000101124 001__ 101124
000101124 005__ 20181203020746.0
000101124 02470 $$2DAR$$a9858
000101124 02470 $$2ISI$$a000243926500002
000101124 037__ $$aARTICLE 000101124 245__$$aSelectivity of montmorillonite catalyzed prebiotic reactions of D, L-nucleotides
000101124 260__ $$c2007 000101124 269__$$a2007
000101124 336__ $$aJournal Articles 000101124 520__$$aThe montmorillonite-catalyzed reactions of the 5′-phosphorimidazolides of D, L-adenosine (D, L-ImpA) (Figure 1a. N = A, R  = H) and D, L-uridine (Figure 1a., N = U, R = H) yields oligomers that were as long as 7 mers and 6 mers, respectively. The  reactions of dilute solutions of D-ImpA and D-ImpU under the same conditions gave oligomers as long as 9 and 8 mers respectively.  This demonstrated that oligomer formation is only partially inhibited by incorporation of both the D- and L-enantiomers. The  structures of the dimers, trimers and tetramer fractions formed from D, L-ImpA was investigated by selective enzymatic hydrolysis,  comparison with authentic samples and mass spectrometry. Homochiral products were present in greater amounts than would be  expected if theoretical amounts of each were formed. The ratio of the proportion of homochiral products to that of the amount  of each expected for the dimers (cyclic and linear), trimers and tetramers, was 1.3, 1.6, and 2.1, respectively. In the D,  L-ImpU reaction homochiral products did not predominate with ratios of dimers (cyclic and linear), trimers and tetramers 0.8, 0.44, and 1.4, respectively. The proportions of cyclic dimers in the dimer fraction were 52–66% with D, L-ImpA and 44–69%  with D, L-ImpU. No cyclic dimers were formed in the absence of montmorillonite. The differences in the reaction products of  D, L-ImpA and D, L-ImpU are likely to be due to the difference in the orientations of the activated monomers when bound to  the catalytic sites on montmorillonite. The consequences of the selectivity of montmorillonite as a prebiotic catalyst are  discussed.
000101124 6531_ $$amontmorillonite 000101124 6531_$$acatalysis
000101124 6531_ $$achiral 000101124 6531_$$aRNA
000101124 6531_ $$aorigin of life 000101124 6531_$$aprebiotic
000101124 700__ $$aJoshi1, Prakash C. 000101124 700__$$0240732$$aPitsch, Stefan$$g145837
000101124 700__ $$aFerris, James P. 000101124 773__$$j37$$k1$$q3-26$$tOrigins of Life and Evolution of Biospheres 000101124 909C0$$0252378$$pLCAN 000101124 909CO$$ooai:infoscience.tind.io:101124$$particle 000101124 937__$$aLCAN-ARTICLE-2007-003
000101124 973__ $$aEPFL$$rREVIEWED$$sPUBLISHED 000101124 980__$$aARTICLE