Novel Tetrahydroquinazolinamines as Selective Histamine 3 Receptor Antagonists for the Treatment of Obesity

J Med Chem. 2019 May 9;62(9):4638-4655. doi: 10.1021/acs.jmedchem.9b00241. Epub 2019 Apr 29.


The histamine 3 receptor (H3R) is a presynaptic receptor, which modulates several neurotransmitters including histamine and various essential physiological processes, such as feeding, arousal, cognition, and pain. The H3R is considered as a drug target for the treatment of several central nervous system disorders. We have synthesized and identified a novel series of 4-aryl-6-methyl-5,6,7,8-tetrahydroquinazolinamines that act as selective H3R antagonists. Among all the synthesized compounds, in vitro and docking studies suggested that the 4-methoxy-phenyl-substituted tetrahydroquinazolinamine compound 4c has potent and selective H3R antagonist activity (IC50 < 0.04 μM). Compound 4c did not exhibit any activity on the hERG ion channel and pan-assay interference compounds liability. Pharmacokinetic studies showed that 4c crosses the blood brain barrier, and in vivo studies demonstrated that 4c induces anorexia and weight loss in obese, but not in lean mice. These data reveal the therapeutic potential of 4c as an anti-obesity candidate drug via antagonizing the H3R.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anti-Obesity Agents / chemical synthesis
  • Anti-Obesity Agents / pharmacokinetics
  • Anti-Obesity Agents / therapeutic use*
  • Blood Glucose / metabolism
  • Diet, High-Fat
  • HEK293 Cells
  • Histamine H3 Antagonists / chemical synthesis
  • Histamine H3 Antagonists / pharmacokinetics
  • Histamine H3 Antagonists / therapeutic use*
  • Humans
  • Male
  • Mice, Inbred C57BL
  • Molecular Structure
  • Obesity / drug therapy*
  • Proto-Oncogene Proteins c-fos / metabolism
  • Quinazolines / chemical synthesis
  • Quinazolines / pharmacokinetics
  • Quinazolines / therapeutic use*
  • Receptors, Histamine H3 / metabolism*
  • Stereoisomerism
  • Structure-Activity Relationship
  • Weight Loss / drug effects


  • Anti-Obesity Agents
  • Blood Glucose
  • Histamine H3 Antagonists
  • Proto-Oncogene Proteins c-fos
  • Quinazolines
  • Receptors, Histamine H3