3,5-二甲基-2-(3'''',5''''-二氟苯基)-2-吗啉醇盐酸盐的合成

目的：合成抗抑郁药安非他酮类似物3，5-二甲基-2-（3’，5’-二氟苯基）-2-吗啉醇盐酸盐。方法：以3，5-二氟苯丙酮为原料，经溴代、胺化、环合、酸化合成了目标产物。结果：合成目标产物的总收率为77．3％，中间体和产物经红外光谱和核磁共振谱确证。结论：以溴化铜为α-溴代反应溴化剂进行澳代反应，选择性高，产物易于分离。在非质子极性溶剂中进行胺化反应，反应时间短，溶剂无毒性，具有较高的应用价值。     

3-己基异香豆素的合成研究

目的研究3-己基异香豆素的合成方法。方法以邻碘苯甲酸为原料,经酯化、Sonogashira交叉偶联以及亲电环化反应三步合成3-己基异香豆素。结果重点考察了催化剂、配体和碱等因素对Sonogashira交叉偶联反应的影响,以及催化剂、溶剂和温度等因素对亲电环化反应的影响,在最佳的反应条件下,反应总产率为79.5%,中间产物和目标产物的结构经NMR和MS得以确证。结论该法操作简单,收率较高,产物立体选择性好。     

β-二酮的制备

α-溴代芳酮在CH2Cl2中,加入1．2倍的Furukawa试剂（EtZn,CH2I）,室温反应3～6h,经C—C键Sigmatropic重排得到β-二酮,15例收率在40％～85％：底物为α-溴代脂肪酮时,则得2,4-二取代呋喃或1,2-二取代环丙醇,6例收率中等。     

1,3—二溴—5,5—二甲基海因选择性溴化反应研究

考察了在不同极性溶剂中以1,3-二溴-5,5-二甲基海因作溴化剂对溴化6-甲氧基-2,酰基萘反应的影响,13-二-5,5-二甲基海因作为溴化剂,在二氯甲烷,三氯甲烷,二氯乙烷中,于一定温度下,搅拌反应,高选择性溴化6-甲氧基-2-酰基萘的萘环,得到高收率的溴化产物6-甲氧基-5-清算溴-2-酰基萘,该化合物是全盛非甾体消炎镇痛药萘普生(S)-( )-2-(6-甲氧基-2-萘基)丙酸的关键中间体.     

4—溴—3，5—二甲氧基苯甲酸的合成工艺研究

目的：研究4－溴－3，5－二甲氧基苯甲酸合成新方法，方法：以天然原料没食子酸为起始原料，经甲基人与溴化反应合成4－溴－3，5－二甲氧基苯甲酸。结果：利用该合成路线得到了目标物质，总收率为31．4％，结论：该合成工艺还需要进一步研究所优化反应条件。提高反应收率。     

中间体2-溴甲基-3,5,6-三甲基吡嗪的合成工艺优化

目的 对川芎嗪系列衍生物合成中间体：2-溴甲基-3,5,6-三甲基吡嗪（TMP-Br）的合成工艺进行优化.方法 HPLC-MS法对反应物中的主要化学成分进行初步归属;HPLC法考察反应时间、原料比例、光照强度、溶剂用量对TMP-Br产率的影响;最后由正交工艺优化法初步确定中间体的最佳合成工艺.结果 以1 g川芎嗪计算,合成TMP-Br的最佳反应条件为：NBS/TMP=0.9,CCl4/TMP=5 mL·g^-1,选用4盏85 W节能灯作为引发剂,反应时间为1 h.结论 影响川芎嗪溴代反应的4个因素中,NBS和CCl4的用量对单溴代物产率的影响最大;在今后的工艺放大过程中,可优先考察最佳投料比与溶剂用量.     

