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1.
The effects of PGD2, PGF and PGE1 were studied on the circular muscle of post-ovulatory rabbit oviducts in vitro. PGE1 inhibited spontaneous contractile activity. Lower concentrations of PGD2 and PGF were stimulatory and higher concentrations were inhibitory. Since PGD2 may be produced in the oviduct, any hypothesis concerning the role of prostaglandins in the control of oviductal motility and ovum transport should include PGD2 as well as PGFs and PGEs.  相似文献   

2.
The Pt2 (II) isomeric terminal hydrides [(CO)(H)Pt(μ-PBu2)2Pt(PBu2H)]CF3SO3 (1a), and [(CO)Pt(μ-PBu2)2Pt(PBu2H)(H)]CF3SO3 (1b), react rapidly with 1 atm of carbon monoxide to give the same mixture of two isomers of the Pt2 (I) dicarbonyl [Pt2(μ-PBu2)(CO)2(PBu2H)2]CF3SO3 (3-Pt); the solid state structure of the isomer bearing the carbonyl ligands pseudo-trans to the bridging phosphide was solved by X-ray diffraction. A remarkable difference was instead found between the reactivity of 1a and 1b towards carbon disulfide or isoprene. In both cases 1b reacts slowly to afford [Pt2(μ-PBu2)(μ,η22-CS2)(PBu2H)2]CF3SO3 (4-Pt), and [Pt2(μ-PBu2)(μ,η22-isoprene) (PBu2H)2]CF3SO3 (6-Pt), respectively. In the same experimental conditions, 1a is totally inert. A common mechanism, proceeding through the preassociation of the incoming ligand followed by the PH bond formation between one of the bridging P atoms and the hydride ligand, has been suggested for these reactions.  相似文献   

3.
Bi-nuclear neutral sulfur-nitrosyl iron complex [Fe2(SR)2(NO)4] (I) has been obtained by replacement of thiosulfate ligands in dianion [Fe2(S2O3)2(NO)4]2− by 1-methyl-imidazole-2-yl. From X-ray analysis data, the complex has centrosymmetrical dimeric structure, with the iron atoms being linked via μ-N-C-S bridge. From Mossbauer spectroscopy, isomeric shift δFe is 0.180(1) mm/s and quadrupole splitting ΔEQ is 0.928(2) mm/s at T = 290 K. By comparative studying the mass-spectra in the gaseous phase of solid samples decomposition and kinetics of NO release in 1% aqueous solutions of dimethylsulfoxide, using of the ligand with CH3 substituent in position 1 of imidazole-2-thiol was shown to yield a more stable donor of nitrogen monoxide than earlier obtained analog with imidazole-2-thiol, [Fe2(C3H3N2S)2(NO)4].  相似文献   

4.
The room temperature electronic absorption spectra of the oxalate bridged MM quadruply bonded complexes [(tBuCO2)3M2]2(μ-O2C2O2), where M = Mo or W have been recorded in H2O, THF:H2O mixtures, THF, CH2Cl2, toluene, DMSO, aniline, toluene saturated with N,N-dimethylaniline and ethanol. The strong absorptions in the visible region of the electronic absorption spectra assignable to the metal-to-ligand (bridge) charge transfer are shown to be highly solvent dependent. Those samples prepared in H2O, CH2Cl2 and toluene are shown to comprise of a suspension of microcrystalline particles ranging in size from 100 nm to 5 μm. Individual particles were found by scanning electron microscopy to have an aspect ratio of ∼10:1, all being needle shaped. The spectra in THF, EtOH, aniline, DMSO and toluene-N,N-dimethylaniline all show similar vibronic progressions and are attributed to discrete solvated molecular species. The spectra recorded in aniline are notably red-shifted which is proposed to arise from a combination of hydrogen bonding and Lewis base stabilization of the photoexcited state.  相似文献   

