L-蛋氨酸类似物 L-2-氨基-４-叠氮基丁酸的合成

目的 优化L-2-氨基-４-叠氮基丁酸的合成工艺。方法 以L-蛋氨酸为起始原料经硫甲基化、水解一锅法合成L-2-氨基-4-羟基丁酸（2）,2在浓盐酸中环合得到重要中间体α-氨基-γ-丁内酯盐酸盐（3）,3 经溴代开环、成酯、叠氮化、水解4步反应制得目标产物。结果与结论 以L-蛋氨酸为起始原料,经 6 步反应合成目标产物,其结构经¹H-NMR 和 IR 谱确证。该合成方法原料易得、条件温和、操作简单、易于中试放大。     

抗肿瘤药物 linifanib 的合成

目的 合成抗肿瘤药物 linifanib 并优化其工艺。方法 以 2,6-二氟苯甲腈为原料经取代、重氮化、环合等 4 步反应制得关键中间体3-氨基-4-碘吲唑（5）;以对氟硝基苯为原料经 Suzuki 偶联、还原、缩合反应得到关键中间体1-(2-氟-5-甲基苯基)-3-[4-(4,4,5,5-四甲基-1,3,2-二氧杂环硼乙烷-2-基)苯基]脲（10）;中间体 5 与 10 经 Suzuki 偶联反应制得抗肿瘤药 linifanib。结果 目标化合物的结构经¹H-NMR 谱和质谱确证,总收率为39.4%。结论 与文献报道的工艺比较, 新工艺成本低廉,操作简单,反应时间缩短,有利于工业化生产。     

泰比培南酯的合成工艺研究

目的 研究新型碳青霉烯类抗生素泰比培南酯的合成工艺。方法 以 (4R,5S,6S)-3-二苯基磷酰氧基-6-[(1R)-1-羟乙基]-4-甲基-7-氧代-1-氮杂双环[3.2.0]庚-2-烯-2-羧酸对硝基苄酯和3-巯基-1-(1,3-噻唑啉-2-基)氮杂环丁烷盐酸盐为起始原料,经过缩合、氢化、亲核取代3步反应,得到目标产物。结果与结论 目标化合物及中间体的结构经熔点、IR、MS、¹H-NMR和¹³C-NMR 谱确证。该合成工艺反应步骤少、操作简便、收率高、产品纯度高,有利于工业化生产。     

2,2-二甲基苯并吡喃类衍生物的合成

目的 设计合成一系列苯并吡喃类衍生物。方法 以2-甲基-丁-3-炔-2-醇为起始原料,经氯代、Williamson 成醚、环合、Aldol 缩合4步反应得到目标化合物。结果与结论 合成了16个未见文献报道的新化合物,其结构经¹H-NMR 和 MS 谱确定。所有目标化合物的抗肿瘤活性测试正在进行中。     

(S)-1-(N-烯丙氧羰基)亚胺乙基-3-巯基吡咯烷的合成

目的 合成帕尼培南关键中间体 (S)-1-( N-烯丙氧羰基)亚胺乙基-3-巯基吡咯烷。方法 以氯甲酸烯丙酯为酰化剂,与盐酸乙脒进行 N-酰化反应得到 1-亚胺乙基氨基甲酸烯丙酯,该化合物与 3-R-羟基吡咯烷进行缩合,再经甲磺酰化、S_N2 取代、水解共 5 步反应得到目标化合物。结果与结论 该合成路线中使用新型保护基烯丙氧羰基替代传统的保护基—对硝基苄氧羰基,目标化合物的结构经 ¹H-NMR、MS 谱确证,总收率为 41.6%,各步反应操作简便,条件温和,有利于工业化生产。     

环扁桃酯的新合成路线的研究

目的 设计周围血管扩张药环扁桃酯的新合成路线。方法 以苯为原料,与草酰氯单乙酯反应制备苯乙酮酸乙酯（2）, 2 与顺式 3,3,5-三甲基环己醇通过酯交换合成顺式 3,3,5-三甲基环己醇苯乙酮酸酯（3）, 3 在锌粉和甲酸铵条件下发生还原得到环扁桃酯。结果与结论 合成目标化合物的总收率为59.6%,目标化合物的结构经¹H-NMR、¹³C-NMR、IR 谱确证。新合成路线具有原料廉价易得、操作简便、收率高的特点。     

