The chemistry of Mandelin’s test for strychnine

Sánchez-Viesca, None Francisco; Gómez, Reina

doi:10.53022/oarjcp.2023.3.1.0040

Cited by 9 publications

(8 citation statements)

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“…In this communication we provide the reaction route of the interaction of noscapine with ammonium tellurate in sulphuric acid. This paper is a follow up of our studies on reaction mechanism, [5][6][7][8][9].…”

Section: Figure 1 the Structure Of Noscapinementioning

confidence: 90%

On the Interaction of Noscapine (Narcotine) with Ammonium Tellurate in Sulphuric Acid

Sánchez-Viesca,

Gómez

2023

EJCS

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The purpose of this study is to clear up what is happening in the test tube during the interaction of ammonium tellurate with noscapine in sulphuric acid (Brociner test). The approach is a Theoretical Organic Chemistry Study based on the chemical deportment of reagent and substrate, the reaction medium, and experimental conditions. This point out that a redox process is going up, with the following results: meta-telluric acid is formed in situ whose protonation yields the reactive species. Reaction with the methylenedioxy group present in noscapine affords an oxonium salt. Reaction proceeds when a water molecule forms a hemiacetal and an organometallic ester, a tellurate. Acidolysis of the latter gives rise to a concerted mechanism involving five electron-shifts. This way the following compounds are formed: tellurious acid, an ortho-benzoquinone, and formaldehyde. Tellurium dioxide results by acid catalyzed dehydration of tellurious acid.

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Section: Figure 1 the Structure Of Noscapinementioning

confidence: 90%

On the Interaction of Noscapine (Narcotine) with Ammonium Tellurate in Sulphuric Acid

Sánchez-Viesca,

Gómez

2023

EJCS

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“…In this communication we give the mechanism of the oxido degradation of uric acid that takes place during its interaction with phosphotungstic reagent (Folin test). This paper is a follow up of our studies on reaction mechanism, [2][3][4][5][6].…”

Section: Introductionmentioning

confidence: 90%

On the mechanism of the Folin test for uric aci

Sánchez-Viesca¹,

Gómez²

2023

World J. Chem. Pharm. Sci.

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The mechanism of the interaction of uric acid with sodium tungstate in phosphoric acid (Folin test) is described. This insight involves the following steps: addition of tungstic acid to the carbon-carbon double bond in uric acid. Protolysis of the organometallic ester gives rise to dihydroxyoxotungsten and an epoxide, via a concerted mechanism. Acid catalyzed ring opening of the oxirane produces a vicinal diol via reaction of the intermediate carbocation with water. Isomerization of the resulting carbinolamide groups is enhanced by the resonance of the ureido group. Breaking of the second carbinolamide gives urea and alloxan, 5-ketobarbituric acid hydrate. Uric acid oxidation in strong acidic medium like phosphoric acid produces alloxan, whereas oxidation in alkaline, neutral, or slightly acidic medium, gives allantoin.

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“…Colorimetric assays offer simple visual readouts and do not require instruments for the analysis. This communication is a follow up of our studies on reaction mechanism, [5][6][7][8][9].…”

Section: Figure 1 Morphine and Codeine Structuresmentioning

confidence: 97%

The mechanism of Mecke’s test for opioids

Sánchez-Viesca¹,

Gómez²

2023

World J. Chem. Pharm. Sci.

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Mecke colour test is an official assay for opioids, either for opium or for purified compounds. It employs a solution of selenious acid in sulphuric acid. However, organoselenium chemistry was misunderstood for many years. The reaction mechanism involving selenium (IV) compounds was explained by way of electron back donation, which is a theoretical contravention. In this communication we provide the reactions that take place during this test. Each step is fully commented and the electron flow is given. The reaction proceeds by way of an enol selenite. Acidolysis gives rise to a reduced selenium (II) intermediate and an activated ketone at C-2, that is, a redox reaction with polarity inversion. Addition of selenious acid and further electron shifts affords morphine ortho-quinone and elemental selenium.

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The chemistry of Mandelin’s test for strychnine

Cited by 9 publications

References 0 publications

On the Interaction of Noscapine (Narcotine) with Ammonium Tellurate in Sulphuric Acid

On the Interaction of Noscapine (Narcotine) with Ammonium Tellurate in Sulphuric Acid

On the mechanism of the Folin test for uric aci

The mechanism of Mecke’s test for opioids

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