Use of a bacteriophage to depolymerize a polysaccharide to an oligosaccharide; comparison of the 1H and 13C nuclear magnetic resonance spectra of the polymer and its hexasaccharide repeating unit

1980 ◽  
Vol 58 (23) ◽  
pp. 2588-2591 ◽  
Author(s):  
Guy G. S. Dutton ◽  
Angela V. Savage ◽  
Michel Vignon

A β-D-galactosidase associated with bacteriophage [Formula: see text] has been used to depolymerize the capsular polysaccharide of Klebsiella serotype K18 into the hexasaccharide corresponding to one repeating unit of the polymer. The nmr spectra of the polymer and of the oligosaccharide are comparable, leading to the conclusion that the conformations in solution of the repeating unit of the two substances are similar.


1979 ◽  
Vol 57 (13) ◽  
pp. 1652-1655 ◽  
Author(s):  
S. William Pelletier ◽  
Naresh V. Mody ◽  
Rajinder S. Sawhney

The natural abundance carbon-13 nuclear magnetic resonance spectra of some C19-diterpenoid alkaloids and their alkamines (lappaconitine, lappaconine, lapaconidine, ranaconine, 14-dehydrobrowniine, aconine, pseudoaconine, deoxyaconine, and hypaconine) have been determined at 15.03 MHz. With the aid of proton decoupling techniques, additivity relationships, and comparison with spectra of related alkaloids, self-consistent and unambiguous assignments of nearly all carbon resonances for these alkaloids have been made. Some important chemical shift trends have been observed, which are useful for identifying the basic C19-diterpenoid alkaloid skeleton and the hydroxy and methoxy group substitution patterns in these alkaloids. On the basis of 13C nmr spectra of lappaconitine and lappaconine, the anthranoyl ester moiety is assigned to the C-4 position in lappaconitine. The 13C nmr spectra of lapaconidine, aconine, and pseudoaconine taken in pyridine and chloroform have been compared to determine the conformational changes of the ring A hydroxy groups in these alkaloids.



1983 ◽  
Vol 61 (8) ◽  
pp. 1795-1799 ◽  
Author(s):  
Philip A. W. Dean

The previously reported 1:1 complexes formed in MeNO2, between M(SbF6)2 (M = Sn or Pb) and Ph2P(CH2)2PPh2, PhP[(CH2)2PPh2]2, MeC(CH2PPh2)3, P[(CH2)2PPh2]3, and [Formula: see text] have been studied by metal (119Sn or 207Pb) nmr. The metal chemical shifts span the comparatively narrow range of −586 to −792 ppm and 60 to −269 ppm, relative to the resonance of MMe4, for 119Sn and 207Pb nmr, respectively. The implications of these data regarding the denticity of the ligand in M(P[(CH2)2PPh2]3)2+ are discussed, and a comparison with the metal nmr spectra of related stannous and plumbous complexes is made.







Sign in / Sign up

Export Citation Format

Share Document