帕尼培南关键中间体2-酮碳青霉烷-3-羧酸对硝基苄酯的合成改进

目的 合成帕尼培南关键中间体(3R,5R,6S)-6-[(1R)-羟乙基]碳青霉烷-2酮-3-羧酸对硝基苄酯。方法 以对硝基苯甲醛为起始原料，经还原、酯化、重氮化、烯醇化、与单环β-内酰胺结合、水解及环合等7步反应制得目标化合物。结果与结论 合成的目标化合物经IR、¹H-NMR、MS确证结构，总收率达60.7 %。该合成工艺省去文献中两步需要分离纯化的步骤，使合成路线大为简化。     

米力农的合成工艺改进

目的 研究强心药物米力农的合成工艺。^方法 以4-甲基吡啶为起始原料,经乙酰化、缩合及环化3步反应制得目标化合物米力农。^{结果与结论} 目标化合物的结构经IR和1H-NMR谱数据确证。改进后的工艺,操作简便,原料和试剂价廉易得,总收率为52.9%,适合工业化生产。     

(Z)-2-(5-氨基-1,2,4-噻二唑-3-基)-2-甲氧亚氨基乙酸的合成

目的 合成头孢唑兰中间体(Z)-2-(5-氨基-1,2,4-噻二唑-3-基)-2-甲氧亚氨基乙酸。方法 以氰乙酰胺为起始原料,依次经甲氧亚氨化、加成、酯化、与硫氰化钾反应、构型转换和水解共6步反应制得目标化合物。结果和结论 目标化合物的结构经¹H-NMR和MS谱确证。该工艺路线原料易得,操作简便,总收率为29.8%,具有一定的工业化价值。     

他唑巴坦的合成新方法

目的 研究他唑巴坦的合成新方法。方法 以2α-甲基-2β-氯甲基青霉烷酸二苯甲酯(2)为原料,经碘代、1,2,3-三氮唑取代、氧化、脱保护4步反应得到他唑巴坦。结果与结论 他唑巴坦及关键中间体的结构经1H-NMR, MS, IR确证,目标化合物的4步反应总收率为51.3 %。该合成路线具有原料易得、反应步骤少、收率高、安全性高、操作简便的特点。     

Identification of MEK1 as a novel target for the treatment of neuropathic pain

(1) In the present study we have attempted to identify changes in gene expression which are associated with neuropathic pain using subtractive suppression hybridization analysis of the lumbar spinal cord of animals suffering streptozocin induced diabetic neuropathy. (2) Using this approach, we found a significant up-regulation of several key components of the extracellular signal-regulated kinase (ERK) cascade. These findings were confirmed by Western blot analysis, which demonstrated that the levels of active ERK1 and 2 correlated with the onset of streptozocin-induced hyperalgesia. (3) Intrathecal administration of the selective MAPK/ERK-kinase (MEK) inhibitor PD 198306 dose-dependently (1-30 micro g) blocked static allodynia in both the streptozocin and the chronic constriction injury (CCI) models of neuropathic pain. (4) The antihyperalgesic effects of PD 198306, in both the streptozocin and CCI models of neuropathic pain, correlated with a reduction in the elevated levels of active ERK1 and 2 in lumbar spinal cord. (5) Intraplantar administration of PD 198306 had no effect in either model of hyperalgesia, indicating that changes in the activation of ERKs and the effect of MEK inhibition are localized to the central nervous system. (6) In summary, we have demonstrated for the first time that the development of neuropathic pain is associated with an increase in the activity of the MAPK/ERK-kinase cascade within the spinal cord and that enzymes in this pathway represent potential targets for the treatment of this condition.     

