Synthesis and pharmacological evaluation of N-benzyl substituted 4-bromo-2,5-dimethoxyphenethylamines as 5-HT2A/2C partial agonists.
Bioorganic & medicinal chemistry – July 15, 2015
Source: PubMed
Summary
Surprisingly, some potent serotonin-modulating compounds don't need a specific chemical group previously thought essential. Researchers explored how adding N-benzyl phenethylamines to certain molecules affects their interaction with serotonin receptors, specifically 5-HT(2A) agonists. They found that modifying the N-benzyl group significantly impacts receptor selectivity and overall structure activity relations. Many new compounds showed high affinity for these receptors, even some lacking the 2'-benzyl substituent, challenging prior beliefs and revealing new pathways for developing targeted therapies.
Abstract
N-Benzyl substitution of phenethylamine 5-HT2A receptor agonists has dramatic effects on binding affinity, receptor selectivity and agonist activity. In this paper we examine how affinity for the 5-HT2A/2C receptors are influenced by N-benzyl substitution of 4-bromo-2,5-dimethoxyphenethylamine derivatives. Special attention is given to the 2' and 3'-position of the N-benzyl as such compounds are known to be very potent. We found that substitutions in these positions are generally well tolerated. The 2'-position was further examined using a range of substituents to probe the hydrogen bonding requirements for optimal affinity and selectivity, and it was found that small changes in the ligands in this area had a profound effect on their affinities. Furthermore, two ligands that lack a 2'-benzyl substituent were also found to have high affinity contradicting previous held notions. Several high-affinity ligands were identified and assayed for functional activity at the 5-HT2A and 5-HT2C receptor, and they were generally found to be less efficacious agonists than previously reported N-benzyl phenethylamines.