1-乙酰氨基-3,5-二甲基金刚烷的水解反应研究

通过对酰胺水解反应的机理的分析,针对1乙酰氨基3,5二甲基金刚烷空间位阻大、取代基为推电子基团的特点,对其水解反应对收率的影响进行了研究。结果表明:此化合物的水解适宜在碱性条件下进行,且在n(反应物)∶n(苛性钠)=1∶5,溶剂为水:乙二醇=1∶10,150℃下反应12h,得到最终产品盐酸美金刚的收率为92.5%,纯度为99.5%     

盐酸美金刚胺的合成及表征

通过比较不同的反应路线，确定了以1，3-二甲基金刚烷为原料，经溴代、乙酰氨基化、水解反应最后经酸化得到盐酸美金刚胺。改进并优化了合成路线，溴代反应确定为在回流条件下反应12h，n（1，3-二甲基金刚烷）：n（溴素）=1：1．5；水解反应条件是以，7（乙二醇）：n（水）=10：1为溶剂，150℃下反应12h，n（1-乙酰氨基-3，5-二甲基金刚烷）：n（氢氧化钠）=1：5，反应总收率达81．5％。产品用IR、ESI、^1HNMR、^13CNMR确证了产品的结构。     

The Effect of Oxidative Stress and Memantine-Incorporated Reactive Oxygen Species-Sensitive Nanoparticles on the Expression of N-Methyl-d-aspartate Receptor Subunit 1 in Brain Cancer Cells for Alzheimer’s Disease Application

The aim of this study is to fabricate reactive oxygen species (ROS)-sensitive nanoparticles composed of succinyl β-cyclodextrin (bCDsu), memantine and thioketal linkages for application in Alzheimer’s disease, and to investigate the suppression of N-methyl-d-aspartate (NMDA) receptor 1 (NMDAR1) in cells. Thioketal diamine was attached to the carboxyl group of bCDsu to produce thioketal-decorated bCDsu conjugates (bCDsu-thioketal conjugates) and memantine was conjugated with thioketal dicarboxylic acid (memantine-thioketal carboxylic acid conjugates). Memantine-thioketal carboxylic acid conjugates were attached to bCDsu-thioketal conjugates to produce bCDsu-thioketal-memantine (bCDsuMema) conjugates. SH-SY5Y neuroblastoma cells and U87MG cells were used for NMDAR1 protein expression and cellular oxidative stress. Nanoparticles of bCDsuMema conjugates were prepared by means of a dialysis procedure. Nanoparticles of bCDsuMema conjugates had small particle sizes less than 100 nm and their morphology was found to be spherical in transmission electron microscopy observations (TEM). Nanoparticles of bCDsuMema conjugates responded to H₂O₂ and disintegrated or swelled in aqueous solution. Then, the nanoparticles rapidly released memantine according to the concentration of H₂O₂. In an in vivo animal imaging study, thioketal-decorated nanoparticles labelled with fluorescent dye such as chlorin e6 (Ce6) showed that the fluorescence intensity was stronger in the brain than in other organs, indicating that bCDsuMema nanoparticles can efficiently target the brain. When cells were exposed to H₂O₂, the viability of cells was time-dependently decreased. Memantine or bCDsuMema nanoparticles did not practically affect the viability of the cells. Furthermore, a western blot assay showed that the oxidative stress produced in cells using H₂O₂ increased the expression of NMDAR1 protein in both SH-SY5Y and U87MG cells. Memantine or bCDsuMema nanoparticles efficiently suppressed the NMDAR1 protein, which is deeply associated with Alzheimer’s disease. Fluorescence microscopy also showed that H₂O₂ treatment induced green fluorescence intensity, which represents intracellular ROS levels. Furthermore, H₂O₂ treatment increased the red fluorescence intensity, which represents the NMDAR1 protein, i.e., oxidative stress increases the expression of NMDAR1 protein level in both SH-SY5Y and U87MG cells. When memantine or bCDsuMema nanoparticles were treated in cells, the oxidative stress-mediated expression of NMDAR1 protein in cells was significantly decreased, indicating that bCDsuMema nanoparticles have the capacity to suppress NMDAR1 expression in brain cells, which has relevance in terms of applications in Alzheimer’s disease.     

Characterization of neurotoxic effects of NMDA and the novel neuroprotection by phytopolyphenols in mice.

Excitotoxicity plays a major role in various neurological disorders. In this study, we explored the behavioral and neurotoxic effects of intraventricular NMDA administration in mice. After NMDA injection, acute seizures were followed by impairments in locomotor activity, motor performance on a rotarod, and climbing ability. Mice killed 1 day after NMDA administration showed increased synaptosomal reactive oxygen species ROS production and calcium concentration and decreased mitochondrial membrane potential, mitochondrial reductase activities, and neuronal membrane Na+, K+ -ATPase and mg2+ -ATPase activities. One and 3 days after excitotoxic injury, Golgi stains showed that dendritic length and spine density were significantly decreased in neurons of the hippocampal dentate gyrus. Some mice received honokiol, tea polyphenol plus memantine, and honokiol plus memantine prior to NMDA treatment; the occurrence of generalized seizures was attenuated, seizure scores were reduced, latency to generalized seizures was prolonged, and motor impairments were lessened. Moreover, all of the neurochemical changes of the synaptosomes were also ameliorated. In conclusion, the behavioral and neurotoxic effects of intracerebroventricular injection of NMDA were ameliorated by treatment with honokiol alone or combined treatment with either tea polyphenol plus memantine or honokiol plus memantine, but only partly by either tea polyphenol or memantine alone. The therapeutic potential of these neuroprotective regimens in treating excitotoxicity-related diseases merits for further investigation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

