Arsenic-75 nuclear magnetic resonance: Study of the interaction of arsenate with various molecules of biological interest

Geraldes, Carlos F. G. C.; Saraiva, M.E.; Dias, Brenno Anderson Santiago

doi:10.1016/0162-0134(92)80013-l

Cited by 6 publications

(8 citation statements)

References 22 publications

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“…In spectra with comparatively smaller linewidths, as in the example shown here, an asymmetry was often observed for the two unknown signals, which indicates a superposition of signals. 75 As NMR studies of H3AsO4/Na3AsO4 solutions depending on pH showed that, at pH values above 13.5, the 75 As NMR line became much narrower due to a shift in the dissociation equilibrium to the completely deprotonated, symmetrical tetrahedral anion [25]. Because the separation of arsenic in copper production is performed in strongly alkaline sulfidic solutions, in which the species should also be dominated by completely deprotonated arsenate derivatives, the use of 75 As NMR in combination with high magnetic fields appears to be promising.…”

Section: Resultsmentioning

confidence: 99%

“…Nevertheless, 75 As NMR investigations in solution are rare. Reviews are provided by Klapötke and Pettinari et al [19,20] and range from the investigation of arsenic salts in general [21], As(OTeF 5 ) 5 and As(OTeF 5 ) 6 − in solution [22], Keggin ions [23], and arsenic oxy salts [24], to the AsO 4 3− interaction with biomolecules [25]. Surprisingly, 75 As chemical shift data could not be found for thioarsenates in solution, not even for the tetrathioarsenate [20].…”

Section: Introductionmentioning

confidence: 99%

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75As Nuclear Magnetic Resonance Spectroscopic Investigation of the Thioarsenate Speciation in Strongly Alkaline Sulfidic Leaching Solutions

Brendler,

Meiner,

Wagler

et al. 2024

Molecules

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Copper ores and concentrates thereof feature an increasingly notable content of impurities such as arsenic and other hazardous elements. As an alternative to the state-of-the-art partial roasting process, arsenic could be removed by the alkaline sulfide leaching of the copper concentrates. In order to optimize and understand the processes, knowledge of the speciation and oxidation states is essential. In addition to methods such as UV/Vis spectroscopy, chromatography and ICP/MS methods, 75As NMR spectroscopy may be useful for the differentiation and quantification of the various species. Although arsenate(V) has been characterized by 75As NMR some time ago, to our knowledge, there are no data on tetrathioarsenate(V) AsS43− and the mixed oxygen/sulfur substituted mono-, di- and trithioarsenates(V) AsOxS4−x3−, x = 3, 2, 1, respectively. Therefore, we investigated several model solutions and samples from Cu-As leaching with 75As NMR. The strongly alkaline conditions of the leaching solution proved to be very advantageous for that purpose. Both the tetrathioarsenate(V) and the mixed species AsOxS4−x3− (x = 1–3) could be characterized and provide valuable data for the quantification of the material flows in the leaching process.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

75As Nuclear Magnetic Resonance Spectroscopic Investigation of the Thioarsenate Speciation in Strongly Alkaline Sulfidic Leaching Solutions

Brendler,

Meiner,

Wagler

et al. 2024

Molecules

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“…A presença de iões metálicos pode contribuir para a estabilização da ribose, pois foi previamente descrito que formam complexos com determinadas conformações dos monossacáridos, nomeadamente da ribose, através da coordenação com os grupos de tipo hidroxilo dos carbonos C1, C2 e C3, tal como se verificou com oxoiões de molibdénio, tungsténio e urânio. 44 Também o vanadato 45 e o arsenato 46 complexam a ribose e o molibdato 47 favorece a síntese desta pentose. A complexação destes oxoiões com os açúcares permitiriam que estes tivessem conformações favoráveis a determinadas reações que não seriam possíveis na ausência destas espécies químicas, embora não seja plausível a ocorrência significativa destes oxoiões no ambiente redutor pré--biótico.…”

