Adsorption of adenine and thymine on zeolites: FT-IR and EPR spectroscopy and X-ray diffractometry and SEM studies.
The interactions of adenine and thymine with and adsorption on zeolites were studied using different techniques. There were two main findings. First, as shown by X-ray diffractometry, thymine increased the decomposition of the zeolites (Y, ZSM-5) while adenine prevented it. Second, zeolite Y adsorbed almost the same amount of adenine and thymine, thus both nucleic acid bases could be protected from hydrolysis and UV radiation and could be available for molecular evolution. The X-ray diffractometry and SEM showed that artificial seawater almost dissolved zeolite A. The adsorption of adenine on ZSM-5 zeolite was higher than that of thymine (Student-Newman-Keuls test-SNK p<0.05). Adenine was also more greatly adsorbed on ZSM-5 zeolite, when compared to other zeolites (SNK p<0.05). However the adsorption of thymine on different zeolites was not statistically different (SNK p>0.05). The adsorption of adenine and thymine on zeolites did not depend on pore size or Si/Al ratio and it was not explained only by electrostatic forces; rather van der Waals interactions should also be considered.
Laboratório de Química Prebiótica, Departamento de Química-CCE, Universidade Estadual de Londrina, 86051-990, Londrina, PR, Brazil.
João Paulo T
JP
Baú
Cristine E A
CE
Carneiro
Ivan G
IG
de Souza Junior
Cláudio M D
CM
de Souza
Antonio C S
AC
da Costa
Eduardo
E
di Mauro
Cássia T B V
CT
Zaia
Joaquin
J
Coronas
Clara
C
Casado
Henrique
H
de Santana
Dimas A M
DA
Zaia
D000225:Adenine / Q000737:chemistry*; D000327:Adsorption; D004578:Electron Spin Resonance Spectroscopy; D019418:Evolution, Chemical; D006863:Hydrogen-Ion Concentration; D008855:Microscopy, Electron, Scanning; D016062:Porosity; D012623:Seawater / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D013941:Thymine / Q000737:chemistry*; D014466:Ultraviolet Rays; D014961:X-Ray Diffraction; D017641:Zeolites / Q000737:chemistry*
D017641:Zeolites; D000225:Adenine; D013941:Thymine