共查询到20条相似文献,搜索用时 15 毫秒
1.
Beatriz Werneck Lopes Santos Daniel Carneiro Moreira Tatiana Karla dos Santos Borges Eloisa Dutra Caldas 《Molecules (Basel, Switzerland)》2022,27(8)
Banisteriopsis caapi is used to prepare the psychoactive beverage ayahuasca, and both have therapeutic potential for the treatment of many central nervous system (CNS) conditions. This study aimed to isolate new bioactive compounds from B. caapi extract and evaluate their biological activity, and that of the known β-carboline components of the plant (harmine, harmaline, and tetrahydroharmine), in BV-2 microglial cells, the in vivo activation of which is implicated in the physiopathology of CNS disorders. B. caapi extract was fractionated using semipreparative liquid chromatography (HPLC-DAD) and the exact masses ([M + H]+ m/z) of the compounds in the 5 isolated fractions were determined by high-resolution LC-MS/MS: F1 (174.0918 and 233.1289), F2 (353.1722), F3 (304.3001), F4 (188.1081), and F5 (205.0785). Harmine (75.5–302 µM) significantly decreased cell viability after 2 h of treatment and increased the number of necrotic cells and production of reactive oxygen species at equal or lower concentrations after 24 h. F4 did not impact viability but was also cytotoxic after 24 h. Most treatments reduced proinflammatory cytokine production (IL-2, IL-6, IL-17, and/or TNF), especially harmaline and F5 at 2.5 µM and higher concentrations, tetrahydroharmine (9.3 µM and higher), and F5 (10.7 µM and higher). The results suggest that the compounds found in B. caapi extract have anti-inflammatory potential that could be explored for the development of treatments for neurodegenerative diseases. 相似文献
2.
McIlhenny EH Riba J Barbanoj MJ Strassman R Barker SA 《Biomedical chromatography : BMC》2011,25(9):970-984
Ayahuasca, also known as caapi or yage among various South American groups, holds a highly esteemed and millennia-old position in these cultures' medical and religious pharmacopeia. There is now an increasing interest in the potential for modern medical applications of ayahuasca, as well as concerns regarding its increasing potential for abuse. Toxicological and clinical research to address these issues will require information regarding its metabolism and clearance. Thus, a rapid, sensitive and specific method for characterization and quantitation of the major constituents and of the metabolites of ayahuasca in urine is needed. The present research provides a protocol for conducting such analyses. The characteristics of the method, conducted by sample dilution and using HPLC-electrospray ionization (ESI)-selected reaction monitoring (SRM)-tandem mass spectrometry, are presented. The application of the analytical protocol to urine samples collected from three individuals that were administered ayahuasca has also been demonstrated. The data show that the major metabolite of the hallucinogenic component of ayahuasca, N,N-dimethyltryptamine (DMT), is the corresponding N-oxide, the first time this metabolite has been described in in vivo studies in humans. Further, very little DMT was detected in urine, despite the inhibition of monoamine oxidase afforded by the presence of the harmala alkaloids in ayahuasca. The major harmala alkaloid excreted was tetrahydroharmine. Other excretion products and metabolites were also identified and quantified. The method described would be suitable for use in further toxicological and clinical research on ayahuasca. 相似文献
3.
The pentafluoropropionyl, (PFP) and trifluoroacetyl (TFA) esters of several naturally occurring and synthetically modified simple trichothecenes were synthesized in nanogram amounts and characterized. Optimum conditions for the gas chromatographic (GC) separation of these derivatives and their analysis by negative ion chemical ionization (NICI) mass spectrometric technique were determined. These perfluoroacyl derivatives under the NICI conditions undergo limited but characteristic fragmentations similar to the fragmentations of heptafluorobutyryl esters of trichothecenes under the same conditions. Characteristic ions for the specific detection and accurate quantification of these PFP and TFA derivatives were chosen. Preliminary results indicated that the PFP derivatives are better suited for the analysis of simple trichothecenes by GC-NICI-MS technique. Ultra trace (0.5-2.0 pg) amounts of these PFP derivatives were detected by the developed procedure. 相似文献
4.
