【作者】 刘福龙；

【导师】 江涛；

【作者基本信息】 中国海洋大学 ， 药物化学， 2010， 博士

【摘要】 近年来,有机硼酸化合物逐渐应用于生命科学领域。硼酸中的sp2杂化的硼原子为缺电子中心,它能够与酶中苏氨酸、丝氨酸残基的羟基或者组氨酸残基咪唑环的氮原子共价结合,两个羟基可与氨基、羰基等形成氢键。即硼酸与富电子体系有较强的相互作用。有机硼酸化合物可以与cis-1,2-和cis-1,3-二醇反应生成五元或六元环状酯,从而被广泛应用于分子水平上对不同单糖化合物的识别和检测以及细胞水平上与肿瘤细胞表面过量表达糖链的特异性结合。恶性肿瘤细胞区别于正常细胞的关键是细胞膜N-糖链的改变,而N-糖链的改变又以末端岩藻糖和唾液酸的增多最为明显和最具有特异性,许多特异糖链已经成为肿瘤标志物。利用糖链的改变来提高抗肿瘤药物的靶向性尚未见文献报道。胺吖啶是用于临床的治疗急性粒细胞白血病药物,其吖啶环插入到DNA碱基对之间,侧链则起到辅助作用。白细胞表面具有丰富的sLex抗原,急性粒细胞白血病细胞表面的sLex抗原显著增多,而sLex抗原是可以被硼酸识别的。我们以此为参考设计了带有硼酸基团的吖啶衍生物,希望利用硼酸识别特定糖的能力,将化合物分子富集到肿瘤组织；然后在吖啶环与DNA作用时,硼酸与表面带负电荷的磷酸骨架相互作用,从而增强吖啶衍生物与DNA的作用,提高疗效。本论文的具体内容包括：1.以肿瘤细胞表面糖链末端岩藻糖和唾液酸增多为出发点,利用有机硼酸基团能识别特异性糖分子以及缺电子的性质,参照现有的治疗急性粒细胞白血病药物胺吖啶,设计合成了三大类硼酸吖啶衍生物,共计合成目标化合物50个,均未见文献报道。本文还对含有硼酸基团的化学反应进行了方法学研究。1)在PaCl2(dppf)的催化下,二频哪醇基二硼烷硼与卤代苯反应制备取代苯硼酸频哪醇酯时,发现苯环上取代基对反应有着重要影响。苯环上拉电子基团有利于反应的进行,供电子基团则降低反应收率。C-I键的活性远大于C-Br键。用高碘酸脱除苯硼酸酯的频哪醇时,苯环上供电子基团缩短反应时间,拉电子基团延长反应时间,且与拉电子能力有相关性。通过对反应中副产物的分析,阐明了反应时间对该反应的重要性。用DMT-MM将对羧基苯硼酸和3-羧基-5-硝基苯硼酸高效地连在PAM树脂上,制备了两种苯硼酸树脂,通过酯交换反应脱除硼酸酯中的频哪醇。该两种树脂制备简单、原料易得,具有实用性。2)羧基苯硼酸与胺反应进行酰胺化反应时,溶剂用醇代替DMF,以DMT-MM为缩合剂,高效地得到了二羟基硼基苯甲酰胺衍生物。3)含硼酸基化合物的纯化是一个难点。苯基硼酸是一个比较特殊的基团,它与其缩水产物-硼酐以平衡状态存在,在强碱性和酸性或氧化剂存在的条件下均不稳定,它还可在硅胶的作用下转变为酚。二乙醇胺树脂的出现解决了这个难题。我们参照Merrifield Resin与三乙胺的反应,改进了二乙醇胺树脂的制备方法。利用二乙醇胺树脂成功地分离纯化了目标产物。还发现二乙醇胺树脂可用来脱除硼酸酯中的保护基。将对溴甲基苯硼酸固定在二乙醇胺树脂上,与苯胺反应,将苯胺单苄基化,然后与碘甲烷反应,再氢解脱除苄基,制得了N-甲基苯胺。这是一个方法制备仲胺的新方法。2.对部分化合物的DNA插入活性进行了研究,发现硼酸基团可以增强化合物的插入能力。抑制肿瘤细胞P388实验表明,目标化合物具有明显的活性。其中化合物5a和5b的活性较好。选取分别能稳定表达生存素报告基因和顺铂耐药性报告基因的两种肺癌细胞株H1650,进行了抗肿瘤活性试验,结果显示在1μM浓度下部分化合物具有明显的活性。其中化合物B16对肺癌细胞株表达生存素报告基因的抑制活性最强,化合物B54对肺癌细胞株表达顺铂耐药性报告基因的抑制活性最强。更多还原

