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1.
Sodium salt of a water-soluble, anionic, and monomeric 1:2 complex of Au(I) with a dianion of thiosalicylic acid TSA2−(Hin2TSA) = o-HS(C6H4)COOH) was first prepared and isolated as colorless needle crystals through a stoichiometric reaction of NaAuCl4:H2TSA:NaOH = 1:4:8 molar ratio in aqueous/EtOH solution. In this reaction, TSA2− ligand has played a role of a reducing agent for the starting Au(III) ion and also of donor ligands coordinating to the reduced Au(I). This compound was characterized by complete elemental analyses, TG/DTA, FT-IR, 2D-NMR (1H-1H COSY, 1H-13C HMBC, and 1H-13C HMQC) spectroscopy, and the molmass measurement based on the cryoscopic method. It was shown that this complex was a monomeric species of Au(I) with a formula of Na3[Au(TSA)2]·5H2O in the solid state, but not a polymeric species even in aqueous solution. A full assignment of seven carbon and four proton resonances in the coordinated TSA2− ligand was achieved by the 2D 1H-13C HMBC NMR technique.  相似文献   

2.
Pure sucrose is inexpensive and readily available, making this disaccharide a highly desirable starting material for new polymers. In order to achieve a clean polymerization, the disaccharide must be regioselectively monofunctionalized in good yield. This paper describes the practical, enzyme-mediated synthesis of sucrose-1 '-methacrylate 2 from sucrose and vinyl methacrylate using subtilisin Carlsberg (Sigma, Protease VIII), a readily available bacterial serine protease. A key aspect of this process, ascertaining the positional selectivity of acylation, was unambiguously accomplished using 1H-detected (1H, 13C) one-bond shift correlation (HMQC) spectroscopy and1H-detected (1H, 13C) multiple bond correlation (HMBC) spectroscopy.  相似文献   

3.
从距花山姜(Alpinia calcarata Rosc.)的甲醇提取物中分离得到两个化合物,通过紫外光谱、红外光谱、各种高分辨核磁共振光谱和高分辨质谱,鉴定为两个新的含有环丁烯结构的半日烷型二萜双聚体,命名为距花山姜素(calcaratarin G)和距花山姜素H(calcaratarin H).这种类型的半日烷型二萜双聚体在植物中比较罕见.  相似文献   

4.
The activity of the muscarinic cholinergic system (acetylcholine, ACh; acetylcholinesterase, AChE; choline acetyltransferase, ChAT; muscarinic acetylcholine receptors) was studied in the carp brain. The ACh content (13.9 ± 1.1 nmol/g wet tissue) was estimated by gas chromatography after microwave irradiation focused to the head. The AChE and ChAT activities were 153 ± 13 nmol/min/mg protein and 817 ± 50 pmol/min/mg protein, respectively. The characteristics of [3H](−)quinuclidinyl benzilate ([3H](−)QNB) and [3H]pirenzepine ([3H]PZ) binding were also studied in brain membranes. Their specific binding was linearly dependent on the protein content and they appeared to bind with high affinity to a single, saturable binding site. A dissociation constant (Kd) of 47 ± 6.3 pM and a maximum number of binding sites (Bmax) of 627 ± 65 fmol/mg protein were obtained for [3H](−)QNB, with a Kd value of 3.85 ± 0.67 nM and a Bmax value of 95.3 ± 6.25 fmol/mg protein for [3H]PZ binding. The [3H]PZ binding amounted to only 15% of the [3H](−)QNB-labeled sites, as estimated from the ratio of the Bmax values of [3H](−)QNB and [3H]PZ, suggesting a low density of M1 subtype. Atropine sulfate, atropine methylnitrate and PZ inhibited the binding of both radioligands with Hill slopes (nH) close to unity. The nH value of AF-DX 116 was close to 1 against [3H](−)QNB binding, while it was 0.75 against [3H]PZ binding. The displacement curves of oxotremorine and carbachol were shallow for the binding of both radioligands. The rank order of potency of muscarinic ligands against [3H](−)QNB binding (Ki nM) was atropine sulfate (0.55) > atropine methylnitrate (1.61) > PZ (61.19) > oxotremorine (156.3) > AF-DX 116 (307) > carbachol (1301), while in the case of [3H]PZ binding it was atropine sulfate (0.24) > atropine methylnitrate (0.34) > PZ (10.38) > AF-DX 116 (55.87) > oxotremorine (62.79) > carbachol (1696). The results indicate the presence of a well-developed muscarinic cholinergic system with predominantly M2 receptors in the carp brain.  相似文献   

