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1.
The synthesis and pharmacological evaluation of racemic 14-aryl-10,11,12,14-tetrahydro-9H-benzo[5,6]chromeno[2,3-b]quinolin-13-amines (19-28), prepared by Friedländer reaction of 3-amino-1-aryl-1H-benzo[f]chromene-2-carbonitriles (10-18) with suitable cycloalkanones is described. These molecules are potent, in the nanomolar range [IC50 (EeAChE) = 7-101 nM], and selective inhibitors of acetylcholinesterase (AChE). The most potent inhibitor, 4-(13-amino-10,11,12,14-tetrahydro-9H-benzo[5,6]chromeno[2,3-b]quinolin-14-yl)phenol (20) [IC50 (EeAChE) = 7 ± 2 nM] is four-fold more active than tacrine. Kinetic studies on compound 20 showed that this is a mixed-type inhibitor of EeAChE with a Ki of 5.00 nM. However, racemic 20 was unable to displace propidium iodide, suggesting that the inhibitor does not strongly bind to the peripheral anionic site (PAS) of AChE. Docking, molecular dynamics stimulations, and MM-GBSA calculations agree well with this behavior.  相似文献   

2.
Via high-throughput screening of a natural compound library, we have identified a lipopeptide aldehyde, fellutamide B (1), as the most potent inhibitor of the Mycobacterium tuberculosis (Mtb) proteasome tested to date. Kinetic studies reveal that 1 inhibits both Mtb and human proteasomes in a time-dependent manner under steady-state condition. Remarkably, 1 inhibits the Mtb proteasome in a single-step binding mechanism with Ki = 6.8 nM, whereas it inhibits the human proteasome β5 active site following a two-step mechanism with Ki = 11.5 nM and  = 0.93 nM. Co-crystallization of 1 bound to the Mtb proteasome revealed a structural basis for the tight binding of 1 to the active sites of the Mtb proteasome. The hemiacetal group of 1 in the Mtb proteasome takes the (R)-configuration, whereas in the yeast proteasome it takes the (S)-configuration, indicating that the pre-chiral CHO group of 1 binds to the active site Thr1 in a different orientation. Re-examination of the structure of the yeast proteasome in complex with 1 showed significant conformational changes at the substrate-binding cleft along the active site. These structural differences are consistent with the different kinetic mechanisms of 1 against Mtb and human proteasomes.  相似文献   

3.
With the aim of finding the structural features for the human MAO inhibitory activity and selectivity, in the present communication we report the synthesis, pharmacological evaluation and a comparative study of a new series of 3-phenylcoumarins (compounds 1-4) and 3-benzoylcoumarins (compounds 5-8). A bromo atom and a methoxy/hydroxy substituent were introduced in these scaffolds, at six and eight positions of the coumarin moiety, respectively. The synthesized compounds 1-8 were evaluated as MAO-A and B inhibitors using R-(−)-deprenyl and iproniazide as reference compounds. The presence or absence of a carbonyl group between the coumarin and the phenyl substituent in 3 position remarks, respectively, the MAO-A or MAO-B inhibitory activity. Some of the new compounds showed MAO-B inhibitory activities in the low nanomolar range. Compound 2 (IC50 = 1.35 nM) showed higher inhibitory activity than the R-(−)-deprenyl (IC50 = 19.60 nM) and higher MAO-B selectivity, with more than 74,074-fold inhibition level, respecting to the MAO-A isoform.  相似文献   

