Genomic investigations of unexplained acute hepatitis in children

Since its first identification in Scotland, over 1,000 cases of unexplained paediatric hepatitis in children have been reported worldwide, including 278 cases in the UK1. Here we report an investigation of 38 cases, 66 age-matched immunocompetent controls and 21 immunocompromised comparator participants, using a combination of genomic, transcriptomic, proteomic and immunohistochemical methods. We detected high levels of adeno-associated virus 2 (AAV2) DNA in the liver, blood, plasma or stool from 27 of 28 cases. We found low levels of adenovirus (HAdV) and human herpesvirus 6B (HHV-6B) in 23 of 31 and 16 of 23, respectively, of the cases tested. By contrast, AAV2 was infrequently detected and at low titre in the blood or the liver from control children with HAdV, even when profoundly immunosuppressed. AAV2, HAdV and HHV-6 phylogeny excluded the emergence of novel strains in cases. Histological analyses of explanted livers showed enrichment for T cells and B lineage cells. Proteomic comparison of liver tissue from cases and healthy controls identified increased expression of HLA class 2, immunoglobulin variable regions and complement proteins. HAdV and AAV2 proteins were not detected in the livers. Instead, we identified AAV2 DNA complexes reflecting both HAdV-mediated and HHV-6B-mediated replication. We hypothesize that high levels of abnormal AAV2 replication products aided by HAdV and, in severe cases, HHV-6B may have triggered immune-mediated hepatic disease in genetically and immunologically predisposed children

Synthesis and Utility of New Ynamide and Organo-allyltrifluoroborate Reagents: Application to the Total Synthesis of Geralcin A, Hydrazidomycins A-B, CPC-1, Alline, Splenocin-B, and the Potent Cancer Cell Growth Inhibitors Kitastatin and Respirantin

This thesis is presented in two parts and summarizes work carried out in the laboratory of Professor Robert A. Batey at the University of Toronto from September 2010 through July 2014. Part 1 of this thesis covers the development and synthetic utility of new ynamide reagents toward nitrogen heterocycle generation and natural product synthetic applications (Chapters 1-4). Part 2 of this thesis outlines work related to the synthesis of new organo-allyltrifluoroborate reagents and their application in the synthesis of biologically active depsipeptide natural products (Chapters 5-7).Part 1 begins with an introductory chapter (Chapter 1) to familiarize the reader with previous important ynamide reagent scientific contributions. Next, Chapter 2 describes our discovery of a previously unexplored ynehydrazide alkyne class including their application in the synthesis of pharmaceutically relevant nitrogen heterocycles.Chapter 3 then describes an ynehydrazide approach to the total synthesis of the hydrazide natural product geralcin A and Z-enehydrazides. Also presented is the discovery of a Boc-carbazate epoxide ring opening/Peterson olefination sequence to stereospecifically prepare Z-enehydrazides. Importantly, this methodology was used to prepare the structurally unique Z-enehydrazide containing natural products hydrazidomycins A-B and elaiomycin B.In Chapter 4, our synthetic studies using a terminal N,N-di-Boc ynimide as an aminoethylating reagent and precursor for regioselective synthesis of imide-functionalized heterocycles is outlined. Included are new examples of ynamide-acetylide reactivity and an ynimide approach to the total synthesis of pyrrolidinoindoline alkaloids (±)-CPC-1 and (±)-Alline.Part 2 of this thesis begins with an introduction to allyltrifluoroborates and their synthetic utility (Chapter 5). Chapter 6 then describes our results concerning the synthesis of a prenyltrifluoroborate reagent and its use to gamma-prenylate aldehydes and ketones. In particular, a diastereoselective prenyltrifluoroborate addition to the N-Boc-L-leucinal is featured as a strategy to install the key di-methyl-beta-keto-ester fragment in the total synthesis of the potent cancer cell growth inhibitory depsipeptides kitastatin and respirantin.Finally, Chapter 7 details the total synthesis of the potent cytokine inhibitory natural product splenocin-B. The chapter features a Z-benzyl-allyltrifluoroborate approach to construct the key stereotriad as well as studies on a new Wittig approach to synthesize Z-allyl-functionalized organotrifluoroborates.Ph.D