Dissolution testing of a poorly soluble compound using the flow-through cell dissolution apparatus

Dissolution of Pfizer Compound PD198306, a poorly soluble compound, was studied in 25 mM pH 9 sodium phosphate solution with 0.5% SLS using the flow-through cell dissolution apparatus. Unmicronized and micronized drug powders were tested. Several methods of loading the drug powder into the flow-through dissolution cells and their impact on dissolution were investigated. The influence of flow rate of the dissolution medium on the rate and extent of dissolution were studied. PD198306 has poor wettability even in the presence of 0.5% SLS. It was found that loading the drug powder into the dissolution cell in the form of a suspension provided the best dissolution profile in terms of the rate and extent of dissolution. The flow rate of 4 ml/min resulted in good particle size discrimination.     

Discriminative stimulus effects of putative D3 dopamine receptor agonists in rats

Three separate groups of rats were trained to discriminate the putative D3 dopamine receptor agonists (+/-)-7-hydroxydipropylaminotetralin (7-OH-DPAT) (0.03 mg/kg), PD 128,907 (1.0 mg/kg) and quinpirole (0.03 mg/kg) from saline. Food was presented after each 10 (7-OH-DPAT and PD 128,907) or 20 (quinpirole) consecutive responses on one lever after administration of the training drug, and the other lever after the administration of saline. Once stable performances were obtained, the effects of various doses of several dopaminergic agonists were assessed during test sessions in which responses on either lever were reinforced. The substitution tests were conducted to determine if differences in potencies would be obtained, which would be suggestive of differences in the mechanisms underlying the discriminative effects of the training drugs. Non-selective agonists with activity at both D2 and D3 dopamine receptors (D2-like agonists) substituted for each of the three training drugs. In addition, the selective D2 dopamine receptor agonist U91356A also generalized to both 7-OH-DPAT and PD 128,907. The potencies of the D2-like agonists in substituting for each training drug were highly correlated with potencies in substituting for the others. SKF 82958 and SKF 81297, agonists with selectivity for D1 and D5 dopamine receptors (D1-like agonists), partially substituted for 7-OH-DPAT but not PD 128,907. The D1-like partial agonist SKF 38393 did not substitute for any of the training drugs for which it was tested. Cocaine produced intermediate substitution in 7-OH-DPAT- and PD 128,907-trained subjects and did not substitute at all in quinpirole-trained subjects. The dopamine D1-like antagonist SCH 39166 (0.001-0.03 mg/kg) did not alter the discriminative stimulus effects of PD 128,907, whereas the D2-like dopamine antagonist spiperone (0.001-0.1 mg/kg) produced at the highest dose an insurmountable antagonism of the discriminative effects of PD 128,907. In contrast, there was no appreciable antagonism of the effects of PD 128,907 on response rates. The data collected are consistent with a distinction between the effects of each of these training drugs and the indirectly acting agonist cocaine. Further, these data indicate that there are differences in the mechanisms underlying the discriminative effects of PD 128,907 and its effects on response rates. Moreover, these data indicate that each of the training drugs is distinct from drugs acting through D1 dopaminergic mechanisms. However, there were no data that clearly distinguished these training drugs from each other or from drugs acting through D2 dopaminergic mechanisms.     

来那度胺的合成

N-苄氧羰基-L-谷氨酰胺经酯化和氢化脱保护制得中间体L-谷氨酰胺甲酯(4),另用2-甲基-3-硝基苯甲酸(5)经酯化和溴化制得另一中间体2-溴甲基-3-硝基苯甲酸甲酯(7).4与7经缩合、氢化还原、分子内环合制得来那度胺,总收率约33%(以5计).     