5.
An empirical projection method is described to predict the magnitudes and signs of two-bond 13C-13C spin-coupling constants (2JCC) in aldopyranosyl rings. The method has been applied primarily to the interpretation of 2JCCC values, although the behavior of 2JCOC has also been examined in light of the new approach, producing results which may prove useful in the conformational analysis of O-glycosidic linkages in oligosaccharides. High-level ab initio calculations of 2JCC values in model compounds were found to be in agreement with the predictions.  相似文献   

6.
Two halogenated C15 acetogenins, itomanallenes A and B, with a terminal bromoallene moiety along with a halogenated sesquiterpene, itomanol, have been isolated from the red alga Laurencia intricata collected in Okinawan waters. Their structures were deduced from 1D and 2D NMR experiments including 1H–1H COSY, HSQC, HMBC, and NOESY methods. The alcohol corresponding to itomanallene B seems to be a plausible precursor of itomanallene A, which has an unusual 2,10-dioxabicyclo[7.3.0]dodecene skeleton. Itomanol was found to be a selinane-type bromosesquiterpenoid, and is the first example of a selinane to be isolated from Japanese Laurencia species.  相似文献   

7.
Age-related alterations in major neurotransmitter receptors and voltage dependent calcium channels were analyzed by receptor autoradiography in the gerbil brain. [3H]Quinuclidinyl benzilate (QNB). [3H]cyclohexyladenosine (CHA), [3H]muscimol, [3H]MK-801, [3H]SCH 23390, [3H]naloxone, and [3H]PN200-110 were used to label muscarinic acetylcholine receptors, adenosine A1 receptors, γ-aminobutyric acidA (GABAA) receptors, (NMDA) receptors, dopamine D1 receptors, opioid receptors, and voltage dependent calcium channels, respectively. In middle-aged gerbils (16 months old), the hippocampus exhibited a significant elevation in [3H]QNB, [3H]MK-801, [3H]SCH 23390, [3H]naloxone, and [3H]PN200-110 binding, whereas [3H]CHA and [3H]muscimol binding showed a significant reduction in this area, compared with that of young animals (1 month). On the other hand, the cerebellum showed a significant alteration in [3H]QNB, [3H]CHA, and [3H]naloxone binding and the striatum also exhibited a significant alteration in [3H]SCH 23390 and [3H]CHA binding in middle-aged gerbils. The neocortex showed a significant elevation only in [3H]CHA binding in middle-aged animals. The nucleus accumbens and thalamus also showed a significant alteration only in [3H]muscimol binding. However, the hypothalamus and substantia nigra exhibited no significant alteration in these bindings in middle-aged gerbils. These results demonstrate the age-related alterations of various neurotransmitter receptors and voltage dependent calcium channels in most brain regions. Furthermore, they suggest that the hippocampus is most susceptible to aging processes and is altered at an early stage of senescence.  相似文献   

