Great Efficiency of Nucleosides as Organizing Tools

Bis-porphyrins with flexible linkers such as uridine or 2’-deoxyuridin pre-organize in a face-to-face conformation and form stable sandwich complexes with bidentate base such as DABCO. The gain in stability can be even greater when a dinucleotide linker is used. Such pre-organization increases the association constant by one to two orders of magnitude when compared to the one of DABCO with a reference porphyrin. Comparison with rigid tweezers shows a better efficiency of nucleosidic dimers. The choice of rigid spacers is not the only way to pre-organize bis-porphyrins, and well-chosen nucleosidic linkers offer an interesting option for the synthesis of such devices

Efficiency of Dinucleosides as the Backbone to Pre-Organize Multi-Porphyrins and Enhance Their Stability as Sandwich Type Complexes with DABCO

Flexible linkers such as uridine or 2′-deoxyuridine pre-organize bis-porphyrins in a face-to-face conformation, thus forming stable sandwich complexes with a bidentate base such as 1, 4-diazabicyclo[2.2.2]octane (DABCO). Increased stability can be even greater when a dinucleotide linker is used. Such pre-organization increases the association constant by one to two orders of magnitude when compared to the association constant of DABCO with a reference porphyrin. Comparison with rigid tweezers shows a better efficiency of nucleosidic dimers. Thus, the choice of rigid spacers is not the only way to pre-organize bis-porphyrins, and well-chosen nucleosidic linkers offer an interesting option for the synthesis of such devices

Analisis Penerapan Sistem Akuntansi Penjualan Kredit Dan Penerimaan Kas Dalam Mendukung Pengendalian Intern Perusahaan (Studi Kasus PT. Smart Tbk Refinery Surabaya)

System of selling credit accounting and system of cash receiving from account receivable is the source of life to achieving company goals. This research on the system of credit sales and cash receipts to support the company internal control. This research was conducted at PT. SMART Tbk Refinery Surabaya. PT. SMART Tbk Refinery Surabaya only selling cooking oil in the form of branded product and trading product on credit. PT. SMART Tbk Refinery Surabaya still has any weakness on system of selling credit accounting and system of cash receiving from account receivable, some of the sales transaction activity that occurred less supportive of the company\u27s internal control. This study aims to provide information to companies about the advantages and weakness of credit sales accounting system and cash receipts that have been applied by the company

The Human Urine Metabolome

Urine has long been a “favored” biofluid among metabolomics researchers. It is sterile, easy-to-obtain in large volumes, largely free from interfering proteins or lipids and chemically complex. However, this chemical complexity has also made urine a particularly difficult substrate to fully understand. As a biological waste material, urine typically contains metabolic breakdown products from a wide range of foods, drinks, drugs, environmental contaminants, endogenous waste metabolites and bacterial by-products. Many of these compounds are poorly characterized and poorly understood. In an effort to improve our understanding of this biofluid we have undertaken a comprehensive, quantitative, metabolome-wide characterization of human urine. This involved both computer-aided literature mining and comprehensive, quantitative experimental assessment/validation. The experimental portion employed NMR spectroscopy, gas chromatography mass spectrometry (GC-MS), direct flow injection mass spectrometry (DFI/LC-MS/MS), inductively coupled plasma mass spectrometry (ICP-MS) and high performance liquid chromatography (HPLC) experiments performed on multiple human urine samples. This multi-platform metabolomic analysis allowed us to identify 445 and quantify 378 unique urine metabolites or metabolite species. The different analytical platforms were able to identify (quantify) a total of: 209 (209) by NMR, 179 (85) by GC-MS, 127 (127) by DFI/LC-MS/MS, 40 (40) by ICP-MS and 10 (10) by HPLC. Our use of multiple metabolomics platforms and technologies allowed us to identify several previously unknown urine metabolites and to substantially enhance the level of metabolome coverage. It also allowed us to critically assess the relative strengths and weaknesses of different platforms or technologies. The literature review led to the identification and annotation of another 2206 urinary compounds and was used to help guide the subsequent experimental studies. An online database containing the complete set of 2651 confirmed human urine metabolite species, their structures (3079 in total), concentrations, related literature references and links to their known disease associations are freely available at http://www.urinemetabolome.ca

