共查询到20条相似文献,搜索用时 15 毫秒
1.
《Arabian Journal of Chemistry》2023,16(1):104408
The inhibition of acetylcholinesterase (AChE), the key enzyme in the breakdown of acetylcholine, is presently the most common pharmacological approach available for Alzheimer’s disease (AD). Despite research on the molecular bases of AD, potent therapeutic agent against its expansion is still needed. In searching for natural cholinesterase inhibitors, the present study was focused on the isolation of three new norditerpenoid alkaloids, uncinatine B-D together with known virescenine from Delphinium uncinatum. Chemical structures for all the isolated norditerpenoids (1–4) were established using latest spectroscopic techniques. The isolated undescribed compounds along with known virescenine were testified for their acetylcholinesterase inhibitory activity supported by docking analyses. Molecular docking simulation showed that the isolated compounds (1–4) were observed to adhered in the active site of AChE with docking scores ? 13.5322 (1), ?11.8173 (2), ?12.4240 (3) and ? 8.9352 (4) respectively. Overall results demonstrated that these natural norditerpenoids compounds were found as selective inhibitors of AChE. This is the first report regarding the use of bioactive ingredients of Delphinium uncinatum in testing against Alzheimer's disease. 相似文献
2.
Ge HM Zhu CH Shi da H Zhang LD Xie DQ Yang J Ng SW Tan RX 《Chemistry (Weinheim an der Bergstrasse, Germany)》2008,14(1):376-381
A phytochemical study of Hopea hainanensis has led to the isolation of three new polyphenols and one known compound. The most important of these compounds are hopeahainols A (2) and B (3), which contain an unprecedented carbon skeleton. The structures were elucidated by analysis of the spectroscopic data including single-crystal X-ray spectroscopy and computational methods. Hopeahainol A was an acetylcholinesterase inhibitor with an IC50 value of 4.33 microM, which is comparable to that of huperzine A, a presently prescribed drug for the treatment of Alzheimer, while other similar structures were inactive. This observation was complemented by a 3D interaction model of the inhibitor with active sites. 相似文献
3.
The purpose of this study was to develop a protocol for the purification of acetylcholinesterase (AChE, acetylcholine acetylhydrolase,
E.C.3.1.1.7) enzyme and to extend a purification method for further enzyme characterization. A further aim was to study whether
the edrophonium’s pharmacologic action is due primarily to the inhibition or inactivation of AChE at sites of cholinergic
transmission. The purification of a soluble AChE from sheep liver using affinity chromatography on Concanavalin A–Sepharose
4B and edrophonium–Sepharose 6B is studied. The affinity matrix was synthesized by coupling an inhibitor edrophonium to epoxy-activated
Sepharose at flow rate of 0.5 ml/min. AChE is a pivotal enzyme in the cholinergic nervous system. Its primary function is
to catalyze hydrolysis of released acetylcholine (ACh) and thus maintain homeostasis of this neurotransmitter in the central
and peripheral nervous systems. Hence, AChE is important in both pharmacological and toxicological mechanisms. It was purified
842-fold with a specific activity of 21 U/mg protein. Sodium dodecyl sulfate (SDS) electrophoresis resulted in a monomeric
molecular weight of 67.04 kDa, while on gel chromatography using Sephacryl S-200 under nondenaturing conditions to be 201.5 kDa.
Based on the molecular weight obtained by gel filtration, the purified AChE was assumed to be a tetrameric form. 相似文献
4.
Inhibition of acetylcholinesterase (AChE) activity by essential oils of Citrus paradisi (grapefruit pink in USA) was studied. Inhibition of AChE was measured by the colorimetric method. Nootkatone and auraptene were isolated from C. paradisi oil and showed 17-24% inhibition of AChE activity at the concentration of 1.62 microg/mL. 相似文献
5.
Modified TLC bioautographic method for screening acetylcholinesterase inhibitors from plant extracts
Zhongduo Yang Xu Zhang Dongzhu Duan Zhuwen Song Mingjun Yang Shuo Li 《Journal of separation science》2009,32(18):3257-3259
The present work describes modifications to an existing TLC bioautographic method for detecting acetylcholinesterase inhibitors from plant extracts. The basic principle of the method is that the enzyme converts 1‐naphthyl acetate into naphthol which reacts with Fast Blue B salt to make a purple‐colored background on the TLC plates. Inhibitors of acetylcholinesterases produced white spots on the background. Our modifications involve changes in the concentration of the enzyme, the reagents, and the time of the reaction. With these changes, the consumption of the enzyme was reduced by 85% and the detection limits were decreased remarkably. 相似文献
6.
