I have recently looked around to find information on what substances are active in oneirogens (greek oneiros=dream and gen=get), such as Calea zacatechichi and Silene capensis.
A germacranolid called caleicine has been found in Calea zacatechichi [Jose Luis Diaz in Journal of Psychedelic Drugs, 1979], as well as several other substances with the basic structure of caleicine. 1B-acetoxy-zacatechinolide, 1-oxo-zacatechinolide, budleine A, caleicine I, caleicine II, caleine A, caliene B, caleocromene A, caleocromene B, germacrene 7, O-methyl-acacetine and zexbrevine is reported to have been found.
In James Duke's Handbook of Medicinal Herbs, it is reported that C. zacatechichi contains 0.01 % of a "crystalline alkaloid" with the formula C21H26O8. As it does not contain Nitrogen, it is clearly not an alkaloid, but it is still interesting. It is also mentioned as a possible substance in Silene capensis.
Does anyone know the structure of these compounds? Or does anyone know if one or more of them indeed are the psychoactive compound(s)?