5.
Vijila C Ramalingam A Gowri VS Chua SO Sivakumar K 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2000,56(5):983-989
The absorption and fluorescence characteristics of three substituted imidazonaphthyridine derivatives are studied in a series of organic solvents. The variation of Stokes shift with the polarity parameter of the solvent is studied and the excited state dipole moment of these derivatives is higher than the ground state dipole moment. The fluorescence lifetime profile shows single exponential decay in all the solvents. The fluorescence quantum yield, radiative and non-radiative rate constants are also calculated and these parameters show much variation in the change in substitution of these derivatives. 相似文献
6.
Van Der Borght M Vanderzande D Adriaensens P Gelan J 《The Journal of organic chemistry》2000,65(2):284-289
In our laboratory a precursor route to poly(p-phenylenevinylene) derivatives is developed in which unsymmetrically substituted p-xylene derivatives, possessing a benzylic sulfinylalkyl group, are used as monomers. Because of this unsymmetry, we were forced to investigate thoroughly the synthesis of these sulfoxides, as we start from symmetric and readily accessible molecules, namely, bis(halomethyl)-p-xylene derivatives. In a former publication, a new extremely effective route for the production of these unsymmetrically substituted sulfinyl monomers was presented. This paper expands upon these previously reported results. To examine the scope and limitations of this elegant route, this new method was applied to the synthesis of various derivatives not included in the initial work. 相似文献
7.
Ladder-type oligophenylene derivatives are important compounds for light-emitting devices. However, the closely related ladder-type oligonaphthalene derivatives have received little attention due to the lack of synthetic accessibility. We hereby report the syntheses of these novel conjugated systems by means of an intramolecular cationic cyclization protocol. Utilizing a one-pot-multiple-component reaction, the acyclic precursors to these ladder-type oligomers up to pentamer can be synthesized from small fragments in just two or three steps. Photophysical and electrochemical studies revealed that the electron delocalization in these compounds is considerably enhanced relative to that found in the regular unplanarized oligonaphthalene derivatives. However, such an effect is much weaker than that found in fully planar rylene derivatives. 相似文献
8.
The preparation of the first organosilicon containing derivatives of mercaptoethylamine as possible radioprotective agents is described. The synthesis of these compounds via the thiazolidine intermediate was chosen due to the known radioprotective action of certain thiazolidines. We have prepared seventeen previously unreported organosilicon derivatives of which eleven contain the thiazolidine moiety and six are derivatives of mercaptoethylamine. The ability of these derivatives to protect against ionizing radiation will be determined. 相似文献
9.
The perfluoroacyl derivatives (pentafluoropropionylamides and heptafluorobutrylamides) of the primary and secondary regioisomeric amines, related to the controlled drug substance 3,4-methylenedioxymethamphetamine, are prepared and evaluated in GC-MS studies. These derivatives show excellent resolution on nonpolar stationary phases, such as RTX-1 and RTX-5, with elution order differences from those of the underivatized amines. The mass spectra for these derivatives are significantly individualized, and the resulting unique fragment ions allow for specific side-chain identification. The individualization is the result of fragmentation of the alkyl carbon-nitrogen bond, yielding hydrocarbon fragments and other unique ions. The heptafluoro butrylamides derivatives offer more fragment ions for molecular individualization among these regioisomeric substances. 相似文献
10.
Akira Hirao Mayumi Hayashi Naoki Haraguchi 《Macromolecular rapid communications》2000,21(17):1171-1184
This article covers precise syntheses of well‐defined chain‐end and in‐chain functionalized polymers, multi‐functionalized polymers with a definite number of functional groups, star‐branched and graft polymers by recently developed methodologies using specially designed 1,1‐diphenylethylene (DPE) derivatives. The DPE derivatives include various substituted DPE derivatives with functional groups and their derivatives, DPE‐functionalized DPE derivatives, and well‐defined DPE‐functionalized macromonomers. The synthetic utility and importance of these DPE derivatives are described via such polymer syntheses. 相似文献
11.
