6-氯-2(1 H)-喹喔酮合成方法的改进

设计了以对氯苯胺和氯乙酰氯为原料,经缩合、硝化、还原、环合、氧化五步制得6-氯-2(1H)-喹喔酮的位置选择性合成方法,并对以氯乙酰氯作为苯胺的氨基保护试剂进行硝化的反应和对含活泼氯的硝基化合物进行还原的反应进行了研究.研究结果表明以氯乙酰氯作为苯胺的氨基保护试剂进行硝化的反应符合一般的硝化定位规则,而含活泼氯的硝基化合物的还原在优化条件下以铁粉为还原剂可以高选择性获得目标产物.     

绿豆胰蛋白酶抑制剂片段及其类似物的合成

绿豆胰蛋白酶抑制剂的Lys活性碎片由两条分别含有26及9个氯基酸残基的多肽链通过两对分子间二硫键连接而成。用DTT还原能拆分两链,其中长链含6个半胱氨酸,在空气中氧化后能恢复25％原Lys碎片活力。本文报道了此长链的化学合成和二硫键重组。合成产物的氯基酸组成与文献报道的一致。但活性明显低于天然产物。为此对绿豆抑制剂的部分序列重新进行测定,结果表明原P_2′位的Lys应为Ile按新测定序列,从长链26肽的N端和C端各去掉两个残基合成一个22肽,此22肽的活性与天然的26肽相当。此外还合成了此22肽的类似物,其活性中心的Lys残基由Ala取代,产物对胰蛋白酶和弹性蛋白酶都无抑制活力。     

含有络合功能基的非天然氨基酸的设计、合成及在生物活性肽中的应用

设计合成了一类侧链带有络合基团的非天然氨基酸, 即侧链带有N,N-二羧甲基氨甲基、N,N-二酰胺甲基氨甲基和N,N-二羟乙基氨甲基的苯丙氨酸衍生物, 并将这类非天然氨基酸用于促性腺激素释放激素(LHRH)类似物的固相合成. 高效液相色谱分析结果表明, 粗肽的纯度较好, 易于纯化; 用电喷雾质谱测定了多肽的分子量. 这些非天然氨基酸可作为其它肽类药物合成的构建单元.     

长效LHRH拮抗剂的设计、合成和生物活性

根据抗蛋白酶降解的长效肽设计思想, 合成了一系列新型结构的LHRH拮抗剂类似物. 体内生物活性评价结果表明, 所设计的多肽具有比母体肽和阳性对照更长的体内抑制睾酮作用时间和较低的最低有效剂量, 证实了该设计思想的可行性, 并为开发长效LHRH拮抗剂药物提供了新的候选化合物.     

用固定化氨基酰化酶拆分DL－对氯苯丙氨酸

用固定化氨基酰化酶拆分ＤＬ－对氯苯丙氨酸王道宾，何炳林（南开大学高分子化学研究所，天津３０００７１）Ｌ和Ｄ型对氯苯丙氨酸在生理学及多肽药物合成中有重要作用，Ｌ型光学异构体可抑制５－羟－色胺的形成￣［１］，将Ｄ型氨基酸用于ＬＨＲＨ桔抗类似物的合成中可延...     

三取代硫脲的合成

应用芳伯胺、二甲胺、二硫化碳及少量粉状氢氧化钠在乙醇溶液内反应,可制成多种三取代硫脲,其中3-(对氯苯基)-1,1-二甲基硫脲为优良的除莠剂,经试验证明其效力与3-(对氯苯基)-1,1-二甲基脲相仿,惟杀草所需时间要长些,但易溶于乙醇及其他价廉的有机溶剂. 2-硝基苯胺、2,4-二硝基苯胺、2-羟基苯胺及2-氨基吡啶与二硫化碳及二甲胺作用均得不到硫脲衍生物,可能是由于苯环上的硝基或羟基与邻位的胺基生成五环或六环内络合物.2-氨基吡啶的结构与酰胺相似,氨基上的氢原子可与环上的氮进行互变异构作用也不生成硫脲. 若在氨基邻位上有一较大的基团,则产率大受影响,这可能是由于“位阻”所致.     

