Abstract
Background: Since the cannabinoid receptor 1 (CB1) antagonist SR141716 (rimonabant) was previously reported to modulate food intake, CB1 antagonism has been considered as a new therapeutic target for the treatment of obesity. Discussion: In the present study, biarylpyrazole analogues based on a sulfur-containing pyrazole core coupled with 1,3,4-oxadiazole and 1,3,4-thiadiazole were synthesized and assayed for rat CB1 receptor binding affinity. Results: The structure–activity relationship studies to optimize pyrazole substituents as well as 1,3,4-oxadiazole or 1,3,4-thiadiazole rings led to four novel CB1 antagonists with IC50 values of approximately 1 nM for the rat CB1 receptor binding. Among these derivatives, we identified trifluoromethylcyclobutyl analogues 19e and 19l as promising precandidates for the development as anti-obesity agents.
Acknowledgements
We are grateful to Dr Eun Chul Huh for many valuable discussions throughout small molecule research programs at Central Research Laboratories, Green Cross Corp. (GCC).
Financial & competing interests disclosure
This research was in part (Park H-J and Yoo J) supported by a grant (CBM32-B2000-01-02-00) from the Center for Biological Modulators of the 21st Century Frontier R&D Program, the Ministry of Science, Republic of Korea. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.
No writing assistance was utilized in the production of this manuscript.
Ethical conduct of research
The authors state that they have obtained appropriate institutional review board approval or have followed the principles outlined in the Declaration of Helsinki for all human or animal experimental investigations. In addition, for investigations involving human subjects, informed consent has been obtained from the participants involved.