It has 4.1% of theantiserotonergic activity of LSD in the isolated ratuterus[3][4] and itshallucinogenic activity in humans has not been reported.[5][3] Unlike the related compounds LPD-824 andLSM-775 (lysergic acid morpholide), lysergic acid pyrrolinide does not appear to have been assessed in humans.[5] Like LPD-824, the drug has greaterhypotensive effects than LSD in animals.[4][6]
^abcdHofmann A (June 1959)."Psychotomimetic drugs; chemical and pharmacological aspects"(PDF).Acta Physiologica et Pharmacologica Neerlandica.8:240–258.PMID13852489.Systematic variations of the substituents in the amide grouping has resulted in the synthesis of a great number of substances (STOLL and HOFMANN, 1955) which are listed in table 1. [...] TABLE 1 Variations in the acid amide group of the LSD molecule Amides of d-lysergic acid (C12H15N2–COR) prepared for pharmacological investigation [...] R: [...] d-lysergic acid pyrrolinide
^abcdeGupta SP, Singh P, Bindal MC (1 December 1983)."QSAR studies on hallucinogens".Chemical Reviews.83 (6):633–649.doi:10.1021/cr00058a003.ISSN0009-2665.TABLE XII. Antiserotonin and Hallucinogenic Activities and Hückel's Total MO Energy of LSD and its Analogues [...] compd: 144 [...] anti-Sa: 4.1c. Ha: 10d,e. [...] Data collected by Kumbar and Siva Sankar,91,92 from ref 70a, 87, 88, and 90; all activities are relative to that of LSD taken as 100.
^abcdeCerletti A, Doepfner W (January 1958). "Comparative study on the serotonin antagonism of amide derivatives of lysergic acid and of ergot alkaloids".The Journal of Pharmacology and Experimental Therapeutics.122 (1):124–136.doi:10.1016/S0022-3565(25)11933-2.PMID13502837.TABLE 1 Antiserotonin potency of 16 amide-derivatives of d-lysergic acid [...] C. Cyclic amide, derivatives [...] R = [...] Name: d-lysergic acid pyrrolidid. Relative activity ± s.e.* (LSD = 100): 4.7 ± 0.4. [...] R = [...] Name: d-lysergic acid pyrrolinid. Relative activity ± s.e.* (LSD = 100): 4.1 ± 0.7. [...] 4. Cyclic amide derivatives of lysergic acid. The four compounds listed in section C of table 1 can be considered as having the two aminoethyl groups closed to form a five- or six-membered ring. Although some of the pharmacologic effects of LSD are enhanced by this ring formation (for example, the depressor effect of the pyrrolidide and pyrrolinide is stronger than with LSD (Cerletti, 1955), the antiserotonin activity is reduced ten to fifty times as compared with LSD.
^abOberlender RA (May 1989)."Stereoselective aspects of hallucinogenic drug action and drug discrimination studies of entactogens".Purdue e-Pubs. Purdue University.Table 2. Relative potency values for lysergic acid amides. [...] Cyclic Amides: [...] R2/R3: -CH2CH=CHCH2- (Pyrrolinide). Potency relative to LSDa: From studies employing: Humanb: ?.In Vitroc: 4.1[%]. [...]aRelative potency for both assays are expressed in terms of percent of LSD's potency. A value of 50 indicates one half as potent as LSD.bHuman potency values compiled by Shulgin (1981; 1982). References for the individual studies can be found in these reports.c In vitro values represent serotonin antagonist potency as evaluated by Cerletti and Doepfner (1958) in the isolated rat uterus. [...] Two cyclized amides have been evaluated in humans. The pyrrolidide represents an LSD derivative in which an additional carbon-carbon bond connects the β-carbons of the two ethyl groups. The morpholide can be viewed as a derivative in which these same carbons are bridged by an oxygen. Both of these compounds were about one third as potent as LSD.
^Cerletti A (1956)."Lysergic Acid Diethylamide (LSD) and Related Compounds". In Abramson HA (ed.).Neuropharmacology: Transactions of the 2nd Conference, May 25-27, 1955, Princeton, N.J. New York: Josiah Macy. pp. 9–84.Cerletti: LPD-824 is chemically related to LSD. It is the pyrrolidid of lysergic acid, having the diethylamino group closed to a pyrrolidine nucleus (Figure 7). When this substance was tested in man, doses up to 1/2 μg./kg, were given intravenously without producing any LSD-like symptoms. Pharmacologically LPD is a very strong hypotensive agent. In animals 10 μg./kg. produces hypotension, both in cats and in dogs. As already said, in human subjects it had no psychic effect, but produced nausea in such small doses that a hypotensive effect could not be achieved.
