Specific Co-Absorption of Purines and Pyrimidines by Montmorillonite (Clay-Organic Studies XV)

Lailach, G. E.

doi:10.1346/ccmn.1969.0170207

Cited by 54 publications

(27 citation statements)

References 7 publications

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“…Research has shown that amino acids and nucleic acid bases are readily adsorbed Fripiat et al 1966;Lailach et al 1968 a and b;Lailach and Brindley 1969;Odom et al 1979) and, under certain conditions, polymerized on clays (Ibanez et al 1979;Lahav et al 1978;Paecht-Horowitz 1978). However, clays apparently do not have the ability to sort out protein and non-protein amino acid structures under conditions analogous to those of our experiment.…”

Section: Discussionsupporting

confidence: 43%

Adsorption of protein and non-protein amino acids on a clay mineral: A possible role of selection in chemical evolution

1980

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The adsorption of protein and non-protein amino acids by Na-montmorillonite was studied at pH 3, 7, and 10, in order to determine whether clays could have played a part in selection of protein over non-protein amino acids in prebiotic times. Five pairs of amino acids, containing two to six carbons, were used at a concentration equal to 100% cation exchange capacity of the clay in adsorption experiments. The following pairs of protein and non-protein amino acids were used: glycine and sarcosine, alpha-alanine and beta-alanine, alpha-aminobutyric acid and gamma-aminobutyric acid, valine and norvaline, L-isoleucine and D-alloisoleucine. No selective adsorption of protein amino acids occurred at varying hydrogen ion concentrations. The one difference observed in the adsorption of amino acids in the mixtures was a three- and four-fold greater adsorption of beta- and gamma-amino acids, respectively, than their alpha-amino acid counterparts under acidic and neutral conditions. Strong and weak adsorption of amino acids on the clay were correlated with mechanisms such as cation exchange and hydrogen bonding. The results of this research are significant to understanding the role of clay in chemical evolution because they do not support the role of preferential adsorption of protein over non-protein amino acids by clays.

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Section: Discussionsupporting

confidence: 43%

Adsorption of protein and non-protein amino acids on a clay mineral: A possible role of selection in chemical evolution

1980

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“…In the latter case, i.e. 95% adsorption, it may correspond to the adsorption of cytosine on Fe 3+-montmorillonite, at the same concentrations as before and pH 6 (Lailach et al, 1968b). The calculated concentration factor is about 1300.…”

Section: Concentration Factor Of Nucleic Bases On Montmorillonitementioning

confidence: 80%

“…On the other hand, a review of data on adsorption (mainly in relation to montmorillonite, see Lailach et al, 1968aLailach et al, , 1968b shows that for the majority of nucleic acid bases the adsorption is largest in the acidic range (i.e. around 1 < pH < 5 ) and then it decreases steadily to a very low adsorption level at 7 < pH <_ 8.…”

Section: Ph Of Bulk Solution and Extent Of Adsorption Of Nucleic Basementioning

confidence: 99%

A review of conditions affecting the radiolysis due to40K on nucleic acid bases and their derivatives adsorbed on clay minerals: Implications in prebiotic chemistry

Mosqueira

Albarrán²,

Negrón‐Mendoza³

1996

Origins Life Evol Biosphere

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This paper describes the possible effects of ionizing radiation arising from long-lived soluble radionuclides within clays, in particular 40K, at the epoch of the emergence of life on Earth. The free dispersion of soluble radionuclides constitutes an effective in situ irradiation mechanism that might have acted upon adsorbed nucleic bases and their derivatives on clays, inducing chemical changes on these organic molecules. Several types of well documented reactions for radiolysis of nucleic acid bases and their derivatives are known, even at low doses (i.e., 0.1 Gy). For example, estimates with a dose rate calculated from 40K from deep sea clays at 3.8 Ga ago, indicates that over a period of 1000 years the amount of organic material transformated is 1.8 X 10(-7) moles/kg-clay. Although ionizing radiation may also induce synthetic reactions with prebiological interest, all in all these considerations indicate that nucleic acid bases and their derivatives adsorbed on clays were exposed for long periods to degradation conditions. Such situation promotes decomposition of organic molecules rather than protection of them and enhancement of farther polymerization, as it has been usually taken for granted.

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“…The adsorption of nucleic acid bases was studied in the following minerals: clays (Lailach et al 1968;Lailach and Brindley 1969;StrašáK 1991;Weckhuysen et al 1999;Perezgasga et al 2005;Hashizume and Theng 2007;Benetoli et al 2008;Hashizume et al 2010;Negrón-Mendoza et al 2010;Pucci et al 2010), apatite (Winter and Zubay 1995), silicon dioxide (Plekan et al 2007), graphite (Sowerby et al 2001a, b), metals sulfide compounds (Sowerby et al 1998;Bebié and Schoonen 2000;Plekan et al 2007;Hatton and Rickard 2008) and rutile (Cleaves et al 2010).…”

Section: Introductionmentioning

confidence: 99%

Adsorption of Adenine, Cytosine, Thymine, and Uracil on Sulfide-Modified Montmorillonite: FT-IR, Mössbauer and EPR Spectroscopy and X-Ray Diffractometry Studies

Carneiro

Berndt

Souza

et al. 2011

Orig Life Evol Biosph

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In the present work the interactions of nucleic acid bases with and adsorption on clays were studied at two pHs (2.00, 7.00) using different techniques. As shown by Mössbauer and EPR spectroscopies and X-ray diffractometry, the most important finding of this work is that nucleic acid bases penetrate into the interlayer of the clays and oxidize Fe(2+) to Fe(3+), thus, this interaction cannot be regarded as a simple physical adsorption. For the two pHs the order of the adsorption of nucleic acid bases on the clays was: adenine ≈ cytosine > thymine > uracil. The adsorption of adenine and cytosine on clays increased with decreasing of the pH. For unaltered montmorillonite this result could be explained by electrostatic forces between adenine/cytosine positively charged and clay negatively charged. However for montmorillonite modified with Na(2)S, probably van der Waals forces also play an important role since both adenine/cytosine and clay were positively charged. FT-IR spectra showed that the interaction between nucleic acid bases and clays was through NH(+) or NH (2) (+) groups. X-ray diffractograms showed that nucleic acid bases adsorbed on clays were distributed into the interlayer surface, edge sites and external surface functional groups (aluminol, silanol) EPR spectra showed that the intensity of the line g ≈ 2 increased probably because the oxidation of Fe(2+) to Fe(3+) by nucleic acid bases and intensity of the line g = 4.1 increased due to the interaction of Fe(3+) with nucleic acid bases. Mössbauer spectra showed a large decreased on the Fe(2+) doublet area of the clays due to the reaction of nucleic acid bases with Fe(2+).

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Specific Co-Absorption of Purines and Pyrimidines by Montmorillonite (Clay-Organic Studies XV)

Cited by 54 publications

References 7 publications

Adsorption of protein and non-protein amino acids on a clay mineral: A possible role of selection in chemical evolution

Adsorption of protein and non-protein amino acids on a clay mineral: A possible role of selection in chemical evolution

A review of conditions affecting the radiolysis due to40K on nucleic acid bases and their derivatives adsorbed on clay minerals: Implications in prebiotic chemistry

Adsorption of Adenine, Cytosine, Thymine, and Uracil on Sulfide-Modified Montmorillonite: FT-IR, Mössbauer and EPR Spectroscopy and X-Ray Diffractometry Studies

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