5.
A new molecular loop composed of two quadruply bonded Mo2(DAniF)2 units (DAniF=N,N-di-p-anisylformamidinate) linked by two chiral allene-1,3-dicarboxylate anions has been prepared from the reaction of [cis-Mo2(DAniF)2(MeCN)4](BF4)2 with the bis(tetraethylammonium) salt of allene-1,3-dicarboxylic acid. This compound, [cis-Mo2(DAniF)2]2(O2C-CHCCH-CO2)2 (1), has been characterized by X-ray crystallography and by 1H NMR and UV-Vis spectroscopy. The molecule possesses a center of inversion and hence is meso. There is only weak electronic coupling between the two Mo2 4+ units as revealed by electrochemical measurements.  相似文献   

6.
The coordination chemistry of the metalloligand [Pt2(μ-S)2(PPh3)4] towards cobalt(II) and cobalt(III) centres has been explored using an electrospray ionisation mass spectrometry (ESI MS)-directed methodology. Reaction of [Pt2(μ-S)2(PPh3)4] with CoCl2·6H2O in methanol gave a green-yellow suspension of the known adduct [Pt2(μ-S)2(PPh3)4CoCl2], and the CoBr2 adduct could be similarly prepared. When in situ-generated [Pt2(μ-S)2(PPh3)4CoCl2] is reacted with 8-hydroxyquinoline (HQ) and base, the initial product is the cobalt(II) adduct [Pt2(μ-S)2(PPh3)4CoQ]+, which is then converted in air to the cobalt(III) adduct [Pt2(μ-S)2(PPh3)4CoQ2]+, isolated as its hexafluorophosphate salt. The corresponding picolinate (Pic) derivative [Pt2(μ-S)2(PPh3)4Co(Pic)2]+ was similarly prepared, however reaction of [Pt2(μ-S)2(PPh3)4], CoCl2·6H2O and 8-(tosylamino)quinoline (HTQ) produced only the cobalt(II) adduct [Pt2(μ-S)2(PPh3)4CoTQ]+. Reactions of [Pt2(μ-S)2(PPh3)4], CoCl2·6H2O and dithiocarbamates gave cobalt(III) complexes [Pt2(μ-S)2(PPh3)4Co(S2CNR2)2]+ [R = Et or R2 = (CH2)4], and proceeded much more rapidly, consistent with the known ability of the dithiocarbamate ligand to stabilize cobalt in higher oxidation states. A study of the fragmentation of cobalt(III) adducts by positive-ion ESI mass spectrometry indicated that [Pt2(μ-S)2(PPh3)4CoQ2]+ fragments to form the radical cation [Pt2(μ-S)2(PPh3)4]+, which could also be generated by ESI MS analysis of [Pt2(μ-S)2(PPh3)4] in methanol-NaOH solution. In contrast, the corresponding indium(III) derivative [Pt2(μ-S)2(PPh3)4InQ2]+, and the cobalt(III) dithiocarbamate [Pt2(μ-S)2(PPh3)4Co(S2CN(CH2)4)2]+ are much more reluctant to fragment under analogous conditions, and the differences are discussed in terms of cobalt(III) redox chemistry.  相似文献   

7.
The synthetic cluster [Fe4S4 (SCH2CH2OH)4]2? and ferredoxin I from Desulfovibriogigas have been comparatively reacted in the presence of hydrogen with two enzyme components isolated from the D.gigas electron carrier system: hydrogenase and cytochrome c3. The reactions have been followed by spectrophotometric and manometric methods. No reduction is detected unless both enzymes are simultaneously present. The easy reduction in the presence of hydrogenase-cytochrome c3 combination takes place in two stages corresponding each to one equivalent of reduction. The first stage is reversible while the second is not and yields a super reduced species deriving from the cluster complex.  相似文献   

