共查询到20条相似文献,搜索用时 78 毫秒
1.
2.
3.
4.
研究了1-和2-苯基萘, 1, 1'-和2, 2'-联萘, 2, 2-二羟基-, 2, 2'-二甲氧基和-2, 2'-甲基磺酰氧基-1, 1'-联萘等七种萘衍生物和三氧化硫的磺化反应。1-苯基萘和1, 1'-联萘的磺化先发生在4位上, 第二取代位置为6和7位。2-苯基萘和2, 2'-联萘均首先得到8位磺酸取代物, 进一步磺化得到8, 4'-和8, 8'-二磺酸取代物。2, 2'-二甲氧基-1, 1'-联萘以13:87的比例得到3位和6位磺酸取代物。2, 2'-二甲磺酰氧基-1, 1'-联萘以58:42的比例得到5位和6位磺酸取代物。2, 2'-二羟基-1, 1'-联萘的等摩尔磺化得到比例为35:65的5位和6位磺酸取代物, 和大于6摩尔的SO~3反应则以62:38的比例得到5位和6位磺酸取代物。 相似文献
5.
用二溴对甲基偶氮溴磺光度法测定锶 总被引:3,自引:0,他引:3
1引 言 二溴对甲基偶氮溴磺是在研究不对称变色酸双偶氮磺类显色剂时合成的新显色剂,化学名为3-[(4-溴-2-磺酸基苯)偶氮]-6-[(2,6-二溴-4-甲基苯)偶氮]-4,5-二羟基-2,7-萘二磺酸。研究发现,该试剂是测定锶的良好显色剂。在酸性介质中,能与锶形成稳定的2:1蓝色络合物,与其它测定锶的试剂例如偶氮胂Ⅲ、偶氮氯■Ⅲ、三溴偶氮胂、二溴羧基偶氮胂、二溴甲基偶氮羧胂、偶氮磺Ⅲ、二甲基偶氮磺Ⅲ、二甲基偶氮磺DAL、二硝基偶氮磺Ⅲ、二溴偶氮磺Ⅲ、二溴对甲基偶氮甲磺、二溴对氯偶氮甲磺等相比,具… 相似文献
6.
7.
7-苯基偶氮-变色酸与蛋白质的显色反应研究 总被引:7,自引:0,他引:7
研究了蛋白质与 7-苯基偶氮 -1 ,8-二羟萘 -3 ,6-二磺酸的显色反应。在 p H2 .7的缓冲溶液中 ,7-苯基偶氮 -1 ,8-二羟萘 -3 ,6-二磺酸与蛋白质形成红紫色复合物 ,λmax为 564 nm,ε为 1 .3× 1 0 5L· mol- 1· cm- 1,线性范围为 6.6~ 1 3 2 mg/ L。实验证实7-苯基偶氮 -1 ,8-二羟萘 -3 ,6-二磺酸与蛋白质的作用符合 Pesavento模式。所提出的方法不经任何预处理可直接测定血清和花生中的蛋白质 相似文献
8.
羟基磺酸、氨基磺酸和磺酰肽的合成 总被引:2,自引:0,他引:2
具有四面体结构的磺酸衍生物可用于模拟酯键和酰胺键水解的过渡态,特别是 含有四面体结构磺酰胺键的磺酰肽作为天然肽的硫类似物,广泛用于作为酶抑制剂 以及用来诱导抗体酶的半抗原。综述了羟基磺酸、氨基磺酸和磺酰肽的合成。重点 介绍了消旋的和手性的α-和β-取代的β-氨基磺酸及其酰氯和亚磺酰氯,γ- 氨基-α,β-不饱和磺酸及其酰氯的合成,以及由它们作为基元分子通过液相和 固相方法来合成α-和β-取代的β-磺酰肽、亚磺酰肽及乙烯磺酰肽。 相似文献
9.
合成了 1 (8 氨基喹啉 5 偶氮 ) 8 羟基 3 ,6 萘二磺酸 (AQHNA) ,其结构经红外光谱和元素分析证实。研究了在十六烷基三甲溴化铵 (CTMAB)存在下 ,试剂与锌的显色反应。pH 5的醋酸 醋酸钠缓冲溶液中 ,AQHNA与锌 (Ⅱ )生成 2∶1的紫色络合物 ,其最大吸收峰位于 5 80nm处 ,摩尔吸光系数为1 2 3× 1 0 5L·mol-1·cm-1。锌含量在 0~ 0 4μg mL范围内符合比尔定律 ,方法用于植物样品中锌的测定 ,结果较好。 相似文献
10.
