猪去氧胆酸化学——Ⅳ.从猪去氧胆酸立体选择性合成熊去氧胆酸和鹅去氧胆酸的新法

本文报道以猪去氧胆酸甲酯(4b)为原料立体选择性合成熊去氧胆酸(1)和鹅去氧胆酸(3)的新方法。从猪去氧胆酸甲酯出发经8步反应得熊去氧胆酸(1),总收率26％。经7步反应得鹅去氧胆酸甲酯(3b),总收率31％。     

氧载体的氧物种直接氧化甲烷制合成气

甲烷部分氧化制合成气由于合成气中n(H2)/n(CO)接近2,可直接用于甲醇合成或烃类F-T合成等后续工业过程而在国内外受到了广泛的关注。利用氧载体的氧物种在无气相氧下直接选择氧化甲烷制合成气是天然气化工利用的新方法,本文介绍了该方法的基本原理、概念工艺和对氧载体的性能要求,对应用于该方法的铈基复合氧化物的掺杂和助剂对选择氧化甲烷性能的影响、钙钛矿氧化物氧载体的氧缺陷、氧物种迁移、结构稳定性及其氧物种氧化甲烷的性能进行了阐述和分析,提出了控制氧载体表面状态是获得高合成气选择性的关键,并对该技术今后的研究重点进行了展望。     

亲氧元素及元素的亲氧性

本文阐述亲氧元素及元素的亲氧性的概念,提出了亲氧元素的判断依据以及元素的亲氧性强弱的比较标准,并应用亲氧性概念解释了一些化学反应。     

超细氮碳化物中吸附氧和化合氧的测定

用跟踪式程序升温、红外检测和微机解卷技术，测定氮碳化物超细粉的吸附氧和化合氧，探讨了超细Ｓｉ３Ｎ４，ＡＩＮ，ＴｉＣＮ和ＳｉＣ中不同状态氧量与其制备方法，颗粒度及放置时间的关系。     

Cu/Co/Mn基氧载体释氧动力学及机理研究

以溶胶凝胶法制备了CuO/CuAl₂O₄、Co₃O₄/CoAl₂O₄以及Mn₂O₃/Al₂O₃氧载体,在流化床反应器中CO₂气氛下研究了不同温度下氧载体释氧特性,并通过分析得到各氧载体的释氧动力学机理函数、活化能及指前因子等重要参数。释氧过程中,氧载体CuO/CuAl₂O₄中CuO、CuAl₂O₄均为活性相,释氧后转化为Cu₂O及CuAlO₂,而Co₃O₄/CoAl₂O₄及Mn₂O₃/Al₂O₃中CoAl₂O₄和Al₂O₃均为惰性相,仅有Co₃O₄和Mn₂O₃参与释氧并分别转化为CoO和Mn₃O₄。三种氧载体的释氧过程均可由成核-核生长机理描述,释氧初期氧载体经化学反应形成新的活性核心,随后活性核心聚集形成还原态的氧载体团簇。各氧载体释氧的机理函数G(x)有不同的表达式,CuO/CuAl₂O₄、Co₃O₄/CoAl₂O₄、Mn₂O₃/Al₂O₃释氧的活化能E分别为226.37、130.06和65.90 kJ/mol,相对应的指前因子A分别为2.99×10⁶、4.96×10³和27.37 s^-1。     

脉冲反应技术研究气相氧和晶格氧对甲烷氧化偶联的作用

ＣａＯ的晶格氧对甲烷能发生非选择性氧化反应，经反应消耗的晶格氧可以由气相氧中补充，也可以通过体相晶格氧向表面的迁移来补充。Ｎａ￣＋添加剂能抑制ＣａＯ晶格氧的反应活性，当Ｎａ￣＋含量达到５％时，ＣａＯ晶格氧对甲烷的完全氧化活性被完全抑制。Ｃａ＿ｘＳｒ＿（１－ｘ）ＴｉＯ＿３复合氧化物催化剂的晶格氧对甲烷没有活性。只有当气相氧存在时，在５％Ｎａ￣＋／ＣａＯ和Ｃａ＿ｘＳｒ＿（１－ｘ）ＴｉＯ＿３复合氧化物上才能通过气相氧向表面氧物种的转化而引发甲烷氧化偶联反应。     