【Abstract】 Boronic acids were used in the field of life sciences recently. The boron atom of boronic acids is sp2 hybridized and electron-deficient, hence it can bind with the hydroxide of Thr and Ser residues or the N atom of imidazole ring of His, meanwhile the two hydroxide redicals can interact with the amino or carbonyl group by forming hydrogen bonds. Namely, boronic acids can actively interact with electron-rich systems. Organic boronic acids, which can form five/six membered cyclic lactones by coupling with cis-1,2-or cis-1,3-diols, were widely used as molecular receptors of monosaccharides and also applied to selective binding of tumor cell-surface carbohydrates. The key point distinguished malignant tumor cells from normal ones is the change of cell-surface N-carbonhydrates, which is characterized by the increase of fucose and sialic acid at the end of carbohydrate chains; thus, many distinctive carbonhydrate chains become cancer molecular markers. However, reports employing modification of carbohydrate chains to increase the selectivity of corresponding cancer medicine are yet unknown.sLex could be recognized by boronic acids while sLex antigens are highly expressed on white blood cells and the number of sLex antigen also notably increase on acute myeloid leukemia cells. Acute myeloid leukemia is clinically treated by amsacrine, whose acridine-ring can plug into DNA base pairs assisted by its side chains. Accordingly we designed acridine derivatives containing boronic acid. Boronic acid can recognize particular sugar and then enrichment drug in the tumor tissue. When acridine plug into DNA base pairs, boronic acid can interplay with DNA skelecton participate of negative charge, hence it can raise curative effect.The details of this paper are as follows:1. There series of acridine derivatives containing boronic acid were designed and synthesized refer to amsacrine. Methodology was discussed in the chemical reactions of boronic acid.1) Substituent groups on benzene ring had crucial influences on the experiment results in coupling reactions of bis(pinacolato)diboron with aromatic halides under the catalyzation of PaCl2(dppf). Electron withdrawing groups can enhance the reactions, but electron donating groups can impede the reactions. The activity of C-I bond is greater than C-Br bond. We obtained free boronic acids by using NaI04 to cleavage pinanediol boronate esters. Electron donating groups can fasten the reactions, but electron withdrawing groups can decrease the reaction rates. The importance of time to the reactions was discussed. Two resins containg phenylboronic acid were prepared by coupling reactions of aminomethyl polystyrene resin with p-carboxyl phenylboronic acid or 3-carboxyl-5-nitro-phenylboronic acid. Pinanediol boronate esters were cleavaged by transesterification.2) When carboxylphenylboronic acid reacted with amine, Boronobenzamide derivatives were conveniently preparated in high yield using DMT-MM instead of normal coupling reagents in alcohol.3) It is very difficault to purify the compounds containing boronic acid. Boronic acid is a specially group. Aryl boronic acid can form boroxine, which is the cyclotrimetric anhydride of boronic acid with different equilibrium constants. Boronic acid is not stable under strong alkaline or acidic conditions.Phenylboronic acid can be converted into phenol by silicon gel. N,N-Diethanolaminomethyl polystyrene (DEAM Resin) can purify boronic acid facialy. We simplify the preparation of DEAM Resin according to the reaction between Merrifield Resin and triethylamine. We obtained the target products using Merrifield Resin successfully. To deprotect pinacolyl boronate esters using DEAM Resin was found. The bromomethyl phenylboronic acid can be fixed on DEAM Resin, then reacted with aniline. The obtained N-benzylaniline reacted with iodomethane. Afer hydrogenolysis N-methylaniline was obtained. This is one method to prpare secondary amine.2. Antitumor activity was studied in two cell models lung cancer cell line H1650 which stably express survivin reporter or cisplatin-resistant reporter genes. The tests show that several compounds have evident activity at 1μM. Compound B16 shows the highest activity toward lung cancer cell expressing survivin reporter genes. Compound B54 shows the highest activity toward lung cancer cell expressing cisplatin-resistant reporter genes更多还原