8.
Our previously published prostaglandin (PG) synthesis route, in which the ω-chain is added in the penultimate step, provides facile access to a wide variety of ω-chain variant PG analogs. Each series requires only the synthesis of the appropriate methylated acylphosphonate for the Emmons' condensation. The syntheses of analogs bearing the following methylation pattern are detailed: 15-Me; 17, 17-(Me)2; 17, 17, 20-(Me)3; 18, 18, 20-(Me)3; 15, 18, 18, 20-(Me)4; and 15-Ome-18, 18, 20-(Me)3. The well-known 16, 16-dimethyl prostaglandins have also been prepared by this sequence. The synthesis of 16, 16-tetramethylene-PG analogs is also described.  相似文献   

9.
10.
Reactions of [Pt2(μ-S)2(PPh3)4] with the diarylthallium(III) bromides Ar2TlBr [Ar = Ph and p-ClC6H4] in methanol gave good yields of the thallium(III) adducts [Pt2(μ-S)2(PPh3)4TlAr2]+, isolated as their salts. The corresponding selenide complex [Pt2(μ-Se)2(PPh3)4TlPh2]BPh4 was similarly synthesised from [Pt2(μ-Se)2(PPh3)4], Ph2TlBr and NaBPh4. The reaction of [Pt2(μ-S)2(PPh3)4] with PhTlBr2 gave [Pt2(μ-S)2(PPh3)4TlBrPh]+, while reaction with TlBr3 gave the dibromothallium(III) adduct [Pt2(μ-S)2(PPh3)4TlBr2]+[TlBr4]. The latter complex is a rare example of a thallium(III) dihalide complex stabilised solely by sulfur donor ligands. X-ray crystal structure determinations on the complexes [Pt2(μ-S)2(PPh3)4TlPh2]BPh4, [Pt2(μ-S)2(PPh3)4TlBrPh]BPh4 and [Pt2(μ-S)2(PPh3)4TlBr2][TlBr4] reveal a greater interaction between the thallium(III) centre and the two sulfide ligands on stepwise replacement of Ph by Br, as indicated by shorter Tl-S and Pt?Tl distances, and an increasing S-Tl-S bond angle. Investigations of the ESI MS fragmentation behaviour of the thallium(III) complexes are reported.  相似文献   

11.
Prostaglandins A2, E1, E2, methylated E2s and F2α affected erythropoiesis and/or erythropoietin (Ep) production. This action is indicated in the exhypoxic, polycythemic mouse where radioiron incorporations into RBC increased after administration of these compounds. The kidney and liver have been indicated through previous studies, to actively participate in Ep production. By the removal of one of these active sites in a murine system treated with prostaglandins it is shown that a response is reflected in Ep levels. Interference of the action of prostaglandins (PG) is altered by the removal of one of these target sites of Ep production. The erythropoietic responses elicited by PGA2, E1, and perhaps the methylated PGE2s act through the liver whereas PGE2 may operate through a renal pathway for its response. PGF reveals no effect on erythropoietic activity and is no different than that observed for vehicle-treated controls. The prostaglandins tested appear to act primarily through the kidney or liver but the possibility exists that some yet undetermined organ site may also be involved.  相似文献   

12.
The reduction of ethanolic solutions of niobium pentachloride with zinc, followed by treatment with aqueous acids serves as a versatile entry into the aqueous solution chemistry of niobium. From the zinc-reduced solution, the major intermediate, Nb42-O)22-OC2H5)4Cl4(OC2H5)4(HOC2H5)4, was isolated and the crystal structure determined by X-ray crystallography. The complex crystallizes in the orthorhombic space group Pccn, with Z=4, a=21.0105(9), b=11.0387(5), c=19.1389(8), V=4438.9(3) Å3, Mr=1090.19,R1=0.0327 and wR2=0.0876. The structure revealed a centrosymmetric tetrameric Nb(IV) complex, consisting of a pair of edge-sharing bi-octahedral Nb22-OC2H5)4Cl2(OC2H5)2(HOC2H5)2 units that are joined by two axial oxo ligands. The Nb-Nb distance of 2.7458(3) Å is consistent with a single metal-metal bond.  相似文献   

