Structure Elucidation and Quantitation of 11 N-n-Acylnornicotines in Cherry-Red Tobacco

Abstract

Eleven consecutive N′-n-acylnornicotines from cherry-red tobacco were structurally elucidated and quantitively analyzed using chromatography and mass spectrometry. All of these N′-n-acylnornicotines are first reported in cherry-red tobacco, whereas N′-propionylnornicotine, N′-n-valerylnornicotine, N′-n-nonanoylnornicotine and N′-n-undecanoylnornicotine are first reported in natural products. The concentration distribution of the identified N′-n-acylnornicotines was studied and it was found that N′-n-octanoylnornicotine and N′-n-hexanoylnornicotine showed the highest concentration, accounting for 94% of the detected N′-n-acylnornicotines. The cherry-red color density of the related tobacco leaves was found to be positively correlated with the concentration of the N′-n-acylnornicotines, whereas the ultraviolet-visible spectra of the N′-n-acylnornicotines showed no absorption larger than 300 nm, indicating the discovered compounds are not responsible for the cherry-red color appearance.