273 research outputs found
Structural Implementation of Unsatured Systems Driven by Electrophilic Nitrogen-Containing Functional Groups
No full textThe 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
Photoelectric properties for aromatic triangular tri-palladium complexes and their catalytic applications in Suzuki-Miyaura coupling reaction
No full textThe photoelectric properties and catalytic activities of substituted triphenylphosphine and sulfur/selenium ligand supported aromatic triangular tri-palladium complexes 1-4, abbreviated as [Pd-3](+), were investigated. The cyclic voltammogram of [Pd-3](+) in CH3CN-(Bu4NPF6)-Bu-n showed a single quasi-reversible wave which was consistent with their robust property and provided preliminary proof for their electron transfer processes in catalysis. With excitation at 267 nm, [Pd-3](+) exhibited strong ratiometric fluorescence at 550 and 780 nm at a temperature gradient from 77 K to 287 K. These peculiar triangular tri-palladium complexes showed excellent catalytic activities and exclusive reactivity with aryl iodides over the other halogenated aromatics in the Suzuki Miyaura coupling reaction. The electronic and steric hindrance effects of substituents on the aryl iodides and aryl boronic acids including heteroaromatics like pyridine, pyrazine and thiophenes were explored and most substrates achieved up to 99% of yields. (2-[1,1'-Biphenyl]-2-ylbenzothiazole) which was analogous to the selective cyclooxygenase-2 (COX-2) inhibitors was also synthesized with our tri-palladium catalyst and gave good isolated yield (94%). The study of the catalytic process revealed that the mechanism of the reaction may involve the replacement of the sulphur ligand on [N-3](+) by iodine from aryl iodides, which was beneficial for the matching of C-I bond energy
sj-docx-1-tab-10.1177_1759720X211067304 – Supplemental material for Safety and efficacy of SHR4640 combined with febuxostat for primary hyperuricemia: a multicenter, randomized, double-blind, phase II study
No full textSupplemental material, sj-docx-1-tab-10.1177_1759720X211067304 for Safety and efficacy of SHR4640 combined with febuxostat for primary hyperuricemia: a multicenter, randomized, double-blind, phase II study by Honghu Tang, Beibei Cui, Yiyu Chen, Lin Chen, Zhihong Wang, Ning Zhang, Yanlan Yang, Xiaodong Wang, Xiangliang Xie, Lingyun Sun, Wantai Dang, Xianyang Wang, Runzi Li, Jianjun Zou, Yi Zhao and Yi Liu in Therapeutic Advances in Musculoskeletal Disease</p
sj-docx-2-tab-10.1177_1759720X211067304 – Supplemental material for Safety and efficacy of SHR4640 combined with febuxostat for primary hyperuricemia: a multicenter, randomized, double-blind, phase II study
No full textSupplemental material, sj-docx-2-tab-10.1177_1759720X211067304 for Safety and efficacy of SHR4640 combined with febuxostat for primary hyperuricemia: a multicenter, randomized, double-blind, phase II study by Honghu Tang, Beibei Cui, Yiyu Chen, Lin Chen, Zhihong Wang, Ning Zhang, Yanlan Yang, Xiaodong Wang, Xiangliang Xie, Lingyun Sun, Wantai Dang, Xianyang Wang, Runzi Li, Jianjun Zou, Yi Zhao and Yi Liu in Therapeutic Advances in Musculoskeletal Disease</p
Inside Back Cover: A Simple Synthesis of Triangular All-Metal Aromatics Allowing Access to Isolobal All-Metal Heteroaromatics (Chem. Eur. J. 35/2015)
No full textThe famous dream of the ouroboros, the symbol of the circle, which inspired Kekulè’s structure of benzene leading to the concept of aromatic chemistry, can also be applied to metals. Noble metals can be assembled in molecules with an equilateral metal core. This regular geometry remains untouched even if mixing different atoms, as a result of cyclic electron delocalization, leading to all-metal aromatics and all-metal heteroaromatics. More details can be found in the Communication by G. Maestri et al. on page 12271 f
Renal-protective effect of thalidomide in streptozotocin-induced diabetic rats through anti-inflammatory pathway
No full textHongxia Zhang,1 Yanlan Yang,2 Yanqin Wang,1 Baodong Wang,1 Rongshan Li1 1Department of Nephrology, 2Department of Endocrinology, Affiliated People’s Hospital of Shanxi Medical University, Shanxi Provincial People’s Hospital, Taiyuan, Shanxi, People’s Republic of China Background: Diabetic nephropathy (DN) is a major microvascular complication in diabetes. An increasing body of evidence has shown that DN is related to chronic inflammation, kidney hypertrophy, and fibrosis. While thalidomide has been shown to have anti-inflammatory and antifibrotic effects, the effects of thalidomide on the pathogenesis of DN are unclear. This study was undertaken to explore whether thalidomide has renal-protective effects in diabetic rats.Methods: Male Sprague Dawley rats were injected intraperitoneally with 50 mg/kg streptozotocin to induce diabetes. Diabetic rats were treated with thalidomide (200 mg/kg/d) for 8 weeks, and then blood and urine were collected for measurement of renal function-related parameters. Histopathology, immunohistochemistry, enzyme-linked immunosorbent assay, and Western blot analyses were performed to assess renal proinflammatory cytokines, fibrotic protein, and related signaling pathways.Results: Diabetic rats exhibited obvious renal structural and functional abnormalities, as well as renal inflammation and fibrosis. Compared with diabetic control rats, those treated with thalidomide showed significantly improved histological alterations and biomarkers of renal function, as well as reduced expression of renal inflammatory cytokines, including NF-κB and MCP-1. Furthermore, renal fibrotic proteins, such as TGF-β1, TβRII, TβRI, smad3, collagen IV, and fibronectin were also remarkably suppressed. Treatment with thalidomide markedly stimulated the phosphorylation of AMPKα.Conclusion: In this study, thalidomide suppressed the inflammatory and fibrotic processes in DN. These effects were partly mediated by the activation of AMPKα, and inhibition of the NF-κB/MCP-1 and TGF-β1/Smad signaling pathways. These results suggest that thalidomide may have therapeutic potential in diabetic renal injury through the anti-inflammatory pathway. Keywords: diabetic nephropathy, thalidomide, AMPK, NF-κB, TGF-β