肿瘤的化学治疗 Ⅴ.几种隣位取代-对-[双-(2-氯乙基)氨基]苯丙氨酸的合成

1.本文叙述自邻位取代-对硝基甲苯(Ⅴ)开始经过六步反应合成了邻位取代-对-[双-(2-氯乙基)-氨基]苯丙氨酸(Ⅳ);取代基是:甲氧基,氟,氯,溴和碘. 2.合成了二肽衍生物:α-甲酰氨基-β-{邻甲氧基-对-[双-(2-氯乙基)-氨基]-苯}丙酰-苯丙氨酸乙酯(Ⅻ)和α-甲酰氨基-β-{邻甲氧基-对-[双-(2-氯乙基)氨基]苯}丙酰-缬氨酸乙酸(Ⅷ). 3.邻甲氧基-对-[双-(2-氯乙基)-氨基]苯丙氨酸(Ⅳa)对肉瘤180、梭形细胞肉瘤、艾氏腹水瘤、Yoshida腹水瘤、Guerin癌和Walker瘤都有显著的抑制作用.     

氯丙嗪裂环类似物的合成

对-氯苯基β-氯乙基硫醚与苯胺作用生成N-(β-对-氯苯硫乙基)-苯胺,而通过Gabriel合成法生成对-氯苯基β-氨乙基硫醚。此二化合物分别用β-氯丙酰氯酰化后再与各种仲胺缩合,各生成一系列的β-二烷氨基丙酰基衍生物。将这些化合物用氢化铝锂还原,得到一系列的γ-二烷氨基丙基衍生物(氯丙嗪的裂环类似物)。药理试验结果表明裂环后失去安神作用,但仍保留抗组织胺作用。其中尚有具很强局部麻醉作用者。对-氯苯基β-氯乙基硫醚、对-氯苯基β-氯乙基碸分别与各种仲胺作用,制成一系列对-氯苯基β-二烷氨基乙基硫醚和对-氯苯基β-二烷氨基乙基碸,其中有具抗组织胺作用者。     

托伐普坦类似物的合成及其利尿活性

以2-氨基-5-氯苯甲酸甲酯为原料,经五步反应制得7-氯-5-氧代-2,3,4,5-四氢-1H-苯氮杂草(2);2与5-硝基吡啶-2-甲酰氯(或对硝基苯甲酰氯)发生N-酰化反应,再经SnCl2还原制得关键中间体4a(或4b);在4的氨基上引入取代苯甲酰基或苯磺酰基合成了15个具有潜在AVP-V2受体抑制作用的新型托伐普坦类似物(5a ～5k,6b,6i,7b和8d),其结构经1H NMR,IR和MS表征.SD大鼠利尿活性试验表明,5～8均有一定的利尿活性,且部分化合物活性较高.     

(2S,3S)-1,2-环氧基-3-叔丁氧酰胺基-4-苯丁烷的合成

以(S)-苯丙氨酸为原料,经氨基保护、与对硝基苯酚成酯后与硫叶立德反应制得(S)-1-氯-3-叔丁氧酰胺基-4-苯基-2-丁酮(3);3经Meerwein-Poondrf-Verley还原、环合等反应合成了HIV-1蛋白酶抑制剂的关键中单体——(2S,3S)-1,2-环氧基-3-叔丁氧酰胺基-4-苯丁烷,总收率约45%,其结构经1H NMR和MS确证。     

Ureido-modification of the resin-bound LHRH analogue with N,N''-carbonyldiimidazole

The ureido-modification of the resin-bound a luteinizing hormone releasing hormone (LHRH) analogue was investigated by CDI-activating method. The amino group at the side chain of LHRH analogue could be transformed into various substituted urea moieties in high yields. However, its terminal amino group was partially converted to a hydantoin structure due to the attack of the N atom of the adjacent amide bond.     

