Synthesis,fluorescence properties of Tb(Ⅲ) complexes with novel mono-substituted β-diketone ligands

Two novel pyridine-2,6-dicarboxylic acid derivatives of mono-β-diketone named methyl 6-biphenylacetyl-2-pyridinecarboxylate (MBP) and 6-biphenylacetyl-2-pyridinecarboxylic acid (BAA) and their corresponding binary complexes Tb(MBP)3.6H2O and Tb(BAA)3·6H2O were synthesized. The ligands were characterized by elemental analysis, FT-IR and 1H-NMR, and the complexes were characterized with elemental analysis, FT-IR, 1H-NMR and thermogravimetric and differential thermal analysis(TG-DTA). The investigation of fluorescence properties of the complexes Tb(MBP)3·6H2O and Tb(BAA)3·6H2O showed that the introduction of the biphenyl enlarged the π-conjugated system of the ligands and enhanced the luminescent intensity of the complexes. The Tb(Ⅲ) ion could be sensitized more efficiently by the ligands, in particular, the fluorescence intensity of the complex Tb(BAA)3·6H2O was about 20% higher than that of Tb(MBP)3·6H2O and 30% higher than that of Tb(Ⅲ) complexes with bis-β-diketone-type ligands that we have previously reported.     

As-triazine derivatives with potential therapeutic action. XXVI. Syntheses of 5-substituted-6-azauracil acyclonucleosides

5-Substituted 6-azauracils were alkylated with (2-acetoxyethoxy)methly bromide to give protected acyclic nucleosides which were protected to afford acyclonucleosides of 5-substituted 6-azauracils. Their structures have been established by the UV and 1H-NMR spectra and by elemental analysis.     

Consolidation of memory after its reactivation: involvement of beta noradrenergic receptors in the late phase

In order to test their antimicrobial activity a series of new 3-[(3-substituted-4-methyl-5-carboxy/carbetoxy-4-thiazolin-2 - ylidene)hydrazono]-1H-2-indolinones (3a-i/4) were synthesized from the reaction of 3-(4-substituted-3-thiosemicarbazono-1H-2-indolinones (1a-I) with 2-chloroacetoacetic acid ethyl ester (2). All synthesized compounds were characterized by IR, 1H-NMR, EIMS and elementary analysis.     

XVIth National Days of Biology. Lyon, 6-7 June 1997

Two new benzoquinones with antifungal, antibacterial, and cytotoxic activities have been isolated from liquid cultures of the coprophilous fungus Podospora anserina. The structures of anserinones A (1) and B (2) were assigned on the basis of MS and NMR results, and the absolute stereochemistry of 2 was deduced by analysis of 1H-NMR data for its (R)- and (S)-2-phenylbutyryl ester derivatives.     

Chemical constituents from the aerial part of Epimedium brevicornum Maxim

Six flavonoids were isolated from the aerial part of Epimedium brevicornum and identified as baohuo side I, 2"' O-rhamnosyl icariside II, sagittatoside B, baohuoside II, ikarisoside F and ikarisoside C by means of UV, IR, 1H-NMR, 13C-NMR and FAB-MS spectral analysis, they were isolated from this plant for the first time.     

硝苯柳胺化学结构解析

通过元素分析和紫外、红外、质谱及核磁共振光谱图的解析，得到硝苯柳胺的结构式为Ｎ＝（硝基苯基）－５－氯－水杨酰胺。     

3-Acetyl-4-aryl-5-oxo-2,7,7-trimethyl-1,4,5,6,7,8-hexahydro-quinoline derivatives and their calcium antagonistic activities

Thirteen 3-acetyl-4-aryl-5-oxo-2,7,7-trimethyl-1,4,5,6,7,8- hexahydroquinoline derivatives (5a-m), one of which was synthesized before, have been prepared. The structures of the products 5b-m were characterized by IR,1H-NMR and elemental analysis. The calcium antagonistic activity of these compounds was studied in rabbit taenia coli precontracted with 1 mmol/l Ca+2.     

