四苯基卟啉的催化合成和微波合成研究

采用溶剂催化法和微波激励法合成ｍｅｓｏ－四苯基卟啉（ＴＰＰ）．发现所用溶剂的沸点和极性、催化剂的酸度（Ｐｋａ）及反应体系中的水分含量是决定反应的主要因素．采用甲苯或二甲苯做溶剂,对硝基苯甲酸做催化剂,采用溶剂蒸除—填加同步法合成的四苯基卟啉产率达到５８．４％．同样体系采用微波激励法,３０ｍｉｎ产率达到４２％,反应速度提高了２．２倍．根据ＴＰＰ与其主要副产物四苯基二氢卟啉（ＴＰＣ）的紫外光谱特点以及分光光度法的加合性,采用双波长紫外光谱法测算产品纯度,测得重结晶纯化后产品纯度为９７．７,柱色谱纯化后产品纯度达到９９．７６％．     

水溶性meso-四(4-氯-3-磺酸钠苯基)卟啉合成的改进

以非水溶性卟啉为原料合成水溶性卟啉meso-四(4-氯-3-磺酸钠苯基)卟啉,氯仿作溶剂,氯磺酸作为磺化试剂,与meso-四(4-氯苯基)卟啉反应,并确定其最佳反应条件为n(卟啉):n(氯磺酸)=1.33:29.80,氯仿15 mL,温度60 ℃,反应时间2 h.该法较传统磺化方法反应温度低60～80 ℃且易于控制,不产生粘稠状的副产物,产物易于分离纯化,产率达11.4 %.     

四(对甲氧基苯基)卟啉钴的合成及表征

以对甲氧基苯甲醛与吡咯为原料、丙酸为溶剂、氯乙酸为催化剂,合成四(对甲氧基苯基)卟啉及其钴配合物,用元素分析、紫外-可见光谱、红外光谱、1H核磁共振对化合物进行表征.结果表明,所合成的四(对甲氧基苯基)卟啉及四(对甲氧基苯基)卟啉钴配合物的结构与设计的结构相符;该配体及配合物的荧光光谱数据表明,相对荧光强度是四(对甲氧基苯基)卟啉四(对甲氧基苯基)卟啉钴四苯基卟啉.     

对位取代金属卟啉的合成及其催化氧化对甲基异丙苯的初步研究

用混合溶剂方法,合成了5种对位取代的四苯基卟啉配体,收率范围为23%~52%,对卟啉配体进行轴向金属化反应得到含有中心金属离子(铁、钴、锰)及轴向氯配位的一系列金属卟啉化合物(金属化收率为90%~98%),并用红外光谱、紫外-可见光谱及核磁氢谱对所合成的卟啉化合物进行了结构表征.首次研究了金属卟啉催化分子氧在无溶剂绿色条件下氧化对甲基异丙苯.结果表明:对甲氧基四苯基卟啉和对氯四苯基卟啉的两价钴配合物的催化氧化活性较强.     

乙酸乙酯键联卟啉的合成与表征

从5,10,15,20-四苯基卟啉合成5-(p-β-乙酸乙酯基氨基苯基)-10,15,20-三苯基卟啉：5,10,15,20-四苯基卟啉(A)与发烟硝酸反应得到5-(对-硝基苯基)-10,15,20-三苯基卟啉(B),产率48．7％;B与二氯化锡进行还原反应得到5-(对-氨基苯基)-10,15,20-三苯基卟啉(C),产率72．0％;C在无水碳酸钾和无水碘化钾催化下与氯乙酸乙酯进行亲核取代反应得到5-(p-β-乙酸乙酯基氨基苯基)-10,15,20-三苯基卟啉(D),产率8．5％。该方法的反应条件温和,合成路线短,纯化方法简单。     

水溶性卟啉分子的设计合成与性质

采用Adler缩合的方法成功地合成了四苯基卟啉(TPP),以此为母体,通过Vilsmeier甲酰化反应合成了中间体化合物2-甲酰基-5,10,15,20-四苯基卟啉(FTPP),并以此为中间体,经Knoevenagel缩合反应得到了β位取代的水溶性四苯基卟啉衍生物(TPPA)。用傅里叶变换红外光谱、核磁共振氢谱、碳谱及MALDI-TOF质谱等手段对目标产物的结构进行了表征。并且初步研究了其紫外-可见光谱、荧光光谱和电化学性质,结果表明目标化合物有良好的红色荧光特性,为寻找新的水溶性红光材料提供了参考。     

微波辐射下催化合成四(对硝基苯基)卟啉

在微波辐射下采用乳酸作为催化剂合成四(对硝基苯基)卟啉,考察了溶剂、催化剂、微波辐射时间、微波辐射功率对产率的影响.实验表明:硝基30 mL苯作溶剂,乳酸2.0 mL作催化剂,对硝基苯甲醛0.01 mol,吡咯0.01 mol,微波辐射功率280 W,辐射时间16 min,产率达到23.9%.     

