L-LSD
l-LSD, also known as -LSD or -LSD, as well as l-lysergic acid diethylamide or l-lysergide, is a lysergamide and one of four possible stereoisomers of the lysergic acid diethylamide molecule.
The LSD molecule has two chiral centers at carbons 5 and 8 of the ergoline ring system and hence there are four possible enantiomeric stereoisomers of LSD. l-LSD, also known as -LSD or -LSD, is one of four possible stereoisomers. The other isomers are LSD -LSD, or, iso-LSD -iso-LSD, or, and l-iso-LSD -iso-LSD or. None of them are known to have significant psychoactivity in humans besides LSD.
l-LSD showed only 0.06% of the antiserotonergic activity of LSD in the isolated rat uterus. Hence, it was more than 1,000-fold less potent than LSD in this assay and was regarded as essentially inactive. In subsequent receptor binding studies, l-LSD showed 2,000- to 10,000-fold lower affinity for serotonin receptors than LSD.
l-LSD showed no psychedelic effects in humans at a dose of up to 10mg orally or up to 400times the minimum effective dose of LSD. However, Albert Hofmann reported that although l-LSD produced no LSD-like effects, it caused "very slight drowsiness" at doses above 500μg.
l-LSD was first described in the scientific literature by at least the 1950s.
File:Lysergide stereoisomers structural formulae v.1.png|thumb|left|400px|class=skin-invert-image|Chemical structures of LSD and its three stereoisomers, including l-LSD.