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Structural Implementation of Unsatured Systems Driven by Electrophilic Nitrogen-Containing Functional Groups
Get PDFThe present thesis can be divided into four chapters. The first chapter reports an
efficient synthesis of conjugated nitrotrienes and benzothiaziones. The second chapter
describes a new simple synthesis of unsymmetrical bisindoylmethanes and their
anti-cancer activity test. The third chapter reports the biological tests between soy
protein isolate and stilbene representatives. The fourth chapter lists the references and
1H NMR 13C NMR spectra.
CHAPTER ONE: Efficient Synthesis of Conjugated Nitrotrienes and
Benzothiaziones
Nitro-containing compounds are excellent scaffolds for synthesizing small
molecules and heterocyclic systems that can be used in pharmaceuticals,
agrochemicals, and materials science. β-Nitroenones (1, Figure 1) and β-nitroacrylates
(2, Figure 1) can be considered as good starting materials for various targets.
This chapter reports a brief overview of the chemistry of nitro-containing
compounds and the efficient synthesis of conjugated nitrotrienes and benzothiaziones.
For the synthesis of conjugated nitrotrienes, -nitroenones 1 can be allylated with
allylboronic pinacol ester 3 to give tertiary homoallylic alcohols 4. Subsequently, 4
can eliminate water to generate the corresponding conjugated nitrotrienes in the
presence of the Lewis acid boron trifluoride etherate (Scheme 1). The successful
application of this route with a wide range of substituents and the excellent yield
obtained demonstrate its versatility. The nitrotrienes are obtained as a mixture of two
isomers. However, this procedure can prevent the elimination of the nitro group which
is retained in the triene molecule.
The critical situation caused by the increasing number of tuberculosis and the
synergetic effect between tuberculosis and human immunodeficiency virus or
multidrug-resistance makes the discovery of a drug with the structure of
benzothiazinone an emergency. Considering the drawbacks of previous studies, such
as long reaction times, limited substituents or pretreatment before reaction, a
sustainable, convenient one-pot synthesis of benzothiazinones was proposed. The
synthesis can be carried out in three steps: (i) Michael addition of -nitroacrylates 2
and aminothiophenols 5 to form adducts 6 under neat condition; (ii) elimination of
nitrous acid to afford 7; (iii) intramolecular cyclization to obtain benzothiazinones 8
(Scheme 2). Since solid promoters (carbonate on polymer and Amberlyst-15) were
used in the last two steps, the whole three steps can be combined in one-pot procedure
by simple filtration and final flash column chromatography. This synthetic method
can produce a series of benzothiazinones with good overall yields, in addition,
products with different substituents can be prepared.
CHAPTER TWO: Synthesis of Unsymmetrical Bisindolylmethanes
and Their Anti-cancer Activity Test
Bisindolylmethanes, widely distributed in various vegetables, have the ability to
regulate plant growth and prevent cancer. Several studies on the synthesis of
symmetrical bisindoylmethanes are currently available. However, the development of
synthetic protocols for unsymmetrical bisindoylmethanes is limited by the use of
harmful Lewis acid or Brønsted acid catalysts and plagued by the formation of
by-products or low yield of targets. In this chapter, a new, mild procedure was
proposed to obtain unsymmetrical bisindoylmethanes from sulfonyl indoles.
Sulfonyl indoles (Lg = SO2Ar) 9 can afford a weakly electrophilic
alkylideneindolenine 10 upon basic promoted elimination of arylsulfinic acids.
Reaction of intermediate 10 with a rather strong, stabilized nucleophilic indole 11,
otained by metalation of indoles with Grignard reagents, can generate the
unsymmetrical bisindoylmethanes 12 by a Michael-type process (Scheme 3). The
target products with different substituents can be prepared in moderate to excellent
yields, and the reaction of pyrrolylmagnesium bromides with sulfonyl indoles under
un-optimized conditions showed the wide boundaries of this route.
In addition, the anti-cancer activity of five selected compounds was tested and
compared with cisplatin. The results indicate that unsymmetrical bisindoylmethanes
have anti-cancer activity and can be considered as good anti-cancer reagents.
CHAPTER THREE: Effect of the Binding of Piceatannol and
Oxyresveratrol to Soybean Protein Isolate on the Structural and
Functional Properties
Piceatannol (PIC, 13, Figure 2), oxyresveratrol (OXY, 14, Figure 2), and soy
protein isolate (SPI) are essential nutritional molecules for a human’s daily life. In this
chapter, the interaction between PIC/OXY and SPI was investigated using multiple
spectroscopic techniques and molecular docking simulations. Steady-state
fluorescence, Förster resonance energy transfer and time-resolved fluorescence
spectroscopy confirmed the static quenching mechanism. In addition, the binding
affinity of PIC to SPI was stronger than that of OXY, and the interactions were
spontaneous and exothermic. The surface hydrophobicity, sulfhydryl group content,
particle size, zeta potential, and -helical contents can determine the subtle change in
the secondary structure of SPI after binding. The emulsifying and foaming properties
of SPI were improved after complexing with PIC or OXY. The molecular docking
results and thermodynamic parameters showed that PIC and OXY were bound to SPI
at the same sites, van der Waals forces and hydrogen bonds were the main interaction
forces. The results also showed that the encapsulation of SPI can enhance the
antioxidant activity of PIC and OXY. The in vitro gastrointestinal digestion of PIC
and OXY in the presence of SPI helps patients with stomach problems.
CHAPTER FOUR: References and 1H NMR
13C NMR Spectra
This chapter displays the references and 1H NMR
13C NMR Spectra
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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