Increased saturated triacylglycerol levels in plasma membranes of human neutrophils stimulated by lipopolysaccharide

Neutrophils isolated from patients with bacterial infections or stimulated in vitro with lipopolysaccharide (LPS) produce a high resolution, lipid-dominated spectrum on 1H-NMR spectroscopy (May et al, 1993. J. Infect. Dis. 168: 386-392). We have investigated the origin of this lipid signal using NMR and chemical analyses of both whole neutrophils and purified plasma membranes. Plasma membranes from neutrophils that had been stimulated with 50 microg/ml LPS exhibited the high resolution 1H-NMR signal, and contained double the triacylglycerol (TAG) content of plasma membranes isolated from resting cells. Chemical analysis of the whole cells indicated that the TAG also increased at the cellular level (1.7-fold) after stimulation with LPS. Diradylglycerol increased 2- to 3-fold in both whole cells and plasma membranes after stimulation, but was only a minor component compared with TAG. The plasma membrane protein/phospholipid ratio increased 2.6-fold, whereas cholesterol (free and esterified) was unchanged. The membranes from LPS-stimulated neutrophils exhibited increased fluidity, as judged by increased merocyanine 540 binding, consistent with a 2-fold reduction in cholesterol/phospholipid ratio. LPS induced a shift in fatty acid content of whole cell polar lipids towards more oleic acid and less palmitic acid, whereas the neutral lipid fraction contained increased amounts of palmitic and stearic acids. The TAG fraction of plasma membrane lipids contained increased amounts of palmitic acid when prepared from cells stimulated with LPS. We conclude that the 1H-NMR signal in LPS-stimulated neutrophils arises from increased amounts of plasma membrane TAG with an elevated content of palmitic acid.     

Structural studies of the O-specific polysaccharide of Hafnia alvei strain 1209 lipopolysaccharide

The structure of the O-specific side chains of the Hafnia alvei strain 1209 lipopolysaccharide has been investigated. Methylation analysis and 1H-NMR and 13C-NMR spectroscopy were the principal methods used. It is concluded that the polysaccharide is composed of pentasaccharide repeating units that have the following structure: -->3)-beta-D-Galp-(1-->4)-alpha-D-Glcp-(1-->4)-beta-D-GlepA-(1--> 3)-beta-D-GalpNAc-(1 --> 4 increases 1 alpha-L-Rhap The relative intensity of the signals from the terminal repeating unit in the 1H-NMR spectrum, the amount of 2,3,6-tri-O-methylgalactose in the methylation analysis, and the matrix-assisted laser-desorption ionisation time-of-flight (MALDI-TOF) mass spectrum of the O-polysaccharide indicated that the structure is also the biological repeating unit and that the O-chains mainly consisted of 8-11 repeating units and, on average, ten repeating units.     

Defining the statistical distribution of vesicle diameters facilitates quantitative assessment of spectral narrowing from small vesicles in protein/lipid interaction studies by 2H-NMR

The diameters of vesicles comprising complexes of an integral membrane protein and 1,2-dimyristoyl-sn-glycero-3-phosphocholine, deuterated in the choline gamma-methyl groups, exhibited a lognormal distribution defined by the geometric mean (GM) and the logarithmic standard deviation (LSD). The range of vesicle sizes within each complex was very large (e.g., 99% of vesicles measured between 60 nm and 4,000 nm in one complex). This complicated assessment of spectral narrowing artefacts from small vesicles in broad line 2H-NMR results. Artefacts (e.g., decreases in quadrupole splitting and generation of two component spectra) resembled results attributed to membrane proteins in other 2H-NMR studies for which spectral narrowing was dismissed by demonstration of some vesicles > 400 nm in diameter. This was inadequate since 2H-NMR spectra from complexes with GM < 350 nm exhibited spectral narrowing artefacts despite the presence of some vesicles 1,200 nm in diameter. The nature and degree of artefact were determined by both GM and LSD. Quantifying vesicle sizes by GM and LSD accommodated the large size variation within a complex and facilitated quantitative assessment of artefacts through comparison of different complexes.     

A Ternary-associating system of genes

A significant association is described between genes of the erythrocyte acid phosphatase (ACP1B), erythrocyte adenosine deaminase (ADA2) and plasma haptoglobin (Hp2) systems. Most of the heterogeneity is shown to reside in the ADA2-Hp2 association and in the ACP1B-Hp2 association among persons of type ADA 1.     