8.
WAY–100635 is the first selective, silent 5–HT1A (5-hydroxytryptamine1A, serotonin-1A) receptor antagonist. We have investigated the use of [3H]WAY–100635 as a quantitative autoradiographic ligand in post-mortem human hippocampus, raphe and four cortical regions, and compared it with the 5–HT1A receptor agonist, [3H]8–OH–DPAT. Saturation studies showed an average Kd for [3H]WAY–100635 binding in hippocampus of 1.1 nM. The regional and laminar distributions of [3H]WAY–100635 binding and [3H]8–OH–DPAT binding were similar. The density of [3H]WAY–100635 binding sites was 60–70% more than that of [3H]8–OH–DPAT in all areas examined except the cingulate gyrus where it was 165% higher. [3H]WAY–100635 binding was robust and was not affected by the post-mortem interval, freezer storage time or brain pH (agonal state). Using [3H]WAY–100635, we confirmed an increase of 5–HT1A receptor binding sites in the frontal cortex in schizophrenia, previously demonstrated with [3H]8–OH–DPAT. Compared to [3H]8–OH–DPAT, [3H]WAY–100635 has two advantages: it has a higher selectivity and affinity for the 5–HT1A receptor, and it recognizes 5–HT1A receptors whether or not they are coupled to a G-protein, whereas [3H]8–OH–DPAT primarily detects coupled receptors. Given these considerations, the [3H]WAY–100635 binding data in schizophrenia clarify two points. First, they indicate that the elevated [3H]8–OH–DPAT binding seen in the same cases is attributable to an increase of 5–HT1A receptors rather than any other binding site. Second, the enhanced [3H]8–OH–DPAT binding in schizophrenia reflects an increased density of 5–HT1A receptors, not an increased percentage of 5–HT1A receptors which are G-protein-coupled. We conclude that [3H]WAY–100635 is a valuable autoradiographic ligand for the qualitative and quantitative study of 5–HT1A receptors in the human brain.  相似文献   

9.
Complete 1H and 13C resonance assignments were made for a new type of 3β,7β-dihydroxy-5-cholen-24-oic acid doubly conjugated with sulfuric acid at C-3 and N-acetylglucosamine at C-7 and its glycine- and taurine-amidated triple-conjugates by the combined use of several homonuclear and heteronuclear shift-correlated 2D NMR techniques. The effects of sulfation at C-3, N-acetylglucosaminidation at C-7, and aminoacyl amidation at C-24 on the 1H and 13C chemical shifts and signal multiplicity were clarified. The shielding data serving to characterize each of the bile acid multi-conjugates are also discussed.  相似文献   

10.
[3H]Neurotensin (NT) was found to bind specifically and with high affinity to crude membranes prepared from rat uterus. Scatchard analysis of saturation binding studies indicated that [3H]NT apparently binds to two sites (high affinity Kd 0.5 nM; low affinity Kd 9 nM) with the density of high affinity sites (41 fmoles/mg prot.) being about one-third that of the low affinity sites (100 fmoles/mg prot.). In competition studies, NT and various fragments inhibited [3H]NT binding with the following potencies (IC50): NT 8–13 (0.4 nM), NT 1–13 (4 nM), NT 9–13 (130 nM), NT 1–11, NT 1–8 (>100 μM). Quantitatively similar results were obtained using brain tissue. These findings raise the possibility of a role for NT in uterine function.  相似文献   

11.
The availability of tritium-labelled sufentanil ([3H]SUF) allowed for a further radioligand analysis of opiate binding sites in rat brain. A comparison of the binding characteristics of [3H]SUF and [3H]dihydromorphine ([3H]DHM) revealed a very similar potency in their mutual displacement by unlabelled analogues. Furthermore, a series of putative μ-opiate agonists displayed equal potencies in displacing either [3H]SUF and [3H]DHM, the only striking exception being the highly μ-selective opioid peptide morphiceptin which was 33 times less potent in inhibiting [3H]SUF as compared to [3H]DHM binding. Additional experiments revealed further pronounced differences in [3H]SUF and [3H]DHM binding characteristics: the total amount of binding sites for [3H]SUF was 4 times higher than that for [3H]DHM and the regional distribution within particular brain areas displayed considerable differences. Furthermore, the binding of [3H]SUF was differentially modulated by sodium and GTP as compared to [3H]DHM binding. These data suggest that in rat brain, [3H]SUF interacts both with μ-opiate sites recognizing [3H]DHM and another type of opiate site, which cannot be equated with any of the, as yet, described δ- or κ-binding sites, and rather, represents a subclass of μ-opiate receptor sites. These experiments, thus, support the notion of subclasses (isoreceptors) for different types of opiate receptors.  相似文献   

