USING SIMILARITY SEARCHES OVER DATABASES OF ESTIMATED C-13 NMR-SPECTRA FOR STRUCTURE IDENTIFICATION OF NATURAL PRODUCT COMPOUNDS

Structure elucidation for natural product compounds is assisted by mak ing similarity comparisons between the uncharacterized experimental C- 13 NMR spectrum with relevant databases of estimated spectra. Database s of estimated spectra are deduced from a small set of assigned struct ures using HOSE codes. Using spectra estimated from structures circumv ents problems of inconsistent, incomplete, missing or irrelevant data. It also enables rapid generation of reasonably sized databases that a re unavailable from commercial sources. We validate the similarity met hod theoretically by analyzing what can be best expected from a match of an estimated set of peaks to the experimental spectrum. We also sho w by example that the method is successful when used in the laboratory .