chapter 1. Why do plants contain biologically active compounds? / One R. Pagan -- chapter 2. Short overview of mitragynines / Robert B. Raffa, Jaclyn R. Beckett, Vivek N. Brahmbhatt, Theresa M. Ebinger, Chrisjon A. Fabian, Justin R. Nixon, Steven T. Orlando, Chintan A. Rana, Ali H. Tejani, and Robert J. Tomazic -- chapter 3. Psychopharmacological indole alkaloids from terrestrial plants / Allan Patrick G. Macabeo -- chapter 4. Salvinorin A : example of a non-alkaloidal bioactive opioid from a plant source / Jordan K. Zjawiony -- chapter 5. The botany of Mitragyna speciosa (Korth.) Havil. and related species / Sasha W. Eisenman -- chapter 6. Phytochemistry of Mitragyna speciosa / Vedanjali Gogineni, Francisco Leon, Bonnie A. Avery, Christopher McCurdy, and Stephen J. Cutler -- chapter 7. Chemistry of mitragynines : a brief introduction / Robert B. Raffa -- chapter 8. Chemistry of Mitragyna alkaloids / Mariko Kitajima and Hiromitsu Takayama -- chapter 9. Medicinal chemistry based on mitragynine / Hiromitsu Takayama and Mariko Kitajima -- chapter 10. Chemical structures of opioids / Robert B. Raffa -- chapter 11. The detection of mitragynine and its analogs / Ruri Kikura-Hanajiri -- chapter 12. The ADME of mitragynine and analogs / Annette Cronin, Ines A. Ackerman, and Jochen Beyer -- chapter 13. Analgesic effects of mitragynine and analogs / Kenjiro Matsumoto and Syunji Horie -- chapter 14. Non-analgesic CNS effects / Jaclyn R. Beckett, Justin R. Nixon, and Ali H. Tejani -- chapter 15. Other opioid-associated endpoints / Steven T. Orlando and Vivek N. Brahmbhatt -- chapter 16. The kratom experience from firsthand reports / Earth Erowid and Fire Erowid -- chapter 17. The toxicology of indole alkaloids / Jennifer L. Ingram-Ross -- chapter 18. Opioid-induced adverse effects and toxicity / Joseph V. Pergolizzi, Jr. -- chapter 19. Toxicology of mitragynine and analogs / Surash Ramanathan and Sharif M. Mansor -- chapter 20. The use of animal models to measure tolerance, dependence, and abuse potential / Scott M. Rawls -- chapter 21. Kratom : the epidemiology, use and abuse, addiction potential, and legal status / Zoriah Aziz.