4.
The synthesis, biological assessment, and molecular modelling of new tacrine analogues 11-22 is described. Compounds 11-22 have been obtained by Friedländer-type reaction of 2-aminopyridine-3-carbonitriles 1-10 with cyclohexanone or 1-benzyl-4-piperidone. The biological evaluation showed that some of these molecules were good AChE inhibitors, in the nanomolar range, and quite selective regarding the inhibition of BuChE, the most potent being 5-amino-2-(dimethylamino)-6,7,8,9-tetrahydrobenzo[1,8-b]-naphthyridine-3-carbonitrile (11) [IC50 (EeAChE: 14 nM); IC50 (eqBuChE: 5.2 ??M]. Kinetic studies on the easily available and potent anticholinesterasic compound 5-amino-2-(methoxy)-6,7,8,9-tetrahydrobenzo[1,8-b]-naphthyridine-3-carbonitrile (16) [IC50 (EeAChE: 64 nM); IC50 (eqBuChE: 9.6 ??M] showed that this compound is a mixed-type inhibitor (Ki = 69.2 nM) of EeAChE. Molecular modelling on inhibitor 16 confirms that this compound, as expected and similarly to tacrine, binds at the catalytic active site of EeAChE. The neuroprotective profile of molecules 11-22 has been investigated in SH-SY5Y neuroblastoma cells stressed with a mixture of oligomycin-A/rotenone. Compound 16 was also able to rescue by 50% cell death induced by okadaic acid in SH-SY5Y cells. From these results we conclude that the neuroprotective profile of these molecules is moderate, the most potent being compounds 12 and 17 which reduced cell death by 29%. Compound 16 does not affect ACh- nor K+-induced calcium signals in bovine chromaffin cells. Consequently, tacrine analogues 11-22 can be considered attractive therapeutic molecules on two key pharmacological targets playing key roles in the progression of Alzheimer, that is, cholinergic dysfunction and oxidative stress, as well as in neuronal cerebrovascular diseases.  相似文献   

5.
Ryu HW  Cho JK  Curtis-Long MJ  Yuk HJ  Kim YS  Jung S  Kim YS  Lee BW  Park KH 《Phytochemistry》2011,72(17):2148-2154
An ethanol extract of the fruit case of Garcinia mangostan, whose most abundant chemical species are xanthones, showed potent α-glucosidase inhibitory activity (IC50 = 3.2 μg/ml). A series of isolated xanthones (1-16) demonstrated modest to high inhibition of α-glucosidase with IC50 values of 1.5-63.5 μM. In particular, one hitherto unknown xanthone 16 has a very rare 2-oxoethyl group on C-8. Kinetic enzymatic assays with a p-nitrophenyl glucopyranoside indicated that one of them, compound (9) exhibited the highest activity (Ki = 1.4 μM) and mixed inhibition. Using, a physiologically relevant substrate, maltose, as substrate, many compounds (6, 9, 14, and 15) also showed potent inhibition which ranged between 17.5 and 53.5 μM and thus compared favorably with deoxynojirimycin (IC50 = 68.8 μM). Finally, the actual pharmacological potential of the ethanol extract was demonstrated by showing that it could elicit reduction of postprandial blood glucose levels. Furthermore, the most active α-glucosidase inhibitors (6, 9, and 14) were proven to be present in high quantities in the native seedcase by a HPLC chromatogram.  相似文献   

6.
Pregnenolone (1) was used as a template to develop new anticancer compounds. Ring-D modification of 1 resulted in the synthesis of benzylidenes 2-17, pyrazolines 18-76, pyrazoles 85-91, hydrazones 77-84, and oximes 92-107 derivatives. The structure of compound 107 was also deduced through single crystal X-ray diffraction studies. The inclusion of furanyl and pyridyl rings to pregnenolone skeleton increases the cytotoxicity of all compounds significantly. Among benzylidene derivatives, only heterocyclic enone 8 (IC50 = 0.74 μM/mL against HepG2), and 17 (IC50 = 4.49 μM/mL against HepG2, IC50 = 5.01 μM/mL against MDA-MB-230 cancer cell line) exhibited a significant activity. The cytotoxicity data of pyrazoline derivatives 18-76 revealed that only furanyl bearing pyrazolines 40, 42-44, 48, and 49 exhibited significant activities. While all (O-carboxymethyl) oximes, hydazones, and pyrazoles derivatives of pregnenolone did not show any significant activity against both the cell lines. Thus the furanyl bearing enone 8 (IC50 = 0.74 μM/mL against HepG2), and its pyrazoline derivative 48 (IC50 = 0.91 μM/mL against MDA-MB-230 cancer cell lines) were identified as the most active compounds in all derivatives of pregnenolone.  相似文献   

