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High-field proton NMR study of the liquid solution structure of monomeric bacteriochlorophyll a and chlorophyll a

✍ Scribed by S. Lötjönen; T. J. Michalski; J. R. Norris; P. H. Hynninen

Publisher
John Wiley and Sons
Year
1987
Tongue
English
Weight
469 KB
Volume
25
Category
Article
ISSN
0749-1581

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✦ Synopsis

The 500 MHz proton spectra of monomeric bacteriochlorophyll a and chlorophyll a were recorded and assigned.

The proton chemical shifts and proton-proton coupling constants were all determined except for the P-5 to P-15 phytyl side-chain protons. The conformational structures of the reduced rings and associated side-chains in these compounds were deduced from vicinal coupling constants. The reduced ring IV and the propionic ester side-chain in bacteriochlorophyll a and chlorophyll a have identical conformations which, in addition, are very similar to those reported previously for methyl pheophorbide a and pheophytin a. The reduced ring IV of bacteriochlorophyll a, which is attached to the phytyl side-chain, is more buckled than the other reduced ring (ring 11).

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