N-nitroso-N-methyldodecylamine and N-nitroso-N-methyltetradecylamine in hair-care products

N-Nitroso-N-methyldodecylamine and N-nitroso-N-methyltetradecylamine, which cause urinary bladder tumours in experimental animals, were detected in several hair-care products formulated with N,N-dimethyldodecylamine oxide. Quantitative determinations were made using a gas-liquid chromatograph interfaced with a thermal energy analyser and using [1-¹⁴C]N-nitroso-N-methyldodecylamine as an internal standard. The presence of the two nitrosamines was confirmed by high-pressure liquid chromatography with a thermal energy analyser as detector, by photolysis of samples and by combined gas chromatography-mass spectrometry. To test the reproducibility of the method, a single shampoo was selected for replicate analysis and was found to contain 90 ± 8 ppb N-nitroso-N-methyldodecylamine and 37 ± 11 ppb N-nitroso-N-methyltetradecylamine. Levels of N-nitroso-N-methyldodecylamine in other hair-care products ranged from 11 to 873 ppb and those of N-nitroso-N-methyltetradecylamine from 8 to 254 ppb.     

Estimation of volatile N-nitrosamines in rubber nipples for babies' bottles

A method is described for the estimation of volatile N-nitrosamines in the rubber nipples of babies' bottles. In a study of rubber nipples from one manufacturer. N-nitrosodimethylamine. N-nitrosodiethylamine and N-nitrosopiperidine were determined by gas chromatography, using a thermal energy analyser, and their presence was confirmed by mass spectrometry with average levels of individual nitrosamines ranging from 22 to 281 ppb. When the nipples were sterilized in a conventional sterilizer together with milk or infant formula the three nitrosamines migrated into the milk or formula. Storing a bottle of milk with a rubber nipple inverted in it for 2 hr at room temperature or overnight in a refrigerator after sterilization resulted in an 8–l3% average increase in the nitrosamine levels migrating into the milk. On repeated sterilization of a single nipple, the quantities of nitrosamines migrating into milk from rubber nipples declined steadily, but after seven sterilizations, nitrosamines were still readily detectable in the milk. Nitrosamine levels were higher in rubber nipples after sterilization, indicating the presence of nitrosamine precursors in the nipples. No nitrosamines were found in raw, uncured rubber. Chemical accelerators and stabilizers added during the vulcanization process are the source of the amine precursors in rubber nipples.     

A multi-analyte LC-MS/MS method for screening and quantification of nitrosamines in sartans

An incident of sartan medicine contamination was notified by Europe in June 2018. The contaminant was identified as a probable carcinogenic nitrosamine and the recalls of sartan medicines were soon made. Since then, more nitrosamine contaminants in sartan medicines were reported. To broaden the applicability and variety in nitrosamine determination, a multi-analyte method is required. In this study, a feasible and sensitive multi-analyte LC-MS/MS method for determination of 12 nitrosamines in sartans was established, where the active pharmaceutical ingredients and final products merchandised in Taiwan were also examined. Chromatographic separation was achieved on an Xselect^® HSS T3 column (15 cm × 3 mm i.d., 3.5 μm) with gradient elution using mobile phase A consisting of 0.1% formic acid in water and mobile phase B consisting of 0.1% formic acid in acetonitrile/methanol (2:8). Validation of the proposed method was also carried out. The limit of detection and limit of quantification for 12 nitrosamines were 20 ng/g and 50 ng/g, respectively. The intra-day and inter-day recoveries of nitrosamines were among 80–120% with precision of 20% for most nitrosamines within sartans matrices. The method was successfully established and applied to authentic samples which a total of 98 positive samples containing 5 distinct nitrosamines, including N-nitrosodiethylamine, N-nitrosodimethylamine, N-nitroso-N-methyl-4-aminobutyric acid, N-nitrosomorpholine and N-nitrosopiperidine, were detected from 557 authentic samples.     