7.
A series of novel substituted (Z)-5-((1-benzyl-1H-indol-3-yl)methylene)imidazolidin-2,4-diones (3a-f) and (Z)-5-((1-benzyl-1H-indol-3-yl)methylene)-2-iminothiazolidin-4-ones (3g-o) have been synthesized utilizing microwave irradiation. These analogs were evaluated for in vitro cytotoxicity against a panel of 60 human tumor cell lines. Compound 3i exhibits potent growth inhibition against melanoma UACC-257 (GI50 = 13.3 nM) and OVCAR-8 ovarian (GI50 = 19.5 nM) cancer cells while possessing significant cytotoxicity (LC50 = 308 nM and LC50 = 851 nM, respectively) against the same cell lines within this series of compounds. A second analog, 3a, had GI50 values of 307 and 557 nM against SK-MEL-2 melanoma and A498 renal cancer cell lines, and exhibited GI50 values ranging from 0.30 to 6 μM against 98% of all cancer cell lines in the 60-cell panel. Thus, (Z)-5-((5-chloro-1-(4-fluorobenzyl)-1H-indol-3-yl)methylene)-2-iminothiazolidin-4-one (3i) and (Z)-methyl 1-(4-cyanobenzyl)-3-((2,5-dioxoimidazolidin-4-ylidene)methyl)-1H-indole-6-carboxylate (3a) can be regarded as useful lead compounds for further structural optimization as antitumor agents.  相似文献   

8.
In order to investigate SAR regarding glucose moiety in novel C-aryl glucoside SGLT2 inhibitors containing a thiazole motif, a series of chemical modifications on glucose was conducted to explore potential utility as a suitable replacement of glucose per se. Among the compounds prepared, deshydroxy 29 (IC50 = 7.01 nM) demonstrated the best in vitro inhibitory activity against SGLT2 in this series to date. But, none of the compounds were better than the parent molecule 5 (IC50 = 1.75 nM).  相似文献   

9.
In vitro antitumour activity of the [Pt(ox)(Ln)2] (1-7) and [Pd(ox)(Ln)2] (8-14) oxalato (ox) complexes involving N6-benzyl-9-isopropyladenine-based N-donor carrier ligands (Ln) against ovarian carcinoma (A2780), cisplatin resistant ovarian carcinoma (A2780cis), malignant melanoma (G-361), lung carcinoma (A549), cervix epitheloid carcinoma (HeLa), breast adenocarcinoma (MCF7) and osteosarcoma (HOS) human cancer cell lines was studied. Some of the tested complexes were even several times more cytotoxic as compared with cisplatin employed as a positive control. The improved cytotoxic effect was demonstrated for the platinum(II) complexes 3 (IC50 = 3.2 ± 1.0 μM and 3.2 ± 0.6 μM) and 5 (IC50 = 4.0 ± 1.0 μM and 4.1 ± 1.4 μM) against A2780 and A2780cis, as compared with 11.5 ± 1.6 μM, and 30.3 ± 6.1 μM determined for cisplatin, respectively. The significant in vitro cytotoxicity against MCF7 (IC50 = 8.2 ± 3.8 μM for 12) and A2780 (IC50 = 5.4 ± 1.2 μM for 14) was evaluated for the palladium(II) oxalato complexes, which again exceeded cisplatin, whose IC50 equalled 19.6 ± 4.3 μM against the MCF7 cells. Selected complexes were also screened for their in vitro cytotoxic effect in primary cultures of human hepatocytes and they were found to be non-hepatotoxic.  相似文献   