Reactivity of electrophilic iron, ruthenium and cobalt metallocenes towards the elaboration of nanomatérials
No full textLes métallodendrimères sont des macromolécules précises contenant des centres métalliques dont les propriétés sont exploitables pour la fabrication de nanodevices utiles en catalyse, reconnaissance moléculaire et en tant que précurseurs de nanoparticules. Pour leur contruction, de nouvelles réactions ont été mises au point à partir d’alcynes organométalliques électrophiles qui ont permis la formation de liaisons C-C, C-N et M=C, mettant en jeu des métallocènes du fer, du ruthénium et du cobalt. Cette ingéniérie moléculaire a conduit à de nouvelles métallo-étoiles, dendrimères et nanoparticules d’or aux propriéties rédox originales.Metallodendrimers are precise macromolecules containing metallic centers with properties that are exploitable for nanodevice fabrication providing uses in catalysis, molecular recognition and as nanoparticle precursors. For their construction, new reactions have been disclosed from electrophilic organometallic alkynes leading to the formation of C-C, C-N and C=C bonds that involve iron, ruthenium and cobalt metallocenes. This molecular engineering has produced new metallo-stars, metallodendrimers and gold nanoparticles with original redox properties
Reactivity of electrophilic iron, ruthenium and cobalt metallocenes towards the elaboration of nanomatérials
No full textLes métallodendrimères sont des macromolécules précises contenant des centres métalliques dont les propriétés sont exploitables pour la fabrication de nanodevices utiles en catalyse, reconnaissance moléculaire et en tant que précurseurs de nanoparticules. Pour leur contruction, de nouvelles réactions ont été mises au point à partir d’alcynes organométalliques électrophiles qui ont permis la formation de liaisons C-C, C-N et M=C, mettant en jeu des métallocènes du fer, du ruthénium et du cobalt. Cette ingéniérie moléculaire a conduit à de nouvelles métallo-étoiles, dendrimères et nanoparticules d’or aux propriéties rédox originales.Metallodendrimers are precise macromolecules containing metallic centers with properties that are exploitable for nanodevice fabrication providing uses in catalysis, molecular recognition and as nanoparticle precursors. For their construction, new reactions have been disclosed from electrophilic organometallic alkynes leading to the formation of C-C, C-N and C=C bonds that involve iron, ruthenium and cobalt metallocenes. This molecular engineering has produced new metallo-stars, metallodendrimers and gold nanoparticles with original redox properties
Advances for Triangular and Sandwich-Shaped All-Metal Aromatics
No full textMuch experimental work has been contributed to all-metal σ, π and δ-aromaticity among transition metals, semimetallics and other metals in the past two decades. Before our focused investigations on the properties of triangular and sandwich-shaped all-metal aromatics, A. I. Boldyrev presented general discussions on the concepts of all-metal σ-aromaticity and σ-antiaromaticity for metallo-clusters. Schleyer illustrated that Nucleus-Independent Chemical Shifts (NICS) were among the most authoritative criteria for aromaticity. Ugalde discussed the earlier developments of all-metal aromatic compounds with all possible shapes. Besides the theoretical predictions, many stable all-metal aromatic trinuclear clusters have been isolated as the metallic analogues of either the σ-aromatic molecule’s [H3]+ ion or the π-aromatic molecule’s [C3H3]+ ion. Different from Hoffman’s opinion on all-metal aromaticity, triangular all-metal aromatics were found to hold great potential in applications in coordination chemistry, catalysis, and material science. Triangular all-metal aromatics, which were theoretically proved to conform to the Hückel (4n + 2) rule and possess the smallest aromatic ring, could also play roles as stable ligands during the formation of all-metal sandwiches. The triangular and sandwich-shaped all-metal aromatics have not yet been specifically summarized despite their diversity of existence, puissant developments and various interesting applications. These findings are different from the public opinion that all-metal aromatics would be limited to further applications due to their overstated difficulties in synthesis and uncertain stabilities. Our review will specifically focus on the summarization of theoretical predictions, feasible syntheses and isolations, and multiple applications of triangular and sandwich shaped all-metal aromatics. The appropriateness and necessities of this review will emphasize and disseminate their importance and applications forcefully and in a timely manner
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