The Human Serum Metabolome

Continuing improvements in analytical technology along with an increased interest in performing comprehensive, quantitative metabolic profiling, is leading to increased interest pressures within the metabolomics community to develop centralized metabolite reference resources for certain clinically important biofluids, such as cerebrospinal fluid, urine and blood. As part of an ongoing effort to systematically characterize the human metabolome through the Human Metabolome Project, we have undertaken the task of characterizing the human serum metabolome. In doing so, we have combined targeted and non-targeted NMR, GC-MS and LC-MS methods with computer-aided literature mining to identify and quantify a comprehensive, if not absolutely complete, set of metabolites commonly detected and quantified (with today's technology) in the human serum metabolome. Our use of multiple metabolomics platforms and technologies allowed us to substantially enhance the level of metabolome coverage while critically assessing the relative strengths and weaknesses of these platforms or technologies. Tables containing the complete set of 4229 confirmed and highly probable human serum compounds, their concentrations, related literature references and links to their known disease associations are freely available at http://www.serummetabolome.ca

Pinces Bis-Porphyriniques à Espaceur Nucléosidique pour la Reconnaissance Moléculaire

Elaboration of bis-porphyrinic tweezers bearing nucleosidic linkers for molecular recognitionLes édifices multi-porphyriniques retiennent de plus en plus l'attention des chercheurs et leur compréhension n'a cessé de croître ces dernières années en raison de leur vaste domaine d'application, que ce soit pour l'élaboration de complexes collecteurs d'énergie lumineuse, pour la construction de fils moléculaires photoniques ou électroniques ainsi que pour la formation de complexes supramoléculaires originaux.Dans l'optique de synthétiser des pinces bis-porphyriniques capables de former des complexes supramoléculaires stables avec des bases bidentates de tailles variées, nous avons synthétisé plusieurs architectures moléculaires de type bis- et tris-porphyrines dans lesquelles les chromophores sont liés entre eux par des espaceurs nucléosidiques flexibles dérivés de l'uridine. Nous avons donc fait varier les positions d'ancrage des deux porphyrines sur l'uridine en accrochant soit les deux porphyrines en des positions différentes du sucre, soit en greffant un chromophore sur le ribose et l'autre sur l'uracile. La caractérisation par spectroscopie UV-visible de l'ensemble des architectures moléculaires nous a permis d'observer l'existence d'interactions électroniques entre les différents chromophores au sein de ces composés. Pour deux des trois dimères ainsi que pour les trimères, l'espaceur nucléosidique bloque la conformation de ces molécules sous la forme de pinces comportant une cavité pré-organisée. Ainsi, la complexation de bases bidentates de tailles variées a été suivie par spectroscopie UV-visible, et des constantes d'association supérieures de 1,5 à 2 ordres de grandeur par rapport à la complexation des mêmes bases par une mono-porphyrine ont été trouvées. La pré-organisation des cavités bis-porphyriniques augmente donc la stabilité des complexes supramoléculaires de type hôte/récepteurs formés. En outre, l'ajustement de la cavité à la taille de l'hôte complexé a pu être démontré. Un piégeage efficace de la luminescence de la porphyrine de Zn(II) a également été observé au sein des deux dimères porteurs à la fois d'une porphyrine de Zn(II) et d'une porphyrine base-libre, et attribué à un transfert d'énergie ayant lieu vers la porphyrine base-libre.Enfin, ces espaceurs nucléosidiques offrent la possibilité d'établir des liaisons hydrogène avec un synthon complémentaire de l'uracile fonctionnalisé par une porphyrine ou deux, et ainsi d'augmenter le nombre de chromophores collecteurs de photons

Pinces bis-porphyriniques à espaceur nucléosidique pour la reconnaissance moléculaire

TOULOUSE3-BU Sciences (315552104) / SudocSudocFranceF

Bis-porphyrin tweezers: rigid or flexible linkers for better adjustment of the cavity to bidentate bases of various size

International audienc

Pre-organized dinucleosides with pendant porphyrins for the formation of sandwich type complexes with DABCO with high association constants

International audienc