Classical cannabinoids structure-activity relationships

Several studies on the structure-activity relationships (SAR) of cannabinoids have been recently published [34-37]. Three important features have been determined for classical and nonclassical cannabinoids a side-chain of three to seven carbon atoms in the 3-position of the phenol, a phenolic hydroxyl, and a suitable conformation or substituents in the C 9 position. However, not all these features are necessarily required to produce analgesic effects. 

However, studies on structure-activity relationships have revealed that, in addition to classical cannabinoids, other structurally different compounds can also be CB receptor ligands. Thus, the term cannabinoids is now applied to any compound with good affinity for cannabinoid receptors. 

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