Biogenic amines in the brain of the American cockroach have been identified and quantified by an extraction-derivatisation procedure involving their reaction with ditrifluoromethylbenzoyl chloride (DTFMB) in the aqueous phase followed by extraction into an organic solvent, hydrolysis of phenolic esters and conversion of free hydroxyl groups to trimethylsilyl (TMS) ethers and subsequent analysis by gas chromatography-negative ion chemical ionisation mass spectrometry. The molecular ion of these DTFMB-TMS derivatives carried most of the ion current which made the method highly specific and gave a potential limit of detection below the picogram level. This method establishes unequivocally that the principal amines in cockroach brain are tyramine, p-octopamine, dopamine, 5-hydroxytryptamine and noradrenaline. In contrast to mammalian nervous tissue, the other positional isomers of octopamine, together with the isomeric synephrines, are absent. 相似文献
We discuss how the cosmic ray signals reported by the PAMELA and ATIC/PPB-BETS experiments may be understood in a Standard Model (SM) framework supplemented by type II seesaw and a stable SM singlet scalar boson as dark matter. A particle physics explanation of the ‘boost’ factor can be provided by including an additional SM singlet scalar field. 相似文献
A selective and sensitive liquid chromatography–mass spectrometric method in ESI (+ve) mode was developed and validated completely in human plasma. Clonidine and IS, carbamazapine, were extracted from human plasma via liquid–liquid extraction with ethyl acetate. Following evaporation under nitrogen, the residue was reconstituted with mobile phase and analyzed using API 4000 LC–MS–MS system. An isocratic program with binary mobile phases (0.1% formic acid in water and acetonitrile) was used to separate interference peaks by a C18 analytical column. Linearity range was 0.49–73.98 ng mL−1. The intra- and inter-day accuracy and precision were within acceptable limits (≤15%). This method was successfully applied to a single dose 25 μg tablets BE study of clonidine in healthy male volunteers.
The synthesis and characterization of Ru (II) terpyridine complexes derived from 4′ functionalized 2,2′:6′,2″‐terpyridine (tpy) ligands are reported. The heteroleptic complexes comprise the synthesized ligands 4′‐(2‐thienyl)‐ 2,2′:6′,2″‐terpyridine) or (4′‐(3,4‐dimethoxyphenyl)‐2,2′:6′,2″‐terpyridine and (dimethyl 5‐(pyrimidin‐5‐yl)isophthalate). The new complexes [Ru(4′‐(2‐thienyl)‐2,2′:6′,2″‐terpyridine)(5‐(pyrimidin‐5‐yl)‐isophthalic acid)Cl2] ( 9 ), [Ru(4′‐(3,4‐dimethoxyphenyl)‐2,2′:6′,2″‐terpyridine)(5‐(pyrimidin‐5‐yl)‐isophthalic acid)Cl2] ( 10 ), and [Ru(4′‐(2‐thienyl)‐2,2′:6′,2″‐terpyridine)(5‐(pyrimidin‐5‐yl)‐isophthalic acid)(NCS)2] ( 11 ) were characterized by 1H‐ and 13C‐NMR spectroscopy, C, H, N, and S elemental analysis, UPLC‐ESI‐MS, TGA, FT‐IR, and UV‐Vis spectroscopy. The biological activities of the synthesized ligands and their Ru (II) complexes as anti‐inflammatory, antimicrobial, and anticancer agents were evaluated. Furthermore, the toxicity of the synthesized compounds was studied and compared with the standard drugs, namely, diclofenac potassium and ibuprofen, using hemolysis assay. The results indicated that the ligands and the complex 9 possess superior anti‐inflammatory activities inhibiting albumin denaturation (89.88–100%) compared with the standard drugs (51.5–88.37%) at a concentration of 500 μg g?1. These activities were related to the presence of the chelating N‐atoms in the ligands and the exchangeable chloro‐ groups in the complex. Moreover, the chloro‐ and thiophene groups in complex 9 produce a higher anticancer activity compared with its isothiocyanate derivative in the complex 11 and the 3,4‐dimethoxyphenyl moiety in complex 10 . Considering the toxicity results, the synthesized ligands are nontoxic or far less toxic compared with the standard drugs and the metal complexes. Therefore, these newly synthesized compounds are promising anti‐inflammatory agents in addition to their moderate unique broad antimicrobial activity. 相似文献