低温燃料电池氧电极催化剂*

氧电极催化剂及缓慢的阴极氧还原动力学是制约低温燃料电池商业化的关键瓶颈因素之一。为此,国内外研究者近年来从提高低温燃料电池氧电极催化剂的催化活性和稳定性、降低催化剂的成本、发展非贵金属氧还原催化剂等方面开展了大量的研究工作,有力地促进了低温燃料电池的发展进程。本文在简要介绍低温燃料电池氧电极反应机理的基础上,从催化剂载体、贵金属及其合金催化剂、金属大环化合物及M-N/C类催化剂和过渡金属硫族化合物类催化剂等方面详细综述了低温燃料电池氧电极催化剂近年来的主要研究进展,并指出了各类催化剂目前尚待解决的问题和发展方向。     

苯乙烯和叔丁氧羰氧苯乙烯的分散共聚合

苯乙烯和叔丁氧羰氧苯乙烯在有机溶剂中分散共聚得到１．３～６．６μｍ均一尺寸聚合物粒子。考察了溶剂的溶度参数、反应温度、单体比和分散剂对生成粒子的影响，溶剂和生成的共聚物粒子的极性（溶度参数）相差越大导致位于尺寸减小；反应温度较低时，得到的粒子尺寸亦较小。     

尖晶石锂锰氧结构中的氧缺陷及其修复方法

研究了氧缺陷型尖晶石锂锰氧化物的结构与电化学性能, 根据缺陷化学理论提出了弥补氧缺陷的办法. X射线衍射(XRD)结果表明, 在真空条件下于750 ℃焙烧不同时间后锂锰氧化物主要物相仍可保持尖晶石结构, 并伴随有少量Mn₃O₄和Li₂MnO₃杂相. 充放电测试及交流阻抗结果表明, 锂锰氧化物材料的放电容量随氧缺陷的增加而降低, 随着氧缺陷的增大, 表面膜阻抗及电荷传递阻抗增大、锂离子在锂锰氧固体中的嵌入与累积量减小使电化学性能恶化. 加入LiOH•H₂O和通入氧气焙烧可在一定程度上修复氧缺陷.     

分子氧、活性氧与生命

分子氧、活性氧与生命刘剑波，宋心琦（清华大学化学系１０００８４）氧气维持着地球上绝大多数生物的生命，它涉及到需氧生物生命过程的许多环节。过去，人们认为氧对需氧生物总是有益无害的。但自从１９６８年ＭｃＣｏｒｄ与Ｆｒｉｄｏｖｉｃｈ［１］发现了超氧化物歧化...     

Synthesis,anti‐inflammatory,and anticancer activity evaluation of some heterocyclic amidine and bis‐amidine derivatives

Heterocyclic amidine derivatives of benzothiazole ( 6a , 6b , 6c ), benzimidazole ( 6d , 6e , 6f ), benzoxazole ( 6g , 6h , 6i ), and bis‐amidine derivatives of pyrimidine, ( 7a , 7b ) & triazole ( 7c , 7d , 7e ) ring system have been synthesized by nucleophilic addition reaction. All these compounds were screened for anti‐inflammatory and anticancer activities. At a dose of 50 mg/kg p.o., compounds 6c (39%), 6e (39%), and 6f (39%) exhibited anti‐inflammatory activity comparable to standard drug ibuprofen, which showed 39% activity and compounds 6b , 6e , 7a , and 7c exhibited moderate anticancer activity against cervix (HELA); neuroblastoma (IMR‐32); breast (MCF‐7), leukemia (THP‐1); and cervix (HELA) human cancer cell lines, respectively. J. Heterocyclic Chem., (2011).     

伞型酮类似物的合成及抗菌作用

2-甲基间二酚或5-甲基间二酚分别与dl-苹果酸或乙酰乙酸乙酯, 在浓硫酸催化下, 经Peachmann缩合反应得到伞型酮(7-羟基香豆素)类似物5～7. 5～7经甲基化得新化合物5a, 6a和7a; 经Williamson反应, TBAB(四正丁基溴化铵)相转移催化合成了14个新的香豆素类化合物5b～5e, 6b～6f, 7b～7f. 经IR, MS, ¹H NMR及元素分析对所有化合物的结构进行了表征. 初步生物活性实验结果表明, 在50 μg/mL浓度下, 化合物6对辣椒疫霉病菌(Phytophythora capsici)抑制率达58.5%, 化合物7c对番茄灰霉病菌(Botrytis cinerea)抑制率为54.0%, 化合物6c对水稻纹枯病菌(Rhizoctonia solani)的抑制率达83.7%.     

