Does Eggplant Extract Contain Nicotine?

Reports of nicotine in eggplant are technically old news, and though I haven't been able to find any conclusive answers as to whether eggplant does in-fact contain Nicotine or just Nicotinic Acid (i.e. 'Niacin', the B vitamin), I got curious about eggplant extract.

There are a lot of wild claims regarding eggplant extract out there (that I admittedly didn't bother to look into), but I am primarily curious about whether or not the extract would contain nicotine as well (assuming eggplant actually does in the first place).

According to that 1993 study, eggplant has about 100ng of nicotine per gram. And since there seem to be some reports of beneficial effects when using nicotine during the short-term at (presumably) low dosages, it seems logical to look into eggplant as a good source of it as opposed to tobacco.

So it's really 2 questions: does eggplant really contain proper 'Nicotine'? And if so, would it be likely to end up in its extract products in noticeable amounts? Forgive me if this seems silly/obvious, I'm not terribly knowledgeable on chemistry...