Synthesis of deramciclane* labeled with tritium in various positions

[(1R)‐endo]‐(+)‐3‐bromocamphor was dehalogenated with tritium gas to [3‐³H]camphor and via [3‐³H]phenylborneol converted to [3‐³H]deramciclane isolated as the fumarate salt (specific activity 51.8 GBq/mmol). This three step synthesis from [3‐³H]camphor gave an overall yield of 22%. Benzyloxy‐acetic acid methyl ester was reduced with sodium‐borotritide to 2‐benzyloxy‐ethanol‐[1‐³H], and through a four step procedure was converted to 2‐dimethylaminoethyl‐[2‐³H] chloride. The latter was condensed with the sodium derivative of 2‐phenylborneol giving rise to [2‐dimethylamino‐[2‐³H]ethoxy]deramciclane isolated as the fumarate (specific activity 8.177 GBq/mmol). This six step synthesis from [³H]NaBH₄ gave an overall yield of 6%. Copyright © 2005 John Wiley & Sons, Ltd.     

Raman and UV–vis spectroscopic study of polyaniline membranes containing a bulky cationic additive

Electrically conducting soluble polyaniline (PANI), containing different amounts of a bulky lipophilic cationic additive, tridodecylmethylammonium chloride (TDMACl), was studied by Raman (λ_exc=780 nm) and UV–vis spectroscopy. PANI was made simultaneously electrically conducting and soluble with bis[4-(1,1,3,3-tetramethylbutyl)phenyl]phosphoric acid in dichloromethane. The PANI membranes were prepared by drop casting on glassy carbon or ITO substrates. Raman and UV–vis measurements were carried out in a 0.1 M CaCl₂ solution at potentials between 400 and ?600 mV (vs. SCE) at pH 6, or alternatively at the open circuit potential at pH 10. The results of Raman, UV–vis and cyclic voltammetric measurements confirm that the incorporation of TDMACl into the PANI membrane facilitates the oxidation and reduction of PANI.     

1—甲基—4—苯基吡啶啶离子诱发大鼠小脑颗粒细胞凋亡

目的 建立1－甲基－4－苯基吡啶离子（1－methy1-4-phenyl pyridinium ion,MPP^ )诱导的大鼠小脑颗粒细胞凋亡模型。方法 MPP^ 处理大鼠小脑颗粒细胞,分别用甲基绿－派诺宁染色,DNA凝胶电泳,流式细胞术进行检测。结果 浓度为50μmol/L MPP^ 使小脑颗粒细胞发生凋亡。结论 以MPP^ 为诱导剂建立的大鼠小脑颗粒细胞凋亡模型,可用于研究和帕金森病（PD）有关的细胞凋亡的调控机制和筛选抗PD药物。     

大高良姜的化学成分研究

目的：对大高良姜的根茎部位化学成分进行系统研究。方法：采用硅胶和Sephadex LH-20柱色谱等手段进行分离纯化，运用UV、IR、^1H—NMR13C—NMR、MS等谱学方法进行结构鉴定。结果：共分离鉴定了11个化合物，分别为4-[（E）-3-hydroxyprop-1-enyl]phenylacetate（1），反式对羟基桂皮醛乙酯（2），5-hydroxy-7-（4″-hydroxy-3″-methoxyphenyl）-1-phenyl-3-heptanone（3），7-（4″-hydroxy-3″-methoxy—phenyl）-1-phenylhep-4-en-3-one（4），[1′S]-1′-乙酰氧丁香酚乙酯（5），反式对羟基桂皮醛（6），对羟基苯甲醛（7），1-（4-hydroxyphenyl）propan．1-one（8），高良姜素（9），trans—P—coumaryl diacetate（10），β-谷甾醇（11）。结论：化合物1是首次从自然界分离得到的天然产物，化合物2为首次从该属植物中分离得到的苯丙素类化合物，化合物3和4是首次从该种植物中分离得到的双苯庚烷类化合物。     

柱前衍生化HPLC法测定N(2)-L-丙氨酰-L-谷氨酰胺注射液的含量

目的建立柱前衍生化高效液相色谱(HPLC)法测定N(2)-L-丙氨酰-L-谷氨酰胺注射液含量的方法。方法采用异硫氰酸苯酯作柱前衍生剂,色谱柱为Waters sunfire ODS柱(4.6 mm×250 mm),流动相为:乙腈-0.1 mol/L醋酸钠(用稀醋酸调整pH 5.50)为44∶56,柱温30℃,检测波长254 nm。结果线性范围为0.025~2.5mg/mL(r=0.999 8),平均加样回收率为99.9%,RSD为0.5%。结论此法操作简单快速,灵敏度高,结果准确可靠,适用于N(2)-L-丙氨酰-L-谷氨酰胺注射液中N(2)-L-丙氨酰-L-谷氨酰胺的含量测定。     

Altered platelet calsequestrin abundance,Na/Ca exchange and Ca signaling responses with the progression of diabetes mellitus

Introduction

Downregulation of calsequestrin (CSQ), a major Ca^2 + storage protein, may contribute significantly to the hyperactivity of internal Ca^2 + ([Ca^2 +]_i) in diabetic platelets. Here, we investigated changes in CSQ-1 abundance, Ca^2 + signaling and aggregation responses to stimulation with the progression of diabetes, especially the mechanism(s) underlying the exaggerated Ca^2 + influx in diabetic platelets.

