Synthesis of a neoglycoprotein containing the Lewis X analogous trisaccharide beta-D-GalpNAc-(1-->4)[alpha-L-Fucp-(1-->3)]-beta-D-GlcpNAc

The trisaccharide allyl glycoside 36 and related disaccharide part structures have been prepared using the 2-trichloroacetamido-2-deoxy-alpha-D-galactopyranosyl trichloroacetimidate derivative 9 as glycosyl donor under promotion with TMSOTf or Sn(OTf)2, respectively, to produce the beta-(1-->4) linkage to suitably protected glucosamine derivatives in fair yields. Fucosylation was effected employing the ethyl 1-thio glycosyl donor 20 in the presence of IDCP. Deprotection of the intermediates afforded the disaccharide allyl glycosides beta-D-GalpNAc-(1-->4)- beta-D-GlcpNAc 13, beta-D-GalpNClAc-(1-->4)-beta-D-GlcpNAc 14, alpha-L-Fucp-(1-->3)-beta-D-GlcpNAc 24, alpha-L-Fucp-(1-->4)-beta-D- GlcpNAc 31 and the branched trisaccharide allyl glycoside beta-D-GalpNAc-(1-->4)[alpha-L-Fucp-(1-->3)]-beta-D-GlcpNAc 36. The trisaccharide which corresponds to a structural motif occurring in N-glycoprotein glycans from human urokinase, human recombinant protein C, phospholipase A2 as well as O-glycans, was converted into a neoglycoprotein following introduction of a cysteamine-derived spacer group and subsequent activation with thiophosgene.     

Structural analysis of oligosaccharide-alditols released by reductive beta-elimination from oviducal mucins of Bufo bufo: characterization of the carbohydrate sequence Gal(alpha1-3)GalNAc(alpha1-3)[Fuc(alpha1-2)]Gal

We report the isolation and extensive analysis of highly polymorphic MHC class I genes from sharks (Triakis scyllia), which belong to the most primitive vertebrate group with jaws, the cartilaginous fish. Predicted complete peptide-binding domains showed retention of the critical amino acid residues that would interact with antigenic peptide termini and revealed extensive allelic polymorphisms comparable to those of classic human MHC class I molecules. Mosaic structures were apparent in these domains, suggesting recombinational mechanisms to create allelic diversity. The present study demonstrates the establishment of the basic strategy for antigen-presentation employed by MHC class I molecules and documents complete divergence of two polymorphic MHC classes at a phylogenetically primitive stage of vertebrate evolution.     

Conformational differences between Fuc(alpha 1-3) GlcNAc and its thioglycoside analogue

Although Ronald Ross carried out his pioneering investigations on the role of the mosquito in the transmission of malaria in India, antimalarial activities in the sub-continent were disappointing. After the unsuccessful attempt at mosquito control at the military cantonment at Mian Mir (near Lahore, present day Pakistan), quinine prophylaxis was adopted as a compromise solution. While this strategy also failed, a good deal of important work was carried out in India in the first two decades of the twentieth century, so that by the 1920s, the magnitude of the malaria problem was fully appreciated.     

Pharmacodynamics of (-)-beta-2',3'-dideoxy-3'-thiacytidine in chronically virus-infected woodchucks compared to its pharmacodynamics in humans

The pharmacodynamics of (-)-beta-2',3'-dideoxy-3'-thiacytidine (3TC) was studied in chronically woodchuck hepatitis virus-infected woodchucks and compared to that in previous studies in hepatitis B virus (HBV)-infected humans. Net depletion rates of serum virus DNA in woodchucks receiving 3TC were modeled as a sum of an exponentially declining virus input and a first-order elimination. Preceding shoulders and pseudo-first-order virus half-lives in serum ranged from 1 to 7 days and were dose dependent. Higher plasma 3TC concentrations were needed in woodchucks for virus depletion similar to that attained in humans. Human HBV depletion curves from a previous clinical study with 3TC (>/=100 mg per day) were described by a biexponential relationship. The average half-life value in humans, normalized to fraction of area under the serum virus load-time curve, was similar to the average half-life value observed in woodchucks given the highest 3TC dose (2.4 and 2.0 days, respectively). On cessation of therapy, virus load rebounds in woodchucks were dose dependent and resembled posttherapy virus "flares" reported to occur in humans. The estimates of drug exposures that could lead to optimal antiviral effects presented indicate that 3TC should not be underdosed and compliance should be monitored. The study of chronically infected woodchucks may prove useful for optimizing drug regimens for hepadnavirus infections.     