Neonatal Binge Ethanol Exposure Using Intubation: Timing and Dose Effects on Place Learning

Neonatal rats were given ethanol using an acute intubation procedure that resulted in daily binge-like exposure with minimal effects on somatic growth. Acquisition of place learning in the Morris water maze was evaluated on postnatal days (PD) 26-31. In Experiment 1, a total of 5.25 g/kg/day of ethanol was administered in two daily intubations on PD 4-6, PD 7-9, or PD 4-9, producing mean peak BACs of 265 mg/dl. Place learning acquisition deficits in a 114-cm-diameter tank were found for the PD 4-9 and PD 7-9 groups, but not the PD 4-6 group. In Experiment 2, either 4.5 or 5.25 g/kg/day of ethanol was administered on PD 7-9 and place learning was tested in a 171-cm-diameter tank. Significant acquisition deficits resulted from the higher dose, and probe trial search patterns for both ethanol groups were significantly less localized than controls. In Experiment 3, no significant effects of either PD 7-9 dose were found on a visible platform task. These findings reveal selective place learning deficits in this intubation model of neonatal binge exposure, and confirm a temporal window of vulnerability to spatial learning deficits during the second neonatal week.     

35% CO2 sensitivity in social anxiety disorder

The 35% carbon dioxide (CO(2)) challenge is a well-established model of panic. This study aimed to investigate 35% CO(2) sensitivity in patients with social anxiety disorder (SAD) compared with patients with panic disorder (PD) and normal controls. First, a 35% CO(2) challenge was conducted including 16 patients with generalized SAD, 16 with PD and 16 normal subjects. Outcome was assessed by a Visual Analogue Scale for Fear (VAS-F) and the Panic Symptom List (PSL). Second, meta-analyses of fear and panic scores were performed, including data from the present experiment and from previous 35% CO(2) challenge studies in patients with SAD. The present 35% CO(2) challenge found equal increases in VAS-F and PSL in patients with SAD compared with normal controls, whereas the CO(2) response in patients with PD was significantly stronger than in controls. The meta-analyses confirmed the experimental data from this study, and in addition showed an intermediate panic rate in SAD patients, in between that of normal controls and patients with PD. In conclusion, neither our experiment nor the meta-analyses found evidence for a similarly exaggerated 35% CO(2) sensitivity in SAD and PD, suggesting that the pathogenesis of SAD is different from PD, although patients with SAD may be slightly more sensitive than non-anxious controls.     

Discriminative stimulus properties of the dopamine D3 receptor agonists, PD128,907 and 7-OH-DPAT: a comparative characterization with novel ligands at D3 versus D2 receptors

Rats were trained to recognize a discriminative stimulus (DS) elicited by the preferential dopamine D3 receptor agonists, PD128,907 (0.16 mg/kg, i.p.) and 7-OH-DPAT (0.16 mg/kg, i.p.). PD128,907 and 7-OH-DPAT showed "full" (> or = 80%) and mutual generalization. Chemically-diverse, preferential D3 versus D2 agonists, quinelorane, CGS15855A, pramipexole, ropinirole and piribedil, generalized to PD128,907 (and 7-OH-DPAT) in this order of potency, which correlated more strongly with affinity/activity at cloned human (h)D3 (r=0.68/0.81, n=7) than hD2 (0.27/0.64, n=7) receptors. Further, generalization potency strongly correlated with potency for suppression of response rates (0.86), induction of hypothermia (0.92), reduction of striatal dopamine turnover (0.92) and diminution of immobility in a forced-swim procedure (0.97). Nafadotride, UH232 and AJ76, which show a mild preference for D3 versus D2 sites, blocked the PD128,907 DS, and the modestly-selective D3 antagonist, U99194A, was partially effective. Both nafadotride and U99194A blocked the 7-OH-DPAT DS. However, antagonist potency (n=4) versus PD128,907 correlated better with affinity at D2 (0.89) versus D3 (0.27) sites. Further, whereas the preferential D2 versus D3 antagonist, L741,626, antagonized the PD128,907 DS, the selective D3 antagonists, S11566, S14297 (its eutomer) and GR218,231 were ineffective against PD128907 and 7-OH-DPAT DS. S11566 and GR218,231 likewise did not generalize to PD128,907. In conclusion, under the present conditions, D2 receptors are principally implicated in the DS properties of PD128,907 and 7-OH-DPAT.     

