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Alex Sinclair

Bio: Alex Sinclair is an academic researcher from Kingston University. The author has contributed to research in topics: Dioxolane & Nicholas reaction. The author has an hindex of 5, co-authored 12 publications receiving 90 citations.

Papers
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Journal ArticleDOI
TL;DR: The application of DOSY (Diffusion Ordered SpectroscopY) NMR as a technique for the virtual separation of key components of manuka honey and the implications for future discriminatory analysis of honey types is reported for the first time.

32 citations

Journal ArticleDOI
A. Le Gresley1, V. Gudivaka1, S. Carrington1, Alex Sinclair1, J. E. Brown1 
TL;DR: A small library of cryptolepine analogues were synthesised incorporating halogens and/or nitrogen containing side chains to optimise their interaction with the sugar-phosphate backbone of DNA to give improved binding, interfering with topoisomerase II hence enhancing cytotoxicity as discussed by the authors.
Abstract: A small library of cryptolepine analogues were synthesised incorporating halogens and/or nitrogen containing side chains to optimise their interaction with the sugar-phosphate backbone of DNA to give improved binding, interfering with topoisomerase II hence enhancing cytotoxicity. Cell viability, DNA binding and Topoisomerase II inhibition is discussed for these compounds. Fluorescence microscopy was used to investigate the uptake of the synthesised cryptolepines into the nucleus. We report the synthesis and anti-cancer biological evaluation of nine novel cryptolepine analogues, which have greater cytotoxicity than the parent compound and are important lead compounds in the development of novel potent and selective indoloquinone anti-neoplastic agents.

21 citations

Journal ArticleDOI
TL;DR: Investigations revealed that the novel lupulone derivatives were very efficient at killing cancer cells by apoptosis but appear to do so in a time-dependant process, of great significance as MDA-MB-231 cell lines are characterised by an aggressive phenotype with a propensity to invade other tissue, to form metastases as well as an ability to become insensitive to chemotherapeutic agents.

19 citations

Journal ArticleDOI
TL;DR: In this article, the enantiospecific synthesis of chromanes and isochromanes obtained from an intramolecular Nicholas cyclisation reaction is discussed and the formation of chroman-4-ones from a CAN deprotection step of a dioxolane is observed.

15 citations

Journal ArticleDOI
TL;DR: The application of DOSY (Diffusion Ordered Spectroscopy) NMR as a technique for the virtual separation of toothpaste adjuvants in model saliva is reported for the first time and the scope and limitations ofDOSY NMR are considered using the DOSY Tool Box processing software.
Abstract: The application of DOSY (Diffusion Ordered Spectroscopy) NMR as a technique for the virtual separation of toothpaste adjuvants in model saliva is reported for the first time. In addition, the scope and limitations of DOSY NMR are considered using the DOSY Tool Box processing software, as is the quantification of the adjuvants and components of saliva by quantitative NMR (qNMR). These techniques represent a new and powerful tool for the evaluation of complex mixtures of natural products with a view to identifying biomarkers for disease within the oral cavity.

6 citations


Cited by
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Journal ArticleDOI
TL;DR: This article reviews the literature on the use of analytical techniques, mainly NMR spectroscopy, for authentication of honey, its botanical and geographical origin, and adulteration by sugar syrups between 2000 and 2016.