13.
PGF2α, but not PGE2, induces a slight pedal edema when given alone. Both compounds were equipotent in the carrageenin-induced rat paw edema. Locally administered, PGE2 and PGF2α did not exacerbate, but rather inhibited inflammations induced by various agents such as 1% carrageenin or 1% egg white. The administration of PGE2 directly into cotton pellets or into the rat's hind paw in combination with M. butyricum significantly inhibited, respectively, granuloma formation and the polyarthritis. Subcutaneously, both prostaglandins inhibited the adjuvant induced polyarthritis. Neither PGE2 nor PGF2α inhibited the anti-edema properties of non-steroidal or steroidal anti-inflammatory standards. A greater anti-edema activity was observed with the combination treatment than with the anti-inflammatory standards alone. We were unable to decrease the anti-inflammatory activity of the steroidal and non-steroidal standards or increase the inflammatory potential of the phlogistic agents.  相似文献   

14.
Addition of trifluoroacetic acid to syn-[MoO(μ-N-o-tol)(S2CNEt2)]2 in chloroform affords tetranuclear [{Mo2O(S2CNEt2)(η1-O2CCF3)(μ-N-o-tol)2}2(μ-O)(μ-O2CCF3)2] which has been crystallographically characterised. It consists of four molybdenum(V) centres linked via bridging imido, trifluoroacetate and oxo ligands and results from replacement of a dithiocarbamate by two trifluoroacetate ligands.  相似文献   

15.
Plasma levels of progesterone, total estrogens and HCG were measured after the administration of 15 (S) 15-methyl prostaglandin E2 methyl ester (15-methyl PGE2) or 15 (S) 15-methyl prostaglandin F free acid (15-methyl PGF) for therapeutic abortion during the first trimester of pregnancy. 15-methyl PGE2 given intramuscular (im) in a dose of 50μg resulted in the termination in pregnancy in four out of five patients; these subjects exhibited falls in hormone concentrations. However, an im injection of 500μg 15-methyl PGF did not affect the hormone levels nor did it produce abortion in any of the five subjects studied. The results confirm that 15-methyl PGE2 is a potent abortifacient and this action may be related to an effect that this compound has on hormone production by the corpus luteum or the feto-placental unit; 15-methyl PGF does not share the same action in the dose range investigated.  相似文献   

16.
The following experiments were designed in order to examine the inter-relationships of various prostaglandins (PG's) and the adrenergic nervous system, in conjunction with blood pressure and heart rate responses, in vivo. Stimulation of the entire spinal cord (50v, 0.3–3 Hz, 1.0 msec) of the pithed rat increased blood pressure, heart rate and plasma epinephrine (EPI) and norepinephrine (NE) concentration (radioenzymatic-thin layer chromatographic assay). Infusion of PGE2(10–30 μg/kg. min, i.v.) suppressed blood pressure and heart rate responses to spinal cord stimulation while plasma EPI (but not NE) was augmented over levels found in control animals. PGI2 (0.03–3.0 μg/kg. min, i.v.) suppressed the blood pressure response to spinal cord stimulation without any effect on heart rate or the plasma catecholamine levels. PGE2 and PGF2α(10–30 μg/kg. min, i.v.) did not change the blood pressure, heart rate or plasma EPI and NE responses to the spinal cord stimulation although PGF2α disclosed an overall vasopressor effect during the pre-stimulation period. At the pre-stimulation period it was also observed that PGE2, PGF2α and PGI2, had a positive chronotropic effect on the heart rate, the cardiac accelerating effect of PGE2 was not abolished by propanolol. These in vivo studies suggest that in the rat, PGE2 and PGI2 modulate sympathetic responses, primarily by interaction with the post-synaptic elements — PGE2 on both blood vessels and the heart and PGI2 by acting principally on blood vessels.  相似文献   

