Alkaloids from tobacco leaves: Isolation, alkaloid contents, and potential application as a natural pesticide against Bactrocera dorsalis

Abstract

The essential oils from three different kinds of discarded tobacco leaves (flue-cured tobacco, burley tobacco, and sun-cured yellow tobacco) were extracted and isolated, and their isolation method, alkaloid contents, and potential application as a natural pesticide against Bactrocera dorsalis were investigated. The yields of the crude extracts were ranked as follows: sun-cured yellow tobacco was greater than flue-cured tobacco, which was greater than burley tobacco; all their alkaloid contents were analyzed via high performance liquid chromatography tandem mass spectrometry. The total contents of the 4 primary alkaloids (nicotine, anatabine, nornicotine, and anabasine) in the extracts were as follows: flue-cured tobacco (62.1%) was greater than sun-cured yellow tobacco (58.2%), which was greater than burley tobacco (50.7%). The insecticidal activities of the extracts against Bactrocera dorsalis were evaluated via the stomach poisoning method, and the results indicated that sex had no considerable effect on the activity. Surprisingly, the activity of burley tobacco, which contained the lowest nicotine content, showed the best toxicity against Bactrocera dorsalis.