The role of halogen substitution in classical cannabinoids: a CB1 pharmacophore model.
The presence of halogens within the classical cannabinoid structure leads to large variations in the compounds' potencies and affinities for the CB1 receptors. To explore the structure activity relationships within this class of analogs we have used a series of halogen-substituted (-)-Delta8-tetrahydrocannabinol analogs and compared their affinities for the CB1 cannabinoid receptor. Our results indicate that halogen substitution at the end-carbon of the side chain leads to an enhancement in affinity with the bulkier halogens (Br, I) producing the largest effects. Conversely, 2-iodo substitution on the phenolic ring leads to a 2-fold reduction in affinity while iodo-substitution in the C1'-position of the side chain lowers the compound's affinity for CB1 by more than 8-fold. The pharmacophoric requirements resulting from halogen-substitution are explored using computer modeling methods.
Nikas
Spyros P
SP
Department of Pharmaceutical Sciences and Center for Drug Discovery, University of Connecticut, 372 Fairfield Road, Storrs, CT 06269, USA.
Grzybowska
Jolanta
J
Papahatjis
Demetris P
DP
Charalambous
Avgui
A
Banijamali
Ali R
AR
Chari
Ravi
R
Fan
Pusheng
P
Kourouli
Therapia
T
Lin
Sonyuan
S
Nitowski
Albert J
AJ
Marciniak
Gilbert
G
Guo
Yan
Y
Li
Xiuyan
X
Wang
Chia-Lin J
CL
Makriyannis
Alexandros
A
D000818:Animals; D013759:Dronabinol / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism; D006219:Halogens / Q000737:chemistry*; D008024:Ligands; D008958:Models, Molecular; D051381:Rats; D043884:Receptor, Cannabinoid, CB1 / Q000378:metabolism*
D006219:Halogens; D008024:Ligands; D043884:Receptor, Cannabinoid, CB1; C035731:delta-8-tetrahydrocannabinol; D013759:Dronabinol