Structure elucidation and chemical synthesis of stigmolone, a novel type of prokaryotic pheromone

Approximately 2 micromol of a novel prokaryotic pheromone, involved in starvation-induced aggregation and formation of fruiting bodies by the myxobacterium Stigmatella aurantiaca, were isolated by a large-scale elution procedure. The pheromone was purified by HPLC, and high-resolution MS, IR, 1H-NMR, and 13C-NMR were used to identify the active substance as the hydroxy ketone 2,5, 8-trimethyl-8-hydroxy-nonan-4-one, which has been named stigmolone. The analysis was complicated by a solvent-dependent equilibrium between stigmolone and the cyclic enol-ether 3,4-dihydro-2,2, 5-trimethyl-6-(2-methylpropyl)-2H-pyran formed by intramolecular nucleophilic attack of the 8-OH group at the ketone C4 followed by loss of H2O. Both compounds were synthesized chemically, and their structures were confirmed by NMR analysis. Natural and synthetic stigmolone have the same biological activity at ca. 1 nM concentration.     

Videotape assessment of changes in aberrant meal-time behaviors in anorexia nervosa after treatment

Samples for use in the fluorometric enzymatic assay of sorbitol in erythrocytes are normally prepared using HClO4 and K2CO3. We have replaced these reagents with NaOH and ZnSO4. Human whole blood, erythrocyte and plasma samples prepared with NaOH and ZnSO4 are colorless and clear, while erythrocyte samples prepared with HClO4 and K2CO3 are a pale yellow-brown color. The sorbitol dehydrogenase reaction in the supernatant of the mixture of NaOH and ZnSO4 is inhibited, but ethylenediaminetetraacetate completely eliminates this effect. The sorbitol assay in erythrocytes prepared with NaOH and ZnSO4 shows higher sensitivity and reproducibility than did that with HClO4 and K2CO3. Recovery of sorbitol added to erythrocytes is similar in both assay methods. Concentrations of whole blood and erythrocyte sorbitol assayed by the present method are significantly higher in diabetics than in normals. Poorly controlled diabetics had higher whole blood and erythrocyte sorbitol than well-controlled diabetics. Whole blood sorbitol concentrations differed more between diabetic and normal subjects than did erythrocyte sorbitol concentrations.     

1H- and 2H-NMR studies of a fragment of PMP1, a regulatory subunit associated with the yeast plasma membrane H(+)-ATPase. Conformational properties and lipid-peptide interactions

PMP1 is a 38-residue polypeptide associated with the yeast plasma membrane H(+)-ATPase, found to regulate the enzyme activity. To investigate the molecular basis of the PMP1 biological function, the conformational properties of a synthetic PMP1 fragment, A18-F38, comprising the predicted C-terminal cytoplasmic domain and a part of the transmembrane anchor have been studied by 1H- and 2H-NMR spectroscopies. High resolution 1H-NMR experiments showed that, in deuterated DPC micelles, the A18-G34 segment adopts a well defined helix conformation. Our data suggest that the whole PMP1 molecule forms a unique helix whose axis might be slightly tilted with respect to the bilayer normal. Protonated DPC, DMPC and DMPS were incorporated in deuterated micelles containing the PMP1 fragment for studying lipid-peptide interactions. Unusually strong and selective intermolecular NOEs between lipid chain and peptide side chain protons, especially those of the unique Trp residue, were observed. Solid state 2H-NMR experiments performed on pure deuterated POPC and mixed deuterated POPC:POPS (5:1) bilayers revealed that the PMP1 fragment specifically interacts with negatively charged PS lipids.     

Lymphomas with testicular localisation show a consistent BCL-2 expression without a translocation (14;18): a molecular and immunohistochemical study

Rabbits were immunised with stage 1 and stage 2 soluble haemagglutinins (sHA) of Helicobacter pylori strain NCTC 11637 and with rabbit erythrocytes coated with stage 1 sHA. After adsorption of stage 1 sHA on erythrocytes, SDS-PAGE analysis showed that 4 major protein bands were removed from the preparation. The anti-sHA coated erythrocyte serum had the highest HA inhibition titre of 16. Crossed immunoelectrophoresis of the stage 1 sHA, against stage 1 and 2 antisera showed multiple precipitin arcs; however, the anti-sHA coated erythrocyte serum produced only two arcs. One arc produced by the anti-stage 2 serum was absent with the anti-stage 1 serum. This arc could have been produced against a 20 kDa polypeptide which was absent in the stage 1 sHA. The other arc was stronger when compared with that produced by anti-stage 1 serum. These two arcs corresponded to the two arcs produced by the anti-sHA coated erythrocyte serum, which had the highest inhibition titre. The two arcs were markedly reduced in crossed immunoelectrophoresis with an adsorbed stage 1 sHA preparation, which indicates that these arcs were produced against the sHAs.     