新型吡唑酰腙类化合物的合成及其生物活性

以取代肼和取代乙酰乙酸乙酯为起始原料,依次经闭环、氯酰化、氧化、酯化及取代反应制得1,3-取代-5-氯-4-吡唑甲酰肼（7a, 7d, 7g和7j); 7分别与取代呋喃或噻吩甲醛经加成反应合成了12个新型的吡唑酰腙类化合物(9a~9l),其结构经¹H NMR, ¹³C NMR, IR和元素分析表征。初步的生物活性测试结果表明：在500 μg·mL^-1浓度下,部分化合物对烟草花叶病毒(TMV)具有一定的抑制活性,其中1-苯基-3-三氟甲基-5-氯-4-(2-噻吩)-腙基羰基吡唑(9k)的治疗活性、保护活性和钝化活性分别为63.6%, 85.7%和93.1%,与对照药宁南霉素(65.9%, 86.4%和97.8%)相当;在50 μg·mL^-1浓度下,部分化合物表现出一定的抑菌活性,其中1,3-二甲基-5-氯-4-(2-噻吩)-腙基羰基吡唑(9b)与1-甲基3-三氟甲基-5-氯-4-(2-噻吩)-腙基羰基吡唑(9e)对小麦赤霉病菌(Gibberella zeae)的抑制率分别为42.5%和46.8%。     

6-溴-4-烃硫基喹唑啉类化合物的合成及抑菌活性研究

以6-溴-4-巯基喹唑啉和卤代烃为原料, 用相转移催化法合成了10个新的6-溴-4-烃硫基取代喹唑啉类化合物. 化合物经1H NMR, 13C NMR, IR及元素分析证明其结构. 初步生物活性试验结果表明, 在50 mg•L－1浓度下, 化合物6g对小麦赤霉病菌、辣椒枯萎菌、苹果腐烂菌抑制率分别为63.8%, 51.9%, 55.1%, 与对照药剂恶霉灵抑制活性相当.     

新型噻吩并四氢吡啶类化合物的合成及其抗血小板聚集活性

噻吩并［3,2-c］四氢吡啶和噻吩并［2,3-c］四氢吡啶分别与取代苄溴(2a~2g)经取代反应后,用2 mol·L^-1氯化氢乙醚溶液成盐合成了噻吩并四氢吡啶衍生物(3b~3e, 3g和5a~5g);噻吩并［3,2-c］四氢吡啶酮与取代苄溴经取代反应,再与乙酸酐缩合,最后经2 mol·L^-1氯化氢乙醚溶液成盐合成了噻吩并四氢吡啶衍生物(7d, 7e, 7g~7i)。 3, 5和7均为新化合物,其结构经¹H NMR 和ESI-MS表征。大鼠体内抗血小板聚集活性研究结果表明：3, 5和7均有一定的抗血小板聚集活性,其中7d, 7h和7i的抑制率分别为66.2%, 86.8%和88.3%,活性优于阳性对照药噻氯匹啶。     

Synthesis and Antimicrobial Studies of Novel Imidazole Containing Bisazetidinones and Bisthiazolidinone Derivatives

A simple, practical, and efficient approach to new series of imidazole containing bisazetidinones ( 7a , 7b , 7c , 7d , 7e , 7f , 7g , 7h , 7i , 7j and 9a , 9b , 9c , 9d , 9e , 9f , 9g , 9h , 9i , 9j ) was prepared by Staudinger [2 + 2] cycloaddition reaction, and bisthiazolidinones ( 8a , 8b , 8c , 8d , 8e , 8f , 8g , 8h , 8i , 8j and 10a , 10b , 10c , 10d , 10e , 10f , 10g , 10h , 10i , 10j ) were obtained by cyclization of bisimines with thioglycolic acid. The bisimines ( 5a , 5b , 5c , 5d , 5e , 5f , 5g , 5h , 5i , 5j and 6a , 6b , 6c , 6d , 6e , 6f , 6g , 6h , 6i , 6j ) were synthesized by the condensation of 3‐(1‐(3‐aminobenzyl)‐4, 5‐dihydro‐1H‐imidazol‐2‐yl) aniline ( 3 , 4 ) with a series of different substituted aromatic aldehydes. All the newly synthesized target compounds were evaluated for their in vitro antimicrobial activity against two Gram‐positive bacteria and two Gram‐negative bacteria. Additionally, these synthesized compounds were tested for their antifungal activities. Few compounds showed very good antibacterial and antifungal activity.     

