https://pubs.rsc.org/en/content/articlepdf/2019/NP/C8NP00092A

Marine natural products.

/pdf/aryl-aryl-bond-formation-one-century-after-the-discovery-of-1jdyxlkwix.pdf

Aryl-aryl bond formation one century after the discovery of the Ullmann reaction.

Rate of depurination of native deoxyribonucleic acid.

Catalytic cross-coupling reactions in biaryl synthesis

INTRODUCTION . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . 201 S OURCES OF AP SITES . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . 202 Spontaneous DepurinationlDepyrimidination . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202 Chemically Induced DepurinationlDepyrimidination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . 203 DepurinationlDepyrimidination by DNA Glycosylases . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . 207 REPAIR OF AP SITES . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . 209 MUTAGENESIS BY AP SITES . . . .... . . . . . . . . .. . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 210 Misincorporation by DNA Polymerases in vitro . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . 210 Mutagenesis in E. coli... . . . . . . . . . ..... . . . . . . . . . 2 1 2 Mutagenesis in Animal Cells . . . .. . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 1 3 A P Sites a s Intermediates in Spontaneous Mutagenesis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214 AP Sites as Intermediates in Chemical Mutagenesis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216 MOLECULAR MECHANISMS FOR MUTAGENESIS BY AP S ITES . . . . . . . . .. . . . . . . . . . 219

Mutagenesis by Apurinic/Apyrimidinic Sites

Kinetics and mechanism of the acid-catalyzed hydrolysis of some purine nucleosides

The goals of this study were to develop compounds that were selective and highly efficacious agonists at alpha-7 receptors, while varying in antagonist activity; and to test the hypothesis that these compounds had memory-related and neuroprotective actions associated with both agonist and antagonist alpha-7 receptor activities. Three compounds were identified; E,E-3-(cinnamylidene)anabaseine (3-CA), E,E-3-(2-methoxycinnamylidene) anabaseine (2-MeOCA) and E,E-3-(4-methoxycinnamylidene) anabaseine (4-MeOCA) each displaced [125I]alpha-bungarotoxin binding from rat brain membranes and activated rat alpha-7 receptors in a Xenopus oocyte expression system fully efficaciously. The potency series for binding and receptor activation was 2-MeOCA > 4-MeOCA = 3-CA and 2-MeOCA = 3-CA > 4-MeOCA, respectively. No compound significantly activated oocyte-expressed alpha-4beta-2 receptors. Although each cinnamylidene-anabaseine caused a long-term inhibition of alpha-7 receptors, as measured by ACh-application 5 min later, this inhibition ranged considerably, from less than 20% (3-CA) to 90% (2-MeOCA) at an identical concentration (10 microM). These compounds improved passive avoidance behavior in nucleus basalis lesioned rats, with 2-MeOCA most potent in this respect. In contrast, only 3-CA was neuroprotective against neurite loss during nerve growth factor deprivation in differentiated rat pheochromocytoma (PC12) cells. Choline, an efficacious alpha-7 agonist without antagonist activity, was also protective in this model. These results suggest that the neurite-protective action of alpha-7 receptor agonists may be more sensitive to potential long-term antagonist properties than acute behavioral actions are.

Neuroprotective and memory-related actions of novel alpha-7 nicotinic agents with different mixed agonist/antagonist properties.

This invention relates to compositions for benzylidene- and cinnamylidene-anabaseines and methods for using these compositions for treating conditions associated with defects or malfunctioning of nicotinic subtypes brain receptors. These compositions target the alpha7 receptor subtype with little or no activation of the alpha4beta2 or other receptor subtypes.

Methods of use and compositions for benzylidene- and cinnamylidene-anabaseines

Publisher Summary This chapter focuses on important developments dealing with quaternization of annular nitrogen atoms of heterocyclic compounds The chapter is essentially divided into two main parts The first part describes the main electronic and steric factors of heteroaromatic nucleophilic reactants that influence their reactivity The second part provides references to recent important developments The chapter considers six-membered heteroaromatic rings before five-membered ones as the six-membered rings are studied in greater detail and consequently their reactions are better understood The chapter notes that quaternization of an annular nitrogen atom is carried out with a wide range of alkylating agents Most quaternization reactions involving an annular nitrogen atom and an alkylating agent proceed by way of an S N 2 reaction in which the inversion of configuration of a chiral reagent takes place One novel method, which indicates that the transition state is early, involves the study of volume changes Many approaches are made to obtain information about the nature of the transition state of quaternization reactions, including a study of kinetic isotope effects

John A. Zoltewicz

Papers

Kinetics and mechanism of the acid-catalyzed hydrolysis of some purine nucleosides

Neuroprotective and memory-related actions of novel alpha-7 nicotinic agents with different mixed agonist/antagonist properties.

Methods of use and compositions for benzylidene- and cinnamylidene-anabaseines

Quaternization of Heteroaromatic Compounds: Quantitative Aspects

Unusual influence of nitrogen on rates of anion formation. Hydrogen-deuterium exchange of pyridine and the diazines