Synthesis,fluorescence properties of Tb(III) complexes with novel mono-substituted β-diketone ligands

Two novel pyridine-2,6-dicarboxylic acid derivatives of mono-β-diketone named methyl 6-biphenylacetyl-2-pyridinecarboxylate (MBP) and 6-biphenylacetyl-2-pyridinecarboxylic acid (BAA) and their corresponding binary complexes Tb(MBP)₃.6H₂O and Tb(BAA)₃·6H₂O were synthesized. The ligands were characterized by elemental analysis, FT-IR and ¹H-NMR, and the complexes were characterized with elemental analysis, FT-IR, ¹H-NMR and thermogravimetric and differential thermal analysis(TG-DTA). The investigation of fluorescence properties of the complexes Tb(MBP)₃·6H₂O and Tb(BAA)₃·6H₂O showed that the introduction of the biphenyl enlarged the π-conjugated system of the ligands and enhanced the luminescent intensity of the complexes. The Tb(III) ion could be sensitized more efficiently by the ligands, in particular, the fluorescence intensity of the complex Tb(BAA)₃·6H₂O was about 20% higher than that of Tb(MBP)₃·6H₂O and 30% higher than that of Tb(III) complexes with bis-β-diketone-type ligands that we have previously reported.     

Irreversible inhibition of plasma membrane (Ca2+ + Mg2+)-ATPase and Ca2+ transport by 4-OH-2,3-trans-nonenal

4-OH-2,3-trans-nonenal (HNE), a major aldehydic lipid peroxidation product, has been shown to cause cellular toxicities and has been linked to a number of pathophysiological processes including atherogenesis. Specifically, in vitro exposure of erythrocyte plasma membrane preparations to HNE resulted in the inhibition of membrane transport function and integrity. To characterize the nature of the inhibitory effects of HNE on plasma membrane regulatory mechanisms, we investigated its effects on substrate and calmodulin (CaM) stimulation on erythrocyte Ca2+ transport and (Ca2+ + Mg2+)-ATPase activities. Concentration-effect relationship analysis in erythrocyte membrane "ghosts" and inside-out vesicles (IOVs) yielded purely noncompetitive kinetics for Ca2+, ATP, and CaM activation of (Ca2+ + Mg2+)-ATPase and Ca2+ transport. Reductions of Vmax from direct addition of 0.1 mM HNE to the assay incubation mixtures ranged from 23 to 41%. Similarly, pretreatment with HNE of both membrane ghosts and IOVs resulted in a concentration-dependent inactivation of ATPase and transport activities without changes in affinity for Ca2+, ATP, or CaM. Conversely, pretreatment of CaM itself did not impair its ability to stimulate (Ca2+ + Mg2+)-ATPase activity threefold. Moreover, HNE-pretreated membranes exhibited unaltered acetylcholinesterase activity compared to sham-pretreated membranes. Together, these results suggest that HNE may structurally, and thus irreversibly, modify one or more functionally important sites on the transport protein itself.     

Cloning and characterization of subtracted cDNAs from a human ciliary body library encoding TIGR, a protein involved in juvenile open angle glaucoma with homology to myosin and olfactomedin

Conformational and dynamic properties of the synthetic peptides, amino acid sequence of which correspond to biologically active fragments of the following human cytokines: alpha 2, gamma interferons and interleukins 1 beta, 2, were studied in aqueous solution and dimethylsulfoxide by one-dimensional and two-dimensional 1H-NMR spectroscopy (400 MHz). The analysis of nuclear Overhauser effect data, values of vicinal J3(NH-C alpha H) coupling constants of amide protons and their temperature coefficients of chemical shifts indicate an unordered flexible conformation of the peptides in aqueous solutions. The structural and dynamic features of the peptides investigated are discussed together with their biological activity.     

Gastroparesis after celiac plexus block

Pectin constituents, which were about 70 w/w% of extracellular polysaccharides (ECP) from a cell-suspension culture of Mentha, were purified by gel filtration chromatography, and their sugar composition and linkage were investigated. Two major constituents identified were (1-->3)-linked galactan carrying arabinosyl residues on C-6 and (1-->4)-alpha-linked galacturonan partially interspersed with (1-->2)-linked rhamnosyl resides. Acetylated or methylated pectins were not identified on 1H-NMR analysis.