Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 18 of 18 for “"Furanones"”.
-
Synthesis of 2(3H)-furanones via electrophilic cyclization
… A variety of highly substituted 2(3H)-furanones are readily prepared from 3-alkynoate esters and the corresponding acids via electrophilic cyclization. This highly efficient approach proceeds under mild conditions, tolerates various functional groups, and generally provides …
-
Controlling Bacterial Persister Cells and Biofilms by Synthetic Brominated Furanones
… the effects of synthetic brominated furanones, a group of QS inhibitors, on the persistence of P. aeruginosa and Escherichia coli. Our results revealed that (Z)-4-bromo-5-(bromomethylene)-3-methylfuran-2(5H)-one (BF8) can reduce persister formation in P. aeruginosa PAO1 and E. coli …
-
Fused and spiro furanones from tetronic acid synthons: Oxa and azacycles featuring the butenolide ring
Diverse 4-O-allyl tetronates were obtained by reaction of allyl (alpha-hydroxy)carboxylates with keteneylidenetriphenylphosphorane (Ph3PCCO) in a domino reaction (addition – Wittig olefination) and by direct allylation of tetronic acid via Fischer esterification. 3-Allyl tetronic acids were …
-
Chemistry and synthesis of 3(2H)-furanones and 4,5-dihydro analogues: mechanistic investigations and stereochemical control
… of the five-membered oxygen heterocycles – 3(2H)-furanones and their 4, 5-dihydro analogues. Chapter one of the thesis is a review of the relevant chemistry of the compounds: their synthesis and key transformations. In chapter two, new research on 3(2H)-furanones is outlined in two parts. The …
-
Organocatalytic conjugate addition reactions
… base catalyzed conjugate addition between 2(3H)-furanones and maleimides. Aromatic furanones substrates proved to be better than alkyl furanones, giving higher yields and better ees. The best result is a decent ee of 70%. There is still room for improvements in increasing both the yield and the …
-
Synthesis and evaluation of novel quorum sensing inhibitors
This thesis details the synthesis of a range of furanones and the subsequent evaluation of their quorum sensing inhibitory effects. Chapter One focuses on the role of quorum sensing in bacteria and fungi. It explores the potential use of quorum sensing inhibitors as an alternative to, or in …
-
Access to modified geiparvarins using Pd(0)-mediated C-C bond forming reactions
… syntheses of selected naturally occurring 3(2H)-furanones. The known syntheses of geiparvarin and closely related analogues are examined, along with the documented biological activity of these compounds. The synthetic routes which allow access to 4-substituted-3(2H)-furanones are also described. …
-
Discovering the Biological Activities of Maltose Derivatives for Controlling Bacterial Multicellular Behaviors
… agents, maltose derivatives and brominated furanones, as modulators of different bacterial multicellular behaviors has been demonstrated. Rhamnolipids secreted by Pseudomonas aeruginosa are biosurfactants that are known to be essential for at least three multicellular behaviors of P. …
-
Novel small molecules for modulation of bacterial signaling pathways
… heterocyclic systems derived from halogenated furanones (Fimbrolides). Indole and glucosamine-based amides and oxo-amides were synthesized as non-native AHL mimics by applying EDC, DCC or EDC/HOBt mediated amide coupling methods. On docking study, the indole-based AHL mimics showed strong …
-
Chemoenzymatic routes to enantiopure hydroxytetrahydrofurans: muscarine and its analogues
… to the 3-hydroxytetrahydrofurans via 3(2H)- furanones. Steps amongst which include Rh(II) mediate cyclisation and kinetic resolution via baker’s yeast mediated carbonyl reduction, resulting in enantioenriched 3- hydroxytetrahydrofuran derivatives. Finally, application of this methodology to …
-
I. Stereochemical Control of Chiral Assembly and Liquid Crystal Phase Formation of Nonamphiphilic Molecules in Water II. Control Bacterial Quorum Sensing and Quorum Sensing-mediated Activities Using Small Unnatural Molecules
… studies of a class of bicyclic brominated furanones. These molecules interacted with quorum sensing in an opportunistic pathogen P. aeruginosa. Some representative compounds in this class inhibited quorum sensing-controlled activities such as biofilm formation and virulence factor …
-
Controlling Biofouling by Surface Engineering and Molecular Inhibition
… of a class of molecules called brominated furanones, which are known to inhibit biofilm formation in E. coli. Chapter 7 reports the synthesis of novel squarate based molecules named squarylated homoserine lactones (SHLs), which are structural mimics of the bacterial autoinducer molecules …
-
Quroum sensing disruption and the use of short-chain fatty acids and polyhydroxyalkanoates to control luminescent vibriosis
… franciscana) nauplii. Subsequently, halogenated furanones were shown to disrupt quorum sensing in these bacteria by decreasing the DNA-binding activity of the quorum sensing master regulator protein LuxR. Interestingly, the addition of 20 mg l-1 of the furanone to the culture water of gnotobiotic …
-
Characterization of aroma components of raw and roasted almonds and the effect of the oxidative state of the nut on roasted flavor formation
… pyrazines, pyridines, pyrrolines, aldehydes and furanones. Aroma changes of stored raw (SR) and stored raw-then-roasted (SRTR) almonds were investigated by gas chromatography-olfactometry (GCO) and aroma extract dilutions analysis (AEDA) and GC-mass spectrometry (GC-MS). Raw almonds were stored …
-
A Fungal secretome tailored to enable a radical (oxidative) wood decay mechanism in brown rot fungi
… such as organic acids, sugars, pyranones, and furanones contributed to this result. The finding of several pyranones and furanones being differentially more abundant in brown rot fungi was interesting since it agrees with the expansion of polyketide synthase genes in brown rot fungi. In …
-
Comprehensive Mapping of Volatile Organic Compounds in Fruits
… alcohols, esters, acids, terpenes, aldehydes, furanones, pyrazines, isoprenoids and many more. VOCs play important role as they determine the flavor of grapes and wine made from it. The objective of this thesis is to study of VOCs through development of different mass spectrometry based …
-
Impact of roasting on the physicochemical characteristics of cacao beans and dark chocolate flavor profile
… samples. The main differences were observed in furanones, Strecker aldehydes, and pyrazines, which presented higher values in roasted chocolate. Additionally, volatiles developed during fermentation and drying, such as acetic acid, were preserved in minimally processed (unroasted) chocolate. …
-
Sensory directed determination of odor important components of natural (raw) and roasted pecan oil
… volatiles such as pyrazines, pyrrolines, furanones, and lactones that possess nutty, popcorn-like, caramel-like, and creamy, coconut-like aromas, as well as volatile aldehydes and ketones that possess malty and buttery aromas in RPO, all of which can be attributed to the reactions …