10.
Sch-642305 is the major compound produced by the endophytic fungi Phomopsis sp. CMU-LMA. Incubation of Sch-642305 with Aspergillus ochraceus ATCC 1009 resting cells leads to three new derivatives through an oxido-reduction of the six-membered ring of the molecule. Reduction of the double bound leads to compound (1), which subsequently undergoes carbonyl reduction to (2) and ring hydroxylation to (3). According to the previously solved crystal structure of Sch-642305 coupled with 1H NMR NOE correlation and the crystal structure of compound 1, the absolute configurations of the new derivatives were established. In contrast to the parent compound Sch-642305, compound (1) exhibits antimicrobial activity against Gram-negative bacteria. Furthermore, while all derivatives exhibit cytotoxic activity against various cancer cell lines, compound (2) achieved an IC50 of 4 nM against human myelogenous leukemia K 562, compared to 20 nM for the parent Sch-642305.  相似文献   

11.
Neutral dioxovanadium (V) complexes [VO2(HL)] (H2L = I: 1, H2L = II: 2 and H2L = III: 3; H2L are the thiosemicarbazones H2pydx-tsc (I), H2pydx-chtsc (II) and H2pydx-clbtsc (III); pydx = pyridoxal, tsc = thiosemicarbazide, chtsc = N4-cyclohexylthiosemicarbazide, clbtsc = N4-(2-chloro)benzylthiosemicarbazide) have been isolated and characterised on the basis of elemental and electrochemical analyses, spectroscopic (IR, UV-Vis, 1H and 51V NMR) data, thermogravimetric studies and reactivity patterns. These complexes are stable in solution at ambient temperature but heating of the methanolic solutions yields the μ-oxo binuclear complexes [(VOL)2μ-O] (H2L = I: 4, H2L = II: 5, H2L = III: 6). Treatments of dioxo species with H2O2 yield oxoperoxo species, the formations of which have been established spectrophotometrically. Similarly, the formations of oxohydroxo species, an intermediate proposed during the catalytic action of haloperoxidases, have also been established in solution by treating 1, 2 and 3 with a methanolic solution of HCl. The antiamoebic activities were carried out to ascertain the effectiveness of dioxovanadium(V) and μ-oxobis(oxovanadium(V)) complexes in comparison to their corresponding thiosemicarbazones. These complexes possess noteworthy potencies against HM1:1MSS strain of Entamoeba histolytica. Complexes 2, 3, 5 and 6 showed less IC50 values than metronidazole, indicating that these metal thiosemicarbazones may be the lead molecules to inhibit the growth of E. histolytica. Within the series, complex 5 showed the most promising amoebicidal activity (IC50 = 0.5 μM versus IC50 = 1.8 of metronidazole).  相似文献   

12.
A series of pyrazole-bridged heterometallic 3d-4f complexes, [CuDy(ipdc)2(H2O)4] · (2H2O)(H3O+) (1) and [CuLn(pdc)(ipdc)(H2O)4] · H3O+ (Ln = Ho (2), Er (3), Yb (4); H3ipdc = 4-iodo-3,5-pyrazoledicarboxylic acid; H3pdc = 3,5-pyrazoledicarboxylic acid), {[Cu3Ln4(ipdc)6(H2O)16] · xH2O}n (Ln = Sm (5), x = 8.5; Ln = Eu (6), x = 7; Ln = Gd (7), Tb (8), x = 9), have been synthesized and structurally characterized. Ligand H3ipdc was in situ obtained by iodination of ligand H3pdc. Complexes 1-4 are pyrazole-bridged heterometallic dinuclear complexes, and 2-4 are isostructural. Complexes 5-8 are isostructural and comprised of an unusual infinite one-dimensional tape-like chain based on pyrazole-bridged heterometallic dinuclear units. The magnetic properties of compounds 1-4, 7 and 8 have been investigated through the magnetic measurement over the temperature range of 1.8-300 K.  相似文献   

