酒石酸托特罗定的合成研究

目的:合成酒石酸托特罗定并进行工艺改进。方法:以对甲苯酚为起始原料,经缩合、甲基化、还原、酯化、胺化、脱甲基化、拆分、精制等反应合成酒石酸托特罗定,并对脱甲基化反应进行了工艺改进。结果:通过改进工艺,总收率由9.23%提高到13.5%。结论:优化工艺后,收率提高,成本降低,解决了劳动保护和环保问题,更适合工业化生产。     

一氧化氮供体N-芳基-N′-羟基胍类化合物的合成

目的:改进新型一氧化氮供体N-芳基-N′-羟基胍的合成工艺。方法:以取代苯胺为起始原料,通过缩合、水解、肟化反应获得目标化合物。结果:肟化收率由文献报道的20%提高至40%,目标化合物的结构经IR、1HNMR和MS确证。结论:本合成工艺具有原料易得、操作简便、收率较高等优点,适合工业化生产。     

硫普罗宁的合成工艺研究

目的:改进硫普罗宁的合成工艺.方法:以丙酸为起始原料,经溴化、取代、缩合、置换、水解反应合成硫普罗宁,对置换剂硫代苯甲酸的合成方法进行了改进.结果:对各步反应条件进行了优化,总收率达到66.1%,高于文献报道的38.2%.结论:合成工艺操作简便,提高了收率,降低了成本,适合工业化生产.     

温度对枸橼酸铋钾合成中的影响

研究以枸橼酸铋与枸橼酸钾为原料合成枸橼酸铋钾的工艺中温度的影响。在原辅料、反应条件一致的前提下,不同反应温度情况下,产品一:含量达36.5%,总收率达115%;产品二:含量达37.8%,总收率达105%;产品三:含量达36.3%,总收率达116%;产品四:含量达38.1%,总收率达104%。根据实验对比数据论述温度在枸橼酸铋钾合成过程中的影响,从而为枸橼酸铋钾合成工艺优化,提供重要依据。     

新型抗心绞痛药物雷诺嗪的合成工艺改进

目的:对抗心绞痛药雷诺嗪现有合成工艺进行改进.方法:以2,6-二甲基苯胺为起始原料,经过酰化、缩合、环加成、成盐等4步反应合成产品雷诺嗪.结果:产品总收率为51.9%,其化学结构经1H NMR、MS、IR确证,HPLC法检测纯度达到99.2%.结论:该工艺反应条件温和,收率较高,操作简便,易于工业化生产.     

联苯乙酸的合成工艺研究

目的:改进非甾体抗炎药联苯乙酸合成工艺。方法:以联苯为原料,经酰化、缩合、水解反应制备。结果:酰化反应通过改变反应条件,使该步反应收率由文献方法的89%提高到90.2%,成品由文献方法的醋酸重结晶改为氨水-醋酸重结晶。结论:酰化反应中改变了其反应条件,提高了反应收率;成品改进了重结晶的方法,使杂质含量及杂质数量减少。     

法西多曲合成工艺的改进

目的:对法西多曲合成工艺改进.方法:以胡椒丙烯酸为原料,经加成、拆分、缩合反应以及结晶分离,制得法西多曲.结果:合成目标化合物,总收率39.2%.结论:该方法操作简单,收率较高.     

帕米格雷的合成

目的:帕米格雷的合成及工艺优化.方法:以α-氨基-对甲氧基苯乙酸和苯甲醚为原料,经傅克酰化、缩合、取代3步反应制得帕米格雷.结果:合成目标化合物,总收率47%.结论:该方法原料易得,操作简单.     

抗病毒药喷昔洛韦的合成工艺改进

目的 对喷昔洛韦的合成工艺改进.使之适合工业化生产.方法 以鸟嘌呤为原料,经氯化,缩合,水解等三步反应合成喷昔洛韦.结果与结论 合成经工艺改进,多步收率有较大提高,总收率为19.5%.     

佐米曲普坦的合成及工艺改进

目的:改进佐米曲普坦的合成工艺.方法:以(L)-苯丙氨酸为原料,经硝化,酯化,还原(酯基),环合,还原(硝基),重氮化,还原(重氮盐)和费歇尔吲哚合成共八步反应制得佐米曲普坦.结果:改进了佐米曲普坦的合成工艺,总收率提高至16%.结论:改进后的合成工艺操作简便,成本低,收率高,适于工业化生产.     