反相高效液相色谱/基质辅助激光解吸电离飞行时间质谱 分离鉴定螺蛳血管紧张素转换酶抑制肽

运用反相高效液相色谱(RP-HPLC)对酶解螺蛳腹足肌得到的血管紧张素转换酶(ACE)抑制肽进行两步分离提纯,第一步主要得到8个组分;选取其中活性最高的组分进一步分离,得到2个组分,其中活性较高组分的ACE半抑制浓度为43.5 μmol/L,基本为单一肽组分。对提纯的组分分别使用高效液相色谱/电喷雾离子质谱法(HPLC/ESI-MS)和基质辅助激光解吸电离飞行时间质谱法(MALDI-TOF MS)进行分析,同时结合氨基酸组成分析结果,最终得到的肽链一级结构为Lys-Glu-Ile-Trp(KEIW),符合已知的高活性ACE抑制肽的结构规律。经过对两种方法分析过程的比较,认为ESI-MS可以得到多方面的信息,但无法确定肽的序列;MALDI-TOF MS可以得到精确的二级质谱图(m/z精确至0.0001),从而可以得到确定的肽的序列。     

Nitration and amination of polyphenylene oxide: Synthesis, gas sorption and permeation analysis

A high degree of nitration of polyphenylene oxide (PPO) was successfully achieved by carefully optimizing synthetic protocol. The reduction of nitro group to amino could be done quantitatively. The physical properties of formed polymers were investigated and correlated with gas sorption and permeation properties. The formed polymers were amorphous in nature as revealed by wide angle X-ray diffraction spectra. An increase in the packing density in comparison to unsubstituted PPO as a result of induced polarity was indicated by lowering of fractional free volume and d-spacing. The substitution by either nitro or amino group increased the chain stiffness as revealed by the dynamic mechanical analysis. Though both, nitro and amino group substitution on PPO led to a decrease in pure gas permeability, the selectivity of various gas pairs was increased by these substitutions. The gas sorption analysis revealed that both, solubility selectivity and diffusivity selectivity were increased by these polar group substitutions. The nitro group substitution was more effective in improving solubility selectivity, while amino group substitution was more effective in improving diffusivity selectivity.     

A spectrophotometric and polarographic investigation of three new cyclohexene-substituted benzodiazepines

Three recently introduced benzodiazepine derivatives, tetrazepam (I), nortetrazepam (II) and menitrazepam (III) have been subjected to spectral and polarographic investigation. From the ultraviolet spectral data their pK(a)-values have been determined: 4.28 (I), 4.3 (II) and 3.5 (III). From the polarographic measurements it can be concluded that in I and II the 4,5 CN double bond is reduced with 2 electrons. For the first time for the benzodiazepine series it has been observed that in slightly alkaline solutions this process takes place in two separate 1-electron steps. In III, first the aromatic nitro group is reduced to a hydroxylamine group, then at more negative potentials the CN double bond is also reduced; its reduction wave mostly coalesces with that for the 6-electron reduction of the nitro group to an amino group. A differential pulse polarographic method is presented, for the determination of I, II, III at concentrations as low as 10(-7)M.     

楔形短肽表面活性剂A3V3D纳米自组装结构的表征及机理研究

通过对传统短肽表面活性剂氨基酸序列的改良, 设计了具有楔形几何结构的新型短肽表面活性剂A3V3D. 圆二色谱(CD)分析表明, 该短肽的二级结构为无规则卷曲, 透射电子显微镜(TEM)和原子力显微镜(AFM)表征发现, 该短肽在水溶液中能够发生有序的自组装, 形成稳定的光滑平直的纳米纤维. 芘探针荧光光谱分析显示, 该短肽形成了疏水区并将芘分子包裹其中. 由此推测A3V3D在其楔形几何结构的影响下, 以柱状胶束的形式发生自组装, 是一种新型的自组装短肽材料, 说明了几何形状效应在控制短肽的自组装行为中起着关键作用.     