三种阿尔茨海默症治疗药物促体外培养小鼠皮层神经元活性的比较

目的:观察并比较3 种阿尔茨海默症治疗药物盐酸美金刚胺、美曲磷酯及白藜芦醇对体外培养小鼠皮层神经元活性的影响, 为寻找作用机理更优的先导化合物提供理论依据。方法:采用体外培养皮层神经元细胞的方法, 解剖分离15 d 胚胎小鼠皮层神经细胞, 接种于96 孔板, 48 h 后加药并培养72 h, 相差显微镜及免疫组织细胞化学方法进行形态学观察, 并以MTT 法观察3 种药物对小鼠皮层神经元活性的影响。结果:盐酸美金刚胺显著促进小鼠皮层神经元活性, 并呈现出一定的量效关系;美曲磷酯10 pmol·L^-1, 0.1, 1, 10 nmol·L^-1 剂量组对皮层神经元细胞活性没有影响, 而美曲磷酯0.1,1 μmol·L^-1剂量组显著抑制皮层神经元细胞活性;0.1 nmol·L^-1白藜芦醇显著促进皮层神经元细胞活性, 而白藜芦醇0.1, 1, 10 μmol·L^-1剂量组显著抑制皮层神经元细胞活性。结论:盐酸美金刚胺促小鼠皮层神经元活性较高, 故以其为先导化合物设计药效更高的阿尔茨海默症治疗药物的方案是可行的。     

Efficacy of an NMDA receptor antagonist for Parkinson's disease dementia: A brain perfusion SPECT study

Memantine's efficacy has been demonstrated in patients with moderate to severe Alzheimer's disease. However, memantine therapy is not typically used in treating Parkinson's disease dementia (PDD), although the deviating glutamatergic pattern evidenced in neuropathological findings suggests that N‐methyl D‐aspartate receptor antagonists in patients with Lewy‐body disorder may be effective. Therefore, we conducted this longitudinal study to confirm the efficacy of memantine for PDD by analyzing comparative changes in regional cerebral blood flow (rCBF) and neuropsychological tests before and after memantine administration in PDD. A total of 18 patients with PDD were enrolled in this study. All patients underwent technetium‐99m hexamethylpropyleneamine oxime single photon emission computed tomography and completed neuropsychological tests before and 12 months after memantine administration. This study showed that there was no significant difference in cognitive functioning before and after memantine administration. No significant difference in rCBF was observed in any regions at baseline compared to 12 months after memantine administration. Our results suggest that memantine delays the speed of deterioration in cognitive functioning and behavioral symptoms in PDD because we found no significant changes in rCBF and cognition after memantine treatment.     

Memantine Attenuates Delayed Vasospasm after Experimental Subarachnoid Hemorrhage via Modulating Endothelial Nitric Oxide Synthase

Delayed cerebral vasospasm is an important pathological feature of subarachnoid hemorrhage (SAH). The cause of vasospasm is multifactorial. Impairs nitric oxide availability and endothelial nitric oxide synthase (eNOS) dysfunction has been reported to underlie vasospasm. Memantine, a low-affinity uncompetitive N-methyl-d-aspartate (NMDA) blocker has been proven to reduce early brain injury after SAH. This study investigated the effect of memantine on attenuation of vasospasm and restoring eNOS functionality. Male Sprague-Dawley rats weighing 350–450 g were randomly divided into three weight-matched groups, sham surgery, SAH + vehicle, and SAH + memantine groups. The effects of memantine on SAH were evaluated by assessing the severity of vasospasm and the expression of eNOS. Memantine effectively ameliorated cerebral vasospasm by restoring eNOS functionality. Memantine can prevent vasospasm in experimental SAH. Treatment strategies may help combat SAH-induced vasospasm in the future.     

脑功能显像剂99Tcm-Memantine的初步研究

用~(99)Tc~m标记N-[2-(N-(2-巯基乙基))氨基甲酰甲基]-N-(2-巯基乙基)-3,5-二甲基金刚烷胺基乙酰胺(N_2S_2-Memantine),生成了~(99)Tc~m(V)-Memantine。采用纸层析对此标记物进行质控并检测其体外稳定性。结果显示,湿法的标记率>90%,药盒化标记的标记物经乙酸乙酯萃取纯化后,放化纯度>95%,体外稳定性良好,有望成为一种新的脑功能显像剂。     

气相色谱法测定盐酸美金刚原料药中有机溶剂残留量

目的:用毛细管柱气相色谱法建立测定盐酸美金刚原料药中二氯甲烷、乙腈、乙醚、乙醇的残留量的方法。方法:采用内壁涂有5%苯基-95%聚二甲基硅氧烷的毛细管柱(DB-5毛细管色谱柱30m×0.53mm×1.5μm),以氮气为载气,流速1.0ml/min。柱温箱:50℃保持12min,然后以30℃/min升温至230℃,至少保持12分钟。分流直接进样,进样口温度230℃,进样量:1.0μl。FID检测器,检测器温度280℃。按内标法计算残留溶剂的含量。结果:在考察的浓度范围内呈现良好的线性关系(二氯甲烷r=0.99885、乙腈r=0.99975、乙醚r=0.99659、乙醇r=0.99985),方法的精密度良好,回收率较为理想。结论:该法适用于盐酸美金刚原料药中二氯甲烷、乙腈、乙醚、乙醇的残留量的检测。