13.
Eight triorganotin complexes of the types [(R3Sn)2(C24H16N8S2)].Y (R = Ph, Y = 0 (1); R = PhCH2, Y = 2CH3OH (2); R = n-Bu, Y = 0 (3)), [(R3Sn)2(C24H16N8S2)]n (R = Me (4)), [(R3Sn)2(C12H6N6S4)] · Y (R = Ph, Y = CH2Cl2 (5); R = PhCH2, Y = 0 (6)) and [(R3Sn)2(C12H6N6S4)] (R = Bu (7), R = Me (8)) have been obtained by H2L1 (H2L1 derived from 4-amino-5-phenyl-4H-1,2,4-triazole-3-thiol) and H2L2 (H2L2 derived from 5-amino-1,3,4-thiadiazole-2-thiol) with triorganotin chloride in the presence of sodium ethoxide. All the complexes were characterized by elemental, IR and NMR spectra analyses, except for complexes 1, 3, 6 and 8, other complexes were also characterized by X-ray diffraction analyses, which reveal that complexes 2 and 5 are dinuclear structures, complex 4 has a 2D network structure and complex 7 forms a macrocyclic structure linked by intermolecular N → Sn interactions.  相似文献   

14.
We designed and synthesized a small series of 2-aryl-imidazo[2,1-b]benzothiazole, representing a combination of motifs from the two most potent amyloid imaging agents, PIB and IMPY. The binding affinity of the new compounds ranged from 6 to 133 nM. Among the best compounds, 3b (Ki = 6 nM) can be labeled with 11CH3 for PET imaging whereas 3j (Ki = 10.9 nM) can be labeled with 123I for SPECT imaging.  相似文献   

15.
A series of N-substituted 4-azahexacyclo[5.4.1.02,6.03,10.05,9.08,11]dodecan-3-ols incorporating the respective arylalkyl subunits from several known sigma (σ) receptor ligands were synthesized and evaluated for their affinity against σ receptors and dopamine receptors. The hybrid trishomocubane-derived ligands (4-6) showed good selectivity for σ1 and σ2 receptors over multiple dopamine receptors. The molecular hybrid obtained from haloperidol and 4-azahexacyclo[5.4.1.02,6.03,10.05,9.08,11]dodecan-3-ol (4, σ1Ki = 27 nM, σ2Ki = 55 nM) showed reduced affinity for D1-D5 dopamine receptors when compared to haloperidol itself. The compound with the greatest σ1 affinity in the series, benzamide 4 (σ1Ki = 7.6 nM, σ2Ki = 225 nM) showed a complete reversal of the subtype selectivity displayed by the highly σ2 selective parent benzamide, RHM-2 (3, σ1Ki = 10412 nM, σ2Ki = 13.3 nM).  相似文献   

16.
In order to develop a fluorinated radiotracer for imaging of ??1 receptors in the central nervous system a series of (2-fluoroethyl) substituted spirocyclic piperidines 3 has been prepared. In the key step of the synthesis 2-bromocinnamaldehyde acetal 5 was added to piperidones 6 with various substituents at the N-atom. Unexpectedly, this reaction led to 2-benzoxepines 8, which were contracted with acid to afford the spirocyclic 2-benzofuranacetaldehydes 9. The best yields were obtained, when the transformations up to the alcohols 10 were performed without isolation of intermediates. Generally the (2-fluoroethyl) derivatives 3 have higher ??1 affinity and ??1/??2 selectivity than the corresponding (3-fluoropropyl) derivatives 2. The most promising candidate for the development as radiotracer is the (2-fluoroethyl) derivative 3a (WMS-1828, fluspidine, 1′-benzyl-3-(2-fluoroethyl)-3H-spiro[[2]benzofuran-1,4′-piperidine]), which shows subnanomolar ??1 affinity (Ki = 0.59 nM) and excellent selectivity over the ??2 subtype (1331-fold) as well as some other receptor systems. The novel synthetic strategy also allows the systematic pharmacological evaluation of intermediate alcohols 10. Despite their high ??1 affinity (Ki = 6-32 nM) and selectivity the alcohols 10 are 10-30-fold less potent than the bioisosteric fluoro derivatives 3.  相似文献   

