"Cathinone and its derivatives are closely related to the phenethylamine family (which includes amphetamine and methamphetamine), but with a lower potency than the latter.13 They are characterised by the presence of a ?-keto group on the side chain of the phenethylamines. Cathinone, the principal active ingredient in the leaves of the khat plant (catha edulis), can be considered as the prototype from which a range of synthetic cathinones have been developed.
"Synthetic cathinones appeared in drug markets in the mid 2000s. In 2005, methylone, an analogue of MDMA, was the first synthetic cathinone reported to the European Monitoring Centre on Drugs and Drug Addiction (EMCDDA). In 2007, reports of 4-methyl-methcathinone (mephedrone) use emerged, first in Israel and then in other countries and regions, including Australia, Scandinavia, Ireland and the United Kingdom.14 Mephedrone was reportedly first synthesized in 1929.15"

Source

UN Office on Drugs and Crime, "The Challenge of New Psychoactive Substances: A Report from the Global SMART Programme" (Vienna, Austria: UNODC Laboratory and Scientific Section, March 2013), p. 5.
http://www.unodc.org/document…