Mass spectrometry as a valuable tool for the study of tautomerism of amides and thioamides

Allegretti, Patricia Ercilia; Milazzo, Cecilia; Castro, Eduardo A.; Furlong, Jorge

doi:10.1016/s0166-1280(02)00258-0

Cited by 26 publications

(34 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…These conclusions are supported by temperature studies at the ion source (negligible effect) and at the injection port of the gas chromatograph with a shifting effect in agreement with the corresponding heats of tautomerization [10]. In fact, this process would take place very fast under the working conditions in the GC.…”

Section: Introductionsupporting

confidence: 67%

“…As it has been demonstrated in the case of keto-enol tautomerism of a series of 1-and 3-substituted acetylacetones [9] and a variety of carbonylic and thiocarbonilic compounds [10][11][12][13][14][15][16][17], there is no significant interconversion of the tautomeric forms in the gas phase following electron impact ionization in the mass spectrometer (molecular ions, M + .…”

Section: Introductionmentioning

confidence: 99%

“…Separation of the tautomers in the analytical column are usually very difficult, consequently, the different pathways of fragmentation of the tautomeric forms have to be used for identification of the individual tautomers [10]. For this reason and because of the high similarity between MS (commercial databases) and GC/MS spectra, analytical separation has not been considered critical for the present work.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Spectrometric Studies and Semi-Empirical Calculations of Some Thiomorpholides

Allegretti¹,

Ruiz²,

Castro³

et al. 2009

TOPCJ

View full text Add to dashboard Cite

Mass spectra of selected thiomorpholides have been analysed and specific fragmentation assignments have been done to characterised and weigh co-existing keto and enol tautomers. The predictive value of this methodology in regard to keto-enol equilibria occurring in gas phase is not only supported by the influence of substitution nature and size of these but also by the good correlation found between the selected fragments abundances ratio, semi-empirical calculation (AM1) of the corresponding heats of tautomerization and nuclear magnetic resonance data. The results show that the thioketo-thioenol equilibrium can be studied by mass spectrometry where ionization in the ion source has a negligible effect on the position of that equilibrium and by GC/MS where solvent separation in the analytical column seems to preclude shifts from the equilibrium reached at the injection port of the gas chromatograph.

show abstract

Section: Introductionsupporting

confidence: 67%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Spectrometric Studies and Semi-Empirical Calculations of Some Thiomorpholides

Allegretti¹,

Ruiz²,

Castro³

et al. 2009

TOPCJ

View full text Add to dashboard Cite

show abstract

“…Evidently, among organic compounds families, esters are rather unique in regard to their mass spectra and the use of mass spectrometry data to study their tautomeric equilibria (equation 5), methodology that has been very useful to predict tautomerism occurrence for other compounds families [28][29][30][31][32][33][34][35][36] . For esters, the spectral interferences have to be considered carefully for the comparison among family members.…”

Section: Resultsmentioning

confidence: 99%

Mass spectral and theoretical studies on the tautomerism of selected thioesters

Allegretti¹,

Asens²,

Schiavoni³

et al. 2004

Arkivoc

View full text Add to dashboard Cite

show abstract

“…After ionization, compounds with functional thioamide group exist under tautomeric equilibria [71] and, despite of that, it has been possible to develop new ETH derivatives, denominated by oxazolinyl (10, Fig (10)) and N-hydroxy-alkyl (11, Fig. (10)) [72].…”

Section: Eth Metabolismmentioning

confidence: 99%

Metabolism of the Antituberculosis Drug Ethionamide

Vale

Gomes²,

Santos³

2012

CDM

View full text Add to dashboard Cite

Ethionamide (ETH) is an important second-line antituberculosis drug used for the treatment of patients infected with multidrug-resistant Mycobacterium. Although ETH is a structural analogue of isoniazid (INH), both are pro-drugs that need to be activated by mycobacterial enzymes to exert their antimicrobial activity. ETH mechanism of action is thought to be identical to INH although the pathway of activation is distinct from that of INH. ETH is activated by an EthA enzyme, leading to the formation of an Soxide metabolite that has considerably better activity than the parent drug. This review comprehensively examines the aspects related with the metabolism of ETH since its discovery up to today.

show abstract

Mass spectrometry as a valuable tool for the study of tautomerism of amides and thioamides

Cited by 26 publications

References 14 publications

Spectrometric Studies and Semi-Empirical Calculations of Some Thiomorpholides

Spectrometric Studies and Semi-Empirical Calculations of Some Thiomorpholides

Mass spectral and theoretical studies on the tautomerism of selected thioesters

Metabolism of the Antituberculosis Drug Ethionamide

Contact Info

Product

Resources

About