【作者】 程杰；

【导师】 方志杰；

【作者基本信息】 南京理工大学 ， 应用化学， 2010， 博士

【摘要】 以来源丰富的单糖为原料,合成和修饰具有生物活性的糖类化合物是糖化学研究的重要领域之一。本论文着眼于现代合成化学对原子经济和环境友好的发展要求,针对现有某些糖类药物或其先导化合物难以满足生物化学、药理学和临床研究的需要,主要对稀有庚酮糖和糖苷化合物进行了化学合成和方法学研究。天然稀有庚酮糖的合成上研究了三种方法：(1)对2,3；5,6-二-O-异丙叉-D-甘露呋喃糖的C-2上引入羟甲基侧链,再脱异丙叉保护后得到2-C-羟甲基-D-甘露糖,钼酸催化下,C-2上的羟甲基迁移到C-1上、醛糖转变为酮糖,实现了钼酸催化碳链重排合成D-葡萄庚酮糖,总产率37%；(2)以2,3,4,5,6-五-O-苄基-D-甘露糖为原料,通过Wittig反应增长碳链得苄基保护的甘露庚糖烯,进而在KMnO4/HOAc体系中对烯键的选择性氧化得到羟基半缩酮结构中间体,最后脱保护、酸性水解得到D-甘露庚酮糖,四步产率39%,纯度>99%；(3)使用CH2I2/n-BuLi体系对糖酸内酯的酯羰基进行碘甲基化加成,并通过碱性水解等步骤,制得葡萄庚酮糖、甘露庚酮糖和半乳庚酮糖的苄基化衍生物,加成、水解两步产率35%。以上三种方法丰富和发展了稀有庚酮糖的合成方法,具有条件温和,试剂易得的优点,有着重要的理论意义和一定的应用前景。在本课题组对四-O-苄基-Valiolone成功合成的基础上,初步研究了Valielone、Validone的苄基化衍生物的化学合成(产率分别为95%和20%),还制备了Valiolone(四步产率36%)、Valielone(产率90%)的甘露糖构型的类似物,为此类糖苷酶抑制剂类药物的先导化合物提供实验基础。具有生物活性的糖苷合成上包括两方面研究：(1)以四-O-乙酰基-α-溴代葡萄糖、半乳糖为糖基给体,对中药丹皮酚及其在生物体内的代谢中间体2,4-二-羟基苯乙酮进行了糖苷化修饰,立体专一性的合成了p-构型的糖苷化产物,糖苷化产率30-73%；(2)以游离单糖为原料,通过炔丙苷化(产率50-90%)、碘代(产率75-92%)等两步反应,制备了7种具有抗菌活性的新型1’-碘代炔丙基糖苷。选取4种合成的碘代炔丙基糖苷化合物对引起农作物疾病的几种常见真菌进行了抑菌活性测试,发现均有一定的抗菌效果,为此类低毒、环保型农药的研究提供了思路。更多还原

【Abstract】 Synthesis and modification of carbohydrates with biological activity from monosaccharides which are abundant in source is one of important fields for the carbohydrate chemistry research. This paper, focusing on atom economic and environment-friendly development requirements of modern synthetic chemistry, was primarily concerned with the current synthesis and the methodological research of rare heptulose and glycosides in view of existing situation that some carbohydreate drugs or their precursors could not serve the needs of biochemical, pharmacological and clinical researches.First of all, three methods were studied in the synthesis of nature rare heptulose.(1) Synthesis of D-glucoheptulose was realized by molybdic acid as catalyst, with the yield of 37% in 4 steps that successively were hydroxymethylation on C-2 of 2,3;5,6-di-O-isopropylidene-D-mannfuranose, acquiring 2-C-hydroxymethyl-D-mannose after deprotection of isopropyaltion, and then preparation of the target product through hydroxymethyl transferred from C-2 to C-1 and simultaneity aldose changed to ketose by molybdic acid-catalyzed carbon-skeleton rearrangement.(2) D-mannoheptulose was synthesized with the yield 39% in 4 steps (purity>99%) that were obtaining mannoheptu-glycal through elongation of carbon chain of 2,3,4,5,6-pent-O-benzyl-D-mannose via Wittig reaction, getting the intermediate of a-hydroxy semi-ketal structure by selective oxidation to olefinic bond using KMnO4/HOAc system as the key step, and preparing the target molecular via deprotection of benzyls, hydrolysis under acid condition.(3) Preparation of benzylation derivatives of D-glucoheptulose, D-mannoheptulose, D-galactoheptulose was carried out with the yield 35% in 2 steps that were iodomethylated addition to ester carbonyl of sugar acid lactone using CH2I2/n-BuLi system, and hydrolysis under base condition.Three methods introduced above, having the advantages of mild condition and the reagents with easy availability, enrich and develop methodological research of synthesis of rare heptulose, which has major theoretic value and application prospect.Secondly, preliminary synthesis and methodological research of benzylation derivatives of Valielone (the yield 95%), Validone (the yield 20%) and analogues of Valiolone (the yiled of 4 steps was 36%), Valielone (the yield 90%) with D-mannose configuration were processed on the basis of successful synthesis of tert-O-benzyl-Valiolone done by our research team, which provided experimental basis for the precursors of these glycosidase inhibitor drugs.Finally, there were two aspects of the synthesis of glycosides with biological activity.(1) Stereospecific glycosylated modifications of paeonol-a kind of traditional Chinese medicine, and 2,4-dihydroxyphenyl ethanone that was metabolized intermediate of paeonol in organism, were actualized from tert-O-acetyl-a-glucopyranosyl/galactopyranosyl bromide as glycosyl donors with the yield of the glycosylated step 30-73%, and all the products were P-glycosides completely.(2) A novel series of 1’-iodopropargyl glycosides were synthesized through only two steps including glycosylated reaction with propargyl alcohol (the yield 50-90%), iodo-substitution (the yield 75-92%) from seven common monosaccharides without protection. Four kinds of synthetic 1’-iodopropargyl glycosides, which were chosen to carry out antibacterial test, had inhibitory activity to some normal kinds of fungi arousing diseases of crops, which offered a new opinion for the research of environmental protective pesticide with low toxicity.更多还原