Study on synthesis of biologically active compounds based on modification of biological phosphates

1)与人嘌呤核苷磷酸化酶（PNP）高度同源的三聚体小牛脾脏磷酸化酶（PNP）与基态类似物抑制剂9-（5,5-二呋喃-5-磷戊基）鸟嘌呤（DFPP-G）在立方空间群P2_13中结晶。晶体结构证实了DFPP-G作为多底物类似物抑制剂的作用，因为它结合核苷和磷酸盐结合位点。分析还表明，连接嘌呤和二氟甲基膦酸片段的连接器被PNP的疏水氨基酸残基（Ala 116和Phe 159）所包围。在此基础上，对DFPP-G及其次黄嘌呤类似物（DFPP-H）进行了修饰，在连接物的所有可能位置上引入一个甲基，以评估甲基对PNP结合亲和力的疏水影响。连接体上的甲基以位置依赖的方式影响抑制作用。2)制备了一系列短链的N-pa -1-磷酸亚甲基鞘磷脂类似物，分别用水解稳定的二氟亚甲基膦酸酯和苯基取代磷酸基和烯基长侧链，研究了其抑制鞘磷脂酶（SMase）的构效关系。该研究表明，抑制作用高度依赖于酰基氨基部分的不对称中心的立体化学，并导致鉴定出一种非竞争性抑制剂，其抑制活性与schyphostatin相同，schyphostatin是已知的几种N-SMase小分子抑制剂中最有效的。我们的SMase抑制剂抑制了血清/葡萄糖缺失PC-12细胞中N-SMase活性的增强，以及细胞核中DNA的断裂。与对照组小鼠相比，大脑中动脉闭塞小鼠服用该抑制剂可显著减少脑梗死灶的大小。3)除上述结果外，我们还研究了用二氟乙烯膦酸取代磷酸基团来修饰二磷酸腺苷和磷酸肌醇。在目标分子的合成过程中，我们开发了在3α-位置具有二氧基磷酸基二氟甲基官能团的2,3-二脱氧呋喃基的高选择性β-糖基化反应，并以立体和区域选择性的方式在环阵列的烯丙基位置上引入了二氟甲基膦酸盐单元。少

1)The binary complex of the trimeric calf spleen phosphorylase, which is highly homologous to human purine nucleoside phosphorylase(PNP), with the potent ground state analogue inhibitor 9-(5,5-difuoro-5-phosphonopentyl)guanine (DFPP-G) was crystallized in the cubic space group P2_13. The crystal structure confirms that DFPP-G acts as a multi-substrate analogue inhibitor as it binds to both nucleoside-and phosphate-binding sites. The analysis also indicates that the linker connecting a purine and difluoromethylenephosphonic acid moiety is surrounded by hydrophobic amino acid residues (Ala 116 and Phe 159) of PNP. On the basis of these findings, DFPP-G and its hypoxanthine analogue(DFPP-H) were modified by introducing a methyl group to all possible positions of the linker to evaluate the hydrophobic effects of the methyl group on the binding affinity to PNP. The methyl group on the linker affected the inhibition in a positional-dependent manner.2)A series of short-chain analogues of N-pa … More lmitoylsphingosine-1-phosphate, modified by replacement of the phosphate and the long alkenyl side chain with hydrolytically stable difluoromethylene phosphonate and phenyl, respectively, were prepared to study the structure-activity relationship for inhibition of sphingomyelinase(SMase). The study revealed that inhibition is highly dependent upon the stereochemistry of the asymmetric centers of the acylamino moiety, and resulted in identification of a non-competitive inhibitor with the same level of inhibitory activity of schyphostatin, the most potent of the few known small molecular inhibitors of N-SMase. Our SMase inhibitor inhibited the enhanced N-SMase activity in the serium/gulucose-deprived PC-12 cells, and DNA fragmentation in the nuclei. Administration of the inhibitor to mice whose middle cerebral arteries were occluded reduced significantly the size of the cerebral infarcts, compared the control mice.3)In addition of the above results, we examined modification of adenosine bisphosphates and inositol phosphates by replacement of the phosphate group with a difluoromethylene phosphoninc acid. During the synthesis of the target molecule, we have developed a highly-selective β-glycosylation reaction of 2,3-dideoxyfuranosies having diethoxyphosphoryldifluoromethyl functionality at 3α-position and a facile method for introducing a difluoromethylenephosphonate unit to the allylic position within a cyclic array in a stereo-and regioselective manner. Less