12.
Addition of (Cp*2YH)2 (4) to 2-methyl-1,4-pentadiene produced the yttrium-alkyl-alkene chelate complex Cp*2YCH2CH2CH2C(CH3)=CH2 (2) in which a disubstituted alkene is complexed to the metal center. Evidence for coordination of the alkene unit of 2 comes from the 1H and 13C NMR chemical shifts of the vinyl units and from observation of nOe effects between Cp* protons and vinyl hydrogens. The disubstituted alkene ligand of 2 is weakly bound, and evidence for an equilibrium with substantial amounts of complex 3 with a free alkene was obtained from variable temperature 1H NMR spectroscopy.  相似文献   

13.
[3H]Lysergic acid diethylamide (LSD) in the presence of 40 nM ketanserin labeled the 5-HT1A receptor subtype in rat hippocampal membranes. In the presence of guanosine triphosphate (GTP), the Bmax and affinity of [3H]LSD binding to the 5-HT1A binding site were significantly decreased. [3H]LSD in the presence of 40 nM WB4101 labeled the 5-HT2 receptor subtype in homogenates of rat frontal cortex. In contrast to the effect on [3H]LSD binding to the 5-HT1A binding site, GTP produced no significant effect on either the Bmax or the KD of [3H]LSD binding to the 5-HT2 binding site. Competition of 5-HT for [3H]LSD binding to the 5-HT2 binding site was best described by a computer-derived model assuming two binding sites. In the presence of GTP, the 5-HT competition curve was shifted significantly to the right with an approx. 3-fold increase in the IC50. These binding characteristics are consistent with [3H]LSD acting as an antagonist at the 5-HT2 receptor which has multiple affinity states for agonists and is coupled to a guanine nucleotide regulatory subunit. Thus, [3H]LSD has binding characteristics consistent with it acting as an agonist at the 5-HT1A receptor subtype but as an antagonist at the 5-HT2 receptor subtype in rat brain.  相似文献   

14.
The assignment of 1H and 13C NMR signals of a complex type triantennary asialooligosaccharide was examined using 2D selective-TOCSY–DQFCOSY and HSQC–TOCSY experiments. The 2D selective-TOCSY–DQFCOSY experiment exhibits a 2D DQFCOSY spectrum of an individual monosaccharide in the undecasaccharide, although the NMR signals of several monosaccharides in the triantennary undecasaccharide are heavily overlapped. Selective excitation of each anomeric proton signal and subsequent TOCSY experiment afforded transverse magnetization corresponding to all of the proton signals of the monosaccharide. This magnetization was then developed with the corresponding DQFCOSY pulse sequence to afford the DQFCOSY spectrum of the individual monosugars. In this case, four GlcNAc-b, -e, -j, and -h residues were excited as a mixture. In order to assign 13C signals, a conventional 2D HSQC–TOCSY spectrum was examined and compared with an unambiguous assignment of 2D selective-TOCSY–DQFCOSY thus obtained. This systematic analysis made it possible to obtain an assignment of the 1H and 13C NMR signals of the triantennary undecasaccharide. In addition, these experiments also revealed all of the glycosyl positions in the triantennary undecasaccharide.  相似文献   

15.
Low-molecular-weight (LMW) κ-carrageenan was achieved through mild hydrochloric acid hydrolysis of κ-carrageenan. The acylation of LMW κ-carrageenan was performed by use of tetrabutylammonium (TBA) salt of the anionic polysaccharide fragments, succinic anhydride, 4-dimethylaminopyridine and tributylamine under homogeneous conditions in N,N-dimethylformamide at 80 °C. Investigation of FT-IR spectrum of the succinylated LMW κ-carrageenan showed that a monoester derivative with succinyl group was formed when LMW κ-carrageenan reacted with succinic anhydride. The 1H and 13C NMR spectroscopy has been used to characterize the fine structure of O-succinyl derivative of the LMW κ-carrageenan. The 13C and 1H NMR chemical shifts of disaccharide unit of O-succinyl LMW κ-carrageenan have been fully assigned using 2D NMR spectroscopic techniques.  相似文献   