四苯基卟啉衍生物的合成、表征及光物理和电化学性质

为寻求更高效的发光材料,通过改进的Alder法合成了四苯基卟啉、含吸电子基团的四(对硝基苯基)卟啉和含推电子基团的四(对甲氧基苯基)卟啉,对这些化合物进行了红外、质谱、元素分析等表征,并测试了其紫外、荧光与电化学性质,探讨了取代基对卟啉化合物光物理性能及电化学性质的影响.     

四-(2-羟基苯基)卟啉化合物的合成

用水扬醛与吡咯反应合成的四－（２－羟基苯基）卟啉,在卟啉环上的取代苯基上引入了四个羟基,可部分地解决水溶性差的问题．该化合物的合成具有理论研究的价值和实用前景．     

四（2—羟在苯基）卟啉化合物的合成

用水扬醛与吡咯反应合成的四－（２－羟基苯基）卟啉，在卟啉环上的取代苯基上引入了四个羟基，可部分地解决水溶性差的问题。该化合物的合成具有理论研究的价值实用前景。     

Structural basis for gene regulation by a thiamine pyrophosphate-sensing riboswitch

Riboswitches are metabolite-sensing RNAs, typically located in the non-coding portions of messenger RNAs, that control the synthesis of metabolite-related proteins. Here we describe a 2.05 angstroms crystal structure of a riboswitch domain from the Escherichia coli thiM mRNA that responds to the coenzyme thiamine pyrophosphate (TPP). TPP is an active form of vitamin B1, an essential participant in many protein-catalysed reactions. Organisms from all three domains of life, including bacteria, plants and fungi, use TPP-sensing riboswitches to control genes responsible for importing or synthesizing thiamine and its phosphorylated derivatives, making this riboswitch class the most widely distributed member of the metabolite-sensing RNA regulatory system. The structure reveals a complex folded RNA in which one subdomain forms an intercalation pocket for the 4-amino-5-hydroxymethyl-2-methylpyrimidine moiety of TPP, whereas another subdomain forms a wider pocket that uses bivalent metal ions and water molecules to make bridging contacts to the pyrophosphate moiety of the ligand. The two pockets are positioned to function as a molecular measuring device that recognizes TPP in an extended conformation. The central thiazole moiety is not recognized by the RNA, which explains why the antimicrobial compound pyrithiamine pyrophosphate targets this riboswitch and downregulates the expression of thiamine metabolic genes. Both the natural ligand and its drug-like analogue stabilize secondary and tertiary structure elements that are harnessed by the riboswitch to modulate the synthesis of the proteins coded by the mRNA. In addition, this structure provides insight into how folded RNAs can form precision binding pockets that rival those formed by protein genetic factors.     

Novel Substitution Reactions of 5-（4-Nitrophenyl）-10,15,20-TriphenylPorphyrin with Nucleophilic Reagents

Substitution reactions of 5-（4-nitrophenyl）-10, 15,20-triphenylporphyrin （NO2 TPP） and its metal complexes with different nucleophilic reagents were studied for preparing asymmetric porphyrin. The reaction products are different with the nucleophilic reagents changing, and three different products were found. The first obtaining product was diporphyrin when NO2 TPP reacted with sodium phenoxide or diphenoxide in DMF solution; The second was reduced product 5-（4-aminophenyl）-10, 15, 20-triphenylporphrin-M （Ⅱ） when the metal （Ni,Zn） complex of NO2 TPP reacted with above nucleophilic reagents, as well as NO2 TPP reacted with lithium mercaptoethanolate or lithium thiophenolate; The third product CNTPP was achieved with the substitution of nitro group by cyanic anion when NO2 TPP reacted with radium cyanide. Above results were explained with reduction and single electron transfer reaction respectively.     

硝基四苯基卟啉及其衍生物的合成

质量分数65%的浓硝酸与硝基四苯基卟啉(TPP)反应较完全且没有副产物生成,单硝化TPP(m-NTPP)的收率达到约80%;其他试剂由于活性太高,生成较多的副产物而收率不高.结果表明,氮氧化合物气体在TPP硝化反应中起到关键作用.具有生物活性的小分子与还原m-NTPP所得的单氨基TPP(m-ATPP)连接,得到收率大于90%的氨基TPP衍生物,它们具有较氨基TPP更高的光动力疗法(PDT)抗肿瘤活性,同时对正常细胞的毒性降低.     

