Visible fluorescence and chemical constitution of compounds of the benzopyrone group

Balaiah, V.; Seshadri, T. R.; Venkateswarlu, V.

doi:10.1007/bf03177739

Cited by 23 publications

(7 citation statements)

References 7 publications

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“…This finding is in line with previous work on the coumarin chromophore that showed that the addition of an OH group at C-7 of coumarin gives rise to a distinctly fluorescent molecule while attachment of three OH groups affords nonfluorescent coumarin derivatives. 9 Accordingly, trihydroxydabcyl derivatives were not fluorescent either. Moreover, the three hydroxy groups had to be positioned in a way that precludes the formation of catechol chelate complexes with biologically relevant metal ions (e.g., Fe(III) 10 ) which would possibly interfere with the system under investigation.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

Hydrodabcyl: A Superior Hydrophilic Alternative to the Dark Fluorescence Quencher Dabcyl

Kempf

Schobert

et al. 2017

Anal. Chem.

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Dark fluorescence quenchers are nonfluorescent dyes that can modulate the fluorescence signal of an appropriate fluorophore donor in a distance-dependent manner. Dark quenchers are extensively used in many biomolecular analytical applications, such as studies with fluorogenic protease substrates or nucleic acids probes. A very popular dark fluorescence quencher is dabcyl, which is a hydrophobic azobenzene derivative. However, its insolubility in water may constitute a major drawback, especially during the investigation of biochemical systems whose natural solvent is water. We designed and synthesized a new azobenzene-based dark quencher with excellent solubility in aqueous media, which represents a superior alternative to the much-used dabcyl. The advantage of hydrodabcyl over dabcyl is exemplarily demonstrated for the cleavage of the fluorogenic substrate hydrodabcyl-Ser-Phe-EDANS by the proteases thermolysin and papain.

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Section: ■ Results and Discussionmentioning

confidence: 99%

Hydrodabcyl: A Superior Hydrophilic Alternative to the Dark Fluorescence Quencher Dabcyl

Kempf

Schobert

et al. 2017

Anal. Chem.

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“…Yield 78%, mp 271-272°C, lit. [11] mp 264°C, [12] General Method of Synthesizing Amides 3-11. Method A.…”

Section: 7-dihydroxy-4-methyl-2-oxochromen-3-yl)acetic Acid (2)mentioning

confidence: 99%

Modified coumarins. 27. Ssynthesis and antioxidant activity of 3-substituted 5,7-dihydroxy-4-methylcoumarins