Unification at MGUT∼3×1016 GeV of the three Standard Model (SM) gauge couplings can be achieved by postulating the existence of a pair of vectorlike fermions carrying SM charges and masses of order 300 GeV–1 TeV. The presence of these fermions significantly modifies the vacuum stability and perturbativity bounds on the mass of the SM Higgs boson. The new vacuum stability bound in this extended SM is estimated to be 117 GeV, to be compared with the SM prediction of about 128 GeV. An upper bound of 190 GeV is obtained based on perturbativity arguments. The impact on these predictions of type I seesaw physics is also discussed. The discovery of a relatively ‘light’ Higgs boson with mass ∼117 GeV could signal the presence of new vectorlike fermions within reach of the LHC. 相似文献
Cholest-3,5-diene-7-one-oxime (C27H43NO) was prepared using a usual synthetic route and its three-dimensional structure was determined by X-ray diffraction methods. The transparent platelike crystals of this compound crystallized in the monoclinic space group P21, with unit cell parameters a = 14.302(2) Å, b = 11.475(2) Å, c = 15.919(4) Å, = 106.04(1)°, (Cu K) = 1.5418 Å, Z = 4. The structure was solved by direct methods and refined to an R-value of 0.075 for 4640 observed reflections. Two crystallographically independent molecules were observed in the asymmetric unit cell. The ring A in both the molecules was found to exist in 1,10
half-chair conformation while ring C in chair conformation. The rings B and D in both the molecules adopted different conformations. Three intermolecular interactions of the type C–H O and C–H N were also observed. 相似文献
5-Butynylisoxazoles were obtained in high yields through a domino addition, C-O heterocyclization involving allenylmagnesium bromide and benzonitrile oxide in dry THF, in which the corresponding 5-methylisoxazoles were isolated in trace amounts. However, when the reactions were attempted in aqueous media using allenylindium bromide, 5-methylisoxazoles were formed as the sole products in high yields. 相似文献
Here we report on a mixed oxide system, gamma-Fe2O3 nanoparticles doped with Mn(III), where the transition from the cubic to the more stable hexagonal alpha-Fe2O3 structure is suppressed. When amorphous Fe2O3 is heated at 300 degrees C for 3 h, ferrimagnetic gamma-Fe2O3 is observed as the sole product. On the other hand, when the temperature is raised to 500 degrees C, one observes only antiferromagnetic alpha-Fe2O3 as the product. However, upon doping with 8.5 wt % Mn(III), the amorphous nanoparticles crystallized to mainly the gamma-Fe2O3 matrix after heating at 500 degrees C for 3 h, and need to be heated to >650 degrees C for the complete transition to the alpha-Fe2O3 structure to take place. 相似文献
A series of methyl β-D-galactopyranoside (MGP, 1) analogs were selectively acylated with cinnamoyl chloride in anhydrous N,N-dimethylformamide/triethylamine to yield 6-O-substitution products, which was subsequently converted into 2,3,4-tri-O-acyl analogs with different acyl halides. Analysis of the physicochemical, elemental, and spectroscopic data of these analogs revealed their chemical structures. In vitro antimicrobial testing against five bacteria and two fungi and the prediction of activity spectra for substances (PASS) showed promising antifungal functionality comparing to their antibacterial activities. Minimum inhibition concentration (MIC) and minimum bactericidal concentration (MBC) tests were conducted for four compounds (4, 5, 6, and 9) based on their activity. MTT assay showed low antiproliferative activity of compound 9 against Ehrlich’s ascites carcinoma (EAC) cells with an IC50 value of 2961.06 µg/mL. Density functional theory (DFT) was used to calculate the thermodynamic and physicochemical properties whereas molecular docking identified potential inhibitors of the SARS-CoV-2 main protease (6Y84). A 150-ns molecular dynamics simulation study revealed the stable conformation and binding patterns in a stimulating environment. In-silico ADMET study suggested all the designed molecules to be non-carcinogenic, with low aquatic and non-aquatic toxicity. In summary, all these antimicrobial, anticancer and in silico studies revealed that newly synthesized MGP analogs possess promising antiviral activity, to serve as a therapeutic target for COVID-19. 相似文献