适冷菌Pseudomonas extremaustralis PF中海藻糖的合成途径及TreS基因的克隆

通过对一株高寒冰缘植物内生适冷假单胞菌Pseudomonas extremaustralis PF的研究,发现该菌中同时存在TPS/TPP,TreY/TreZ和neS三种海藻糖合成途径,其中TreS途径的合成酶活性最高.对该菌的海藻糖合成酶TreS的基因进行克隆,得到一个新的TreS基因PFTreS,该基因与已报道的细菌TreS基因在核酸序列上表现出较高的同源性(最高达80.2%).根据基因序列预测的PFTreS氨基酸序列具有TreS酶的催化功能保守区,与假单胞菌P.fluorescens Pf-5的TreS有很高的同源性.这些结果表明了Pseudomonas extremaustralis中海藻糖的合成特性,为进一步揭示海藻糖的合成与Pseudomonas extremaustralis PF的低温响应机制的关系奠定了基础.     

磷酸三苯酯/锡酸锌对环氧树脂酸酐固化物的阻燃与抑烟性能研究

采用极限氧指数法,热重分析和烟密度测试法研究了磷酸三苯酯(TPP)、锡酸锌(ZS)在环氧树脂酸酐固化物(EP)中的阻燃作用和抑烟机理.研究表明TPP对EP具有良好的阻燃效果,并通过增加在高温下的热稳定性和降低热失重速率等在凝缩相和气相中发挥阻燃作用;TPP通过分解时形成的液态含磷物质吸附少量的烟尘.ZS的阻燃效果一般,它的用量为30份,其阻燃体系的最大烟密度值可降低至491.7,但降低了t16,TPP和ZS合用时具有一定的阻燃协同效应,但并不一定具有抑烟协同效应.     

丝状液晶与铁卟啉的配位作用

研究了掺杂5，10，15，20－四苯基铁（Ⅲ）卟啉氯化物（Fe(TPP)Cl)的丝状液晶5CB在光场下的弗雷德里克兹转变和其Uv-vis光谱，掺杂Fe(TPP)Cl，能有效地降低液晶5CB在光场下发生弗雷德里克兹转变的阈值，Fe(TPP)Cl的Soret带随着液晶5CB含量增大而红移，这是液晶5CB与Fe(TPP)Cl发生轴向配位的结果。     

TPP1 is a homologue of ciliate TEBP-beta and interacts with POT1 to recruit telomerase

Telomere dysfunction may result in chromosomal abnormalities, DNA damage responses, and even cancer. Early studies in lower organisms have helped to establish the crucial role of telomerase and telomeric proteins in maintaining telomere length and protecting telomere ends. In Oxytricha nova, telomere G-overhangs are protected by the TEBP-alpha/beta heterodimer. Human telomeres contain duplex telomeric repeats with 3' single-stranded G-overhangs, and may fold into a t-loop structure that helps to shield them from being recognized as DNA breaks. Additionally, the TEBP-alpha homologue, POT1, which binds telomeric single-stranded DNA (ssDNA), associates with multiple telomeric proteins (for example, TPP1, TIN2, TRF1, TRF2 and RAP1) to form the six-protein telosome/shelterin and other subcomplexes. These telomeric protein complexes in turn interact with diverse pathways to form the telomere interactome for telomere maintenance. However, the mechanisms by which the POT1-containing telosome communicates with telomerase to regulate telomeres remain to be elucidated. Here we demonstrate that TPP1 is a putative mammalian homologue of TEBP-beta and contains a predicted amino-terminal oligonucleotide/oligosaccharide binding (OB) fold. TPP1-POT1 association enhanced POT1 affinity for telomeric ssDNA. In addition, the TPP1 OB fold, as well as POT1-TPP1 binding, seemed critical for POT1-mediated telomere-length control and telomere-end protection in human cells. Disruption of POT1-TPP1 interaction by dominant negative TPP1 expression or RNA interference (RNAi) resulted in telomere-length alteration and DNA damage responses. Furthermore, we offer evidence that TPP1 associates with the telomerase in a TPP1-OB-fold-dependent manner, providing a physical link between telomerase and the telosome/shelterin complex. Our findings highlight the critical role of TPP1 in telomere maintenance, and support a yin-yang model in which TPP1 and POT1 function as a unit to protect human telomeres, by both positively and negatively regulating telomerase access to telomere DNA.     

光谱法研究酸和溶剂对四苯基卟啉聚集体形成的影响

研究四苯基卟啉(H₂TPP)的二氯甲烷溶液在盐酸、 硝酸、 氢溴酸和硫酸条件下形成聚集体的电子吸收和拉曼光谱.  结果表明, 在盐酸、 硝酸和氢溴酸条件下形成了H2TPP的J聚集体,  在硫酸条件下形成了H2TPP的H和J聚集体, 特征双峰818/834 cm^-1和1 072/1 093 cm^-1体现了H和J聚集体振动频率的差别.  通过分析硫酸条件下在甲苯和氯仿溶剂中分别形成聚集体的拉曼光谱可知,  双质子化H₂TPP在高溶解度溶液中有利于J聚集体的形成, 而在低溶解度溶剂中有利于形成H和J聚集体.  