Houari Benamar Lamberto Tomassini Alessandro Venditti Abderrazak Marouf Malika Bennaceur Marcello Nicoletti 《Natural product research》2016,30(22):2567-2574
The whole plant ethanolic extract of Solenanthus lanatus was used for the isolation of acetylcholinesterase inhibitors. A new pyrrolizidine alkaloid, 7-O-angeloylechinatine N-oxide, 1, was isolated together with three known compounds of the same class (3′-O-acetylheliosupine N-oxide, 2, heliosupine N-oxide, 3, and heliosupine, 4), by bioassay-guided approach. Their structures were elucidated by spectroscopic methods. All the isolated compounds showed inhibition activity against the AChE, with IC50 0.53–0.60 mM. 相似文献
7.
家蝇中乙酰胆碱酯酶的提取纯化及应用研究 总被引:1,自引:0,他引:1
研究了用Procainamide亲和层析色谱纯化家蝇头部乙酰胆碱酯酶(AChE),AChE的纯化倍数为63.27倍,产率为93.86%。通过测定AChE活力被抑制的程度可以快速测定敌敌畏和克百威残留量。研究结果表明,在0.09~200μg/L范围内,AChE抑制率与敌敌畏和克百威质量浓度的回归方程分别为Y=9.1321 Lnρ 33.904(r=0.9893),Y=10.738 Lnρ 26.125(r=0.9962);敌敌畏与克百威的检出限分别为1.13±0.42μg/L和2.28±0.76μg/L,对果蔬等实际样品的加标回收率为74%~118%。 相似文献
8.
A series of electrospun mats of styrene-maleic anhydride copolymers has been functionalized by modification with two types of spacers - a polymer with a flexible hydrophilic polyether chain (Jeffamine® ED) and a rigid low-molecular-weight spacer (р-phenylenediamine). The successful modification of the microfibrous mats with these bifunctional compounds has been proved by ATR-FTIR and X-ray photoelectron spectroscopy (XPS) analyses. In a further step, acetylcholinesterase (AChE) has been covalently immobilized onto the modified mats using glutaraldehyde as a binding agent. The amount of bound protein and the specific activity of the immobilized AChE have been determined. The highest activity has been displayed by AChE covalently bound to Jeffamine-modified microfibrous mats. Moreover, the immobilized AChE is characterized by enhanced thermal and storage stability as compared to the free enzyme. 相似文献
9.
Cuevas F Di Stefano S Magrans JO Prados P Mandolini L de Mendoza J 《Chemistry (Weinheim an der Bergstrasse, Germany)》2000,6(17):3228-3234
The methanolysis of choline p-nitrophenylcarbonate in chloroform containing 1% methanol is catalyzed with turnover by ditopic receptors 1 and 2, consisting of a calix[6]arene connected to a bicyclic guanidinium by means of a short spacer. The calix[6]arene subunit strongly binds to the trimethylammonium head group through cation-pi interactions, whereas the guanidinium moiety is deputed to stabilize through hydrogen bonding reinforced by electrostatic attraction the anionic tetrahedral intermediate resulting from methoxide addition to the ester carbonyl. The observed cholinesterase activity had been anticipated on the basis of the ability of the ditopic receptors 1 and 2 to bind strongly to the choline phosphate DOPC, which is a transition state analogue for the BAc2-type cleavage of choline esters. 相似文献
10.
The methanol, ethyl acetate and chloroform extracts of selected Croatian plants were tested for their acetylcholinesterase (AChE) inhibition and antioxidant activity. Assessment of AChE inhibition was carried out using microplate reader at 1?mg?mL?1. Antioxidant capacities were determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging test and ferric reducing/antioxidant power assay (FRAP). Total phenol content (TPC) of extracts were determined using Folin-Ciocalteu colorimetric method. Out of 48 extracts, only methanolic extract of the Salix alba L. cortex exerted modest activity towards AChE, reaching 50.80% inhibition at concentration of 1?mg?mL?1. All the other samples tested had activity below 20%. The same extract performed the best antioxidative activity using DPPH and FRAP method, too. In essence, among all extracts used in the screening, methanolic extracts showed the best antioxidative activity as well as highest TPC. 相似文献
11.
[structure: see text] A novel Lycopodium alkaloid with an unprecedented fused-tetracyclic ring system consisting of an aza-cyclononane ring having a N-hydroxy group, a cyclohexanone, a cyclopentanone, and a tetrahydrofuran ring, sieboldine A (1), was isolated from the club moss Lycopodium sieboldii. The structure and relative stereochemistry were elucidated on the basis of 2D NMR data and X-ray analysis. Sieboldine A (1) exhibited a potent inhibitory activity against acetylcholinesterase and modest cytotoxicity. 相似文献
12.
13.
The larvicidal potential of several dopamine 1-phenylisoquinoline derivatives against Culex quinquefasciatus third instar larvae was investigated in a rational search for insecticides. The results showed that these isoquinolines presented moderate larvicidal activity, that the presence of a substituent is needed on carbon 1 for such activity to be presented and that it may be possible to develop novel insecticidal compounds having potential use in controlling insects by appropriate structural modification of 1-phenylisoquinolines. This article presents a possible structure-larvicidal activity relationship for isoquinolinic compounds. 相似文献
14.
