Download or read book Design Synthesis and Evaluation of Fluorescent Probes for the Diagnosis of Alzheimer s Disease and Parkinson s Disease written by Jiamin Gu and published by . This book was released on 2013 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Synthesis and characterization of fluorescent stilbene based probes targeting amyloid fibrils written by Jun Zhang and published by Linköping University Electronic Press. This book was released on 2018-11-27 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt: Alzheimer’s disease (AD) is characterized by two main protein aggregate hallmarks in the brain: extracellular deposition of the amyloid-? (A?) in senile plaques and intracellular neurofibrillary tangles (NFTs) consisting of hyperphosphorylated tau protein. The past decade has seen great progress in the development of imaging probes for the non-invasive detection of A? and tau aggregates. Here positron emission tomography (PET), single-photon emission computed tomography (SPECT) and magnetic resonance imaging (MRI), are highly promising technologies for clinical diagnostics. However, as a research tool, optical imaging is superior because it is real-time, sensitive, inexpensive, not radioactive and that it in particular affords high-resolution studies both in vitro and in vivo. Fluorescent probes are especially useful for designing novel binding scaffolds for structure investigations of protein aggregates. This thesis describes design, synthesis and evaluation of a series of fluorescent probes for detection of amyloid fibrils, especially A? or tau aggregates in vitro. Firstly, trans-stilbenoid vinylbenzene-1,2-diol with benzene, naphthalene, anthracene, and pyrene are investigated with respect to their photophysical properties free in solution and when bound to amyloid fibrils, including time-resolved fluorescence measurements. It is noted that the extended conjugated systems retained the amyloid targeting properties of the probes and both the anthracene and pyrene moieties extensively enhanced the fluorescence intensity and prolonged lifetimes. Secondly, the synthesis of two molecules, Py1SA and Py2SA, based on pyrene linked to salicylic acid via a trans-stilbene C = C bond is presented. The compounds show strikingly different emission spectra when bound to preformed A?1-42 fibrils as well as to fibrils from four other distinct proteins. Additionally, excited state intramolecular proton transfer (ESIPT) coupled-charge transfer (ICT) is observed for the anionic form of the probes in polar solvents. This is likely the reason for the spectral differences of the probes when bound to amyloid fibrils. Moreover, the synthesis of a further development of the Congo red analogue X-34 [2,5-bis(4’-hydroxy-3’-carboxy-styryl) benzene] by rational design and synthesis is described. Full photophysical characterization was performed, including recording absorbance and fluorescence spectra, Stokes shift, quantum yield and fluorescence lifetimes. All ligands displayed high affinity towards recombinant amyloid fibrils of A?1-42 and tau as well as selectivity towards the corresponding disease-associated protein aggregates in human post mortem AD tissue. Lastly, the synthesis of a set of 2,1,3-benzothiadiazole (BTD)-based ligands with different conjugated spacers and variable patterns of OH substitutions of bis-styryl-BTD prototypes were developed. A? binding affinities (A?1-42 and A?1-40 fibrils) and the specificity towards A? plaques of all ligands were determined. These findings extend the structure to activity relationships of BTD-based ligands for A? fibril binding. Throughout the studies in this dissertation, new interesting properties of small molecule fluorescence probes have been discovered and analyzed. This knowledge should facilitate the development of noninvasive probes for early detection of Alzheimer's disease and to distinguish different A? fibril polymorphs.