183 citations

Journal ArticleDOI
25 Mar 2014-PeerJ
TL;DR: New Zealand manuka-type honeys, at the concentrations they can be applied in wound dressings are highly active in both preventing S. aureus biofilm formation and in their eradication, and do not result in bacteria becoming resistant.
Abstract: Chronic wounds are a major global health problem. Their management is difficult and costly, and the development of antibiotic resistance by both planktonic and biofilm-associated bacteria necessitates the use of alternative wound treatments. Honey is now being revisited as an alternative treatment due to its broad-spectrum antibacterial activity and the inability of bacteria to develop resistance to it. Many previous antibacterial studies have used honeys that are not well characterized, even in terms of quantifying the levels of the major antibacterial components present, making it difficult to build an evidence base for the efficacy of honey as an antibiofilm agent in chronic wound treatment. Here we show that a range of well-characterized New Zealand manuka-type honeys, in which two principle antibacterial components, methylglyoxal and hydrogen peroxide, were quantified, can eradicate biofilms of a range of Staphylococcus aureus strains that differ widely in their biofilm-forming abilities. Using crystal violet and viability assays, along with confocal laser scanning imaging, we demonstrate that in all S. aureus strains, including methicillin-resistant strains, the manuka-type honeys showed significantly higher anti-biofilm activity than clover honey and an isotonic sugar solution. We observed higher anti-biofilm activity as the proportion of manuka-derived honey, and thus methylglyoxal, in a honey blend increased. However, methylglyoxal on its own, or with sugar, was not able to effectively eradicate S. aureus biofilms. We also demonstrate that honey was able to penetrate through the biofilm matrix and kill the embedded cells in some cases. As has been reported for antibiotics, sub-inhibitory concentrations of honey improved biofilm formation by some S. aureus strains, however, biofilm cell suspensions recovered after honey treatment did not develop resistance towards manuka-type honeys. New Zealand manuka-type honeys, at the concentrations they can be applied in wound dressings are highly active in both preventing S. aureus biofilm formation and in their eradication, and do not result in bacteria becoming resistant. Methylglyoxal requires other components in manuka-type honeys for this anti-biofilm activity. Our findings support the use of well-defined manuka-type honeys as a topical anti-biofilm treatment for the effective management of wound healing.

131 citations

Journal ArticleDOI
09 Oct 2017-Analyst
TL;DR: An overview of the DOSY NMR mapping and its applications is presented, to demonstrate the potential of the method for unravelling the components of complex matrices comprising pharmaceuticals, dietary supplements, foods and beverages, and biological extracts.
Abstract: While NMR is the most used analytical method for determining the molecular structure of isolated chemical entities, small compounds as well as macromolecules, its capability of analysing complex mixtures is less known. The advent of Diffusion Ordered SpectroscopY (DOSY) NMR has made diffusion experiments popular, enabling diffusion coefficients to be routinely measured and used to characterize chemical systems in solution. Indeed, since the translational diffusion coefficients of molecular species reflect their effective sizes and shapes, DOSY NMR allows the separation of the chemical entities present in multicomponent systems and, as in all diffusion NMR experiments, provides information on their intermolecular interactions as well as on their size and shape. The main aim of this review is to present an overview of the DOSY NMR mapping and its applications. The paper starts with a brief introduction to pulsed-field gradient (PFG) NMR and then focuses on the methodological procedures that can be used to perform good diffusion data acquisition and to obtain good-quality DOSY maps. The second part describes, through selected literature examples, different applications of DOSY NMR to demonstrate the potential of the method for (i) unravelling the components of complex matrices comprising pharmaceuticals, dietary supplements, foods and beverages, and biological extracts, and (ii) probing intermolecular interactions and evaluating association constants between different hosts and guests, as well as estimating the sizes and molecular weights of molecular species.

92 citations

Journal ArticleDOI
TL;DR: Honey represents an attractive antimicrobial treatment that might have the potential to be used alongside current therapies as a prophylactic or to treat wound infection with multidrug-resistant bacteria in future.
Abstract: Resistance to antibiotics continues to rise and few new therapies are on the horizon. Honey has good antibacterial activity against numerous microorganisms of many different genera and no honey-resistant phenotypes have yet emerged. The mechanisms of antimicrobial activity are just beginning to be understood; however, it is apparent that these are diverse and often specific for certain groups or even species of bacteria. Manuka honey has been most thoroughly characterized and is commercially available as a topical medical treatment for wound infections. Furthermore, since most data are available for this honey, there is a considerable focus on it in this review. It is becoming evident that honeys are more than just bactericidal, as they impact on biofilm formation, quorum sensing and the expression of virulence factors. With this in mind, honey represents an attractive antimicrobial treatment that might have the potential to be used alongside current therapies as a prophylactic or to treat wound infection with multidrug-resistant bacteria in future.

85 citations

Journal ArticleDOI
TL;DR: The aim of this review is to provide a comprehensive overview of the molecular imaging tracers developed for optical and nuclear identification of bacteria and bacterial infections and envision that such tracers can be used to diagnose infections and aid their clinical management.

81 citations