title: On the stereoselective aminoacylation of RNA.
abstract: Aminoacylation of the "internal" 2'hydroxyl groups of poly(A) with the imidazolide of racemic DL-leucine resulted in the formation of an enantiomeric excess of the D-ester, whereas aminoacylation with the imidazolide of racemic N-3,5-dinitrobenzoyl-DL-leucine gave an enantiomeric excess of the L-ester.  Comparison of these results with those obtained earlier for alanine shows that the larger side chain tends to favor the formation of the D-ester.  High resolution proton magnetic resonance spectroscopy was performed on the D- and L-alanyl "internal" 2'-esters of 3'5'-ApA.  The resonance of the side chain methyl group of the D-ester is upfield from that of the L-ester, and the separation of the peaks increases with a decrease in temperature.
authors.affiliation: Department of Chemistry, Cornell University, Ithaca, NY 14853, USA.
authors.forename: D A
authors.initials: DA
authors.lastname: Usher
authors.forename: M C
authors.initials: MC
authors.lastname: Needels
mesh_terms: D000215:Acylation; D000409:Alanine / Q000031:analogs & derivatives*; D004952:Esters; D019418:Evolution, Chemical; D007093:Imidazoles / Q000737:chemistry; D007930:Leucine / Q000031:analogs & derivatives* / Q000737:chemistry; D009579:Nitrobenzoates / Q000737:chemistry*; D000069497:Origin of Life; D011061:Poly A / Q000737:chemistry; D014176:Protein Biosynthesis; D012313:RNA / Q000737:chemistry*; D013696:Temperature
chemical_list: D004952:Esters; D007093:Imidazoles; D009579:Nitrobenzoates; D011061:Poly A; D012313:RNA; C051872:N-(3,5-dinitrobenzoyl)leucine; D007930:Leucine; D000409:Alanine