The four possible stereoisomers of<unk> . Only (+)-LSD is psychoactive.<unk>  is a chiral compound with two stereocenters at the carbon atoms C-5 and C-8, so that theoretically four different optical isomers of<unk>  could exist.<unk> , also called (+)-D-LSD, has the absolute configuration (5R,8R). The C-5 isomers of lysergamides do not exist in nature and are not formed during the synthesis from d-lysergic acid. Retrosynthetically, the C-5 stereocenter could be analysed as having the same configuration of the alpha carbon of the naturally occurring amino acid L-tryptophan, the precursor to all biosynthetic ergoline compounds. However,<unk>  and iso-LSD, the two C-8 isomers, rapidly interconvert in the presence of bases, as the alpha proton is acidic and can be deprotonated and reprotonated. Non-psychoactive iso-LSD which has formed during the synthesis can be separated by chromatography and can be isomerized to<unk> . Pure salts of<unk>  are triboluminescent, emitting small flashes of white light when shaken in the dark.<unk>  is strongly fluorescent and will glow bluish-white under UV light. Synthesis<unk>  is an ergoline derivative. It is commonly synthesized by reacting diethylamine with an activated form of<unk>  acid. Activating reagents include phosphoryl chloride and peptide coupling reagents.<unk>  acid is made by alkaline hydrolysis of lysergamides like ergotamine, a substance usually derived from the ergot fungus on agar plate; or, theoretically possible, but impractical and uncommon, from ergine<unk>  acid amide, LSA) extracted from morning glory seeds.<unk>  acid can also be produced synthetically, although these processes are not used in clandestine manufacture due to their low yields and high complexity. Dosage White on White blotters (WoW) for sublingual administration A single dose of<unk>  may be between 40 and 500 micrograms—an amount roughly equal to one-tenth the mass of a grain of sand. Threshold effects can be felt with as little as 25 micrograms of<unk> . The practice of using sub-threshold doses is called microdosing. Dosages of<unk>  are measured in micrograms (µg), or millionths of a gram. By comparison, dosages of most drugs, both recreational and medicinal, are measured in milligrams (mg), or thousandths of a gram. For example, an active dose of mescaline, roughly , has effects comparable to 100 µg (0.0001 g) or less of<unk> . In the mid-1960s, the most important black market<unk>  manufacturer (Owsley Stanley) distributed acid at a standard concentration of 270 µg, while street samples of the 1970s contained 30 to 300 µg. By the 1980s, the amount had reduced to between 100 and 125 µg, dropping more in the 1990s to the 20–80 µg range, and even more in the 2000s (decade). Reactivity and degradation "LSD," writes the chemist Alexander Shulgin, "is an unusually fragile molecule ... As a salt, in water, cold, and free from air and light exposure, it is stable indefinitely."<unk>  has two labile protons at the tertiary stereogenic C5 and C8 positions, rendering these centers prone to epimerisation. The C8 proton is more labile due to the electron-withdrawing carboxamide attachment, but removal of the chiral proton at the C5 position (which was once also an alpha proton of the parent molecule tryptophan) is assisted by the inductively withdrawing nitrogen and pi electron delocalisation with the indole ring.<unk>  also has enamine-type reactivity because of the electron-donating effects of the indole ring. Because of this, chlorine destroys<unk>  molecules on contact; even though chlorinated tap water contains only a slight amount of chlorine, the small quantity of compound typical to an<unk>  solution will likely be eliminated when dissolved in tap water. The double bond between the 8-position and the aromatic ring, being conjugated with the indole ring, is susceptible to nucleophilic attacks by water or alcohol, especially in the presence of UV or other kinds of light.<unk>  often converts to "lumi-LSD," which is inactive in human beings. A controlled study was undertaken to determine the stability of<unk>  in pooled urine samples. The concentrations of<unk>  in urine samples were followed over time at various temperatures, in different types of storage containers, at various exposures to different wavelengths of light, and at varying pH values. These studies demonstrated no significant loss in<unk>  concentration at 25 °C for up to four weeks. After four weeks of incubation, a 30% loss in<unk>  concentration at 37 °C and up to a 40% at 45 °C were observed. Urine fortified with<unk>  and stored in amber glass or nontransparent polyethylene containers showed no change in concentration under any light conditions. Stability of<unk>  in transparent containers under light was dependent on the distance between the light source and the samples, the wavelength of light, exposure time, and the intensity of light. After prolonged exposure to heat in alkaline pH conditions, 10 to 15% of the parent<unk>  epimerized to iso-LSD. Under acidic conditions, less than 5% of the<unk>  was converted to iso-LSD. It was also demonstrated that trace amounts of metal ions in buffer or urine could catalyze the decomposition of<unk>  and that this process can be avoided by the addition of EDTA. Detection<unk>  may be quantified in urine as part of a drug abuse testing program, in plasma or serum to confirm a diagnosis of poisoning in hospitalized victims or in whole blood to assist in a forensic investigation of a traffic or other criminal violation or a case of sudden death. Both the parent drug and its major metabolite are unstable in biofluids when exposed to light, heat or alkaline conditions and therefore specimens are protected from light, stored at the lowest possible temperature and analyzed quickly to minimize losses. The apparent plasma half life of<unk>  is considered to be around 5.1 hours with peak plasma concentrations occurring 3 hours after administration.<unk>  can be detected using an Ehrlich's reagent and a Hofmann's reagent.
Lysergic acid diethylamide
Brevetoxin
Anatoxin-a
Bungarotoxin
Botulinum toxin
Charybdotoxin
Muscimol
N1-Methyl-lysergic acid diethylamide