卡培他宾的合成工艺研究

目的 合成抗肿瘤药卡培他宾。方法 以D-核糖为起始原料,通过缩醛保护、对甲苯磺酰化、溴代、氢化脱卤、脱保护和乙酰化共6步反应制得中间体5-去氧-1,2,3-三-O-乙酰基-D-核糖(7),N4-正戊氧羰基-5-氟胞嘧啶与中间体7进行缩合后,再经氨解脱乙酰基得到目标化合物。结果与讨论 目标化合物的总收率为16.4 %(以D-核糖计),其结构经1H-NMR、MS确证。该合成工艺简化了操作,降低了合成成本,适于工业化生产。     

5-氧-烯丙基-2,3,4-三-氧-苄基-D-核糖醇的合成工艺改进

目的合成5-氧-烯丙基-2,3,4-三-氧-苄基-D-核糖醇。方法以D-核糖为原料,经甲苷化、苄基化、水解、肟保护、烯丙基化、脱肟、还原7步反应得到5-氧-烯丙基-2,3,4-三-氧-苄基-D-核糖醇。结果与讨论总收率55%,目标产物结构经核磁共振氢谱确认。该合成路线步骤少,绿色环保,适合工业化生产。     

地西他滨α-型异构体的制备

为对地西他滨产品中的有关物质进行定量控制,2-脱氧-D-核糖经甲基化及乙酰化反应得到1-O-甲基-2-脱氧-3,5-二-(O-乙酰基)-α,β-呋喃核糖,再与2,4-O,N-双三甲基硅烷基-1,3,5-三嗪(6)发生糖苷化反应后重结晶得到1-[3,5-二-(O-乙酰基)-2-脱氧-α-D-核糖]-5-氮杂胞嘧啶,最后经氨气脱保护得到地西他滨α-型异构体,并经X-单晶衍射确证结构。其中6可由5-氮杂胞嘧啶(5)经六甲基二硅烷胺保护得到。     

1-脱氮腺苷的改良合成法

腺苷类似物1-脱氮腺苷(1)具有广泛的生物活性,有抑制血小板凝聚和腺苷脱氨酶的作用。本文介绍1的新合成方法。合成路线如方程式所示。化合物2与硝酸-三氟醋酸混合物反应生成7-硝基咪唑并[4.5-6]吡啶4-氧化物(3)。和PCl_3处理3,生成脱氧衍生物4。在催化量的SnCl_4作用下,4再与等摩尔的1,2,3,5-四-O-乙酰基-β- D映喃核糖(TAR)进行反应,得到7-硝基-3-(2,3,5-三-O-乙酰基-β-D-呋喃核糖)-3H咪唑并[4,5-b]吡啶(5),收率82%。在化合物5的甲醇溶液中通入氨气,脱去保护基,生成化合物6,收率86%。用Pd/C加压氢化,     

卡培他滨的合成

1,2,3-三乙酰基-5-脱氧-D-核糖和硅烷化的5-氟胞嘧啶在无水氯化锌催化下糖基化得到2′,3′-O-二乙酰基-5′-脱氧-5-氟胞嘧啶核苷,再与氯甲酸正戊酯反应得到2′,3′-O-二乙酰基-5 ′-脱氧-5-氟-N-[(戊氧基)羰基]胞嘧啶核苷,最后经脱保护得到抗肿瘤药卡培他滨,总收率约74％.     

氯法拉滨的合成

1-乙酰基-2，3，5-三-O-苯甲酰基-β-D-呋喃核糖经重排获得的1，3，5-三-O-苯甲酰基-α-D-呋喃核糖，与硫酰氯、咪唑反应生成易离去基团磺酰咪唑酯，经氟代、溴化得1-溴-2-脱氧-2-氟-3，5-二-D-苯甲酰基-α-D-阿拉伯糖，再与2-氯腺嘌呤缩合后脱保护即可制得抗白血病药氯法拉滨，总收率5％。     

地西他滨的合成

2-脱氧-D-核糖在吡啶作用下与乙酐进行乙酰化,再在TMSOTf作用下与5-氮杂胞嘧啶偶联得1-（3,5-二-O-乙酰基-2-脱氧-D-核糖）-5-氮杂胞嘧啶,最后经氨气脱保护、甲醇重结晶得抗肿瘤药地西他滨,总收率约32%。     