Download or read book Design Synthesis and Evaluation of Fluorescent Probes for Biological Applications written by Andrea Fin and published by . This book was released on 2012 with total page 229 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Design Synthesis and Evaluation of Fluorescent Small Molecule Probes of Biological Systems written by Michael James DeGrazia and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Design Synthesis and Evaluation of Fluorescent Sensors for the Detection of Saccharide and Reactive Oxygen Species written by Xiaolong Sun and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Design Synthesis and Evaluation of Fluorescent Sensors for Intracellular Imaging of Monovalent Copper written by Liuchun Yang and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The main theme of this thesis is to develop a fluorescent probe for imaging the subcellular distribution of kinetically labile copper pools that might play a critical role in copper homeostasis. Various copper-selective sensors were designed by combining 1,3,5-triaryl-2-pyrazoline fluorophores with polythioethers as receptor moieties. A series of donor-substituted 1,3,5-triaryl-2-pyrazoline fluorophores were synthesized and characterized in terms of their photophysical and electrochemical properties. Interestingly, the aryl substituents attached to the 1- and 3-position of the pyrazoline ring influence the photophysical properties of the fluorophore in distinctly different ways. The excited-state equilibrium energy is primarily influenced by changes of the substituent in the 1-position, whereas the reduction potential of the fluorophore is determined by the 3-aryl group. Results from computational analyses agree well with the experimental data. A pyrazoline fluorophore library was synthesized, and their photophysical and electrochemical properties were studied. The compounds cover a broad range of excited state energies and reduction potentials, and allow for selective and differential tuning of these two parameters. A series of thiazacrownethers and tripodal aniline copper(I) receptors were synthesized and their copper binding stoichiometries, stability constants, and copper-self-exchange kinetics were investigated. The measured self-exchange activation parameters revealed for all studied ligands a negative activation entropy, suggesting a predominant associative exchange mechanism. With detailed knowledge of the fluorophore platform and copper receptors, sensor CTAP-1 was designed, synthesized and characterized. The probe shows a 4.6-fold emission enhancement and reaches a quantum yield of 14% upon saturation with Cu(I). The sensor exhibits excellent selectivity towards Cu(I) and is insensitive towards millimolar concentrations of Mg(II) or Ca(II). Mouse fibroblast cells (3T3) incubated with the sensor produced a copper-dependent perinuclear staining pattern, which colocalizes with the subcellular location of the mitochondria and the Golgi apparatus. The subcellular topography of copper was further determined by synchrotron-based x-ray fluorescence (SXRF) microscopy. Furthermore, microprobe x-ray absorption measurements at various subcellular locations showed a near-edge feature that is characteristic for low-coordinate monovalent copper. The data provide a coherent picture with evidence for a kinetically labile copper pool, which is predominantly localized in the mitochondria and the Golgi apparatus.

Download or read book Design Synthesis and Evaluation of Fluorogenic BODIPY based Probes for Specific Protein Labelling in Live Cells written by Sydney Acton and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Visualizing proteins in living cells without perturbing biological function remains a key challenge in chemical biology. A chemical approach to this problem is the synthesis of small molecule fluorophores that react specifically with a protein of interest (POI). We have developed a site-specific labelling method based on a Fluorogenic Addition Reaction (FlARe). The FlARe probe's fluorescence is quenched until it undergoes thiol addition with a small, genetically encoded dicysteine peptide tag fused to the POI. Recent blue coumarin probes were shown to be highly selective for target proteins over other cellular thiols; however, fluorogens that can label in the red and green channels of the fluorescence microscope are more desirable for cellular imaging, as red light is lower in energy and therefore less photo-toxic. In the work presented herein, we use DFT calculations to guide the design of red-shifted, PeT-quenched BODIPY based dimaleimide fluorogens. Driven by the preliminary results of a FlARe probe (YC29) that emitted in the red channel, we attempted to prepare the hit compound through a new synthetic approach to further evaluate kinetics and in cellulo labelling. Given the time available, this compound was unable to be synthesized through an SNAr or Pd-catalyzed approach. Alternatives probes lacking the red-shifting substituent were synthesized and evaluated in vitro and in cellulo. The fluorescent enhancement and reaction kinetics of these probes were evaluated in detail, in order to determine the suitability of their application to cellular labelling. A green-BODIPY fluorogen was synthesized that exhibits suitable kinetics for labelling and a dramatic fluorescent enhancement of 8̃00-fold upon tagging. This probe was successfully applied to the specific, fluorescent labelling of a nuclear histone protein in cellulo.