1-(4-安替比林)-3-(2-苯并噻唑)-三氮烯的合成及其与汞(Ⅱ)的显色反应

合成并鉴定了一种新三氮烯试剂1-(4-安替比林)-3-(2-苯并噻唑)-三氮烯(ABTTA),研究了该试剂与Hg2 的显色反应条件,并建立了一个测定汞的光度分析新方法。在溴化十六烷基三甲铵(CTMAB)存在下,试剂与汞在pH11.0Na2B4O7-NaOH缓冲溶液中迅速生成褐色络合物,其最大吸收波长为480nm。在最佳实验条件下,体系在480nm处的表观摩尔吸光系数为5.46×104L.mol-1.cm-1,25mL溶液中Hg2 的质量在5.0~70.0μg范围内符合比尔定律。对20多种共存离子的影响进行试验,结果表明,大多数常见离子不干扰测定。本方法虽然灵敏度不高,但线性范围宽、选择性较好,用于环境水样中汞的测定,结果满意。     

1-(2-苯并噻唑偶氮)-2-羟基-3-萘甲酸与镍(Ⅱ)的显色反应研究及应用

用分光光度法研究了新试剂1-(2-苯并噻唑偶氮)-2-羟基-3-萘甲酸(BTAHN)与镍Ⅱ的显色反应性能。在pH4·6~10·4范围内,BTAHN与镍Ⅱ形成2∶1的蓝色络合物,该络合物的最大吸收波长λmax在612nm处,25mL溶液中镍的质量在0~34μg范围内服从比尔定律,测定的表观摩尔吸光系数ε612为3·52×104,所拟方法用于合金钢样品中微量镍的测定,结果满意。     

1-(2-苯并噻唑偶氮)-2-羟基-3-萘甲酸与铜(Ⅱ)的显色反应研究及应用

合成了新试剂1-(2-苯并噻唑偶氮)-2-羟基-3-萘甲酸(BTAHN),并研究了该试剂与铜(Ⅱ)的显色反应.在pH 6.0～8.5范围内,BTAHN与铜(Ⅱ)形成21的蓝色络合物,该络合物的最大吸收波长λmax在590 nm处,25 mL溶液中,铜的质量在0～25μg服从比尔定律,表观摩尔吸光系数ε590为2.94×10 4.所拟方法用于铝合金、合金钢、茶叶和面粉样品中微量铜的测定,结果满意.     

1-（4-硝基苯基）-3-（4，6-二甲基-2-嘧啶）-三氮烯的合成及与镉的显色反应

报道了1-(4-硝基苯基)-3-(4,6-二甲基-2-嘧啶)-三氮烯(NPDMPMT)的合成及其与镉(Ⅱ)的显色反应.在非离子表面活性剂Triton X-100存在下,于pH 11.5的Na2B4O7-NaOH缓冲介质中,镉(Ⅱ)与NPDMPMT形成1:3的橙黄色络合物,在454 nm处有一最大正吸收,在530 nm处有一最大负吸收,建立了以530 nm为参比波长,454 nm为测量波长的双峰双波长分光光度法测定镉(Ⅱ).25 mL溶液中,镉(Ⅱ)量在0～15μg范围内符合比尔定律,其表观摩尔吸光系数为2.41×105L·mol-1·cm-1,方法的检出限为6.69×10-9g/mL.方法用于废水中微量镉的测定,相对标准偏差在2.9%～3.4%之间,测定结果与原子吸收光谱法相符.     

1-(6-硝基-2-苯并噻唑)-3-(5-溴-8-喹啉)-三氮烯的合成及其与镍的显色反应

报道了新试剂1-(6-硝基-2-苯并噻唑)-3-(5-溴-8-喹啉)-三氮烯(NBTBQT)的合成、纯化、结构鉴定及性质,并研究了其与镍的显色反应.在pH 9.5的硼砂-氢氧化钠缓冲介质中,在表面活性剂CTMAB存在下,试剂与镍形成2:1蓝色络合物,络合物最大吸收波长位于633 nm,表观摩尔吸光系数为2.16×105 L·mol-1·cm-1,镍的质量浓度在9～240μg/L范围内符合比尔定律,检出限为2.70×10-9g/mL.方法应用于铝合金中镍的测定,相对标准偏差在1.2%～1.7%之间,测定结果与认定值相符.     

2-[2'-(5-硝基-吡啶)-偶氮]-1,8-二羟基萘-3,6-二磺酸与镍显色反应的研究与应用

研究了新显色剂2-[2'-(5-硝基-吡啶)-偶氮]-1,8-二羟基萘-3,6-二磺酸(简称为5-NO2-PACA)的合成路线和方法,并应用光度法对其与Ni2 的显色反应进行了研究.以5-硝基-2-氨基吡啶为原料制备5-硝基-2-氨基吡啶重氮酸盐中间体,再与变色酸偶联合成了5-NO2-PACA.在pH11.5的NH3·H2O-NH1Cl缓冲介质中Ni2 与该试剂在室温下很快形成摩尔比为1 : 1的蓝色稳定络合物,其最大吸收波长为635 nm,表观摩尔吸光系数为1.00×106L·mol-1·cm-1,Ni2 浓度在0～500/mL范围内符合比尔定律,常见离子不干扰测定,该方法用于测定环境水样中微量镍,相对标准偏差为2.6%～3.2%(n=6).     