16.
A1 adenosine receptors in coated vesicles have been characterized by radioligand binding and photoaffinity labelling. Saturation experiments with the antagonist 8-cyclopentyl-1,3-[3H]dipropyl-xanthine ([3H]DPCPX) gave a Kd value of 0.7 nM and a Bmax value of 82 ± 13 fmol/mg protein. For the highly A1-selective agonist 2-chloro-N6-[3H]cyclopentyladenosine ([3H]CCPA) a Kd value of 1.7 nM and a Bmax value of 72 ± 29 fmol/mg protein was estimated. Competition of agonists for [3H]DPCPX binding gave a pharmacological profile with R-N6-phenylisopropyladenosine (R-PIA) > CCPA > S-PIA > 5′-N-ethylcarboxamido-adenosine (NECA), which is identical to brain membranes. The competition curves were best fitted according to a two-site model, suggesting the existence of two affinity states. GTP shifted the competition curve for CCPA to the right and only one affinity state similar to the low affinity state in the absence of GTP was detected. The photoreactive agonist 2-azido-N6-125I-p-hydroxyphenylisopropyladenosine ([125I]AHPIA) specifically labelled a single protein with an apparent molecular weight of 35,000 in coated vesicles, which is identical to A1 receptors labelled in brain membranes. Therefore, coated vesicles contain A1 adenosine receptors with similar binding characteristics as membrane-bound receptors, including GTP-sensitive high-affinity agonist binding. Photoaffinity labelling data suggest that A1 receptors in these vesicles are not a processed receptor form. These results confirm that A1 receptors in coated vesicles are coupled to a G-protein, and it appears that the A1 receptor systems in coated vesicles and in plasma membranes are identical.  相似文献   

17.
High quality antique sheets of paper have been characterized by 1H NMR relaxations and 13C CP MAS spectra. Paper can be regarded as a bicomponent material made of cellulose and water plus a small amount of organic and inorganic impurities. Semicrystalline fibrous cellulose, rich in water, is present in the I and Iβ forms. The amorphous cellulose, with a low water content, contains a higher amount of paramagnetic impurities and it is characterized by quite short 1H spin-lattice relaxations and by 113C resonances with noticeable chemical shifts. Ad hoc tailored pulse sequences are able to produce 13C CP MAS spectra in which only the amorphous content of paper is clearly observed. It is shown that water is fully bound to the cellulose lattice. It also seems reasonable to formulate the hypothesis that a larger concentration of paramagnetic ions is located in the amorphous fraction of highly degraded paper compared with paper in good condition.  相似文献   

18.
The effect of the deacetylated (amine) metabolite of diamphenethide (DAMD, 10 μg ml−1) on the uptake and incorporation by adult Fasciola hepatica of radioactively labelled precursors of DNA, RNA and protein synthesis ([3H]thymidine, [3H]uridine and [3H] leucine, respectively) was measured by liquid scintillation counting. Comparison was made between the effects of DAMD and those of specific inhibitors of DNA, RNA and protein synthesis, namely, 5-fluorouracil, cordycepin and cycloheximide, respectively. DAMD caused a significant decrease in the overall uptake and incorporation of [3H]uridine by F. hepatica, decreased the incorporation of [3H] leucine and also caused a significant decrease in the overall protein content of the flukes. The effect of DAMD was similar to that of cycloheximide (1 × 10−3M), a potent inhibitor of protein synthesis, which also caused a significant decrease in the incorporation of [3H] leucine by the fluke and a decrease in the overall protein content of the fluke. Cordycepin (100 μg ml−1) caused a significant decrease in the protein content of the fluke, but had no effect on the uptake or incorporation of [3H]uridine. 5-Fluorouracil (1 × 10−4 ) did not affect the uptake or incorporation of [3H]thymidine, nor did it decrease the protein content of the fluke. The results indicate that DAMD inhibits protein synthesis by F. hepatica, possibly by inhibiting RNA synthesis. The results are also consistent with previous morphological investigations involving DAMD.  相似文献   

