The metabolism of anatabine to α,β-dipyridyl in Nicotiana species

α,β-Dipyridyl isolated from Nicotiana tabacum plants which had been fed anatabine-2′-¹⁴C, ¹³C], and then allowed to dry in air for 20 days was radioactive (82% specific incorporation)An examination of its ¹³C NMR spectra established that it was enriched only at C-2, indicative of its direct formation from anatabineThe labelled anatabine was also fed to Nglauca and Nglutinosa plants, which were extracted immediately after harvestingIn these experiments no radioactive α,β-dipyridyl was detected, suggesting that α,β-dipyridyl is an artifact produced by the oxidation of anatabine in the drying leaves of tobaccoAnabasine isolated from the Nicotiana species which had been fed anatabine-2′- ¹⁴C, ¹³C] was unlabelled, indicating that none of this alkaloid is formed by the reduction of anatabine.