^ abcdefghReith ME, Blough BE, Hong WC, Jones KT, Schmitt KC, Baumann MH, Partilla JS, Rothman RB, Katz JL (February 2015). "Behavioral, biological, and chemical perspectives on atypical agents targeting the dopamine transporter". Drug Alcohol Depend. 147: 1–19. doi:10.1016/j.drugalcdep.2014.12.005. PMC4297708. PMID25548026. Table 1 shows the transporter activity oftwo sets of compounds, one a set of phenethylamine (i.e., amphetamine) analogs and the other a set of β-keto phenethylamine (i.e., cathinone) analogs. Each set of compounds demonstrates predicable structural trends. Amphetamine is a DA releaser with an EC50 value of 8.7 nM. Modifications that increase the size of amphetamine gradually decreased release potency until the increases caused the activity to change to transport inhibition. Specifically, N-alkylation of amphetamine, going from no alkyl group (amphetamine) to methyl (methamphetamine) to ethyl (PAL-99) decreased EC50 values for release from 8.7 to 24.5 to 88.5 nM.Adding an additional methylene to form the N-propyl analog (PAL-424) caused the compound to become a DAT uptake inhibitor with an IC50 value of 1013 nM. Increasing the size even further to butyl (PAL-90) rendered the compound inactive at the DAT.
^ abcdFitzgerald LR, Gannon BM, Walther D, Landavazo A, Hiranita T, Blough BE, Baumann MH, Fantegrossi WE (March 2024). "Structure-activity relationships for locomotor stimulant effects and monoamine transporter interactions of substituted amphetamines and cathinones". Neuropharmacology. 245: 109827. doi:10.1016/j.neuropharm.2023.109827. PMC 10842458. PMID38154512. Although the number of amphetamine analogues with different amine substituents is relatively low in recreational drug markets (Cho and Segal, 1994), N-methyl and N-ethyl substitutions are sometimes found. Pharmacological activity of amphetamine-type drugs is decreased substantially if the N-alkyl chain is lengthened beyond ethyl, as previous studies show that N-propylamphetamine and N-butylamphetamine are ∼4-fold and ∼6-fold less potent than amphetamine in rats (Woolverton et al., 1980).
^ abcWoolverton WL, Shybut G, Johanson CE (December 1980). "Structure-activity relationships among some d-N-alkylated amphetamines". Pharmacol Biochem Behav. 13 (6): 869–876. doi:10.1016/0091-3057(80)90221-x. PMID7208552.
^Nicole, Lauren (2022). "In vivo Structure-Activity Relationships of Substituted Amphetamines and Substituted Cathinones". ProQuest. Retrieved 5 December 2024. FIGURE 2-6: Release: Effects of the specified test drug on monoamine release by DAT (red circles), NET (blue squares), and SERT (black traingles) in rat brain tissue. [...] EC50 values determined for the drug indicated within the panel. [...]
^Rothman RB, Baumann MH (October 2003). "Monoamine transporters and psychostimulant drugs". European Journal of Pharmacology. 479 (1–3): 23–40. doi:10.1016/j.ejphar.2003.08.054. PMID14612135.
^Rothman RB, Baumann MH (2006). "Therapeutic potential of monoamine transporter substrates". Current Topics in Medicinal Chemistry. 6 (17): 1845–1859. doi:10.2174/156802606778249766. PMID17017961.
^ abBeckett AH, Shenoy EV (October 1973). "The effect of N-alkyl chain length of stereochemistry on the absorption, metabolism and during excretion of N-alkylamphetamines in man". J Pharm Pharmacol. 25 (10): 793–799. doi:10.1111/j.2042-7158.1973.tb09943.x. PMID4151673.
^Bach MV, Coutts RT, Baker GB (March 2000). "Metabolism of N,N-dialkylated amphetamines, including deprenyl, by CYP2D6 expressed in a human cell line". Xenobiotica. 30 (3): 297–306. doi:10.1080/004982500237686. PMID10752644. Ring hydroxylation was also expected because CYP2D6 can mediate the ring oxidation of other amphetamines such as N-n-butylamphetamine, N-ethylamphetamine and amphetamine (Bach et al. 1999).
^Bach MV, Coutts RT, Baker GB (July 1999). "Involvement of CYP2D6 in the in vitro metabolism of amphetamine, two N-alkylamphetamines and their 4-methoxylated derivatives". Xenobiotica. 29 (7): 719–732. doi:10.1080/004982599238344. PMID10456690.