Materials and methods

Type 1 diabetes was induced by streptozotocin in rats. Platelet [Ca^2 +]_i and aggregation responses upon ADP stimulation were assessed by fluorescence spectrophotometry and aggregometry, respectively. CSQ-1 expression was evaluated using western blotting.

Results

During the 12-week course of diabetes, the abundance of CSQ-1, basal [Ca^2 +]_i and ADP-induced Ca^2 + release were progressively altered in diabetic platelets, while the elevated Ca^2 + influx and platelet aggregation were not correlated with diabetes development. 2-Aminoethoxydiphenyl borate, the store-operated Ca^2 + channel blocker, almost completely abolished ADP-induced Ca^2 + influx in normal and diabetic platelets, whereas nifedipine, an inhibitor of the nicotinic acid adenine dinucleotide phosphate receptor, showed no effect. Additionally, inhibition of Na⁺/Ca^2 + exchange induced much slower Ca^2 + extrusion and more Ca^2 + influx in normal platelets than in diabetic platelets. Furthermore, under the condition of Ca^2 +-ATPase inhibition, ionomycin caused greater Ca^2 + mobilization and Ca^2 + influx in diabetic platelets than in normal platelets.

Conclusions

These data demonstrate that platelet hyperactivity in diabetes is caused by several integrated factors. Besides the downregulation of CSQ-1 that mainly disrupts basal Ca^2 + homeostasis, insufficient Na⁺/Ca^2 + exchange also contributes, at least in part, to the hyperactive Ca^2 + response to stimulation in diabetic platelets.     

Age-related loss of cardiac preconditioning: impact of protein kinase A

Helium induces preconditioning (He-PC) by mitochondrial calcium-sensitive potassium (mK_Ca) channel-activation, but this effect is lost in the aged myocardium. Both, the upstream signalling pathway of He-PC and the underlying mechanisms for an age-related loss of preconditioning are unknown. A possible candidate as upstream regulator of mK_Ca channels is protein kinase A (PKA).We investigated whether 1) regulation of PKA is involved in He-PC and 2) regulation of PKA is age-dependent.Young (2-3 months) and aged (22-24 months) Wistar rats were randomised to eight groups (each n = 8). All animals underwent 25 min regional myocardial ischemia and 120 min reperfusion. Control (Con, Age Con) animals were not further treated. Young rats inhaled 70% helium for 3 × 5min (He-PC). The PKA-blocker H-89 (10 μg/kg) was administered with and without helium (He-PC + H-89, H-89). Furthermore, we tested the effect of direct activation of mK_Ca channels with NS1619. The adenylyl cyclase activator forskolin (For) was administered in young (300 μg/kg) and aged animals (300 and 1000 μg/kg).He-PC reduced infarct size from 60 ± 4% (Con) to 37 ± 10% (p < 0.05). Infarct size reduction was completely abolished by H-89 (58 ± 5%; p < 0.05), but H-89 alone had no effect (57 ± 2%). NS1619 reduced infarct size in the same concentration in both, young and aged rats (35 ± 6%; p < 0.05 vs. Con and 34 ± 8%; p < 0.05 vs. Age Con). Forskolin in a concentration of 300 μg/kg reduced infarct size in young (37 ± 6%; p < 0.05) but not in aged rats (48 ± 13%; n.s.). In contrast, 1000 μg/kg Forskolin reduced infarct size also in aged rats (28 ± 3%; p < 0.05).He-PC is mediated by activation of PKA. Alterations in PKA regulation might be an underlying mechanism for the age-dependent loss of preconditioning.     

4-甲磺酰基苯乙酸的合成工艺研究

目的对4-甲磺酰基苯乙酸的合成工艺进行改进,使其更利于工业化生产。方法以4-甲磺酰基苯乙酮为起始原料,在硅胶固载氟硼酸(HBF4·Si O2)的催化下,合成2-(4-(甲磺酰基)苯基)-1-吗啉代乙硫醇,再经水解得到4-甲磺酰基苯乙酸。结果制得的4-甲磺酰基苯乙酸质量分数为99.8%,总收率约75%。结论改进后的工艺原料便宜易得,反应温度低,时间短,操作简单,更适用于4-甲磺酰基苯乙酸工业化生产。     

Photolytic Labeling and Its Applications in Protein Drug Discovery and Development

In this mini-review, the major types of photolytic labeling reagents are presented together with their reaction mechanisms. The applications of photolytic labeling in protein drug discovery and development are then discussed; these have expanded from studies of protein-protein interactions in vivo to protein-matrix interactions in lyophilized solids. The mini-review concludes with recommendations for further development of the approach, which include the need for new and more chemically diverse photo-reactive reagents and better understanding of the mechanisms of photolytic labeling reactions in various media.