LONG-RANGE NMR 1H,13C-COUPLING AND CONFORMATIONAL ANALYSIS OF POLYPHENOLIC GLYCOSIDES
Introduction/Abstract
Unambiguous structure assignment of standards is essential for metabolome characterization of infected plants. Complete structure elucidation of four natural polyphenols, resveratrol, pelargonidin chloride, cyanin chloride, and keracyanin chloride by 1H-, 13C, COSY-, and HMBC-NMR is described. The sinusoidal modulation frequency of cross-peaks (J-HMBC) was fitted iteratively to sin(πJH,Ctvar) and yielded 2,3J-values. Statistical distributions of dihedral angles (MD-simulation) and variations of the Karplus equation were used to determine weighted coupling constants for comparison with the experimental values. Theoretically calculated and experimentally observed coupling constants across the glycosidic bonds were in agreement with cyanin chloride, but did not match keracyanin chloride.
Location
DeRosa University Center, Stockton campus, University of the Pacific
Format
Poster Presentation
LONG-RANGE NMR 1H,13C-COUPLING AND CONFORMATIONAL ANALYSIS OF POLYPHENOLIC GLYCOSIDES
DeRosa University Center, Stockton campus, University of the Pacific
Unambiguous structure assignment of standards is essential for metabolome characterization of infected plants. Complete structure elucidation of four natural polyphenols, resveratrol, pelargonidin chloride, cyanin chloride, and keracyanin chloride by 1H-, 13C, COSY-, and HMBC-NMR is described. The sinusoidal modulation frequency of cross-peaks (J-HMBC) was fitted iteratively to sin(πJH,Ctvar) and yielded 2,3J-values. Statistical distributions of dihedral angles (MD-simulation) and variations of the Karplus equation were used to determine weighted coupling constants for comparison with the experimental values. Theoretically calculated and experimentally observed coupling constants across the glycosidic bonds were in agreement with cyanin chloride, but did not match keracyanin chloride.
