Synthesis and properties of some aromatic polyamides with coumarin chromophores

Nechifor, M

doi:10.1016/j.reactfunctpolym.2008.10.006

Cited by 38 publications

(19 citation statements)

References 24 publications

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“…In 2, the H-12 hydrogen atom (δ H 5.98) that binds to the carbon atom at C-12 (δ C 107.4) displayed the three key HMBC correlations to the carbon atoms at δ C 163.8 and δ C 171.0 (esterified and free carbonyl carbon atoms, respectively), and δ C 100.1 (C-8); this pattern implied that 2 also possessed a coumarin substructure with a free carboxyl group attached at the C-11 carbon atom (δ C 150.8) although no HMBC correlation to this carbon atom was observed from any hydrogen atom ( Figure 1a). However, very similar 1 H and 13 C NMR chemical shifts have been reported for several 4-carboxylcoumarin derivatives [5] when they are compared with those of a 3-carboxylcoumarin derivative [6]. The presence of a carboxyl group was well supported from the higher-energy collision induced dissociation high resolution tandem mass spectrometry (HCD HR-MS/MS) data because neutral losses of 43.9899 amu (43.9898 calculated for CO 2 ) were observed resulting from decarboxylation from the fragment ions carrying the coumarin substructure.…”

supporting

confidence: 63%

Crataegusins A and B, New Flavanocoumarins from the Dried Fruits of Crataegus pinnatifida var. major (Rosaceae)

Kazuma

Isobe

Asahina

et al. 2016

Natural Product Communications

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Crataegusins A (1) and B (2), new flavanocoumarins, were isolated from the crude drug Crataegus Fructus, i.e., the dried fruits of Crataegus pinnatifida var. major. Their structures were determined by spectroscopic methods. They were unique in terms of carrying a 3-(or 4-)substituted coumarin substructure while a flavanocoumarin generally does not carry any substituents in the 2-pyron ring. They showed a significant DPPH reducing activity compared with epicatechin. Their production would be biosynthetically regulated considering the results of an LC-MS analysis of the dried and fresh fruits, fruit skin, hypanthia, and leaves. Their structures led the authors to consider a hypothetical general biosynthetic pathway of the flavanocoumarins, to which a flavan-3-ol is converted through a Michael addition and successive oxidative decarboxylation or dehydration pathway.

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supporting

confidence: 63%

Crataegusins A and B, New Flavanocoumarins from the Dried Fruits of Crataegus pinnatifida var. major (Rosaceae)

Kazuma

Isobe

Asahina

et al. 2016

Natural Product Communications

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“…Alkylation reactions were done according to procedures previously described with small modifications [23,24], using different alkyl halides; (allyl bromide, geranyl bromide, prenyl bromide and ethyl chloro-acetate) which gave coumarin derivatives: 11 [25], 13 [26], 16 [26], 17 [27], 18 [28], 19 [29], 20 [30] and 21 [31] in satisfactory yields (45.5%–98%, except 18 ). Acetylation was carried out under ultrasonic irradiation (which increases the rate, speed and yield of chemical reactions, by liquids emulsification [32]), using an acetic anhydride and pyridine mixture afforded derivatives 15 [33], 14 [17], and 12 [34], in good yields (77%–90%).…”

Section: Resultsmentioning

confidence: 99%

Synthesis, Structure-Activity Relationships (SAR) and in Silico Studies of Coumarin Derivatives with Antifungal Activity

Araújo

Guerra

Lima

et al. 2013

IJMS

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The increased incidence of opportunistic fungal infections, associated with greater resistance to the antifungal drugs currently in use has highlighted the need for new solutions. In this study twenty four coumarin derivatives were screened in vitro for antifungal activity against strains of Aspergillus. Some of the compounds exhibited significant antifungal activity with MICs values ranging between 16 and 32 μg/mL. The structure-activity relationships (SAR) study demonstrated that O-substitutions are essential for antifungal activity. It also showed that the presence of a short aliphatic chain and/or electron withdrawing groups (NO2 and/or acetate) favor activity. These findings were confirmed using density functional theory (DFT), when calculating the LUMO density. In Principal Component Analysis (PCA), two significant principal components (PCs) explained more than 60% of the total variance. The best Partial Least Squares Regression (PLS) model showed an r2 of 0.86 and q2cv of 0.64 corroborating the SAR observations as well as demonstrating a greater probe N1 interaction for active compounds. Descriptors generated by TIP correlogram demonstrated the importance of the molecular shape for antifungal activity.