Glucosinolates in Moringa stenopetala

Bio-guided fractionation of seed extracts from Moringa stenopetala resulted in a myrosinase hydrolysis product, 5,5-dimethyloxazolidine-2-thione. It is formed from the glucosinolate glucoconringiin, which was identified together with O-(rhamnopyranosyloxy)benzyl glucosinolate from M. stenopetala for the first time. The glucosinolates in seeds, leaves and roots of M. stenopetala were quantified as des-sulphoglucosinolate by HPLC. The seeds without testa contained the highest concentration of glucoconringiin and of O-(rhamnopyranosyloxy)benzyl glucosinolate within the plant, 3 % and 19 % of dry mass, respectively. Abbreviations. GLS:glucosinolate GC:glucoconringiin RB-GLS: O-(rhamnopyranosyloxy)benzyl glucosinolate     

HPLC法同时测定地西泮直肠凝胶中地西泮、 苯甲酸、苯甲醇含量

目的:建立了同时测定地西泮直肠凝胶中地西泮、苯甲酸、苯甲醇含量的高效液相色谱方法。方法:色谱柱为Agilent Eclipse Plus C18(4.6 mm×150 mm,3.5μm),以甲醇-0.05 mol·L^-1乙酸铵缓冲溶液(pH 4.0)为流动相,梯度洗脱,流速1.0 mL·min^-1,检测波长254 nm,柱温30℃,进样量10μL。结果:地西泮、苯甲酸、苯甲醇分离度均大于1.5,地西泮在0.010~0.200 mg·mL^-1范围内线性关系良好(r≥0.9999);苯甲酸在0.030~0.600 mg·mL^-1范围内线性关系良好(r≥0.9999);苯甲醇在0.0718~1.436 mg·mL^-1范围内线性关系良好(r≥0.9999);且地西泮、苯甲酸、苯甲醇的平均回收率均在98%~101%,RSD均小于2.0%(n=9)。结论:本法简单准确可靠,可用于地西泮直肠凝胶中地西泮、苯甲酸、苯甲醇的含量测定。     

HPLC法快速检测苦参素注射液中8个抑菌剂及苯甲醛

目的:建立快速筛查和同时测定苦参素注射液中8个抑菌剂(苯甲醇、苯酚、苯甲酸、山梨酸、对羟基苯甲酸甲酯、对羟基苯甲酸乙酯、对羟基苯甲酸丙酯、对羟基苯甲酸丁酯)及苯甲醇降解产物—苯甲醛含量的高效液相色谱法。方法:应用Welch Materials XB-C18色谱柱(4.6 mm×250 mm,5μm),流动相为乙腈-0.02 mol.L-1醋酸铵溶液(冰醋酸调pH至5.0)梯度洗脱,流速1.0 mL.min-1,检测波长为211 nm(苯甲醇、苯酚),225 nm(苯甲酸),248 nm(苯甲醛),256 nm(山梨酸、对羟基苯甲酸甲酯、对羟基苯甲酸乙酯、对羟基苯甲酸丙酯、对羟基苯甲酸丁酯)。结果:9个成分的峰面积与浓度的线性关系良好(r﹥0.9998),加样回收率为95.6%～102.2%。结论:本方法灵敏,快捷,准确,重复性好,可用于注射剂中抑菌剂的快速筛查与含量分析。     

Effects of benzyl alcohol on aggregation of recombinant human interleukin-1-receptor antagonist in reconstituted lyophilized formulations

A major limitation in the successful development of multidose protein formulations is protein aggregation induced by antimicrobial preservatives such as benzyl alcohol, which are included to maintain product sterility. Studies were conducted to evaluate the strategy of developing lyophilized formulations of a therapeutic protein, recombinant human interlukin-1 receptor antagonist (rhIL-1ra), to be reconstituted with a bacteriostatic amount (0.9% w/v) of benzyl alcohol in water. The strategy was based on the following hypotheses. The first was that benzyl alcohol would foster aggregation during reconstitution of the lyophilized sample. The second hypothesis was that the extent of benzyl alcohol-induced protein aggregation would correlate directly with the degree of structural perturbation of rhIL-1ra in the dried solid after lyophilization. Differential structural retention of rhIL-1ra in the dried solid was obtained by using a combination of formulation variables important for lyophilization and included: protein concentration, type of stabilizer, and presence or absence of NaCl. Infrared spectroscopic analysis of the lyophilized samples indicated that high initial solution protein concentration and the stabilizer sucrose minimized structural perturbation of rhIL-1ra during lyophilization. In contrast, NaCl was destabilizing. Reconstitution of the dried solid with 0.9% (w/v) benzyl alcohol caused a greater degree of protein aggregation than reconstitution with water, confirming our first hypothesis. In support of our second hypothesis, the extent of aggregation induced by benzyl alcohol during reconstitution was strongly modulated by the degree of retention of native rhIL-1ra secondary structure during lyophilization. During storage of the reconstituted lyophilized samples at room temperature, benzyl alcohol did not accelerate aggregation of rhIL-1ra. This study demonstrated that for development a multidose lyophilized protein formulation involving reconstitution with a solution of benzyl alcohol, protein structural perturbations during freeze-drying should be minimized with a stabilizing excipient and appropriate choice of protein concentration and tonicity modifier. Furthermore, postreconstitution storage at reduced temperature (e.g., room temperature or 4 degrees C) could minimize the risk of preservative-induced protein aggregation.     