A novel compound N,N-(Z)-N-(E)-tri-p-coumaroylspermidine isolated from Carthamus tinctorius L. and acting by serotonin transporter inhibition

Safflower, the dry flower of Carthamus tinctorius L., has long been applied for empirically treating cerebral ischemia and depression in traditional Chinese medicine. Pathogenesis of major depression involves monoaminergic transmission. The present study assessed whether safflower or its isolate would be effective in functionally regulating monoamine transporter using in vitro screening cell lines. We discovered that safflower insoluble fraction significantly inhibited serotonin uptake in Chinese hamster ovary cells stably expressing serotonin transporter (i.e. S6 cells). This fraction went through an activity-guided isolation and an active ingredient was obtained, which was subsequently elucidated as a novel coumaroylspermidine analog N¹,N⁵-(Z)-N¹⁰-(E)-tri-p-coumaroylspermidine using NMR techniques. Pharmacologically, this compound potently and selectively inhibited serotonin uptake in S6 cells or in synaptosomes, with IC₅₀ of 0.74 ± 0.15 µM for S6 cells or 1.07 ± 0.23 µM for synaptosomes and with a reversible competitive property for the 5HT-uptake inhibition. The potency of it for 5HT uptake was weaker than that of fluoxetine whereas efficacy generally similar for both. Animals treated with this testing compound showed a significant decrease in synaptosomal 5HT uptake capacity. Thus, N¹,N⁵-(Z)-N¹⁰-(E)-tri-p-coumaroylspermidine is a novel serotonin transporter inhibitor, which could improve neuropsychological disorders through regulating serotoninergic transmission.     

N6-苯甲酰基-2'-叔丁基二甲基硅氧基腺苷-3'-H-膦酸的合成工艺研究

目的 研究N~6-苯甲酰基-2′-叔丁基二甲基硅氧基腺苷-3′-H-膦酸的合成工艺。方法 以腺苷为起始原料,先对腺苷的嘌呤氨基进行苯甲酰基保护,再分别向腺苷的5′位和2′位引入二甲氧基三苯甲基(DMT)和叔丁基二甲基硅基(TBDMS)保护基,制备得到关键中间体N~6-苯甲酰基-5′-二甲氧基三苯甲氧基-2′-叔丁基二甲基硅氧基腺苷(3)。中间体3与磷试剂2-氯-4H-1,3,2-苯并二氧磷杂环己烷-4-酮反应引入膦酸基团,最后使用二氯乙酸脱除DMT保护基得到目标产物。结果 经过5步反应得到了目标化合物N~6-苯甲酰基-2′-叔丁基二甲基硅氧基腺苷-3′-H-膦酸,并利用~1H-NMR、~(31)P-NMR、质谱等方法确证了其结构。本合成工艺的总收率为35.7%,目标化合物的质量分数为98.5%。结论 该合成工艺与原有方法相比步骤短,操作简单,具有良好的应用前景。     

N-Nitro-L-arginine protects against ischaemia-induced increases in nitric oxide and hippocampal neuro-degeneration in the gerbil

To assess the effects of the nitric oxide synthase inhibitor N^G-Nitro-L-arginine on behavioural, biochemical and histological changes following global ischaemia, the Mongolian gerbil was used. Ischaemia was induced by bilateral carotid occlusion for 5 min. N^G-Nitro-L-arginine was administered i.p. at either 1 or 10 mg/kg 30 min, 6, 24, and 48 h after surgery. 5 min bilateral carotid occluded animals were hyperactive 24, 48 and 72 h after surgery. N^G-Nitro-L-arginine caused some attenuation in this hyperactivity. The activity of nitric oxide synthase was increased in the cerebellum, brain stem, striatum, cerebral cortex and hippocampus of 5 min bilateral carotoid occluded animals. N^G-Nitro-L-arginine reversed the increase in nitric oxide synthase activity in all brain regions. Extensive neuronal death was observed in the CA₁ layer of the hippocampus in 5 min bilateral carotid occluded animals 96 h after surgery. N^G-Nitro-L-arginine significantly protected against the neuronal death of cells in the CA₁ layer.     

