Topological classification of fragments of coupling networks and multiplet patterns in two-dimensional NMR spectra

Multiplets in two-dimensional correlation spectra are encoded in a manner that depends on the topol. of the coupling network but not on the values of the coupling consts. Comparison of exptl. multiplets with a data bank contg. some 10,000 possible patterns encoded in this fashion allows one to identify the topol. of fragments of the coupling networks. The chem. shifts and scalar coupling consts. are also detd. The procedure exploits the D2 symmetry inherent to combined multiplets extd. from pairs of complementary two-dimensional spectra to disentangle severely overlapping multiplets. A likelihood function is defined to obtain a measure of the reliability of the anal. The procedure has been applied to the two overlapping four-spin systems of a mixt. of cis- and trans-2-phenylcyclopropanecarboxylic acid Et ester, to the dinucleotide 2'-deoxyadenylyl-(3' -> 5')-2'-deoxythymidine, and to the three seven-spin systems of cyclo-L-Pro-L-Pro-D-Pro. [on SciFinder (R)]