High-Performance Liquid Chromatographic Assay for Thyrotropin Releasing Hormone and Benzyl Alcohol in Injectable Formulation

A stability-indicating, high-performance liquid chromatographic method is presented for the determination of thyrotropin releasing hormone (TRH) and benzyl alcohol in a multidose injectable formulation. Separation is achieved on a microparticulate octadecylsilica column, with pH 2.2 ion-pair reagent (octanesulfonic acid, sodium salt) solution/methanol/acetonitrile/triethylamine (92:4:4:0.01), at a flow rate of 1.5 ml/min and a detection wavelength of 215 nm. p-Aminobenzoic acid is used as an internal standard. The relative standard deviations of the method are ±0.6% for TRH and ±0.7% for benzyl alcohol. Recoveries from standard additions to placebos ranged from 99.0 to 101.3 and 99.7 to 101.8% for TRH and benzyl alcohol, respectively.     

HPLC法快速检测苦参素注射液中8种抑菌剂及苯甲醛

目的:建立快速筛查和同时测定苦参素注射剂中8种抑菌剂(苯甲醇、苯酚、苯甲酸、山梨酸、对羟基苯甲酸甲酯、对羟基苯甲酸乙酯、对羟基苯甲酸丙酯、对羟基苯甲酸丁酯)及苯甲醇降解产物———苯甲醛含量的高效液相色谱法。方法:应用WelchMaterials XB-C18色谱柱(4.6 mm×250 mm,5μm);流动相为乙腈-0.02 mol.L-1醋酸铵(冰醋酸调pH至5.0)梯度洗脱,流速1.0 mL.min-1,检测波长为211 nm(苯甲醇、苯酚),225 nm(苯甲酸),248 nm(苯甲醛),256 nm(山梨酸、对羟基苯甲酸甲酯、对羟基苯甲酸乙酯、对羟基苯甲酸丙酯、对羟基苯甲酸丁酯)。结果:9种成分的峰面积与浓度的线性关系良好(r>0.9998),加样回收率为95.6%～102.2%。结论:本方法灵敏,快捷,准确,重复性好,可用于注射剂中抑菌剂的快速筛查与含量分析。     

Role of benzyl alcohol in the prevention of heat-induced aggregation and inactivation of hen egg white lysozyme

The aim of the study was to investigate the stability of a model protein, lysozyme, in the presence of the commonly used preservative benzyl alcohol. Techniques including lytic assay, size exclusion chromatography, circular dichroism, differential scanning calorimetry, native polyacrylamide gel electrophoresis and dynamic light scattering were used to study the overall stability of lysozyme in the presence of benzyl alcohol. The stability of lysozyme against thermal stress was higher in the presence of benzyl alcohol. In the presence of 0.5%, 0.9% and 2% v/v benzyl alcohol, the enzyme showed 33%, 42% and 75% residual activity, respectively, when exposed to 75 °C for 2 h, as compared to the 22% activity of control sample. A gradual increase in the size of aggregates was observed for the control sample relative to the samples containing benzyl alcohol, as a result of loss of monomer concentration. The effect was found to be concentration-dependent with 2% benzyl alcohol showing maximum prevention of heat-induced unfolding and aggregation. This effect is remarkable since the thermal transition temperature of the enzyme decreases in the presence of benzyl alcohol. Benzyl alcohol favours the thermal denaturation of lysozyme but stabilizes the lysozyme against the heat-induced aggregation.     