19.
An autoradiographic technique was used to study the distribution of changes in pulmonary NK1 and NK2 receptors in guinea pig lung after repeated antigen challenge. Specific labeling of [3H] CP96345 (NK1 receptors) and [3H] SR48968 (NK2 receptors) was localized over the tracheal and bronchial smooth muscle; the density of binding increased towards smaller airways with a higher density for [3H] CP96345 binding. Bronchial epithelium and pulmonary blood vessels were also labeled densely with [3H] CP96345. No remarkable difference in the pattern of distribution of pulmonary NK1 and NK2 tachykinin receptors was observed between control, vehicle-challenged, and repeatedly antigen-challenged (weekly for three times) guinea pigs. A significant reduction in specific labeling of [3H] CP96345 (p < 0.01) and [3H] SR48968 (p < 0.05) over pulmonary structures was observed in antigen-challenged compared to control or vehicle-challenged animals. This study provides evidence that NK1 and NK2 tachykinin receptors are both localized to smooth muscle of all sizes in guinea pig airways and provides further evidence for a discrete distribution of NK1 and NK2 tachykinin receptors, consistent with their relative functional activities. In a established model of airway inflammation a decrease in the expression of NK1 and NK2 tachykinin receptors was evident on several different cell types within the lung, and this could influence airway and vascular reactivity.  相似文献   

20.
The present study was undertaken to characterize the binding activities of propiverine and its N-oxide metabolites (1-methyl-4-piperidyl diphenylpropoxyacetate N-oxide: P-4(N → O), 1-methyl-4-piperidyl benzilate N-oxide: DPr-P-4(N → O)) toward L-type calcium channel antagonist receptors in the rat bladder and brain. Propiverine and P-4(N → O) inhibited specific (+)-[3H]PN 200–110 binding in the rat bladder in a concentration-dependent manner. Compared with that for propiverine, the Ki value for P-4(N → O) in the bladder was significantly greater. Scatchard analysis has revealed that propiverine increased significantly Kd values for bladder (+)-[3H]PN 200–110 binding. DPr-P-4(N → O) had little inhibitory effects on the bladder (+)-[3H]PN 200–110 binding. Oxybutynin and N-desethyl-oxybutynin (DEOB) also inhibited specific (+)-[3H]PN 200–110 binding in the rat bladder. Propiverine, oxybutynin and their metabolites inhibited specific [N-methyl-3H]scopolamine methyl chloride ([3H]NMS) binding in the rat bladder. The ratios of Ki values for (+)-[3H]PN 200–110 to [3H]NMS were markedly smaller for propiverine and P-4(N → O) than oxybutynin and DEOB. Propiverine and P-4(N → O) inhibited specific binding of (+)-[3H]PN 200–110, [3H]diltiazem and [3H]verapamil in the rat cerebral cortex in a concentration-dependent manner. The Ki values of propiverine and P-4(N → O) for [3H]diltiazem were significantly smaller than those for (+)-[3H]PN 200–110 and [3H]verapamil. Further, their Ki values for [3H]verapamil were significantly smaller than those for (+)-[3H]PN 200–110. The Ki values of propiverine for each radioligand in the cerebral cortex were significantly (P < 0.05) smaller than those of P-4(N → O). In conclusion, the present study has shown that propiverine and P-4(N → O) exert a significant binding activity of L-type calcium channel antagonist receptors in the bladder and these effects may be pharmacologically relevant in the treatment of overactive bladder after oral administration of propiverine.  相似文献   

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