Mass Spectra of Aliphatic Thiols and Sulfides

Sawîckî, Eugene; Stanley, T. W.; Häuser, Tobias; Elbert, W.C.; Nee, J. L.

doi:10.1021/ac60174a018

Cited by 116 publications

(90 citation statements)

References 14 publications

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“…Mechanism The literature citation revealed that MBTH on oxidation with cerium(IV) in acidic medium produces an active electrophilic intermediate 15) which further reacts with iminoheteroaromatic compounds such as indole, carbazole, phenothiazine and benzimidazole resulting in the formation of a colored azo cationic species. 16,17) Benzimidazole is the iminoheteroaromatic compound which undergoes electrophilic substitution in the benzene ring. The order of substitution is 7Ͼ6Ͼ5Ͼ4.…”

Section: Resultsmentioning

confidence: 99%

Quantitative Analysis of Rabeprazole Sodium in Commercial Dosage Forms by Spectrophotometry

Rahman

Bano

Azmi

2008

CHEMICAL & PHARMACEUTICAL BULLETIN

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The main aim of this work is to develop and validate two spectrophotometric methods for the quantitative analysis of rabeprazole sodium in commercial dosage forms. Method A is based on the reaction of drug with 3-methyl-2-benzothiazolinone hydrazone hydrochloride (MBTH) in the presence of ammonium cerium(IV) nitrate in acetic acid medium at room temperature to form red-brown product which absorbs maximally at 470 nm.

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Section: Resultsmentioning

confidence: 99%

Quantitative Analysis of Rabeprazole Sodium in Commercial Dosage Forms by Spectrophotometry

Rahman

Bano

Azmi

2008

CHEMICAL & PHARMACEUTICAL BULLETIN

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“…It is not plausible that the formed ketone reacts with hydrazone to form azine because MBTH specifically reacts with aldehydes 13 and is rather slow to react with ketones, 22 and actual tests using MBTZ and MBTH eliminate the formation of MBTA under similar conditions. The examination also shows that no ketone is obtained from the peroxy compound, MBTPO, by OO bond cleavage.…”

Section: Activation Of Dioxygen Inmentioning

confidence: 99%

Activation of Dioxygen in an Aqueous System of [FeIIITMPyP]–MBTH–O2 to Form Peroxide and Azine from MBTH: Reactivity of Superoxohemin ([FeIIITMPyP–OO]•) and Peroxohemin ([FeIIITMPyP–OO]−)

Nakano

Kakuda

Shinoda

et al. 2013

Bulletin of the Chemical Society of Japan

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Activation of dioxygen in the heme system is observed in an artificial aqueous model system. It has been demonstrated that in the system of a water-soluble hemin, tetrakis(N-methylpyridyl)porphinatoiron(III) pentachloride ([FeIIITMPyP]Cl5), and a mild reducing reagent, 3-methyl-2-benzothiazolinonehydrazone (MBTH), a superoxide anion radical and hydrogen peroxide have been produced in air at pH 7.0 that degrades hemin. In this complex system with a reductant and an oxidant, we have found the reaction products derived from MBTH: a bridging peroxide, 2,2′-peroxybis(3-methyl-2,3-dihydrobenzothiazole) (MBTPO), adding to a previously observed azine, 1,2-bis(3-methyl-2,3-dihydrobenzothiazole-2-ylidene)hydrazine (MBTA), and also a small amount of ketone, 3-methyl-2(3H)-benzothiazolone (MBTZ). We suggest that dioxygen is activated to the intermediates, superoxohemin ([FeIII–OO]•) and peroxohemin ([FeIII–OO]−). Because the addition of reactive oxygen species quenchers such as superoxide dismutase (SOD) and catalase allows reaction that prevents the degradation of heme, the roles of liberated superoxide or hydrogen peroxide are excluded from the mechanism. On the other hand, another possible intermediate, a high-valent oxoiron species ([Fe+=O]), is suggested to form the ketone, MBTZ, while under anaerobic conditions organic hydroperoxide (t-BuOOH) instead of O2 solely reacts to form the ketone. The system is discussed in relation to NADPH oxidase, cytochrome P450, NO synthase (NOS), and heme oxidase (HO).

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“…A reação não é imediata, o tempo recomendado pelos autores do método original 34,35 , é de uma hora para a primeira etapa da reação e mais 12 minutos após a adição de Fe(III) para proceder a leitura do sinal de absorbância. A reação não é específica.…”

Section: Considerações Iniciaisunclassified

Gota suspensa para avaliação de aldeído total no ar interno e externo do ambiente

Pereira¹,

Cardoso²,

Dasgupta³

2001

Quím. Nova

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Mass Spectra of Aliphatic Thiols and Sulfides

Cited by 116 publications

References 14 publications

Quantitative Analysis of Rabeprazole Sodium in Commercial Dosage Forms by Spectrophotometry

Quantitative Analysis of Rabeprazole Sodium in Commercial Dosage Forms by Spectrophotometry

Activation of Dioxygen in an Aqueous System of [FeIIITMPyP]–MBTH–O2 to Form Peroxide and Azine from MBTH: Reactivity of Superoxohemin ([FeIIITMPyP–OO]•) and Peroxohemin ([FeIIITMPyP–OO]−)

Gota suspensa para avaliação de aldeído total no ar interno e externo do ambiente

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