S-adenosyl- -methionine N-ole-1-oyltaurate: pharmacokinetic of the orally administered salt in rats

A pharmacokinetic study based on the distribution of radioactivity from the double labelled S-adenosyl- -methionine (SAM) has been carried out by oral administration of the liposoluble stable salt [methyl-¹⁴C, 8-³H]SAM N-ole-1-oyltaurate to rats. The SAM sulfate p-toluensulfonate salt, the only SAM salt at present commercialized as drug, was chosen as reference compound to have a comparative pharmacokinetic analysis. The metabolism of the SAM is characterised by a differential use of the two labelled moieties by the various organs, liver being the most active in metabolizing the sulfonium compound with a preferential uptake of the methyl-¹⁴C fragment. The radioactivity detected after the administration of [methyl-¹⁴C, 8-³H]SAM N-ole-1-oyltaurate is, in all the organs examined, two times higher than the [methyl-¹⁴C, 8-³H]SAM sulfate p-toluensulfonate compound, attesting that the liposoluble [methyl-¹⁴C, 8-³H]SAM N-ole-1-oyltaurate is provided with better bioavailability.     

Effect of N-nitro-l-arginine on shock induced by endotoxin and by platelet activating factor in dogs

When N^G-nitro-l-arginine, a nitric oxide synthase inhibitor, administration was started 5 min prior to shock induction in anesthetized dogs, a partial restoration was observed in endotoxin-induced shock and a complete recovery in platelet activating factor (PAF)-induced shock. When N^G-nitro-l-arginine infusion was started 5 min after shock induction, no significant recovery was observed in endotoxin-induced shock and a complete recovery in PAF-induced shock. These data indicate that enhanced production of nitric oxide by vascular endothelial cells may contribute to endotoxin- or PAF-induced shock and also that some mediators including inducible nitric oxide synthase and/or cellular damage might be involved in endotoxin-induced shock.     

Metabolism of 15N-labelled N-nitrosodimethylamine and N-nitroso-N-methylaniline by isolated rat hepatocytes

The N-demethylation of ¹⁵N-labeled N-nitrosodimethylamine (DMN) and N-nitroso-N-methylaniline (NMA) by isolated rat hepatic cells has been investigated. The values obtained in this system for molecular nitrogen formed during metabolism, compared with substrate consumed, were DMN 47%, NMA 23%, and N-nitroso-N-methylurea (NMU) 105%. The results for DMN are roughly halfway between those previously determined with rat liver S-9 fraction in vitro (33%) and in vivo (67%). For NMA, the hepatocyte data are closer to those obtained from S-9 in vitro (19%), rather than the in vivo (52%). No mixed nitrogen (¹⁵N¹⁴N) or labeled nitrogen oxides were found.     

Chemical properties and immunotropic activity of the products from reaction of N-(6-methyl-2,4-dioxo-1,2,3,4-tetrahydro-5H-pyrimidinesulfone)-N′-isonicotinoylhydrazide with acids and bases in aqueous media

The effect of tautomerism on the structure of products from the reaction of N-(6-methyl-2,4-dioxo-1,2,3,4-tetrahydro-5H-pyrimidinesulfone)-N′-isonicotinoylhydrazide (kristafon) with acids (hydrochloric, phosphoric, acetic, oxalic, succinic, citric, hyaluronic) and bases [sodium hydroxide, triethanolamine, tris-(hydroxymethyl)aminomethane] in aqueous media has been studied using UV, IR, PMR, and ¹³C NMR spectroscopy techniques. The properties of kristafon are compared to those of analogous compounds containing pyridine (isonicotine hydrazide, sulfotolylisonicotine hydrazide) and pyrimidine [bis-p-(2,4-dioxo-6-methylpyrimidinyl-5-sulfonamino)-diphenylsulfone] fragments in acid–base media. It is shown that the immunotropic activity of kristafon phosphate and kristafon are improved in hyaluronic acid solution.     