一种奇特的流体室温磷光现象——无保护性介质水溶液中丹磺酰氯的RTP发射 总被引:6,自引:0,他引:6
一种奇特的流体室温磷光现象──无保护性介质水溶液中丹磺酰氯的RTP发射李隆弟,陈永丽,童爱军(清华大学化学系,北京100084)5-二甲氨基萘磺酰氯(丹磺酰氯,DNS-Cl)是一种重要的荧光衍生、标记试剂[1]。在生物、药物临床、食品分析乃至高分子聚... 相似文献
11.
《Analytical letters》2012,45(5):303-310
Abstract In automated ion-exchange chromatography of amino acids utilizing spectrophotometric measurement., the ratio of the areas under the 40 mμ; and 570 mμ; absorption peak tracings has been shown to be specific for each amino acid. Symmetrical, but impure peaks have ratios deviating from these norms. A simple computer program for the rapid identification of these anomalous peaks has been designed. It is proposed as an addendum to any computer program now in use with amino-acid analyzers. 相似文献
12.
13.
14.
酰胺羰基化的发现为氨基酸及其衍生物的合成提供了一个新方法。该合成方法 步骤简洁,只需一步即可从醛、酰胺-氧化碳合成N-酰基氨基酸,而且该反应是原 子经济型反应。与钴催化的酰胺羰基化相比,钯催化的反应条件更为温和,催化效 率也大为提高,对基团有更广普的适应性。简述近所来这一领域的新进展。 相似文献
15.
16.
Synthesis and conformational studies of α-, β-, γ-hybrid peptides containing a pyrrole amino acid (Paa, 1) and a furan amino acid (Faa, 2), namely Boc-β-Phe-Faa-d-Pro-Gly-Paa-β-HGly-Faa-OMe (3) and Boc-Paa-β-Phe-Faa-d-Pro-Gly-Paa-β-HGly-Faa-OMe (4), were carried out and they adopt β-hairpin structures stabilized via inter-strand π-π and hydrogen bonding interactions. 相似文献
17.
Patcharee Ngamviriyavong Paweena Uppanan Wanida Janvikul 《Macromolecular Symposia》2008,264(1):135-139
Amino acid modified chitooligosaccharides were synthesized by the new synthetic route. The chloroacetyl-chitooliogosaccharide intermediates were prepared under a mild condition via a reaction between chitooligosaccharide (COS) and chloroacetic anhydride. The intermediates were subsequently reacted with a variety of amino acids, e.g., glycine, aspartic acid, alanine, arginine, and serine, under a basic condition, yielding amino acid modified COS products. The degree of chloroacetylation was calculated based on new 1H NMR absorption peaks at 3.80 and 3.94 ppm, corresponding to NH CO CH2 Cl and O CO CH2 Cl, respectively. The degrees of chloroacetylation determined were 0.40, 0.44, 0.62, and 0.93 when the mole ratios of chloroacetic anhydride to COS were 0.5, 1, 2, and 4, respectively. The chemical structures of the COS derivatives were also determined using 1H NMR spectroscopy. The biological properties of the derivatives were evaluated. Cytotoxicity of the derivatives was assessed by a direct contact, using L929 cells. An MTT assay was a method of choice to evaluate the efficacy of the derivatives to enhance the proliferation of L929 cells. 相似文献
18.
19.
Diego Casabona 《Tetrahedron》2006,62(42):10000-10004
This report describes the synthesis of 2-azabicyclo[2.2.2]octane-1-carboxylic acid, a constrained pipecolic acid analogue. The route gives a very good total yield starting from cheap and readily available compounds and uses very easy reactions. 相似文献
20.
Mass spectroscopic characteristics of phosphoryl amino acids were studied in detail by positive and negative electrospray ionization mass spectrometry (ESI-MS) in conjunction with tandem mass spectrometry (MS/MS). Besides N-diisopropyloxyphosphoryl amino acids (N-DIPP-AA), O-phospho- and O-diisopropyloxyphosphoryl amino acids (O-DIPP-AA) were studied and compared to N-DIPP-AA. The fragmentation pathways of [M H]^ ,[M Na]^ and [M-H]^- ions of phosphoryl amino acids were summarized. In addition to several similar patterns, each of them showed its characteristic fragmention. 相似文献