Synthesis and biological activity of peptide derivatives of iodoquinazolinones/nitroimidazoles

Two substituted quinazolinyl/imidazolyl-salicylic acids 5, 6 were synthesized by the reaction of 6-iodo-2-methylbenzoxazin-4-one/5-nitroimidazole with 5-aminosalicylic acid (5-ASA). Coupling of compounds 5 and 6 with different amino acid ester hydrochlorides, dipeptide and tripeptide methyl esters yielded novel quinazolino/imidazolopeptide derivatives 5a-f and 6a-g. The chemical structures of all newly synthesized compounds were confirmed by means of FT-IR, (1)H- and (13)C-NMR, MSand elemental analysis. Selected peptide ester derivatives were further hydrolyzed by using lithium hydroxide (LiOH) to afford the corresponding acid derivatives 5ba-da and 6e(a)-g(a). All peptide derivatives were assayed for antimicrobial and anthelmintic activities against eight pathogenic microbes and three earthworm species. Among the tested compounds, 5e,5d, 6e and their hydrolyzed analogs 5d(a) and 6e(a) exhibited higher antimicrobial activity against Pseudomonas aeruginosa, Klebsiella pneumoniae and Candida albicans, and 5(a),6g and 6g(a) displayed better antifungal activity against the dermatophytes Trichophyton mentagrophytes and Microsporum audouinii. Moreover, 6f and its hydrolyzed derivative6f(a) showed good anthelmintic activity against Megascoplex konkanensis, Pontoscotex corethruses and Eudrilus eugeniea at dose of 2 mg mL(-1).     

Design and synthesis of new imidazolinone derivatives as potential antifungal agents

A new series of chalcones, pyrimidines, and imidazolinone is described; chalcones ( 4a , 4b , 4c , 4d , 4e , 4f , 4g , 4h , 4i , 4j , 4k , 4l , 4m , 4n , 4o ) were prepared from the lead 4‐[2‐(5‐ethylpyridin‐2‐yl)ethoxy]benzaldehyde. Pyrimidines ( 5a , 5b , 5c , 5d , 5e , 5f , 5g , 5h , 5i , 5j , 5k , 5l , 5m , 5n , 5o ) were prepared from the reaction of chalcones and guanidine nitrate in alkali media. Imidazolinones ( 6a , 6b , 6c , 6d , 6e , 6f , 6g , 6h , 6i , 6j , 6k , 6l , 6m , 6n , 6o ) were synthesized from the reaction of pyrimidine and oxazolone derivatives (prepared by Erlenmeyer azlactone synthesis). The structures of the synthesized compounds were assigned on the basis of elemental analyses, IR, ¹H‐NMR, and ¹³C‐NMR spectral data. All the products were screened against different strains of bacteria and fungi. Most of these compounds showed better inhibitory activity in comparison with the standard drugs. J. Heterocyclic Chem., (2011).     

Synthesis of Some New Dihydropyrimidines by Iodine as a Catalyst at Ambient Temperature and Evaluation of Their Biological Activity

An improved method for the synthesis of some new dihydropyrimidines from aromatic aldehydes, 1,3‐dicarbonyl compounds, and thiourea with significant enhancement in reaction rates, short reaction time (4–6 h), good to excellent yields (70–93%), and ambient temperature using molecular iodine as catalyst is described. The biological evaluation revealed that the newly synthesized compounds 4a , 4b , 4c , 4d , 4e , 4f , 4g , 4h , 4i , 4j and 7a , 7b , 7c , 7d , 7e , 7f , 7g , 7h , 7i , 7j exhibited good antimicrobial activity and moderate antimycobacterial activity against Mycobacterium tuberculosis H₃₇RV.     

新型不对称草酰二胺类化合物的设计、合成及生物活性

以氯虫酰胺和氟虫腈骨架结构为基础, 依据生物合理设计思想引入酰胺键活性基团, 设计合成了一系列新型不对称草酰二胺类化合物, 通过核磁共振氢谱和高分辨质谱对合成的化合物进行了结构表征. 初步生物活性测试结果表明, 在浓度为200 mg/L时, 目标化合物未表现出良好的杀粘虫活性, 但具有一定的抑菌活性; 在浓度为50 mg/L时, 化合物6e和6f对番茄早疫病菌的抑菌率为45.0%, 高于其它化合物, 表明含有2,4,6-三氯苯环的该系列化合物对番茄早疫病菌具有良好的抑菌活性; 化合物6g对苹果轮纹病菌的抑菌率为51.9%, 高于其它化合物, 表明含有较大空间位阻的该系列化合物对苹果轮纹病菌具有良好的抑菌活性.