazole derivatives bearing on position 1 or 2 a tetrahydrofuranyl or tetrahydropyranyl moieties were prepared through the addition of the suitable benzazoles on 2,3-dihydrofuran and 3,4-dihydro-2H-pyran. The reactions were carried on either without solvent or in carbon tetrachloride solution. In the last case some peculiar chlorinated side products were isolated and characterized. Twenty compounds were screened for in vitro antitumoral and anti-HIV-1 activities and found poorly active or completely inactive. On the other hand several compounds exhibited good tracheal relaxant activity in vitro; compound 8, 11, 16, 24 and 26 resulted more active than theophylline in this test, while compound 11 was comparable to amrinone till the concentration of 3 micrograms/ml. Finally, compound 5 resulted endowed with a strong diuretic and saluretic activity at the dose of 3 mg/Kg, thus representing a new lead for discovering new diuretic agents.     

Ti(Ⅳ)-Fe(Ⅲ)-H2O2-棓化青体系动力学光度法测定钛(Ⅳ)

在H2SO4介质中,铁(Ⅲ)能催化H2O2氧化棓化青褪色,钛(Ⅳ)对该催化反应有显著的催化作用,据此建立了测定痕量钛(Ⅳ)的动力学分析新方法。研究了该反应的最佳条件和动力学参数。以钛(Ⅳ)为催化剂的Fe(Ⅲ)-H2O2-棓化青催化反应体系中,对棓化青为假零级反应,对钛(Ⅳ)为一级反应,测得没有钛(Ⅳ)和有钛(Ⅳ)反应体系的表观活化能分别为79.75 kJ/mol和49.82 kJ/mol。该方法测定钛(Ⅳ)的检出限为0.01μg/mL,测量范围为0.03~0.16μg/mL,可用于废水样品中痕量钛(Ⅳ)测定。     

Synthesis and biological activities of optically active 6-[3-(3,4-dimethoxybenzylamino)-2-hydroxypropoxy]-2(1H)-quinolinone (OPC-18790)

The enantiomers of 6-[3-(3,4-dimethoxybenzylamino)-2-hydroxypropoxy]-2(1H)-quinolinon e (OPC-18790), a novel cardiotonic agent, were synthesized and evaluated for positive inotropic activity. The key intermediates, 2,3-epoxypropoxy derivatives, were obtained by the alkylation of 6-hydroxy-2(1H)-quinolinone with optically active epichlorohydrin and subsequent ring closure. In an in vitro study, the (R)-(+)-isomer was about 10-fold more potent than the (S)-(-)-isomer.