Antihypertensive Effect of Angiotensin‐Converting Enzyme Inhibitory Peptide Obtained from Hen Ovotransferrin

Angiotensin I‐converting enzyme (ACE) inhibitory peptide was isolated from the hen ovotransferrin hydrolysate using chymotryptic hydrolysis by two steps of reverse‐phase high‐performance liquid chromatography. The amino sequence of this novel peptide was identified as Lys‐Val‐Arg‐Glu‐Gly‐Thr‐Thr‐Tyr that inhibited ACE activity in vitro in a concentration‐dependent manner with an effective concentration (IC₅₀) of 102.8 μM. Also, this inhibition was identified as noncompetitive using the Lineweaver‐Burk plot. Moreover, the antihypertensive action of this novel peptide was investigated by an intravenous injection into spontaneously hypertensive rats (SHR). A dose‐dependent reduction of systolic blood pressure by this peptide was observed after 40 min of treatment and it decreased the blood pressure markedly at the maximal dose (1 nmol/mL/kg). The maximal blood pressure lowering activity of this peptide was calculated as 163% of captopril (10 pmol/mL/kg) that was used as positive control. In conclusion, the obtained data suggests that Lys‐Val‐Arg‐Glu‐Gly‐Thr‐Thr‐Tyr has an ability to inhibit ACE activity and decrease the systolic blood pressure in hypertensive animals.     

AJICAP: Affinity Peptide Mediated Regiodivergent Functionalization of Native Antibodies

The need for atom‐precise biomolecule modification, and particularly the irreversible formation of covalent bonds to specific amino acids in proteins, has become an essential issue in the fields of pharmaceuticals and chemical biology. For example, antibody–drug conjugates (ADCs) are increasingly common entries into the clinical oncology pipeline. Herein, we report a new method of affinity peptide mediated regiodivergent functionalization (AJICAP?) that enables the synthesis of ADCs from native IgG antibodies. We succeeded in introducing thiol functional groups onto three lysine residues in IgGs using Fc affinity peptide reagents without antibody engineering. A cytotoxic molecule was then connected to the newly introduced thiol group, and both a surface plasmon resonance binding assay and in vivo xenograft mouse model results showed that the resulting ADC could selectively target and kill HER2‐positive cells. Our strategy provides a new approach for constructing complex antibody‐derived biomolecules.     

A Photolabile Carboxyl Protecting Group for Solid Phase Peptide Synthesis

A new kind of photolabile protecting group (PLPG) for carboxyl moieties was designed and synthesized as the linker between resin and peptide. This group can be used for the protection of amino acid carboxyl groups. The peptide was synthesized on Nph (2-hydroxy-3-(2-nitrophenyl)-heptanoic acid)-derivatized resins and could be cleaved under UV exposure, thus avoiding the necessity for harsh acid-mediated resin cleavage. The PLPG has been successfully used for solid-phase synthesis of peptides.     

A Sensitive Electrochemical Biosensor for Detection of Histone Deacetylase Activity Using an Acetylated Peptide

A sensitive electrochemical biosensor was developed for activity detection of histone deacetylase sirtuin2 (SIRT2) using an acetylated peptide substrate. This substrate could be recognized by anti‐acetylated peptide antibody, which could be detected using secondary antibody conjugated alkaline phosphatase which provided an amplified electrochemical signal. In the presence of SIRT2, the substrate was deacetylated, resulting in a decreased electrochemical signal that was correlated to the concentration of SIRT2. Under optimized conditions, the biosensor exhibited a wide linear range from 1 nM to 500 nM with a detection limit of 0.1 nM. The proposed biosensor was also used for detection of SIRT2 inhibitor.