β-二酮的制备

α-溴代芳酮在CH2Cl2中,加入1．2倍的Fumkawa试剂（EtZn．CH2I）,室温反应3～6h,经C-C键Sigmatropic重排得到β-二酮,15例收率在40％～85％;底物为α-溴代脂肪酮时,则得2,4-二取代呋喃或1,2-二取代环丙醇,6例收率中等。     

药用1,3-二甲基戊胺盐酸盐的合成工艺改进

目的合成1,3-二甲基戊胺盐酸盐并改进其工艺。方法 以乙酰乙酸乙酯和2-溴丁烷为原料,经4步合成反应得到1,3-二甲基戊胺盐酸盐,并采用单因素考察法对合成工艺进行改进。结果1,3-二甲基戊胺盐酸盐各步反应的收率均>40%,产物总收率达到12.3%。结论产物结构经1 H-NMR和13 C-NMR确认为1,3-二甲基戊胺盐酸盐。     

3-（3，4-二甲氧基苯基）-6-甲基香豆素合成方法的改进

目的：探讨3-芳基取代香豆素衍生物的简易合成方法。方法：以5-甲基水杨醛和3,4-二甲氧基苯乙酸为原料,在醋酐和三乙胺条件下,经加热环合反应,合成3-（3,4-二甲氧基苯基）-6-甲基香豆素。结果：与文献方法相比,本法的一步反应收率从12％～33％提高到73．6％。结论：本法操作简单,收率高,更具实用性。     

6-溴-2-己酮的合成

目的化学合成6-溴-2-己酮。方法以1,3-溴丙烷与乙酰乙酸乙酯为原料经环合、开环、溴代等反应合成。结果与结论目标产物的含量用GC方法测定含量95%以上,收率81.5%。     

Induction of cell damage by menadione and benzo(a)pyrene-3,6-quinone in cultures of adult rat hepatocytes and human fibroblasts

The cytotoxicity of menadione (2-methyl-1,4-naphthoquinone) and benzo(a)pyrene-3,6-quinone (BP-3,6-Q) was tested in cultures of adult rat hepatocytes and human fibroblasts. Menadione induced DNA strand breaks, cell membrane damage and depletion of reduced glutathione (GSH) in both hepatocytes and fibroblasts. In fibroblasts, effects on both DNA and membrane integrity were potentiated by the presence of dicoumarol, a specific inhibitor of the 2-electron reduction of quinones by DT-diaphorase, whereas in hepatocytes only the cell membrane damage was sensitive to dicoumarol. Results indicate that menadione toxicity is mediated via 1-electron reduction, although in hepatocytes different reactive species may be responsible for damage to DNA and to the membrane. BP-3,6-Q induced DNA strand breaks in fibroblasts at concentrations as low as 1 microM. The extent of DNA damage was insensitive to dicoumarol. Even after GSH depletion and inhibition of glucuronidation and sulphate conjugation, BP-3,6-Q caused no DNA damage in hepatocytes. In contrast to menadione, BP-3,6-Q did not induce cell membrane leakage or decrease in GSH levels in either hepatocytes or fibroblasts. These studies show the complexity of the metabolic pathways involved, in terms of activation and detoxification processes, in the toxicity of quinones.     

Effect of microsomal preparations and induction on cytochrome P-450-dependent monooxygenases in fetal and neonatal rat liver.

A study of the sedimentation behavior of fetal and neonatal rat liver microsomes allowed a better recovery of a less contaminated microsomal fraction, especially by the use of an EDTA-containing buffer. The specific cytochrome P-450 content and related catalytic activities in the 105,000 g pellet of fetal and neonatal liver were thus much higher than usually reported, while molecular activities were comparable to adult ones.The transplacental inducing effects of phenobarbital and 3-methylcholanthrene on the monooxygenase system were studied in microsomes prepared by the modified procedure and compared to results obtained in crude liver homogenate: 3-methylcholanthrene induces a net biosynthesis of cytochrome P-450 in fetal liver, whereas phenobarbital produces only a premature transformation of rough into smooth endoplasmic reticulum, which decreases the ‘contamination’ of the 105,000 g pellet by ribosomal protein. As a result, the specific cytochrome P-450 content of the microsomal fraction appears to be increased by phenobarbital, though there is no true induction of the monooxygenase system in near-term rat fetus.     