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“…When included in polymers, these features can be used to acquire tailored macromolecules that have interesting and far-reaching properties: a few of which have been emphasised here (Nechifor, 2009). This article details the preparation of a four-armed macroinitiator prepared from a coumarone end-functionalised poly(methyl methacrylate) and a four-armed graft copolymer by atom transfer radical polymerization in the presence of a four-armed macroinitiator and n-butyl methacrylate, with the characterisation of the macroinitiator and graft copolymer by Fourier transform infrared spectroscopy (FT-IR), Hydrogen-1 Nuclear Magnetic Resonance ( 1 H-NMR) and gel permeation chromatography (GPC).…”

Section: Pigment and Resin Technologymentioning

confidence: 99%

Synthesis and characterisation of a photoresponsive four-armed graft copolymer prepared from coumarin and methyl methacrylate

Bezgin

Demirelli

2014

PRT

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If you would like to write for this, or any other Emerald publication, then please use our Emerald for Authors service information about how to choose which publication to write for and submission guidelines are available for all. Please visit www.emeraldinsight.com/authors for more information. About Emerald www.emeraldinsight.comEmerald is a global publisher linking research and practice to the benefit of society. The company manages a portfolio of more than 290 journals and over 2,350 books and book series volumes, as well as providing an extensive range of online products and additional customer resources and services.Emerald is both COUNTER 4 and TRANSFER compliant. The organization is a partner of the Committee on Publication Ethics (COPE) and also works with Portico and the LOCKSS initiative for digital archive preservation. AbstractPurpose -This paper aims to a newly designed photoresponsive four-armed graft copolymer was synthesised and characterised. The synthesised polymer contains photochemical group and a greater part of the cross-linkable functional group which is not affected by short wavelength when subject to under ultraviolet (UV) irradiation in film status. Design/methodology/approach -The four-armed macroinitiator was prepared by reacting diethanol amine with poly [methyl-2-chloro-4-{7-(chloroacetyl) oxy]-2-oxo-2H-chromen-4-yl}-2-methylbutanoate] and acylating the product with chloroacetyl chloride. A grafting reaction with n-butyl methacrylate was carried out in the presence of the four-armed macroinitiator and the catalyst CuBr/2, 2=-bipyridyne at 90°C. All of the synthesised polymers were structurally characterised by Fourier transform infrared spectroscopy (FT-IR) and Hydrogen-1 Nuclear Magnetic Resonance (1H-NMR) spectra. Gel permeation chromatography was used to obtain the molecular weights of polymer. Findings -1H-NMR, FT-IR and ultraviolet-visible (UV-Vis) spectroscopy demonstrated that the four-armed macroinitiator and the graft copolymer was successfully synthesised. The end-functionalised poly(methyl methacrylate) with 7-hydroxyl-4-chloromethyl coumarone was irradiated at the wavelength larger than 300 nm to create the cyclobutane ring in between the 7-hydroxyl-4-chloro methyl coumarone unities. To characterise the polymer and show the transformation of coumarone unities into photodimers, 1H-NMR, FT-IR and UV-Vis spectroscopy were used. Research limitations/implications -Graft copolymer containing coumarone has involves photocrosslinkable functional group, in which reactive functional group has attracted great interest from both industrial and academic fields. Their synthesis provides the opportunity for a compatible modification of the graft copolymer structure to develop adapted macromolecules for a range of end practices. Practical implications -A photoresponsive graft copolymer can have a role in an active area of polymer chemistry research due to its uses in the areas of photolithography, liquid crystal, non-linear optical materials, laser dyes, fluorescence materials and futur...

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Synthesis and properties of some aromatic polyamides with coumarin chromophores

Cited by 38 publications

References 24 publications

Crataegusins A and B, New Flavanocoumarins from the Dried Fruits of Crataegus pinnatifida var. major (Rosaceae)

Crataegusins A and B, New Flavanocoumarins from the Dried Fruits of Crataegus pinnatifida var. major (Rosaceae)

Synthesis, Structure-Activity Relationships (SAR) and in Silico Studies of Coumarin Derivatives with Antifungal Activity

Synthesis and characterisation of a photoresponsive four-armed graft copolymer prepared from coumarin and methyl methacrylate

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