Section: Síntese De Riboseunclassified

Os semimetais na origem e evolução da vida

Aureliano¹,

Nolasco²,

Silva³

et al. 2012

Quím. Nova

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Recebido em 16/9/11; aceito em 2/12/11; publicado na web em 23/1/12 METALLOIDS IN ORIGIN AND EVOLUTION OF LIFE. Metalloids have characteristics between metals and non-metals which give them, in some cases, specific properties. At least two of this chemical elements, boron and silicon, are essential to a significant number of living organisms and since some years ago it has been observed that the same metalloids may be involved in the synthesis and stabilization of some molecules relevant to the origin of life.Keywords: RNA world; boron; silicon. INTRODUÇÃOEmbora se verifique uma tendência para abandonar o conceito de semimetal (metaloide), tanto a União Internacional da Química Pura e Aplicada como a Sociedade Brasileira de Química não os incluem separadamente nas suas tabelas periódicas dos elementos, 1 continuam a publicar-se muitos trabalhos sobre semimetais, dado que têm algumas especificidades com aplicações, por exemplo, no fabrico de semicondutores.2 No grupo dos semimetais (Figura 1) são, geralmente, incluídos os seguintes elementos químicos: boro (grupo 13), silício e germânio (grupo 14), arsénio e antimónio (grupo 15), e telúrio (grupo 16), sendo, por vezes, a designação alargada ao polónio (grupo 16) e ao ástato (grupo 17). Caracterizam-se por terem propriedades físicas e/ou químicas de metais e de não metais. Note-se que o ástato apresenta propriedades dos semimetais, embora pertença ao grupo dos halogéneos.Este artigo teve por objetivo descrever os semimetais com características mais próximas dos não metais e com pelo menos um isótopo estável, que possam ter dado contributos no processo de origem e evolução da vida na Terra. De notar também que atualmente os elementos boro, silício, arsénio e telúrio têm sido identificados como tendo funções ou eventuais desempenhos casuísticos nos seres vivos. Por outro lado, todos os isótopos de polónio e de ástato são radioativos, e por isso não são adequados aos processos metabólicos que ocorrem nos sistemas biológicos, pois originam reações que degradam as biomoléculas, como consequência do seu decaimento radioativo. 3-6 OS SEMIMETAIS E OS SISTEMAS BIOLÓGICOSAntes de se analisar os semimetais na sua associação com estruturas biológicas (ou eventualmente pré-biológicas) é conveniente efetuar algumas considerações acerca das razões gerais para a escolha dos elementos químicos pelos organismos vivos, as quais podem ser generalizadas para as estruturas pré-biológicas. Essas razões são, pelo menos, duas das seguintes: abundância, disponibilidade (que, de maneira simples, está relacionada com possibilidade dos elementos químicos serem solubilizados sem dispêndio elevado de energia) e eficiência funcional [a aptidão para possibilitarem determinadas reações (bio)químicas]. 4,7 Muitos elementos químicos são incorporados nos seres vivos na forma de compostos químicos com alguma complexidade. Todavia, no período de transição entre os sistemas minerológicos e a ocorrência dos primeiros organismos vivos, a escolha dos elementos químicos teve em conta as limitações da quanti...

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“…10 Arsenic also interacts with nucleic acids. 11,12 Bio-macromolecules such as ribose, glucose and mannose are reported to interact with arsenic at pH Z 12, 4 which is unlikely under in vivo conditions. Moreover, the chemical basis of their interaction is yet to be established.…”

Section: Introductionmentioning

confidence: 99%

“…5 Spontaneous formation of secondary reactive compounds like phosphate analogues of adnocyl, gluconyl and acyl of arsenic inside the body also contributes to this effect. 4 In the present study, an attempt is made to evaluate the interaction of glucose with arsenic in solution using ESI-TOF-MS. The formation of new complexes has been discussed and the dissociation constant estimated.…”

Section: Introductionmentioning

confidence: 99%

A direct determination of a glucose–arsenic complex by electrospray ionization time of flight mass spectrometry

Mandal¹

2011

Metallomics

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Electrospray ionization time of flight mass spectrometry (ESI-TOF-MS) was used to identify elemental ions from the glucose-arsenic interaction in the aqueous phase. In glucose solution, the most abundant ions were m/z 203, m/z 163, m/z 158, m/z 145 and m/z 115, whereas some additional arsenic bearing ions, m/z 271, m/z 235 and m/z 213 were observed from a glucose-arsenic solution in alkaline pH (≥ 7.5) at 37 °C. The binding was best fitted to 1:1 isotherm model and the value of the dissociation constant (K(d)) was 39.8 μM. Results suggest that the polyatomic ions derived from glucose interact with the available arsenic ions in blood and form a complex which might play a role in diseases caused by arsenic exposure.

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Arsenic-75 nuclear magnetic resonance: Study of the interaction of arsenate with various molecules of biological interest

Cited by 6 publications

References 22 publications

75As Nuclear Magnetic Resonance Spectroscopic Investigation of the Thioarsenate Speciation in Strongly Alkaline Sulfidic Leaching Solutions

75As Nuclear Magnetic Resonance Spectroscopic Investigation of the Thioarsenate Speciation in Strongly Alkaline Sulfidic Leaching Solutions

Os semimetais na origem e evolução da vida

A direct determination of a glucose–arsenic complex by electrospray ionization time of flight mass spectrometry

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