1-偶氮苯-3-(5-溴-2-吡啶)-三氮烯的合成及其与镍的显色反应

合成了新试剂1-偶氮苯-3-(5-溴-2-吡啶)-三氮烯(ABBPTA),并研究了它与镍的显色反应。在pH 10.5的Na2B4O7-NaOH缓冲溶液中,Triton X-100表面活性剂存在下,该显色剂与镍生成摩尔比为4∶1的红色络合物,络合物的最大吸收峰位于540 nm,表观摩尔吸光系数为2.11×105L.mol-1.cm-1。在25 mL溶液中,镍量在0~12μg范围内符合比尔定律,相关系数r=0.999 7。该体系有良好的选择性,大多数常见离子有较高的允许量,用拟定方法测定铝合金中微量镍,回收率为98.2%~102.8%,相对标准偏差为2.1%~2.4%。     

1-(5-硝基-3-苯并异噻唑)-3-[4-(苯基偶氮)苯基]- 三氮烯的合成及与钴(Ⅱ)的显色反应

合成了新显色剂1-(5-硝基-3-苯并异噻唑)-3-[4-(苯基偶氮)苯基]-三氮烯(NBPT-PAPT),并研究了该试剂在非离子表面活性剂Tween-80存在下与钴的显色反应。在pH10.54的Na2B4O7-NaOH缓冲溶液介质中,钴与该试剂形成摩尔比为1∶2的黄绿色络合物,其表观摩尔吸光系数ε=1.22×105L.mol-1.cm-1,钴在0～240μg/L范围内符合比尔定律。用双峰双波长光度法测定了水样中微量钴,结果满意。     

1-(4-硝基苯基)-3-(3,5-二溴吡啶)三氮烯的合成及其与铜的显色反应

合成了显色剂1-(4-硝基苯基)-3-(3,5-二溴吡啶)三氮烯(NPDBPDT),并研究了其与铜的显色反应。在pH11.0的Na2B4O7-NaOH缓冲溶液介质中,表面活性剂OP存在下,铜与NPDBPDT生成组成比为1∶4的络合物。该络合物在460nm处有最大正吸收峰,540nm处有最大负吸收峰,以540nm为参比波长,460nm为测量波长进行双波长测定络合物的吸光度。体系表观摩尔吸光系数为2.02×105L.mol-1.cm-1,铜量在8～480μg/L范围内符合比尔定律,方法检出限为7.43×10-9g/mL。所拟方法用于铜矿和铝合金样品中铜的测定,结果与原子吸收光谱法相吻合,相对标准偏差分别为1.63%和1·56%。     

New Zincophosphite with Infinite One-dimensional [Zn(HPO3)(H2PO3)]- Chains: Synthesis, Characterizations and Spectral Properties

With dimethylamine as a template, a new one-dimensional zincophosphite (C2H8N)·[Zn(HPO3)(H2PO3)]was prepared under hydrothermal conditions and characterized by single-crystal X-ray diffraction, FTIR spectrametry, elemental analysis, powder X-ray diffraction, and thermogravimetric analysis. The compound crystallized in the Monoclinic space group P2(1)/c, with cell parameters, a=0.78410(9)nm, b=1.54744(2)nm, c=0.81418(1) nm, β=105.8150(1)°, V=0.95049(2) nm3 and Z=4. The connectivity of the ZnO4 tetrahedron and HPO3 pseudo pyramid resulted in inifinite corner-sharing 4-membered ring chains, which were further linked by the protonated amine molecules to form a 3D structure via hydrogen bonds. To the best of our knowledge, this is the first existence of a zincophosphite with the anionic framework composition of [Zn(HPO3)(H2PO3)]-. The compound exhibits intense photoluminescence at room temperature.     

YM022 [(R)-1-[2,3-dihydro-1-(2''-methylphenacyl)-2-oxo-5-phenyl-1H-1,4- benzodiazepin-3-yl]-3-(3-methylphenyl)urea]: an irreversible cholecystokinin type-B receptor antagonist

It is controversial whether osteopontin (OP) is expressed in glomeruli and involved in glomerular diseases. We examined whether the OP expression is present at gene and protein levels in cultured rat mesangial cells (MCs). Northern blotting revealed a 1.7 kb OP-mRNA expression in MCs. Fetal calf serum (FCS) and TNF-alpha increased OP gene expression in serum-starved MCs by 2.7- and 1.8-fold over 24- and 12-hour periods, respectively. PDGF, IL-1beta, and TGF-beta had little effect on OP gene expression. Western blotting detected the OP protein expression (69 kDa). FCS and TNF-alpha increased OP protein expression in serum-starved MCs over 48- and 24-hour periods, respectively. The present study clearly demonstrated the expression of OP gene and protein in cultured rat MCs. Increased OP production under serum or TNF-alpha stimulation suggests that intraglomerular OP may contribute to the development of glomerular diseases.     