(6R,7R)-7-[2-呋喃基(甲氧亚氨基)乙酰氨基]-3-羟甲基-8-氧代-5-硫杂-1-氮杂二环[420]辛-2-烯-2-甲酸的合成研究

目的　制备(6R,7R) - 7-[2 -呋喃基(甲氧亚氨基)乙酰氨基] - 3-羟甲基- 8-氧代- 5 -硫杂- 1-氮杂二环[4 2 0]辛- 2 -烯- 2 -甲酸。方法　通过7-氨基头孢烷酸的水解,生成去乙酰基7-氨基头孢烷酸,再与2 - (2 -呋喃基)- 2 -甲氧亚胺基乙酸氯反应进行7位氨基的酰化制备上述医药中间体。结果及结论　适宜的反应条件为:7-氨基头孢烷酸在- 2 5℃水解,与2 - (2 -呋喃基) - 2 -甲氧亚胺基乙酰氯在- 10℃反应,二者的摩尔比为1 0∶1. 15,收率可达80 %。     

2′-C-甲基尿苷的合成工艺改进

目的研究2′-C-甲基尿苷的新合成方法。方法以1-O-乙酰基-2,3,5-三-O-苯甲酰基-β-D-呋喃核糖(2)为原料,经酸性水解、Swern氧化、格氏反应、苯甲酰化、缩合、酯水解6步反应得到2′-C-甲基尿苷。结果与结论 2′-C-甲基尿苷及部分中间体的结构经MS、~1H-NMR谱确证,6步反应总收率为27.0%(以2计),产品纯度99.0%(HPLC面积归一化法),该合成路线具有原料易得、路线较短、安全性高、操作简便等特点。     

Dragocins A～C的关键中间体呋喃核糖基供体的合成

目的 对海洋蓝藻来源天然产物Dragocins A-C的关键呋喃核糖砌块进行合成研究,旨在为Dragocins A-C的合成提供一条行之有效的方案,以期解决Dragocins A-C天然来源有限的问题,进而为其生物活性及作用机制研究奠定基础。方法 采用去对称化策略选择性保护支链型核糖6的β面伯羟基、通过氧化7的伯羟基、水解10的丙酮叉及异头位甲氧基和活化11的异头位乙酰基生成硫苷等关键反应操作,完成目标化合物的合成。结果 从已知的支链型核糖甲苷6出发,经8步反应,以39%的总收率获得了关键中间化合物4,为之后的Dragocins A-C的全合成奠定了物质基础。     

Synthesis,Cytotoxicity and Antileishmanial Activity of Some N-(2-(indol-3-yl)ethyl)-7-chloroquinolin-4-amines

We report herein the condensation of 4,7-dichloroquinoline (1) with tryptamine (2) and D-tryptophan methyl ester (3) . Hydrolysis of the methyl ester adduct (5) yielded the free acid (6) . The compounds were evaluated in vitro for activity against four different species of Leishmania promastigote forms and for cytotoxic activity against Kb and Vero cells. Compound (5) showed good activity against the Leishmania species tested, while all three compounds displayed moderate activity in both Kb and Vero cells.     

Efficacy of gut lavage,hemodialysis, and hemoperfusion in the therapy of paraquat or diquat intoxication

Clinical and in vitro investigations were carried out to test the efficacy of gut lavage, hemodialysis, and hemoperfusion in the treatment of poisoning with paraquat or diquat. In a patient suffering from diquat intoxication 130 times more diquat was removed by gut lavage 30 h after ingestion than was removed by complete aspiration of the gastric contents.Determination of in vitro clearances for paraquat and diquat by hemodialysis showed that, at serum concentrations of 1–2 ppm, such as are frequently encountered in poisoning in man, toxicologically relevant quantities of herbicide cannot be removed from the body. At a concentration of 20 ppm, on the other hand, hemodialysis proved to be effective, the clearance being 70 ml/min at a blood flow rate of 100 ml/min. The efficacy of hemoperfusion with coated activated charcoal was on the whole better. Especially at concentrations around 1–2 ppm, the clearance values for hemoperfusion were some 5–7 times higher than those for hemodialysis.In a patient suffering from paraquat poisoning, both hemodialysis as well as hemoperfusion were carried out. The in vitro results could be confirmed: At serum concentrations of paraquat less than 1 ppm no clearance could be obtained by hemodialysis while by hemoperfusion with activated charcoal quite high clearance values were measured and the serum level dropped down to zero.

