Cannabidiphorol (CBDP)

Cannabidiphorol (CBDP), the heptyl homolog of cannabidiol bearing a seven-carbon linear alkyl side chain on the resorcinyl moiety, is a non-psychoactive phytocannabinoid first identified as a natural product in 2019 by Citti, Linciano, Cannazza and colleagues at the University of Modena and Reggio Emilia during mass spectrometric analysis of the Italian medicinal cannabis variety FM2. Although previously prepared synthetically, CBDP had not been recognized as a naturally occurring constituent of Cannabis sativa L. prior to this identification. The compound was reported alongside its psychoactive analog delta-9-tetrahydrocannabiphorol (THCP) in a landmark Scientific Reports publication that expanded the known phytocannabinoid chemical space beyond the established pentyl (C5) series to include seven-term (C7) alkyl chain homologs of both CBD and THC structural types.

The molecular pharmacology of CBDP is characterized by weak antagonism at both CB1 and CB2 cannabinoid receptors broadly similar to cannabidiol, with the notable distinction that CBDP exhibits modestly weaker CB2 antagonist activity relative to CBD (23 percent versus 33 percent of the reference antagonist SR144528 response). Both compounds display weak agonist activity at the serotonin 5-HT1A receptor at concentrations approaching 12 micromolar. A 2024 in vitro receptor-binding investigation revealed an unexpected finding: CBDP acts as a positive allosteric modulator at the mu-opioid receptor, enhancing met-enkephalin-induced receptor internalization by 37 percent at 3 micromolar, a pharmacological profile opposite to the negative allosteric modulation predicted from CBD family behavior. A 2026 study published in Nature Communications Chemistry further established that CBDP functions as a negative allosteric modulator of the CB1 receptor at two distinct binding sites, the established ORG27569 allosteric site and a novel intracellular site located between transmembrane helices 1, 2, 6, 7, and helix 8. This dual-site allosteric mechanism, demonstrated through site-directed mutagenesis and molecular dynamics simulations, enables CBDP to selectively modulate THC-induced cognitive effects while preserving antinociception, a pharmacological profile with potential research applications in cannabinoid combination pharmacology.

Preclinical investigation of CBDP remains in early stages. Cytotoxicity studies in breast cancer cell lines have demonstrated IC50 values of approximately 50 to 60 micromolar across multiple cell types, with mechanisms involving oxidative stress induction, mitochondrial membrane depolarization, and multi-organelle damage. No dedicated pharmacokinetic studies have been published for CBDP; the increased lipophilicity conferred by the extended alkyl chain is predicted to alter absorption, distribution, and protein binding relative to CBD but direct experimental characterization is absent. No clinical trials have been conducted with CBDP as the investigational agent, and no regulatory approvals exist in any jurisdiction. The compound is available as a certified analytical reference standard from multiple research chemical suppliers at purities of 95 percent or greater. This monograph reviews the identification, structural chemistry, and stereoselective synthesis of CBDP; the receptor pharmacology across cannabinoid, serotonergic, and opioid targets; the allosteric modulation at CB1; available preclinical activity data; sourcing and analytical considerations; and a structured comparative assessment of five CBD-type phytocannabinoid homologs against CBDP on five competency standards.