One step copper-catalyzed functionalization of pyridines with alkynes and organoindium reagents

The copper-catalyzed synthesis of functionalized pyridines and partially reduced pyridine derivatives has been developed and the results are presented herein. These studies have shown that pyridines (and related aromatic heterocycles) in the presence of chloroformates will undergo effective coupling with terminal alkynes and organoindium reagents using simple copper (I) salt catalysts to give good yields of dihydropyridine products. In addition, performing these reactions in tandem with base or oxidative additives has led to the copper-catalyzed one-pot preparation of substituted aromatic pyridines.Une méthode catalytique médiée par le cuivre pour la synthèse des dérivés de pyridines ainsi que celles partiellement réduites est décrite dans le texte qui suit. Cette étude démontre que les pyridines (et autres hétérocycles aromatiques reliés), lorsque quaternisées in-situ par des réactifs tel que les chloroformates, celles-ci peuvent être couplées avec des alcynes terminaux ou des réactifs organo-indium au moyen de simple sels de cuivre (I) pour générer, bon rendement, des dihydropyridines. De plus, lorsque cette réaction est effectuée en tandem, soit avec l'ajout d'une base ou d'un agent oxydant, ce processus nous offre une méthodologie en un pot envers la synthèse de pyridines substituées

Total Synthesis of the Cytotoxic Enehydrazide Natural Products Hydrazidomycins A and B by a Carbazate Addition/Peterson Olefination Approach

The first total syntheses of two natural antitumor enehydrazide compounds (hydrazidomycins A and B) and a related positional isomer of hydrazidomycin B (elaiomycin B) have been accomplished in a rapid and stereocontrolled fashion using a Peterson elimination approach. A regioselective silyl epoxide ring opening reaction with Boc-carbazate followed by base-mediated Peterson siloxide elimination stereospecifically installed the key <i>Z</i>-enehydrazide functionality. The use of Boc-carbazate allowed for the differential functionalization of the hydrazide nitrogens

An Organotrifluoroborate-Based Convergent Total Synthesis of the Potent Cancer Cell Growth Inhibitory Depsipeptides Kitastatin and Respirantin

The total syntheses of the highly cytotoxic neo-antimycin macrocyclic depsipeptide natural products kitastatin and respirantin have been accomplished in a convergent manner using MNBA promoted esterifications and an efficient C- and N-terminus bis-deprotection/HATU promoted macrolactamization. The first examples of using a prenyltrifluoroborate reagent in additions to carbonyl groups are disclosed including a diastereoselective multigram scale montmorillonite K10 catalyzed prenylation of <i>N</i>-Boc-l-leucinal to install the structurally unique gem-dimethyl-β-keto-ester fragment

An Organotrifluoroborate-Based Convergent Total Synthesis of the Potent Cancer Cell Growth Inhibitory Depsipeptides Kitastatin and Respirantin

The total syntheses of the highly cytotoxic neo-antimycin macrocyclic depsipeptide natural products kitastatin and respirantin have been accomplished in a convergent manner using MNBA promoted esterifications and an efficient C- and N-terminus bis-deprotection/HATU promoted macrolactamization. The first examples of using a prenyltrifluoroborate reagent in additions to carbonyl groups are disclosed including a diastereoselective multigram scale montmorillonite K10 catalyzed prenylation of <i>N</i>-Boc-l-leucinal to install the structurally unique gem-dimethyl-β-keto-ester fragment

Discovery of PF-5190457, a Potent, Selective, and Orally Bioavailable Ghrelin Receptor Inverse Agonist Clinical Candidate

https://researchrepository.wvu.edu/wvu_herbwvfern/2465/thumbnail.jp