Ultraviolet circular dichroism studies on complexes of synthetic polynucleotides

1969 ◽  
Vol 47 (10) ◽  
pp. 977-981 ◽  
Author(s):  
Fred H. Wolfe ◽  
Kimio Oikawa ◽  
Cyril M. Kay

The ultraviolet circular dichroism spectra of complexes of polyadenylic acid and polyuridylic acid in the molar ratio of 1:1 and 1:2, and that of polyguanylic acid and polycytidilic acid have been examined over the wavelength range of 300–185 mμ. Increased resolution of spectra below 225 mμ has revealed several new ellipticity bands for these complexes which should be of considerable value in the proper counting of optically active electronic transitions and their assignment in these systems, and with naturally occurring RNA's.

1969 ◽  
Vol 47 (6) ◽  
pp. 637-642 ◽  
Author(s):  
Fred H. Wolfe ◽  
Kimio Oikawa ◽  
Cyril M. Kay

The ultraviolet circular dichroism spectra of polyadenylic acid, polyguanylic acid, polycytidylic acid, polyinosinic acid, and polyuridylic acid have been examined at neutral and acidic pH values, and at moderate and low ionic strengths, over the wavelength range 300–185 mμ. Increased resolution of spectra below 225 mμ has revealed heretofore unexamined ellipticity bands in the low wavelength region, which are sensitive to conformational alterations for those polynucleotides which exhibit both single and multistranded secondary structures. It is concluded that these ellipticity bands, in view of their extreme sensitivity to conformation, will be of significance in increasing the usefulness of the homopolynucleotides as model compounds in conformational studies of naturally occurring RNAs.


1989 ◽  
Vol 44 (11) ◽  
pp. 1464-1472 ◽  
Author(s):  
Hermann Bauer ◽  
Jeanine Brun ◽  
Alexius R. Hernanto ◽  
Wolfgang Voelter ◽  
Spyridon Paraskewas

The complexes of tetravanadate ions with optically active polyols and carbohydrates with suitable steric properties show up to four separate cotton effects in the wavelength range of λ = 200-350 nm. Thus it is possible to classify pyranoses into four groups according to their circular dichroitic behaviour and determine the configuration and the conformation of the hydroxyl groups attached to the pyranose ring.


1970 ◽  
Vol 23 (9) ◽  
pp. 1735 ◽  
Author(s):  
CJ Hawkins ◽  
PJ Lawson

The circular dichroism spectra of a series of optically active (α-aminocarboxylato)tetraamminecobalt(111) complexes have been measured in aqueous solution, and in the presence of salts of polarizable anions. The observed spectra in the visible region have been analysed to determine the signs of the Cotton effects of the three components of the 1A1g ↔ 1T1g cobalt(111) transition. For L-amino acids, the transition with A2g(D4h) parentage is negative, and the two transitions with Eg(D4h) parentage have opposite signs. Published circular dichroism spectra of complexes of the type [Co(en)2(L-am)]2+ were similarly interpreted in terms of a perturbed tetragonal chromophore, and it was shown that the vicinal effect of the L-amino acids imposed the same signs onto the component transitions as for the tetraammines and for a similar series of pentaamminecobalt(111) complexes.


1980 ◽  
Vol 45 (2) ◽  
pp. 435-441 ◽  
Author(s):  
Jan Pospíšek ◽  
Štefan Toma ◽  
Ivo Frič ◽  
Karel Bláha

Racemic 3-ferrocenylalanine was resolved in enantiomers using brucine. The absolute configuration was estimated by ozonolytic degradation of the N-trifluoroacetyl derivative of the (-)-enantiomer yielding D-aspartic acid. Diastereoisomeric cyclo(D-ferrocenylalanyl-L-prolyl) and cyclo-(L-3-ferrocenylalanyl-L-prolyl) were synthesized using conventional methods of peptide synthesis. Circular dichroism spectra of these cyclodipeptides are discussed and compared with spectra of the corresponding diastereoisomeric cyclodipeptides containing phenylalanine.


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