et al. 2007

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547.814.5 I. V. Nagorichna, and A. S. OgorodniichukAmides of 5,7-dihydroxy-4-methylcoumaryl-3-ylacetic acid were synthesized by the activated ester method using N-hydroxysuccinimide and diisopropylcarbodiimide or by reaction with N,N-carbonylimidazole. The reactivity of 3-substituted 5,7-dihydroxy-4-methylcoumarins toward 2,2-diphenyl-1-picrylhydrazyl and superoxide radical was analyzed. The effect of the synthesized compounds on xanthineoxidase activity was studied.Natural coumarins and their synthetic structural analogs possess a broad spectrum of biological activity including antiinflammatory, antibacterial, and analgesic action [1,2]. The design of new derivatives of benzopyran-2-one is often based on research of the functions of these compounds in model systems. It has been found that simple natural coumarins containing two ortho hydroxyls (6,7-dihydroxycoumarins, 7,8-dihydroxycoumarins) are effective traps for the superoxide radical and alkylperoxyl radicals and are inhibitors of peroxide oxidation of lipids. However, these compounds in the presence of iron ions can also be prooxidants that are capable under certain conditions of stimulating undesired redox transformations involving molecular oxygen. Therefore, coumarin derivatives containing meta dihydroxyls are definitely interesting for constructing potential synthetic antioxidants. Thus, 5,7-dihydroxy-4-methylcoumarin is not a pro-oxidant, inhibits peroxide oxidation of lipids, and reacts with active oxygen species and hypochlorite [3]. Besides, it inhibits transformations catalyzed by cyclooxygenase and does not affect the activity of 5-lipoxygenase [2,4,5].Because of the importance of the 5,7-dihydroxy-4-methylcoumarin moiety in the structure of a potential antioxidant, we attempted to analyze certain properties of 5,7-dihydroxy-4-methylcoumarins containing 3-substituents. A series of structurally similar amides was synthesized using 5,7-dihydroxy-4-methylcoumarin-3-ylacetic acid as starting material. Their reactivity toward 2,2-diphenyl-1-picrylhydrazyl and superoxide radical was studied. The effect of the synthesized compounds on xanthineoxidase activity was also found. 5,7-Dihydroxy-4-methylcoumarin-3-ylacetic acid (2) that was required for subsequent transformations was prepared by saponification of the ester in 5,7-dihydroxy-4-methylcoumarin (1) by NaOH in aqueous propan-2-ol with subsequent acidolysis of the reaction mixture. Coumarin 1 was synthesized by condensation of phloroglucinol dihydrate and dimethylacetylsuccinate in the presence of dry HCl.Amides of 2 were prepared by two methods. The first used N-acylation based on the activated ester method that is used commonly in peptide synthesis [6]. The carboxylic acid was activated using a highly reactive N-hydroxysuccinimide ester [7]. The activated ester was prepared by reacting 2 and N-hydroxysuccinimide (SuOH) in absolute dioxane using diisopropylcarbodiimide (DIC) as the condensing agent. Condensation of the resulting activated ester with amines in dioxane at room temperature formed amides...

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“…Phenols that have been used in the Pechmann condensation include resorcinol [1-15], 3-methylphenol [16,17], 4-methylphenol [18,19], 2,4-dimethylphenol [20], 3-methoxyphenol [7,21], 2-methylresorcinol [10,[22][23][24], orcine [10,14,25], 4-chlororesorcinol [10,26], 2-bromoresorcinol [27], 4-ethylresorcinol [28,29], β-resorcinolic acid methyl ester [30], 5-pentadecylresorcinol [31], 4-ethyl-2-acetylresorcinol [28], 2-methylhydroquinone [32], 2-ethylhydroquinone [32], pyrogallol [5,10,11,15,33,34,59,64], 4-ethylpyrogallol [35], pyrogallol-4-carboxylic acid ethyl ester [35], phloroglucinol [10,11,13 15,33,[36][37][38][39][40][41][42][43]…”

Section: Pechmann Reactionmentioning

confidence: 99%

Neoflavones. 2. Methods for Synthesizing and Modifying 4-Arylcoumarins

Garazd

Khilya

2005

Chem Nat Compd

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Literature data up to 2003 were presented and information on methods for preparing and modifying natural 4-arylcoumarins and their synthetic analogs were systematized.The first part of this review [1] presented data on the physicochemical and pharmacological properties of natural 4-arylcoumarins. Natural neoflavones and their synthetic analogs can be used as medical preparations because of their wide spectrum of biological activity and low toxicity. However, this necessitates the development of preparative synthetic methods. Therefore, the second part reviews completely all presently known synthetic approaches to the construction and modification of neoflavones.

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Visible fluorescence and chemical constitution of compounds of the benzopyrone group

Cited by 23 publications

References 7 publications

Hydrodabcyl: A Superior Hydrophilic Alternative to the Dark Fluorescence Quencher Dabcyl

Hydrodabcyl: A Superior Hydrophilic Alternative to the Dark Fluorescence Quencher Dabcyl

Modified coumarins. 27. Ssynthesis and antioxidant activity of 3-substituted 5,7-dihydroxy-4-methylcoumarins

Neoflavones. 2. Methods for Synthesizing and Modifying 4-Arylcoumarins

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