RESUMO
AIM: To design novel bifunctional derivatives of huperzine B (HupB) based on the concept of dual binding site of acetylcholinesterase (AChE) and evaluate their pharmacological activities for seeking new drug candidates against Alzheimer's disease (AD). METHODS: Novel 16-substituted bifunctional derivatives of HupB were synthesized through chemical reactions. The inhibitory activities of the derivatives toward AChE and butyrylcholinesterase (BuChE) were determined in vitro by modified Ellman's method. Cell viability was quantified by the reduction of MTT. RESULTS: A new preparative method was developed for the generation of 16-substituted derivatives of HupB, and pharmacological trials indicated that the derivatives were multifunctional cholinesterase inhibitors targeting both AChE and BuChE. Among the derivatives tested, 9c, 9e, 9f, and 9i were 480 to 1360 times more potent as AChE inhibitors and 370 to 1560 times more potent as BuChE inhibitors than the parent HupB. Further preliminary pharmacological trials of derivatives 9c and 9i were performed, including examining the mechanism of AChE inhibition, the substrate kinetics of the enzyme inhibition, and protection against hydrogen peroxide (H2O2)-induced cytotoxicity in PC12 cells. CONCLUSION: Preliminary pharmacological evaluation indicated that 16-substituted derivatives of HupB, particularly 9c and 9i, would be potentially valuable new drug candidates for AD therapy, and further exploration is needed to evaluate their pharmacological and clinical efficacies.
Assuntos
Alcaloides/química , Alcaloides/farmacologia , Inibidores da Colinesterase/química , Inibidores da Colinesterase/farmacologia , Fármacos Neuroprotetores/química , Fármacos Neuroprotetores/farmacologia , Acetilcolinesterase/metabolismo , Doença de Alzheimer/tratamento farmacológico , Animais , Butirilcolinesterase/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Células PC12 , Ratos , Relação Estrutura-AtividadeRESUMO
Recently, the potent cholinesterase inhibitor (-)-huperzine A (HupA) was demonstrated to protect neuronal and glial cells against the cytotoxicity of beta-amyloid (Abeta). Since the unnatural (+)-HupA is a much less potent inhibitor, it was of interest to examine the stereoselectivity of cellular protection by the two isomers. In the present study, effects of (+)- and (-)-HupA on Abeta(25-35)-induced injury were compared in PC12 and NG108-15 neuroblastoma cell lines. Following a 24 h exposure to 1 microM Abeta(25-35), cell survival was markedly reduced, but preincubation with (+)-HupA or (-)-HupA (0.1-10 microM) enhanced survival significantly. The potency of (-)-HupA and (+)-HupA in protecting against Abeta toxicity was similar. This result contrasted with the stereoselectivity of cholinesterase inhibition in vitro and in vivo, in which (-)-HupA is about 50-fold more potent than (+)-HupA. It is concluded that the neuroprotective properties of HupA enantiomers have no relation to anti-cholinesterase activity.
Assuntos
Doença de Alzheimer/tratamento farmacológico , Peptídeos beta-Amiloides/antagonistas & inibidores , Córtex Cerebral/efeitos dos fármacos , Inibidores da Colinesterase/farmacologia , Neurônios/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Fragmentos de Peptídeos/antagonistas & inibidores , Sesquiterpenos/farmacologia , Acetilcolina/metabolismo , Alcaloides , Doença de Alzheimer/metabolismo , Doença de Alzheimer/fisiopatologia , Peptídeos beta-Amiloides/metabolismo , Animais , Córtex Cerebral/metabolismo , Córtex Cerebral/fisiopatologia , Relação Dose-Resposta a Droga , Camundongos , Neurônios/metabolismo , Neurotoxinas/antagonistas & inibidores , Neurotoxinas/metabolismo , Células PC12 , Fragmentos de Peptídeos/metabolismo , Ratos , Sesquiterpenos/química , EstereoisomerismoRESUMO
AIM: To study asymmetric total synthesis of 14-nor-huperzine A 2 and its inhibitory activity on acetylcholinesterase. METHODS: Highly enantioselective synthesis of compound 5 from beta-keto-ester 3 and 2-methylene-1,3-propanediol diacetate 4 by palladium-catalyzed bicycloannulation was carried out using new chiral ferrocenylphosphine ligands, such as 10, 11, followed by regioselective double-bond migration to produce compound 6. Optically pure 6 was obtained after enantio-enrichment recrystallization. Then, according to similar procedures of huperzine A synthesis, the target compound 14-nor-huperzine A 2 was prepared. The inhibitory activity was tested with rat erythrocyte membrame acetylcholinesterase. RESULTS: The inhibitory activity of synthetic (-)-14-nor-huperzine A was 8 fold less potent than that of (-)-huperzine A. CONCLUSION: A hydrogen-bond between 14-methyl group of (-) huperzine A and the main-chain oxygen of His 440 is necessary for the highly acetylcholinesterase inhibitory activity of huperzine A.