Inhibitory effect of N-nitro-

报道11个预期有血管紧张素转化酶抑制活性的N-(4-甲氧羰基-4-邻苯二甲酰亚氨基丁酰基)-N-取代甘氨酸(VII_1～9)、脯氨酸(VII₁₀)和焦谷氨酸(VIl₁₁)的合成和鉴定。所有上述化合物以及与VⅡ_1～9相应的叔丁酯(VI_1～9)均未见文献报道。药理初试结果显示，化合物VII₈，VII₉和VI₁₀均有明显降压活性。     

N-(4-甲氧羰基-4-邻苯二甲酰亚氨基丁酰基)-N-取代甘氨酸、脯氨酸和焦谷氨酸的合成

报道11个预期有血管紧张素转化酶抑制活性的N-(4-甲氧羰基-4-邻苯二甲酰亚氨基丁酰基)-N-取代甘氨酸(VII_1～9)、脯氨酸(VII₁₀)和焦谷氨酸(VIl₁₁)的合成和鉴定。所有上述化合物以及与VⅡ_1～9相应的叔丁酯(VI_1～9)均未见文献报道。药理初试结果显示，化合物VII₈，VII₉和VI₁₀均有明显降压活性。     

Qualitative detection of N-nitrosodiethanolamine in cosmetic products

A relatively quick and simple procedure is described for the detection of N-nitrosodiethanolamine in various cosmetic products. The procedure is based on the irreversible formation of p-nitrosoN,N-dimethylaniline which has a bright yellow colour in basic solution. The compound is formed following extraction of the cosmetic, photolysis of the aqueous extract and the addition of N,N-dimethylaniline to photolysed extract.     

茚三酮柱后衍生法测定丙氨酰-谷氨酰胺的含量

目的建立茚三酮柱后衍生化氨基酸分析仪测定N（2）-L－丙氨酰－L－谷氨酰胺（L－Ala－L－Glu）含量的方法。方法根据L－Ala－L－Glu与茚三酮反应后溶液在570nm处有最大吸收的原理,以钾钠缓冲液为流动相,将L－Ala-L－Glu洗脱后,与茚三酮进行柱后衍生反应,生成可以被分光光度计检测的有色物质,氨基酸分析仪测定L—Ala-L－Glu的含量。结果L－Ala-L-Glu在1-20mg·L^-1、内线性关系良好（r=0.9979）,低、中、高3种浓度的回收率分别为94．5％,97．6％和98.7％;RSD分别为0.52％,0．10％和O．06％。结论本法操作简单,分离度良好,结果准确可靠,可用于L－Ala－L－Glu的含量测定。     

N-Glucuronidation of N-hydroxy aromatic amines: A mechanism for their transport and bladder-specific carcinogenicity

Glucuronide conjugates of carcinogenic N-hydroxy metabolites of the primary aromatic amines, 4-aminobiphenyl (4-ABP), 2-naphthylamine (2-NA), and 1-naphthylamine (1-NA) were isolated from the urine of dogs administered the respective primary amine and from the in vitro incubation of N-hydroxy metabolites with uridine-5′-disphosphoglucuronic acid-fortified dog liver microsomes. The urinary and microsomal conjugates were purified by several sequential chromatographic procedures, including Sephadex G-15, Amberlite XAD-2, and cellulose CF-11 chromatography for microsomal conjugates and Sephadex G-10, DEAE, and Amberlite XAD-2 chromatography for urinary conjugates. The infrared spectra of purified urinary and microsomal conjugates of these three N-hydroxy aromatic amines were identical to spectra of authentic N---C glucuronides prepared by two different synthetic procedures. The urinary and microsomal conjugates comigrated with synthetic N---C glucuronides in two solvent systems. These observations in conjunction with previous studies provide evidence that N---C glucuronidation represents a general metabolic reaction of carcinogenic N-hydroxy aromatic amines which provides the means of transport of these compounds to their site of action in the bladder.     

