Quinine

http://en.wikipedia.org/wiki/Quinine
http://www.nlm.nih.gov/medlineplus/druginfo/meds/a682322.html
http://www.malariajournal.com/content/10/1/144
http://rainforest-database.com/plants/quinine.htm
http://www.medicinenet.com/quinine_antimalarial-oral/article.htm
http://www.britannica.com/EBchecked/topic/487422/quinine
http://tmagazine.blogs.nytimes.com/2011/11/14/case-study-quinine-syrup/
http://en.wikipedia.org/wiki/Cinchona