(3R,4S)-3-[4-(4-fluorophenyl)-4-hydroxypiperidin-1-yl]chroman-4,7-diol: a conformationally restricted analogue of the NR2B subtype-selective NMDA antagonist (1S,2S)-1-(4-hydroxyphenyl)-2-(4-hydroxy-4-phenylpiperidino)- 1-propanol

(1S,2S)-1-(4-Hydroxyphenyl)-2-(4-hydroxy-4-phenylpiperidino)-1-propanol (CP-101,606, 1) is a recently described antagonist of N-methyl-D-aspartate (NMDA) receptors containing the NR2B subunit. In the present study, the optimal orientation of compounds of this structural type for their receptor was explored. Tethering of the pendent methyl group of 1 to the phenolic aromatic ring via an oxygen atom prevents rotation about the central portion of the molecule. Several of the new chromanol compounds have high affinity for the racemic [3H]CP-101,606 binding site on the NMDA receptor and protect against glutamate toxicity in cultured hippocampal neurons. The new ring caused a change in the stereochemical preference of the receptor-cis (erythro) compounds had better affinity for the receptor than the trans isomers. Computational studies suggest that steric interactions between the pendent methyl group and the phenol ring in the acyclic series determine which structures can best fit the receptor. The chromanol analogue, (3R,4S)-3-[4-(4-fluorophenyl)-4-hydroxypiperidin-1- yl]chroman-4,7-diol (12a, CP-283,097), was found to possess potency and selectivity comparable to CP-101,606. Thus 12a is a new tool to explore the function of the NR2B-containing NMDA receptors.     

1—（6—硝基—2—苯并噻唑）—3—（4—硝基苯）—三氮烯与镉的显色反应研究

研究表明,新显色剂1-(6-硝基-2-苯并噻唑)-3-(4-硝基苯)-三氮烯与镉反应,可生成稳定的橙黄色络合物,分别在444nm和530nm波长处有一正一负两个吸收峰,建立以530nm为参比波长,444nm为测定波长的双峰双波长测定法,表观摩尔吸光系数达2.82×105,镉含量在0～280μg/L符合比尔定律,测定了实验室废水和人发中的镉含量,结果满意.     

新试剂5-(H-酸偶氮)-1-苯基-3-甲基吡唑啉酮与铀(Ⅳ)显色反应的研究与应用

研究了新显色剂5-(H-酸偶氮)-1-苯基-3-甲基吡唑啉酮(HAPMP)与铀(Ⅳ)的显色反应,在pH 4.0的HAc-NaAc缓冲介质中,新试剂与铀(Ⅳ)形成11的粉红色铬合物,最大吸收峰位于540 nm处,表观摩尔吸光系数为6.31×104,在25 mL溶液中铀质量在0～35 μg范围内符合比尔定律,方法用于合成样品中微量铀的测定,结果令人满意.     

Cellular response to treatment with 4-(3-(2-chloroethyl)-3-nitrosoureido)-cis-cyclohexanecarboxylic acid, a water-soluble nitrosourea derivative

The lethal effects of 4-(3-(2-chloroethyl)-3-nitrosoureido)-cis-cyclohexanecarboxylic acid (cis-acid), a water-soluble nitrosourea derivative, were investigated on a human lymphoma cell line. The survival of asynchronous cells exposed to increasing concentrations of the drug was characterized by a threshold exponential curve (Do = 20 microgram/ml; Dq = 20 microgram/ml, 1 hour) similar to that of other nitrosourea derivatives. cis-Acid exerted its main killing effect on cells in early S and in late G2 phase. Cells in mid S and early G1 phase were tenfold more resistant. Changes in survival response as a function of cell cycle stage were reflected primarily by changes in the extent of the shoulder region of the survival curve. In contrast to other nitrosoureas, the lethal effectiveness of cis-acid in solution was stable and the drug could sterilize large numbers of cells in short periods of time. Another important major difference observed for cis-acid with respect to classic nitrosourea derivatives was the capacity of treated cells to recover from sublethal and potentially lethal damage. Our studies have shown that cis-acid is as effective in killing cultured human lymphoma cells as other nitrosoureas, but possibly with a mechanism different from that of these compounds. The major shortcoming noted for cis-acid, namely the capacity of treated cells to recover from drug-induced damage, is offset by the relatively long stability of its killing effect. This, and the fact that cis-acid can be administered in an aqueous solution, make this agent an appealing compound for clinical trials.