Metabolism of 2, 6-dimethylnaphthalene in starry flounder (Platichthys stellatus) exposed to naphthalene and p-cresol

Juvenile starry flounder (Platichthys stellatus) were force-fed naphthalene, p-cresol, or a mixture of naphthalene and p-cresol in daily doses of 0.3–0.4 mg/kg body weight, for 6 consecutive days. On the 8th day, each fish was force-fed a dose of 12–15 mg/kg of 2,6-dimethyl[¹⁴C]naphthalene (DMN). Twenty-four hours later, the fish were killed and ¹⁴C-labelled metabolites in the bile were isolated and identified by thin-layer chromatography.Most of the biliary metabolites were recovered as conjugates, principally as glurosides and glucuronides. Analyses of the nonconjugated metabolites and metabolites resulting from enzymatic hydrolysis of the conjugates provided identification of four metabolites of DMN: 2,6-dimethyl-3-naphthol; 2,6-dimethyl-3,4-naphthoquinone; trans-3,4-dihydroxy-3,4-dihydro-2,6-dimethylnaphthalene (dihydrodiol); and b-methyl-2-naphthalenemethanol (alcohol). Enzymatic hydrolysis of the glucuronides yielded two metabolites: the alcohol, representing metabolism at a methyl substituent, and the dihydrodiol, representing oxidation of an aromatic ring. Exposure to naphthalene and/or p-cresol led to a significant reduction (P < 0.05) in the alcohol product and a corresponding increase in the dihydrodiol. This perturbation, which favors the formation of potentially damaging epoxides, may alter the nature of toxicological effects.     

中药大黄的生化学研究——ⅩⅥ.大黄素甲醚在动物体代谢产物的分离和鉴定

用离心薄层层析法从灌胃大黄素甲醚的大鼠和小鼠尿中分离了六种代谢产物。经质谱、高效液相色谱及光谱测定并与部分标准品对照,确定其结构分别为大黄素、大黄酚,3-羟甲基-1,6,8-三羟基葸醌,3-甲酰基-1,6,8-三羟基蒽醌,3-羧基-1,6,8-三羟基蒽醌,3-羧基-6-甲氧基-1,8-二羟基葸蒽。大鼠和小鼠肝匀浆9000×g上清液的体外代谢实验也获得了与上述前五种相同的代谢产物。实验表明大黄素甲醚在C-6位可脱去甲基或甲氧基,在C-3位的甲基可相继氧化为羟甲基、甲酰基和羧基等极性更强化合物。     

MEK信号通路活化在榄香烯致人源U87MG胶质瘤细胞增殖抑制及G0/G1细胞周期阻滞中的作用

目的探讨MKK3和MKK6在榄香烯致人U87MG胶质瘤细胞增殖抑制和细胞周期阻滞中的作用。方法以不同浓度榄香烯作用于人U87MG及U251胶质瘤细胞,应用噻唑蓝(MTT)法检测细胞活性。West-ern blot检测MEK信号通路中MKK3和MKK6的总蛋白及磷酸化蛋白含量。通过转染显性负突变质粒DN-MKK3和DN-MKK6,抑制MKK3和MKK6的活性。然后分别行MTT法和流式细胞术检测榄香烯对胶质瘤细胞的增殖抑制和细胞周期阻滞作用。结果榄香烯显著抑制了人胶质瘤细胞的增殖,呈时间和浓度依赖性,并可使细胞中MKK3和MKK6的磷酸化水平上调。抑制MKK3和MKK6的活性则可显著削弱榄香烯的抗胶质瘤增殖和G0/G1细胞周期阻滞作用。结论榄香烯可以通过将胶质瘤细胞的细胞周期阻滞于G0/G1期,进而有效地抑制肿瘤细胞增殖,且MKK3和MKK6信号通路的激活在其中发挥着不可或缺的作用。     