Neonatal administration of N-omega-nitro-L-arginine induces permanent decrease in NO levels and hyperresponsiveness to locomotor activity by D-amphetamine in postpubertal rats

Nitric oxide (NO) is associated with dopamine (DA) release. Previously, we demonstrated that rats treated with a non-selective nitric oxide synthase inhibitor, N-omega-nitro-l-arginine (l-NNA) at postnatal days 4-6 (PD4-6) show increased locomotion and disrupt neuronal cytoarchitecture after puberty (PD60). Here, we investigate whether the modulation of NO production in rats at PD4-6 causes long term changes of NO system, its impact on DA innervation, and schizophrenia-like behaviors. NO levels were measured in seven brain areas at PD35, PD60, PD90, and PD120. Autoradiographic studies explored the effect of l-NNA on the expression of D₁ and D₂ receptors in the caudate-putamen (CPu) and nucleus accumbens (NAcc) at PD60. Locomotor activity was assessed at PD60 using the non-selective DA agonists, amphetamine and apomorphine, and the selective DA receptor agonist [D₂, quinpirole; D₃, 7-hydroxy-N,N-di-n-propylaminotetralin ((±)-7-OH-DPAT)]. l-NNA treatment produced decreases in NO levels in the frontal cortex, striatum, brainstem and cerebellum, while in the occipital cortex changes were observed at PD120. Hippocampus and temporoparietal cortex showed differential levels of NO. Receptor autoradiography revealed increases in D₁ receptor levels in the NAcc (shell), while decreases in D₂ receptor binding were observed in the CPu and NAcc (core). Amphetamine and quinpirole treatments resulted in increases in locomotion. In contrast, treatment with 7-OH-DPAT produced hypolocomotion at low doses, while increased locomotion was seen at the highest dose. These results show that modulation of NO levels early postnatally (PD4-6) produces long term alteration in NO levels, with possible consequences on DA transmission, and related behaviors relevant to schizophrenia.     

α7 nicotinic acetylcholine receptor mediated neuroprotection in Parkinson's disease

Parkinson's disease (PD) is characterized by relatively selective degeneration of dopaminergic neurons in the substantia nigra and loss of dopamine in the striatum. More than 50 epidemiological studies confirmed the low incidence of PD in smokers. Examining the distribution of subtypes of nicotinic acetylcholine receptors (nAChRs) in dopaminergic neurons of nigrostriatal system and its change in PD patients is quite important to elucidate possible neuroprotective cascade triggered by nicotine. Evidences of nAChR-mediated protection against neurotoxicity induced by rotenone, 6- hydroxydopamine (6-OHDA), and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) are briefly reviewed. In rotenone- and 6-OHDA-induced PD models, nAChR-mediated neuroprotection was blocked not only by α4β2 but also by α7 nAChR antagonists. The survival signal transduction, α7 nAChR-Src family-PI3K-Akt/PKB cascade and subsequent upregulation of Bcl-2, would lead to neuroprotection. These findings suggest that nAChR-mediated neuroprotection is achieved through subtypes of nAChRs and common signal cascades. An early diagnosis and protective therapy with specific nAChR modulations could be effective in delaying the progression of PD.     

Postnatal evaluation of prenatal exposure to p-xylene in the rat

Pregnant Sprague-Dawley rats were exposed to either 3500 or 7000 mg/m3 p-xylene from days 7-16 of gestation. Dams were allowed to give birth, and litters were counted, weighed, and observed for external malformations on postnatal days (PD) 1 and 3. Litters were normalized to 8 pups (4 males and 4 females +/- 1) on PD4. On PD21 animals were weaned and littermates housed by sex. Body weights were recorded weekly until weaning and once every 2 weeks thereafter. Central nervous system (CNS) development was evaluated by acoustic startle response on PD13, 17, 21, and 63 as well as figure-8 maze activity on PD22 and 65. Maternal weight gain during the treatment period was significantly less in the high-dose group. No effects were seen on litter size or weight at birth or on PD3. There were no effects of xylene exposure on growth rate. There were no treatment-related effects on acoustic startle response or figure-8 maze activity. Thus, p-xylene as administered in this study does not appear to be a selective developmental toxicant in the rat.