Effects of pH, temperature, and sucrose on benzyl alcohol-induced aggregation of recombinant human granulocyte colony stimulating factor

Antimicrobial preservatives (e.g., benzyl alcohol), which are required in multidose formulations, can induce protein aggregation. In this study, the mechanism of benzyl alcohol-induced aggregation of recombinant human granulocyte colony-stimulating factor (rhGCSF) was investigated by determining the effects of temperature, pH, and sucrose on this process. rhGCSF was incubated at 25 and 37 degrees C and at pH 7.0 (phosphate-buffered saline, PBS) and pH 3.5 (HCl). Benzyl alcohol (0.9% w/v) accelerated aggregation of rhGCSF at pH 7.0, an effect that was much greater at 37 degrees C than at 25 degrees C and partially counteracted by 1.0 M sucrose. At pH 3.5, benzyl alcohol did not induce aggregation of rhGCSF. Spectroscopic studies showed that 0.9% benzyl alcohol altered the tertiary structure of rhGCSF at both pH, without detectably altering secondary structure. Structural perturbation was greater at 37 degrees C than at 25 degrees C. At both pH 7.0 and 3.5, the hydrogen-deuterium (H-D) exchange rate for rhGCSF was increased by 0.9% benzyl alcohol. Sucrose (1.0 M) partially counteracted the benzyl alcohol-induced perturbation of tertiary structure and the increase in H-D exchange rate. Thus, benzyl alcohol accelerates aggregation of rhGCSF at pH 7.0, because it favors partially unfolded aggregation-prone conformations of the protein. Sucrose partially counteracts benzyl alcohol-induced rhGCSF aggregation by shifting the molecular population away from these species and towards more compact conformations. We postulate that the absence of aggregation at pH 3.5, even with benzyl alcohol-induced structural perturbation, is due to the unfavorable energetics of intermolecular interactions (i.e., colloidal stability) between rhGCSF molecules at this pH.     

Assessment of genotoxic effects of benzyl derivatives by the comet assay

In this study, different concentrations of four benzyl derivatives (benzyl alcohol, benzyl acetate, benzoic acid and benzaldehyde) used as flavour ingredients were investigated for genotoxicity in in vitro. By taking blood from two healthy people comet assay was carried on to investigate the potential health damages of benzyl derivatives. For the evaluation of genotoxic effects, the tail moment and % tail DNA in the treated chemicals were compared to the solvent control, which is distilled water. The alkaline comet assay showed significantly increased tail moment and % tail DNA at 25 and 50 mM concentrations of benzyl alcohol. Benzyl acetate increased both % tail DNA and tail moment at 50 mM concentrations. While % tail DNA was statistically increased at 10 mM and higher concentrations, tail moment has significant difference at 10 and 25 mM concentrations of benzaldehyde. Benzoic acid has apoptotic effects at the concentrations higher than 5 mM, for this reason we tested concentrations less than 5 mM (0.05, 0.1, 0.5, 1 and 5 mM). Only the highest concentration of benzoic acid increased both tail moment and % tail DNA.     

Toxicity of benzyl alcohol in adult and neonatal mice

Benzyl alcohol, a bacteriostatic agent found in many parenteral preparations, has been implicated as the agent responsible for precipitating "the gasping syndrome" in premature neonates. To investigate this toxicity, benzyl alcohol was administered intraperitoneally to adult (23-28 g) and neonatal (2-7 g) CD-1 male mice. Gross behavioral changes were monitored. Low doses (less than 800 mg/kg) produced minimal toxic effects within an initial 4-h observation period. At the end of this time, the LD50 was determined to be 1000 mg/kg for both age groups. When mortality in the adult group was observed after 7 d following a single treatment with benzyl alcohol, the LD50 on day 7 was determined to be 650 mg/kg. Rapid absorption and conversion of benzyl alcohol to its primary metabolite, benzaldehyde, occurred within both experimental groups; the plasma levels of each were comparable in both neonatal and mature animals when determined by GC. In an attempt to alter the toxicity of benzyl alcohol, pyrazole and disulfiram were used to inhibit the activities of alcohol dehydrogenase and aldehyde dehydrogenase, respectively. Treatment with pyrazole, before benzyl alcohol exposure, resulted in an increase in benzyl alcohol levels to 203% of control values and a marked increase in toxicity. Although pretreatment with disulfiram led to benzaldehyde levels which were 368% of control values, toxicity was unchanged. These data imply that the acute toxicity of benzyl alcohol, which includes sedation, dyspnea, and loss of motor function, is due to the alcohol itself and not to its metabolite, benzaldehyde.