---

Zusammenfassung Klinische Untersuchungen und Laboratoriumsversuche wurden durchgeführt, um die Wirksamkeit von Darmspülung, Hämodialyse und Hämoperfusion bei Paraquat- und Deiquat-Vergiftungen zu prüfen.Bei einem Patienten wurde 30 Std nach Deiquat-Aufnahme durch Darmspülung 130mal mehr Deiquat entfernt als durch vollständige Aspiration des Mageninhaltes. In vitro-Versuche ergaben, daß bei Blutserumkonzentrationen von 1–2 ppm, die bei Vergiftungen oft gemessen werden, durch Hämodialyse keine toxikologisch relevanten Paraquat- oder Deiquat-Mengen entfernt werden können. Dagegen erwies sich die Hämodialyse bei 20 ppm und einer Blutumlaufgeschwindigkeit von 100 ml/min mit einer Clearance von 70 ml/min als wirksam. Die Hämoperfusion mit beschicheter Aktivkohle war in diesen Versuchen aber eindeutig überlegen, denn insbesondere bei Konzentrationen um 1–2 ppm waren die Clearance-Werte 5–7mal höher als bei der Hämodialyse.Die in vitro-Ergebnisse wurden bei einem Patienten mit einer Paraquat-Vergiftung bestätigt: Bei Konzentrationen unter 1 ppm war die Hämodialyse wirkungslos, während durch Hämoperfusion relativ hohe Clearance-Werte erreicht wurden, so daß der Serumspiegel rasch unter die Nachweisgrenze abfiel.

     

In vitro studies on sterically stabilized liposomes (SL) as enzyme carriers in organophosphorus (OP) antagonism

This study describes a new approach for organophosphorous (OP) antidotal treatment by encapsulating an OP hydrolyzing enzyme, OPA anhydrolase (OPAA), within sterically stabilized liposomes. The recombinant OPAA enzyme was derived from Alteromonas strain JD6. It has broad substrate specificity to a wide range of OP compounds: DFP and the nerve agents, soman and sarin. Liposomes encapsulating OPAA (SL)* were made by mechanical dispersion method. Hydrolysis of DFP by (SL)* was measured by following an increase of fluoride ion concentration using a fluoride ion selective electrode. OPAA entrapped in the carrier liposomes rapidly hydrolyze DFP, with the rate of DFP hydrolysis directly proportional to the amount of (SL)* added to the solution. Liposomal carriers containing no enzyme did not hydrolyze DFP. The reaction was linear and the rate of hydrolysis was first order in the substrate. This enzyme carrier system serves as a biodegradable protective environment for the recombinant OP-metabolizing enzyme, OPAA, resulting in prolongation of enzymatic concentration in the body. These studies suggest that the protection of OP intoxication can be strikingly enhanced by adding OPAA encapsulated within (SL)* to pralidoxime and atropine.     

Lung disease and PKCs

The lung offers a rich opportunity for development of therapeutic strategies focused on isozymes of protein kinase C (PKCs). PKCs are important in many cellular responses in the lung, and existing therapies for pulmonary disorders are inadequate. The lung poses unique challenges as it interfaces with air and blood, contains a pulmonary and systemic circulation, and consists of many cell types. Key structures are bronchial and pulmonary vessels, branching airways, and distal air sacs defined by alveolar walls containing capillaries and interstitial space. The cellular composition of each vessel, airway, and alveolar wall is heterogeneous. Injurious environmental stimuli signal through PKCs and cause a variety of disorders. Edema formation and pulmonary hypertension (PHTN) result from derangements in endothelial, smooth muscle (SM), and/or adventitial fibroblast cell phenotype. Asthma, chronic obstructive pulmonary disease (COPD), and lung cancer are characterized by distinctive pathological changes in airway epithelial, SM, and mucous-generating cells. Acute and chronic pneumonitis and fibrosis occur in the alveolar space and interstitium with type 2 pneumocytes and interstitial fibroblasts/myofibroblasts playing a prominent role. At each site, inflammatory, immune, and vascular progenitor cells contribute to the injury and repair process. Many strategies have been used to investigate PKCs in lung injury. Isolated organ preparations and whole animal studies are powerful approaches especially when genetically engineered mice are used. More analysis of PKC isozymes in normal and diseased human lung tissue and cells is needed to complement this work. Since opposing or counter-regulatory effects of selected PKCs in the same cell or tissue have been found, it may be desirable to target more than one PKC isozyme and potentially in different directions. Because multiple signaling pathways contribute to the key cellular responses important in lung biology, therapeutic strategies targeting PKCs may be more effective if combined with inhibitors of other pathways for additive or synergistic effect. Mechanisms that regulate PKC activity, including phosphorylation and interaction with isozyme-specific binding proteins, are also potential therapeutic targets. Key isotypes of PKC involved in lung pathophysiology are summarized and current and evolving therapeutic approaches to target them are identified.     

Steroidal sapogenin contents in some domestic plants

In order to find out the values of the steroid resources for the future use. the compositions and contents of steroidal sapogenins from 13 domestic plants have been investigated. As a result,Dioscorea nipponica, D. quinqueloba andSmilax china were found to have large amount of diosgenin. And pennogenin inTrillium kamtschaticum andParis verticillata, yuccagenin inAllium fistulosum, hecogenin inAgave americana and neochlorogenin inSolanum nigum were appeared to be major steroidal sapogenins.