Docking of 6-chloropyridazin-3-yl derivatives active on nicotinic acetylcholine receptors into molluscan acetylcholine binding protein (AChBP)

The crystal structure of Acetylcholine Binding Protein (AChBP), homolog of the ligand binding domain of nAChR, has been used as model for computational investigations on the ligand-receptor interactions of derivatives of 6-chloropyridazine substituted at C3 with 3,8-diazabicyclo[3.2.1]octane, 2,5-diazabicyclo[2.2.1]heptane and with piperazine and homopiperazine, substituted or not at N4. The ligand-receptor complexes have been analyzed by docking techniques using the binding site of HEPES complexed with AChBP as template. The good relationship between the observed binding affinity and the calculated docking energy confirms that this model provides a good starting point for understanding the binding domain of neuronal nicotinic receptors. An analysis of the possible factors significant for the ligand recognition has evidenced, besides the cation-pi interaction, the distance between the chlorine atom of the pyridazinyl group and the carbonylic oxygen of Leu B112 as an important parameter in the modulation of the binding energy.     

Molecular cloning and characterization of Phoneutria nigriventer toxins active on calcium channels.

The aim of the present study was the molecular cloning of toxins active on calcium channels expressed by the spider Phoneutria nigriventer. Clones encoding the toxins Pn3-3A, Pn3-4A, Tx3-5, Pn3-5A, Tx3-6, Pn3-6A and Pn3-6B were identified from a cDNA library derived from the venom gland of this spider, revealing toxins of 49, 76, 45, 39, 55 and 58 amino acids residues, respectively, with polypeptide precursors being composed of three major portions: a signal peptide, a propeptide and finally, the mature toxin. A high degree of homology with the amino acid sequence was found between Pn3-3A and the neurotoxin Tx3-3 (identity of 79%), and between Pn3-4A and the neurotoxin Tx3-4 (identity of 95%). The deduced amino acid sequence for the mature polypeptides Tx3-5 and Tx3-6 confirms the polypeptide sequence previously published for these neurotoxins. In addition, the toxin Pn3-5A showed 58% identity to the Tx3-5 amino acid sequence, and the toxins Pn3-6A and Pn3-6B showed 85 and 33% identity, respectively, to the Tx3-6 amino acid sequence.     

Mexicanolide-type limonoids from the seeds of Swietenia macrophylla

Three new mexicanolide-type limonoids, 3-O-propionylproceranolide (1), 6-O-acetylswietenin B (2), and 6-deoxyswietemahonin A (3), together with 15 known limonoids, were isolated from the seeds of Swietenia macrophylla (Meliaceae). The structures of those new compounds were established by extensive analysis of MS, 1D, and 2D NMR spectral data.     

6-取代苯基哒嗪的3位γ-氨基丁酸衍生物的合成及抗惊活性

GABA的合成类似物是开发新型抗惊剂和抗癫痫药物的新领域。由芳香醛与吗啉、氰化钾反应形成的α-芳基-α-(4-吗啉)乙腈,可对α,β-不饱和腈或酯进行1,4-加成,生成1,4-酮酸型化合物。此物与肼缩合,再经芳构化即得6-芳基-3(2H)哒嗪酮。后者再经氯化后。与GABA缩合,制备3-(N-GABA)-6-芳基哒嗪类及其分子内脱水产物3-(N-丁内酰胺)-6-芳基哒嗪类化合物。本文应用此法合成了17个上述苯代哒嗪的GABA衍生物,并初步测验了它们的抗惊(MES)活性。活性最强的是3-(N-GABA)-6-(2′,4′-二氯苯基)哒嗪(ED_(50)=21.05mg/kg)。