Download or read book Design Synthesis and Sensing Properties of Chiral Amine based Fluorescent Probes written by Xiaobo Zhou and published by . This book was released on 2012 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Design Synthesis and Evaluation of Novel Boronic Acid Based Fluorescent Sensors written by Laurence Isabelle Bosch and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Synthesis and Characterization of Novel Fluorescent Sensors Based on Terpyridine Benzoxazole and Benzothiazole Chromophores written by Xiaoman Bi and published by . This book was released on 2017 with total page 173 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the past few decades, there has been significant interest in developing fluorescent probes, because they are useful tools for biological studies. As effective analytical techniques, fluorescent probes utilize distinct advantages offered by fluorescence detection in terms of sensitivity, selectivity, and fast response time. When fluorescent probes interact selectively with target molecules, ions or biological specimens, they can generate large optical responses. Since most ions or molecules, such as Zn2+, Ca2+, or pyrophosphate ion (PPi), are non-fluorescent, chemosensors having analyte binding-triggered fluorescence are appealing in many fields, like analytical chemistry, clinical biochemistry, medicine, and environmental science.This dissertation is devoted to the design, synthesis, and characterization of novel fluorescent sensors for Zn2+ and its associated applications. Chapter II of this dissertation presents several novel terpyridine-based fluorescent sensors with different substituents affecting the electronic and steric nature of the terpyridine (tpy) fluorophore. Sensors are designed to establish the correlation between sensor structure and its photophysical properties. Low temperature fluorescence is used to evaluate the essential role of intramolecular charge transfer (ICT) in zinc binding-induced fluorescence changes. The tpy molecular fragment has a relatively large [pi]-conjugated system which enables the potential [pi-pi] interaction between two tpy platforms and affects the fluorescence of tpy ligands. Chapter III introduces a dimeric tpy ligand containing two tpy fragments connected via a meta-phenylene unit. The detailed spectroscopic study shows that this ligand displays an attractive fluorescence turn-on, in sharp contrast to mono(tpy) ligand that shows fluorescence quenching upon binding Zn2+. The result suggests the existence of delicate structural influences on fluorescence of tpy derivatives.Chapter IV is devoted to 2-(2'-hydroxyphenyl)-1,3-benzoxazole (HBO) and 2-(2'-hydroxyphenyl)-1,3-benzothiazole (HBT) derivatives featured with a structural potential of excited-state intramolecular proton transfer (ESIPT). The study reveals additional information on the binding of HBO or HBT to metal cations, which aids the sensor design for Zn2+ and PPi detection. The molecular design aims to realize ESIPT process control upon complexation with an analyte. Chapter V is devoted to the synthesis of bis(HBO) derivatives which bind Zn2+ selectively and emit near-infrared (NIR) fluorescence as a consequence of metal ion binding-induced ESIPT turn-on. Preliminary cell stain experiment was conducted and indicated the potential biological applications.

Download or read book Comprehensive Medicinal Chemistry III written by and published by Elsevier. This book was released on 2017-06-03 with total page 4609 pages. Available in PDF, EPUB and Kindle. Book excerpt: Comprehensive Medicinal Chemistry III, Eight Volume Set provides a contemporary and forward-looking critical analysis and summary of recent developments, emerging trends, and recently identified new areas where medicinal chemistry is having an impact. The discipline of medicinal chemistry continues to evolve as it adapts to new opportunities and strives to solve new challenges. These include drug targeting, biomolecular therapeutics, development of chemical biology tools, data collection and analysis, in silico models as predictors for biological properties, identification and validation of new targets, approaches to quantify target engagement, new methods for synthesis of drug candidates such as green chemistry, development of novel scaffolds for drug discovery, and the role of regulatory agencies in drug discovery. Reviews the strategies, technologies, principles, and applications of modern medicinal chemistry Provides a global and current perspective of today's drug discovery process and discusses the major therapeutic classes and targets Includes a unique collection of case studies and personal assays reviewing the discovery and development of key drugs

