Synthesis of 6-formyluridine 5'-monophosphate: 6-formyl-UMP

A synthesis of 6-formyluridine 5'-monophosphate (6-formylUMP) in 6 steps starting from uridine is described. This approach should be applicable to the preparation of other O5'-phosphorylated 6-formylUrds such as 6-formylUDP and 6-formylUTP.     

Symposium 6: 1

Endogenous neural stem cells have been identified in diverse areas of the adult mammalian central nervous system including the subventricular zone, cerebral cortex and hippocampus. These cells have been demonstrated to participate actively in postnatal neurogenesis in restricted territories within the adult brain. They have further been characterized as having a committed neural fate in vivo, capable of generating neurons, astroglia and oligodendroglia. Endogenous CNS stem cells, when cultured in vitro, have been shown to have a much broader potential, capable of differentiating into diverse tissues such as blood, muscle, bone and kidney. Conversely, stem cells taken from other organs and grown in vitro have been demonstrated to differentiate into neurons, and hematopoietic stem cells injected intravenously have been shown to migrate into mature CNS, and differentiate into neurons. We have previously reported the mobilization of endogenous neural stem cells in vivo. Further work to determine if the stem cells so mobilized may include hematopoietic stem cells is reported here. Using immunohistochemical localization of antigens known to be present on primitive hematopoietic stem cells, or antigens present on neural stem cells, we report the presence of cells closely resembling hematopoietic stem cells in the mature CNS whose response to a mobilization paradigm is similar to that of endogenous neural stem cells. We further propose a lineage relationship between primitive hematopoietic stem cells and neural stem cells.     

SYNTHESIS OF 6-FORMYLURIDINE 5′-MONOPHOSPHATE: 6-FORMYL-UMP

A synthesis of 6-formyluridine 5′-monophosphate (6-formylUMP) in 6 steps starting from uridine is described. This approach should be applicable to the preparation of other O5′-phosphorylated 6-formylUrds such as 6-formylUDP and 6-formylUTP.     

6-Deoxy-6-fluoro-L-ascorbic acid: crystal structure and oxidative degradation

Ascorbic acid and its oxidation products have been implicated in non-enzymatic modification of proteins in aging and diseases of oxidative stress. We have studied the feasibility of using 6-deoxy-6-fluoroascorbic acid (6) for identification of ascorbic acid degradation products by 19F NMR spectroscopy. Crystals of compound 6 from nitromethane belonged to the space group P2(1) with a = 5.547(2), b = 6.769(3), c = 9.302(2) A, beta = 91.80(3) degrees and Z = 2. Atomic coordinates, bond lengths and angles, hydrogen coordinates, anisotropic and isotropic displacement parameters were similar if not identical with those of native ascorbic acid. Similarly, UV properties and oxidation kinetics by CuCl2 at different pH values were essentially identical with ascorbic acid. Using 750 MHz 19F NMR spectroscopy, five to six new fluorinated products were detected after overnight oxidation of 6 with Cu2+, suggesting that 6 may be a powerful and sensitive tool for assessment of its catabolism in vivo.     

LE-ACS6启动子在LE-ACS6::GUS转基因拟南芥中的特异性

通过对不同发育时期LE-ACS6::GUS转基因拟南芥中GUS表达特异性的研究,证明LE-ACS6基因的启动子在拟南芥中也表现启动参与第一系统乙烯合成的关键酶基因的活性.在转基因拟南芥中,LE-ACS6启动子还表现响应外源生长素处理、伤害处理等多种刺激因子的特点.     

Conformational Analysis of 6-Substituted Uridine Analogues: Crystal Structures of Uridine-6-Thiocarboxamide and 6-Cyanouridine

Abstract

Crystal structure analyses of uridine-6-thiocarboxamide (I) and 6-cyanouridine (II) show that both structures adopt a syn conformation about the glycosyl bond. The conformation of I is similar to that of orotidine (III). The furanose ring conformation of I is C4′-exo, unusual for syn conformers, and is C3′-endo in II. These results have a bearing on the inhibition of orotidylate decarboxylase by the 5′-phosphate of I.     

Bevölkerungswachstum: Bildung ist die Lösung

Population growth – education is the answer Over the last decades world population has been constantly growing by some 80 million per year. Whereas the growth rate as well as the fertility rate have been cut by half since the 1970th, population growth will continue well over mid‐century. As the developed countries have completed the demographic transition from high mortality and fertility rates to low ones, population growth is fading out there or has already been reversed into decline. In the least developed countries mortality has fallen as well, whereas fertility decline has stalled. Therefor population growth is very high making the solution of the widespread problems in this part of the world more and more difficult. One obvious way out of this trap would be a better education that could open new development perspectives. A positive side effect is that educated women have much less offspring than their counterparts who never went to school.