Thebaine

Thebaine (paramorphine), its name coming from the Greek Θῆβαι, Thēbai, an ancient city in Upper Egypt, is an opiate alkaloid. A minor constituent of opium, thebaine is chemically similar to both morphine and codeine, but has stimulatory rather than depressant effects, causing convulsions similar to strychnine poisoning at higher doses. However the "unnatural" enantiomer (+)-thebaine does show analgesic effects apparently mediated through opioid receptors, unlike the inactive natural enantiomer (-)-thebaine. Thebaine is not used therapeutically but, as the main alkaloid extracted from Papaver bracteatum, it can be converted industrially into a variety of compounds including oxycodone, oxymorphone, nalbuphine, naloxone, naltrexone, buprenorphine and etorphine.