N-硬脂酰酪氨酸的理化性质研究

目的 表征N-硬脂酰酪氨酸及其盐的理化常数和血浆蛋白结合率。方法 采用摇瓶法及HPLC-UV法测定N-硬脂酰酪氨酸及其盐在不同介质和pH值下的溶解度、表观脂水分配系数,采用平衡透析法测定血浆蛋白结合率。结果 N-硬脂酰酪氨酸盐的溶解度和血浆蛋白结合率明显优于其原型药物;N-硬脂酰酪氨酸的溶解度为（27.62±0.43）mg/L,其二钾盐的溶解度为（51.70±0.29）mg/L;N-硬脂酰酪氨酸及其二钾盐的血浆蛋白结合率分别为20.96%～23.11%、35.41%～40.38%。结论 N-硬脂酰酪氨酸成盐后其理化性质得到明显改善。     

油酰乙醇胺对东莨菪碱诱导小鼠认知功能损伤的保护作用

目的 探讨油酰乙醇胺对东莨菪碱诱导小鼠认知功能损伤的保护作用。方法 将小鼠随机分为6组：对照组、模型组、多奈哌奇组（阳性药,3 mg·kg^-1）和油酰乙醇胺低、中、高剂量（50、100、200 mg·kg^-1）组,每组6只。在ig给药4周后,除对照组外,各组ip 3 mg·kg^-1的东莨菪碱建立阿尔茨海默病（AD）模型。避暗、跳台行为学实验检测小鼠记忆功能; ELISA法检测小鼠海马和大脑皮层中乙酰胆碱（Ach）和乙酰胆碱酯酶（AChE）水平;HE染色观察小鼠大脑皮层及海马损伤。结果 与对照组比较,模型组的避暗潜伏期显著缩短、避暗错误次数显著增加（P<0.001）;大脑皮层、海马的Ach水平显著减少（P<0.01、0.001）,AChE活性显著升高（P<0.001）;模型组的小鼠脑组织形态结构不均匀,组织细胞呈弥散状,提示组织存在病变。与模型组比较,各给药组的避暗潜伏期显著升高、避暗错误次数显著减少（P<0.01）;油酰乙醇胺给药组的小鼠大脑皮层、海马组织Ach水平显著升高（P<0.05、0.01）,AChE活性显著降低（P<0.01、0.001）;小鼠脑组织形态结构病理改变减轻。结论 油酰乙醇胺对东莨菪碱诱导学习记忆障碍模型小鼠的认知功能具有改善作用,其作用机制可能与调节胆碱能系统功能、促进神经细胞存活有关。     

N-甲基-N-(α-取代萘甲基)取代苄胺类化合物的合成及抗真菌活性

报道25个N-甲基-N-(α-取代萘甲基)取代苄胺类化合物的合成及抗真菌活性。抑菌测试结果表明,目标化合物对于8种试验菌种均有不同程度的抑菌活性,化合物6,7,8,10,11和21等活性为naftifine的4～20倍,化合物8,10,11和21等活性为butenafine的2～10倍,化合物8,9,10,11和21等对Sporotrichum schencki及Aspergilus fumigatus的活性为clotrimazole的8～15倍,化合物7,8,9和21等对Cryptococus neoformans亦表现出较高活性,MIC为0.31～1.25μg·ml^-1。     

氯霉素类似物——1-对硝基苯-2-(N-甲基二氯乙酰氨基)-丙醇-1[1-p-nitrophenyl-2-(N-methyl-dichloroacetamido)-propanol-1|

A Chloramphenicol analog——1-p-nitrophenyl-2-(N-methyl-dichloroacetamido)-propa- nol-1(V)was synthesized for antibacterial tests.The compound was prepared from pseudo- ephedrine by acetylation,nitratlon,followed by hydrolysis and dichloroacetylation.     

褪黑激素(N-乙酰基-5-甲氧基色胺)的合成

This paper reports the synthesis of melatonin(N-acetyl-5-methoxytryptamine).The structure of all the compounds synthesized were characterized by elemental analysis,IR, MS and ¹HNMR spectra.