The control of regiochemistry in the synthesis of polysaccharide derivatives is one of the most significant scientific challenges
in the field. Its importance is only further highlighted by the individual successes in synthesis of regioselectively substituted
derivatives, in particular cellulose esters and ethers, over the last 20 years. The availability of these samples and studies
of their properties versus randomly substituted analogs has shown clearly that properties like solubility, aggregation phenomena,
and optical properties depend heavily on the regiochemistry of substitution. We report here on the one-pot synthesis of novel
6-bromo-6-deoxy-2,3-O-acylcellulose derivatives, which as more organic soluble derivatives of 6-bromo-6-deoxycellulose should allow broader exploitation
of the highly regioselective cellulose 6-bromination chemistry. We illustrate the potential of these new derivatives by conversion
to 6-cyano-6-deoxycellulose esters. 相似文献
12.
Nitrocellulose (NC)-based propellants require stabilizers to avoid early decomposition or even explosion during storage. A series of novel fullerene-malonamide derivatives with different carbon chain lengths on the p-position of the benzene ring was synthesized as stabilizers for NC-based propellants through the Bingel reaction because of the excellent thermal stability and strong ability of these derivatives to eliminate free radicals. The molecular structures of these fullerene-malonamide derivatives were verified via 1H nuclear magnetic resonance (NMR) spectroscopy, 13C NMR spectroscopy, Fourier-transform infrared (FT-IR) spectroscopy, ultraviolet–visible spectroscopy, and high-resolution mass spectrometry. Meanwhile, their stability was investigated using methyl violet, vacuum stability, and weight loss tests. Results indicated that the stability of the novel fullerene-malonamide derivatives was considerably better than that of traditional stabilizers, such as N,N′-dimethyl-N,N′-diphenylurea and diphenylamine. Moreover, these derivatives exhibited excellent thermal stability at high temperatures. The stability of the fullerene-malonamide derivatives also improved as the carbon chain length on the p-position of the benzene ring on C60 increased. In addition, the stability mechanism of the fullerene-malonamide derivatives was studied through electron paramagnetic resonance spectroscopy, FT-IR spectroscopy, and liquid chromatography-mass spectrometry. Results turned out that the fullerene-malonamide derivatives could react with nitroxide radicals released from the pyrolysis of NC. Hence, these novel fullerene-malonamide derivatives can be used as promising stabilizers for NC-based propellants. 相似文献
13.
Summary Four cyclodetrin dimer derivatives were synthesized by linking two single cyclodextrin derivatives with difunctional spacer
at the primary side of cyclodetrin. The separation properties of these cylodextrin dimer derivatives as CGC stationary phases
were investigated and compared with those of the unbridged native cyclodextrin derivative. The results show that two recognition
sites and one link spacer of these cyclodextrin dimer derivatives cooperate in separation and affect the separation of disubstituted
benzene positional isomers. 相似文献
14.
在模拟生理条件下,运用荧光光谱、激光闪光光解(LFP)和分子对接等技术研究了8种具有抗肿瘤活性的嘧啶衍生物(PDs,其中PDs A 5-FU为成药,PDs B-H为实验室自制)与人血清白蛋白(HSA)的相互作用.利用Stern-Volmer方程和激光闪光光解技术分析了PDs对HSA的荧光猝灭机制,PDs A和B为静态猝灭,PDs G和H为动态猝灭.用双倒数曲线法得出5种PDs与HSA的结合常数Ka和结合位点数n,在测定条件下5种PDs与载体结合位点数均为1,且均以弱结合力结合,通过热力学参数ΔH,ΔS和ΔG推测出PDs B,C和E与HSA之间的作用力为静电作用力和疏水作用力,PDs A和D与HSA之间的作用力是氢键和范德华力,分子对接结果与其一致.根据F9rster非辐射能量转移理论(FRET)分析了HSA和PDs之间的结合距离(r),其结果均小于4 nm,符合能量转移理论.进一步利用同步荧光、三维荧光和圆二色光谱考察了PDs与HSA结合过程中HSA空间构象的变化,结果显示,仅PDs A和C对HSA的芳香族氨基酸周围的疏水性略有增强作用.体外实验结果表明,HSA可以作为优良的载体来运输和储存PDs A~E,这为嘧啶衍生物的后续研究提供了可参考的实验数据. 相似文献
15.