17.
Routes to the synthesis of the mixed sulfide-phenylthiolate complex [Pt2(μ-S)(μ-SPh)(PPh3)4]+ have been explored; reaction of [Pt2(μ-S)2(PPh3)4] with excess Ph2IBr proceeds readily to selectively produce this complex, which was structurally characterised as its PF6 salt. Reactions of [Pt2(μ-S)2(PPh3)4] with other potent arylating reagents (1-chloro-2,4-dinitrobenzene and 1,5-difluoro-2,4-dinitrobenzene) also produce the corresponding nitroaryl-thiolate complexes [Pt2(μ-S){μ-SC6H2(NO2)2X}(PPh3)4]+ (X = H, F). The complex [Pt2(μ-S)(μ-SPh)(PPh3)4]+ reacts with Me2SO4 to produce the mixed alkyl/aryl bis-thiolate complex [Pt2(μ-SMe)(μ-SPh)(PPh3)4]2+, but corresponding reactions with the nitroaryl-thiolate complexes are plagued by elimination of the nitroaryl group and formation of [Pt2(μ-SMe)2(PPh3)4]2+. [Pt2(μ-S)(μ-SPh)(PPh3)4]+ also reacts with Ph3PAuCl to give [Pt2(μ-SAuPPh3)(μ-SPh)(PPh3)4]2+.  相似文献   

18.
19.
Reaction of [Pt2(μ-S)2(PPh3)4] with a number of transition metal-iodo complexes leads to the formation of the cationic iodo analogue [Pt2(μ-S)(μ-I)(PPh3)4]+, identified using electrospray ionisation mass spectrometry (ESI MS). Synthetic routes to this complex were developed, using the reaction of [Pt2(μ-S)2(PPh3)4] with either [PtI2(PPh3)2] or elemental iodine. The complex was characterised by NMR spectroscopy, ESI MS and an X-ray structure determination, which reveals the presence of a planar, disordered {Pt2SI}+ core. Monitoring the iodine reaction by ESI MS allows the identification of various iodine species, including the short-lived intermediate [Pt2(μ-S)2(PPh3)4I]+, which allows a mechanism for the reaction to be proposed.  相似文献   

20.
Reaction at pH = 2.3 of the [Mo2O2S2(OH2)6]2+ aqua cation with the tetravacant ion [β-B-HAs2W8O31]7− leads to the formation of a red solid from which three mixed salts have been obtained as single crystals and characterized by X-ray diffraction analysis. Three mixed salts K-5a, RbNa-5b, DMACs-5c exhibit a similar molecular arrangement consisting in three {β-HAs2W9O34} subunits mutually linked by three {Mo2O2S2} groups. The triangular arrangement delimits a large open-cavity, lined on the periphery by three outer {As-OH} groups and closed at the bottom by a small hexagonal pocket formed by six terminal oxygen atoms. The central hexagonal cavity is filled either by a potassium, a rubidium or a cesium cation. The outer {As-OH} groups are pointed towards two directions labelled up and down, respectively. In K-6a the three {As-OH} bonds are in up configuration leading to the {up, up, up} isomer. The structure of RbNa-5b is rather consistent with the superposition of the two {up, up, up} and {down, up, up} isomers disordered over the same crystallographic site, while only the {down, up, up} isomer is present in DMACs-5c. In solution, 183W NMR characterization of 6a as sodium salt results in a complicated spectrum consistent with the simultaneous presence of the four isomers, {up, up, up}, {down, up, up}, {down, down, up} and {down, down, down}, respectively. 5a reacts with three equivalents of iodine to give CsNa-6 isolated as single crystals. In 6, four β-{AsW9O33} moieties are located at the corner of a super tetrahedron and are mutually connected by six {Mo2O2S2} linkers. The three outer {As-OH} groups can be selectively removed by iodine, this oxidation reaction consisting in fact in a deprotecting process permitting the extension of the arrangement from triangular to tetrahedral.  相似文献   

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