17.
The reactivity of hybrid scorpionate/cyclopentadienyl ligand-containing trichloride zirconium complexes [ZrCl3(bpzcp)] (1) [bpzcp = 2,2-bis(3,5-dimethylpyrazol-1-yl)-1,1-diphenylethylcyclopentadienyl] and [ZrCl3(bpztcp)] (2) [bpztcp = 2,2-bis(3,5-dimethylpyrazol-1-yl)-1-tert-butylethylcyclopentadienyl] toward several lithium alkoxides has been carried out. Thus, alkoxide-containing complexes [ZrCl2(OR)(bpzcp)] (R = Me, 3; Et, 4; iPr, 5; (R)-2-Bu, 6), [ZrCl2(OR)(bpztcp)] (R = Me, 7; Et, 8; iPr, 9; (R)-2-Bu, 10) and [Zr(OR)3(bpztcp)] (R = Et, 11; iPr, 12) were prepared by deprotonation of the appropriate alcohol group with BunLi followed by reaction with 1 or 2. In addition, the imido-complex [Ti(NtBu)Cl(bpztcp)(py)] (13) were also prepared. The structures of these complexes have been proposed on basis of spectroscopic and DFT methods.  相似文献   

18.
A series of phenylimidazole-pyrazolo[1,5-c]quinazolines 1a-q was designed, synthesized and characterised as a novel class of potent phophodiesterase 10A (PDE10A) inhibitors. In this series, 2,9-dimethyl-5-(2-(1-methyl-4-phenyl-1H-imidazol-2-yl)ethyl)pyrazolo[1,5-c]quinazoline (1q) showed the highest affinity for PDE10A enzyme (IC50 = 16 nM).  相似文献   

19.
A series of 3-(pyridin-2-yl-ethynyl)benzamide negative allosteric modulators of the metabotropic glutamate receptor 5 (mGluR5 NAMs) have been prepared. Starting from HTS hit 1 (IC50: 926 nM), potent mGluR5 NAMs showing excellent potencies (IC50s <50 nM) and good physicochemical profiles were prepared by monitoring LipE values. One compound 26 showed excellent mGluR5 binding (Ki: 21 nM) and antagonism (IC50: 8 nM), an excellent rat PK profile (CL: 12 mL/min/kg, %F: 85) and showed oral activity in a mouse 4-Plate Behavioral model of anxiety (MED: 30 mpk) and a mouse Stress Induced Hyperthermia model of anxiety (MED 17.8 mpk).  相似文献   

20.
The reaction of imidoyl chlorides [V(NR)Cl3] (R = Ph 1, Tol 2, tBu 3) and calix[4]arene methyl ether H3Mecalix unexpectedly leads to the formation of the structurally characterized vanadium (IV) complex [VCl(Mecalix)] (4). Calix[4]arene methyl ether stabilized imido complexes of the type [V(NR)(Mecalix)] (R = Ph 7, Tol 8, tBu 9) were afforded from the reaction of [V(NR)Cl3] (R = Ph 1, Tol 2, tBu 3) and the tris(lithium) or tris(sodium) salt of the calix[4]arene ether. The lithium salt [{Li3(Mecalix)}2] (5) is a dimer in the solid state, in which two monomeric trianions are bridged by lithium cations. Imido complexes [M(NR)(Mecalix)] (M = Nb: R = tBu, 12, R = Tol 13, R = Mes 14, R = Dipp 15; M = Ta: R = tBu 16, R = Tol 17) (Tol = 4-C6H4Me, Mes = 2,6-C6H3Me2; Dipp = 2,6-C6H3iPr2) have been prepared from structurally characterized [NbCl2(Mecalix)] (10) and previously known [TaCl2(Mecalix)] (11) via reaction with two equivalents of the appropriately metallated (Li, K) primary amine. The molecular structures of 13 and 15 confirm the mononuclear nature of these complexes.  相似文献   

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