Download or read book Fluorescent Probes of Biological Receptors written by Barry Elledge and published by . This book was released on 1982 with total page 370 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Design and Synthesis of Fluorescent Probes written by Prabin Rai and published by . This book was released on 2013 with total page 426 pages. Available in PDF, EPUB and Kindle. Book excerpt: The fundamental objective of this project is to design, synthesize, and characterize fluorescent dyes, which may be utilized in super resolution imaging techniques. In Chapters 1, 2 and 3, we concentrated on photoswitchable rhodamine dyes. We synthesized several rhodamine dyes and increased their water solubility, installed a bioconjugation unit and, more importantly, we optimized the absorption properties (close to 400 nm) of the rhodamine spirolactams in their closed state and studied their basic photophysical properties as well. In Chapter 4, we synthesized azido-DCDHF fluorogens that can be converted to the bright state after a 1,3-dipolar cycloaddition reaction between an azide-Ph-DCDHF and a strained alkene. We synthesized some strained alkenes, which may speed up the kinetics in 1,3-dipolar cycloaddition. This chemical method of turning the dyes from dark to bright state is a new dimension in the bioconjugation arena. In Chapter 5, we synthesized Nile red derivatives which can switch to a bright state from a dark state by collision on the cell surface utilizing PAINT methodology. We expected that the design of new Nile red derivatives may have better properties than the parent Nile red. Besides the PAINT technique, we worked on some active control of emission by enzymatic cleavage of fluorescent dyes in a dark state to the bright state, which can be utilized in super resolution imaging. Related to the 1,3-dipolar cycloaddition reaction between azido-DCDHF and norbornene, we have examined recently popularized tetrazine chemistry. We linked pyridyl tetrazines to DCDHF with short spacer. In Chapter 6, we describe the preparation of co-crystals between perfluorophenazine and several polynuclear aromatic compounds/polynuclear heteroaromatic compounds. In Chapter 7 we describe the preparation of some partially fluorinated heteropolynuclear aromatic compounds such phenzaine and acridine class of compounds for possible use in organic semiconductors.

Download or read book Design Synthesis and Evaluation of Chemical Probes for Biochemical Applications written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Coumarin and Its Derivatives written by Maria João Matos and published by Mdpi AG. This book was released on 2021-12-29 with total page 416 pages. Available in PDF, EPUB and Kindle. Book excerpt: Coumarins are widely distributed in nature and can be found in a large number of naturally occurring and synthetic bioactive molecules. The unique and versatile oxygen-containing heterocyclic structure makes them a privileged scaffold in Medicinal Chemistry. Many coumarin derivatives have been extracted from natural sources, designed, synthetized, and evaluated on different pharmacological targets. In addition, coumarin-based ion receptors, fluorescent probes, and biological stains are growing quickly and have extensive applications to monitor timely enzyme activity, complex biological events, as well as accurate pharmacological and pharmacokinetic properties in living cells. The extraction, synthesis, and biological evaluation of coumarins have become extremely attractive and rapidly developing topics. A large number of research and review papers have compiled information on this important family of compounds in 2020. Research articles, reviews, communications, and concept papers focused on the multidisciplinary profile of coumarins, highlighting natural sources, most recent synthetic pathways, along with the main biological applications and theoretical studies, were the main focus of this book. The huge and growing range of applications of coumarins described in this book is a demonstration of the potential of this family of compounds in Organic Chemistry, Medicinal Chemistry, and different sciences related to the study of natural products. This book includes 23 articles: 17 original papers and six review papers.

Download or read book Hydrogen Peroxide and Cell Signaling Part B written by and published by Academic Press. This book was released on 2013-07-15 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This new volume of Methods in Enzymology continues the legacy of this premier serial with quality chapters authored by leaders in the field. This is the second of three volumes on hydrogen peroxide and cell signaling, and includes chapters on such topics as the cellular steady-state of H2O2, evaluating peroxiredoxin sensitivity towards inactivation by peroxide substrates, and peroxiredoxins as preferential targets in H2O2-induced signaling.

Download or read book Biomedical Sensors written by Deric P. Jones and published by Momentum Press. This book was released on 2010 with total page 482 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sensors are the eyes, ears, and more, of the modern engineered product or system- including the living human organism. This authoritative reference work, part of Momentum Press's new Sensors Technology series, edited by noted sensors expert, Dr. Joe Watson, will offer a complete review of all sensors and their associated instrumentation systems now commonly used in modern medicine. Readers will find invaluable data and guidance on a wide variety of sensors used in biomedical applications, from fluid flow sensors, to pressure sensors, to chemical analysis sensors. New developments in biomaterials- based sensors that mimic natural bio-systems will be covered as well. Also featured will be ample references throughout, along with a useful Glossary and symbols list, as well as convenient conversion tables.