Dee, the "Orient tobacco absolute" listed as an ingredient of the eliquid on InLife's site (as less than 1%) is actually a flavoring derived from tobacco, an "essence" if you will, used by many eliquid makers for their tobacco flavored eliquids. However, if you go down their ingredients list to #3, you will see L-Nicotine listed, at concentrations of 1.8%, 1.4% and 1.1%, which translates into the more commonly known 18mg, 14mg, and 11 mg levels.
The truth is that while nicotine can be found in other nightshade plants such as tomato, potato, eggplant, etc, it is found in those plants in very much smaller quantities than in tobacco. Nicotine is simply not commercially extracted from anything but tobacco, because to do so from those other plants would be prohibitively expensive, given the very low concentrations present in the first place.
The truth is that while nicotine can be found in other nightshade plants such as tomato, potato, eggplant, etc, it is found in those plants in very much smaller quantities than in tobacco. Nicotine is simply not commercially extracted from anything but tobacco, because to do so from those other plants would be prohibitively expensive, given the very low concentrations present in the first place.