Nine flavonol derivatives were studied. Previously reported NMR data of three of these derivatives were corrected. We report complete assignments of the NMR data for six flavonol derivatives not previously studied. 相似文献
16.
香豆素衍生物在数种薄层基质上的室温磷光发射特性 总被引:1,自引:0,他引:1
考查了二十多种香豆素衍生物在国产MN-P型和MN-C型微晶纤维素膜,DEAE离子交换膜上的室温磷光发射特性,并与用滤纸作基质时的结果作了比较。在这些基质上,多数衍生物都能发射不同强度的RTP信号,且在其RTP特性间呈现,某些取代基效应。从发光稳定性和信背比考虑,MN-C型比MN-P型膜更适合于这些衍生物的RTP发射。 相似文献
17.
《Arabian Journal of Chemistry》2014,7(5):553-596
This review provides a comprehensive survey relating to the synthesis and biological applications of pyrazolines and related heterocycles in the last five years (2007–2011). These compounds are usually prepared from the cyclization of chalcones with hydrazine and its derivatives under the alcoholic conditions. The major incentive behind the synthesis of these compounds was the immense biological activities associated to these heterocyclic derivatives. The aim of this review is to find out different methods for the synthesis of pyrazoline derivatives. 相似文献
18.
G Argouarch R Veillard T Roisnel A Amar H Meghezzi A Boucekkine V Hugues O Mongin M Blanchard-Desce F Paul 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(37):11811-11827
The linear optical (LO) and nonlinear optical (NLO) properties of a series of isocyanurates functionalized by donor arms at the periphery are reported herein. These octupolar derivatives were obtained in a straightforward way from commercial isocyanate derivatives and were fully characterized. Although several of these compounds are known, those that exhibited the largest NLO activities are all new compounds. In terms of second-order activity, several of these derivatives exhibit remarkable activity/transparency tradeoffs. In terms of third-order activity, the longer derivatives with the stronger donor groups (X=NH(2) , NMe(2) , or NPh(2) ) were shown to possess significant two-photon absorption cross sections. These strongly luminescent derivatives exhibit two-photon absorption cross sections up to 410?GM. DFT computations were also conducted to unravel their electronic structures and to rationalize their NLO properties. To our knowledge, the present study is the first concerned with the nonlinear optical properties of these original cyclotrimers. 相似文献
19.
Reactions of 2‐isopropoxy‐1, 3, 2‐ benzodioxaborole with equivalent amounts of Schiff base ligands having two hydroxyl groups ( 1a–3a ) yield mononuclear derivatives with one residual hydroxy group. The reactions of these mononuclear derivatives with hexamethyldisilazane in a 2:1 ratio yield heterodinuclear derivatives. All these newly synthesized derivatives have been characterized by elemental analyses and molecular weight measurements. Tentative structures have been proposed on the basis of IR and NMR (1H, 13C, 11B,29Si)spectral data and Fab‐mass studies. Schiff bases and their corresponding mono‐ and heterodinuclear derivatives of boron have also been screened for antifungal activities. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
20.
The N-unsubstituted nitroimidazoles have an imino hydrogen atom in contrast to the N-substituted derivatives, and react with hydroxide to give the yellow nitroimidazole anions. The difficulty of reducing the nitro-group in these anions, together with the shift of the absorption maximum to longer wavelengths makes it possible to analyse polarographically or spectrophotometrically a mixture of N-unsubstituted nitroimidazole with N-substituted derivatives. The presence of the N-unsubstituted nitroimidazole and the N-substituted derivatives is first established by chromatography. Other criteria are also proposed for distinguishing between these substances. 相似文献