Aminothiazoles and Their Derivatives

Barone, R.; Chanon, Michel; Gallo, R.

doi:10.1002/9780470187067.ch2

Cited by 26 publications

(7 citation statements)

References 619 publications

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“…However, it is known that the exocyclic nitrogen atom of 2-aminothiazoles is the preferred site of reaction with sp 2 C electrophiles (e.g. acid chlorides, formimidates) 34,35 while the N-3 atom of 2-amino[1, 3,4]thiadiazoles has greater nucleophilicity than the exocyclic nitrogen atom, 36 so the findings described above provide consistent evidence that the chloro-substituted amidine carbon atom of 1 is the more electrophilic site.…”

Section: Scheme 14supporting

confidence: 59%

New heteroatom-rich ring systems from N,N-dialkyl-N’-chlorosulfonyl chloroformamidines

Francis¹

2016

Arkivoc

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N,N-Dialkyl-N'-chlorosulfonyl chloroformamidines constitute a class of readily available and very versatile bis-electrophiles. This Account describes the application of these unusual + C=N-S + building blocks for construction of a cornucopia of previously unknown or uncommon heterocyclic ring systems. Regioselectivity encountered during heterocycle formation and some properties and chemistry of the newly-formed ring systems are also discussed.

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Section: Scheme 14supporting

confidence: 59%

New heteroatom-rich ring systems from N,N-dialkyl-N’-chlorosulfonyl chloroformamidines

Francis¹

2016

Arkivoc

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“…The chemistry of aminothiazoles and their derivatives has attracted the attention of chemists, because they exhibit important biological activity in medicinal chemistry 1, such as antibiotic, anti‐inflammatory, antihelmintic, or fungicidal properties 2–4. 2‐Aminothiazoles are known mainly as biologically active compounds with a broad range of activities and as intermediates in the synthesis of antibiotics, well‐known sulfa drugs, and some dyes 5, 6.…”

Section: Introductionmentioning

confidence: 99%

Effects of enhanced bolus flavors on oropharyngeal swallow in patients treated for head and neck cancer

Pauloski

Logemann²,

Rademaker

et al. 2012

Head & Neck

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Background Treatment for head and neck cancer can reduce peripheral sensory input and impair oropharyngeal swallow. This study examined the effect of enhanced bolus flavor on liquid swallows in these patients. Methods Fifty-one patients treated for head and neck cancer with chemoradiation or surgery and 64 healthy adult control subjects served as subjects. All were randomized to receive sour, sweet, or salty bolus flavor. Patients were evaluated at 7–10 days, 1 month, and 3 months after completion of tumor treatment. Control subjects received 1 assessment. Results All bolus flavors affected oropharyngeal swallow; sour flavor significantly shortened pharyngeal transit time across all evaluations. Conclusions Sour flavor influenced the swallow of patients treated for head and neck cancer, as well as that of control subjects in a manner similar to those with neurologic impairment observed in an earlier study. Sour flavor may improve the speed of pharyngeal transit regardless of whether a patient has suffered peripheral or central sensory damage.

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“…The spectrum for CFT-Product 2 had three maxima at ∼235 nm (obscured by the negative methanol absorbance), 263 nm, and 305 nm (Figure E). Previous work has shown adsorption bands associated with substructures of ceftriaxone at maxima of 270 nm for the 2-aminothiazole (5-membered ring) moiety and at 240, 256, and 270 nm for the 7-aminocephalosporanic acid functional group (cephem functional group) . Moreover, using LC–MS analysis, the remaining structure of ceftriaxone (minus the thiotriazinone ring; (6 R ,7 R )-7-[[(2 Z )-2-(2-amino-4-thiazolyl)-2-(methoxyimino)acetyl]amino]-3-(hydroxymethyl)-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid, or 3-desacetyl cefotaxime also known as Cefotaxime Impurity B) was previously identified as the second product of hydrolysis .…”

Section: Resultsmentioning

confidence: 99%

“…The spectrum for CFT-Product 2 had three maxima at ∼235 nm (obscured by the negative methanol absorbance), 263 nm, and 305 nm (Figure 2E). Previous work has shown adsorption bands associated with substructures of ceftriaxone at maxima of 270 nm for the 2-aminothiazole (5-membered ring) moiety 77 and at 240, 256, and 270 nm for the 7-aminocephalosporanic acid functional group (cephem functional group). 72 Moreover, using LC−MS analysis, the remaining structure of ceftriaxone (minus the thiotriazinone ring;…”

Section: Ph Dependence and Compound Dependence Of β-Lactammentioning

confidence: 99%

Probing the Fate of Different Structures of Beta-Lactam Antibiotics: Hydrolysis, Mineral Capture, and Influence of Organic Matter

Klein

Sarri

Kelch

et al. 2021

ACS Earth Space Chem.

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Beta-lactam antibiotics, which are used extensively in human and veterinary applications, are commonly detected in surface waters. To examine how the distinct structures of different generations of beta-lactam antibiotics can influence their persistence or degradation in environmental aqueous media, we examined the fate of two penams (amoxicillin and cloxacillin) and two cephems (cephalexin and ceftriaxone) at pH 5.0 and pH 7.0. By contrast to the lack of hydrolysis of the penam antibiotics at both pHs, we observed hydrolysis of cephalexin at pH 7.0 (t 1/2 = 12 d) and ceftriaxone at pH 5.0 (t 1/2 = 2.8 d). Using highperformance liquid chromatography coupled with a diode array detector or a high-resolution mass spectrometer, we were able to confirm thiotriazinone and 3-desacetyl cefotaxime as major hydrolysis products of ceftriaxone, and propose the hydrolytic cleavage of the benzene and cephem moieties from cephalexin. In addition, we studied the effects of smectite clay particles suspended in solutions without or with dissolved organic matter. The adsorption capacity of the clay was 4-to 9-fold higher at pH 7.0 than at pH 5.0. Subsequent X-ray diffraction analysis revealed that the antibiotic adsorption was not within the clay interlayer nanopores but occurred primarily on the external clay surfaces. The addition of dissolved organic matter interfered with the adsorption of a cephem antibiotic (ceftriaxone) on the clay, but the adsorption of a penam antibiotic (amoxicillin) remained unaffected. We employed molecular modeling simulations to probe the mechanisms of adsorption on the mineral surface. Our findings offer new insights on how the compound structures can dictate different fates of the beta-lactam class of antibiotics in environmental media.

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Aminothiazoles and Their Derivatives

Cited by 26 publications

References 619 publications

New heteroatom-rich ring systems from N,N-dialkyl-N’-chlorosulfonyl chloroformamidines

New heteroatom-rich ring systems from N,N-dialkyl-N’-chlorosulfonyl chloroformamidines

Effects of enhanced bolus flavors on oropharyngeal swallow in patients treated for head and neck cancer

Probing the Fate of Different Structures of Beta-Lactam Antibiotics: Hydrolysis, Mineral Capture, and Influence of Organic Matter

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