Wei Li Xueqiong Yang Yabin Yang Rongting Duang Guangyi Chen Xiaozhan Li 《Natural product research》2016,30(22):2616-2619
Fourteen metabolites with various structure types were isolated from endophytic Chaetomium globosum. Five compounds were separated from genus Chaetomium for the first time. Some compounds exhibited remarkable inhibition against phytopathogenic fungi causing root rot of Panax notoginseng. Compounds 1–5 had significant DPPH-free radical-scavenging activity. Compounds 3 and 5 indicated significant inhibitions against the acetylcholinesterase (AChE). From preliminary structure–activity relationship, it was found that the oxygenic five-membered ring of 3 and 5 was crucial in the anti-AChE activity. These structures provide new templates for the potential treatment and management of plant diseases and Alzheimer disease. 相似文献
15.
In this study we developed a simple capillary electrophoresis (CE) method with an on-line acetylcholinesterase (AChE) microreactor at the inlet of capillary for inhibitor screening. The fused-silica capillary surface was modified with a polycationic polyethylenimine coating. Solutions of the enzyme and chitosan were then injected to immobilize the enzyme in approximately 2.9?cm of the capillary inlet (total length of capillary 60.2?cm) by electrostatic interaction and the film overlay technique. Separation of enzyme reaction product (thiocholine, ThCh) and unreacted substrate (acetylthiocholine, AThCh) was achieved within 3.0?min. The conditions affecting the efficiency of reaction of the enzyme were optimized by measuring the peak area of ThCh. Under the optimum conditions, using Huperzine-A as model inhibitor, K (i) and IC (50) were 0.551?μmol?L(-1) and 1.52?μmol?L(-1), respectively, for immobilized AChE. Finally, screening of a small compound library containing two known AChE inhibitors and 30 natural extracts was conducted, and species with inhibition activity were directly identified. Compared with previous publications on screening for AChE inhibitors in natural products based on CE methods, the method developed in this work has the advantages of lower cost per analysis, less leakage, and better bioaffinity for the immobilized enzyme because of the unique properties of sodium alginate and chitosan. 相似文献
16.
Excoecaria agallocha Linn. the blinding mangrove tree of historical significance, is well known for its curative properties. In this investigation, crude hexane extract from the dried roots of E. agallocha inhibited 50% of the growth of third instar larvae of Culex quinquefasciatus Say. within 24?h (LC(50): 315?ppm). SiO(2) (60-120) column chromatography purification of the extract yielded four fractions, of which fractions 3 (LC(50): 61.2?ppm) and 4 (LC(50): 74.5?ppm) exhibited 100% larvicidal activity within 18-24?h. Bioactive fraction 3 contained sub-fractions R1 and R2. R1 was characterised by (1)H-NMR, (13)C-NMR and FAB mass spectrometry techniques as the acyclic hydrocarbon n-triacontane (C(30)H(62)). 相似文献
17.
18.
Zhang Y Angelin M Larsson R Albers A Simons A Ramström O 《Chemical communications (Cambridge, England)》2010,46(44):8457-8459
A concept of tandem driven dynamic self-inhibition is demonstrated through dynamic inhibitors of acetylcholinesterase (AChE) using reversible transthiolesterification. 相似文献
19.
Carla Proença M. Luísa Serralheiro M. Eduarda Araújo Teresa Pamplona Susana Santos M. Soledade Santos Fátima Frazão 《Journal of heterocyclic chemistry》2011,48(6):1287-1294
Several sulfenamide derivatives were designed as possible acetylcholinesterase (AChE) inhibitors. New sulfenamides were synthesized and proved to be stable under the physiological conditions used in the enzymatic assays. N‐benzyl‐2‐benzoxazolylsulfenamide (8) and N‐benzyl‐2‐benzimidazolylsulfenamide (9) revealed anti‐AChE activity with IC50 values of 0.6 and 0.8 μM, respectively, values of the same magnitude as those reported for galantamine and tacrine. The affinity for the biological site was evaluated in terms of interaction/partition toward sodium dodecyl sulfate (SDS) micelles. The inhibitory activity profiles were reasoned in terms of both partition toward a hydrophobic anionic environment and molecular geometry. The X? CSN dihedral angle deviations from collinearity stood out as a major parameter linked to enzyme specificity. J. Heterocyclic Chem., (2011). 相似文献
20.
Rogers CJ Eubanks LM Dickerson TJ Janda KD 《Journal of the American Chemical Society》2006,128(48):15364-15365
A series of proteins with cocaine esterase ability have been shown to hydrolyze acetylcholine with similar rate enhancements. Docking studies revealed that acetylcholine binds in a similar orientation as cocaine. These results suggest that acetylcholinesterase activity may be inherent to cocaine esterases. 相似文献