Assuntos
Acetilcolinesterase/metabolismo , Inibidores da Colinesterase/síntese química , Sesquiterpenos/síntese química , Alcaloides , Doença de Alzheimer/tratamento farmacológico , Animais , Inibidores da Colinesterase/farmacologia , Inibidores da Colinesterase/uso terapêutico , Membrana Eritrocítica/efeitos dos fármacos , Membrana Eritrocítica/enzimologia , Conformação Molecular , Estrutura Molecular , Ratos , Sesquiterpenos/química , Sesquiterpenos/farmacologia , Sesquiterpenos/uso terapêuticoAssuntos
Fármacos Anti-HIV/química , Inibidores da Protease de HIV/química , 4-Hidroxicumarinas/síntese química , 4-Hidroxicumarinas/química , 4-Hidroxicumarinas/farmacologia , Fármacos Anti-HIV/síntese química , Fármacos Anti-HIV/farmacologia , Sulfato de Atazanavir , Inibidores da Protease de HIV/síntese química , Inibidores da Protease de HIV/farmacologia , Humanos , Estrutura Molecular , Oligopeptídeos/síntese química , Oligopeptídeos/química , Oligopeptídeos/farmacologia , Piridinas/síntese química , Piridinas/química , Piridinas/farmacologia , Saquinavir/síntese química , Saquinavir/química , Saquinavir/farmacologia , Ureia/análogos & derivados , Ureia/síntese química , Ureia/química , Ureia/farmacologiaRESUMO
(1) This study was to evaluate the anti-cholinesterase (ChE), cognition enhancing and neuroprotective effects of FS-0311, a bis-huperzine B derivative. (2) ChE activity was evaluated using a spectrophotometric method. Cognitive deficits in mice were induced by scopolamine or transient brain ischemia and reperfusion. Water maze was used to detect the cognitive performance. PC12 cell injury was induced by beta-amyloid 25-35 (Abeta(25-35)), oxygen-glucose deprivation (OGD), or staurosporine treatment. (3) FS-0311 was a potent, highly specific inhibitor of acetylcholinesterase (AChE). FS-0311 bound to AChE in a reversible manner, causing linear mixed-type inhibition. FS-0311 had a high oral bioavailability and a long duration of AChE inhibitory action in vivo. FS-0311 was found to antagonize cognitive deficits induced by scopolamine or transient brain ischemia and reperfusion in a water maze task. FS-0311 possessed the ability to protect PC12 cells against Abeta(25-35) peptide toxicity, OGD insult and staurosporine-induced apoptosis. The neuroprotective effects of FS-0311 appeared to reflect an attenuation of oxidative stress. (4) With the profile of anti-ChE and neuroprotective activities, FS-0311 might be a promising candidate in neurodegenerative diseases, such as Alzheimer's disease and Vascular dementia.
Assuntos
Doença de Alzheimer/tratamento farmacológico , Inibidores da Colinesterase/farmacologia , Transtornos Cognitivos/tratamento farmacológico , Piridonas/farmacologia , Animais , Isquemia Encefálica/tratamento farmacológico , Inibidores da Colinesterase/síntese química , Cognição/efeitos dos fármacos , Medicamentos de Ervas Chinesas , Feminino , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos , Fármacos Neuroprotetores/farmacologia , Piridonas/síntese química , Ratos , Ratos Sprague-DawleyRESUMO
Natural (-)-huperzine B (HupB), isolated from Chinese medicinal herb, displayed moderate inhibitory activity of acetylcholinesterase (AChE). Based on the active dual-site of AChE, a series of novel derivatives of bis- and bifunctional HupB were designed and synthesized. The AChE inhibition potency of most derivatives of HupB was enhanced about 2-3 orders of magnitude as compared with the parental HupB. Among bis-HupB derivatives, 12h exhibited the most potent in the AChE inhibition and has been evaluated for its pharmacological actions in vivo on ChE inhibition, cognitive enhancement, and neuroprotection. The docking study on the bis-HupB derivatives 12 series with TcAChE has demonstrated that the ligands bound to the dual-site of the enzyme in different level.