{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,29]],"date-time":"2026-03-29T02:50:21Z","timestamp":1774752621462,"version":"3.50.1"},"reference-count":42,"publisher":"MDPI AG","issue":"14","license":[{"start":{"date-parts":[[2024,7,15]],"date-time":"2024-07-15T00:00:00Z","timestamp":1721001600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Charlotte\u2019s Web"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJMS"],"abstract":"<jats:p>Phytocannabinoids with seven-carbon alkyl chains (phorols) have gained a lot of attention, as they are commonly believed to be more potent versions of typical cannabinoids with shorter alkyl chains. At the time of this article, cannabidiphorol (CBDP) and tetrahydrocannabiphorol (THCP) can both be purchased in the North American market, even though their biological activities are nearly unknown. To investigate their relative potency, we conducted in vitro receptor-binding experiments with CBDP (cannabinoid CB1\/CB2 receptor antagonism, serotonin 5HT-1A agonism, dopamine D2S (short form) agonism, and mu-opioid negative allosteric modulation) and compared the observed activity with that of CBD. To our knowledge, this is the first publication to investigate CBDP\u2019s receptor activity in vitro. A similar activity profile was observed for both CBD and CBDP, with the only notable difference at the CB2 receptor. Contrary to common expectations, CBD was found to be a slightly more potent CB2 antagonist than CBDP (p &lt; 0.05). At the highest tested concentration, CBD demonstrated antagonist activity with a 33% maximum response of SR144528 (selective CB2 antagonist\/inverse agonist). CBDP at the same concentration produced a weaker antagonist activity. A radioligand binding assay revealed that among cannabinoid and serotonin receptors, CB2 is likely the main biological target of CBDP. However, both CBD and CBDP were found to be significantly less potent than SR144528. The interaction of CBDP with the mu-opioid receptor (MOR) produced unexpected results. Although the cannabidiol family is considered to be a set of negative allosteric modulators (NAMs) of opioid receptors, we observed a significant increase in met-enkephalin-induced mu-opioid internalization when cells were incubated with 3 \u00b5M of CBDP and 1 \u00b5M met-enkephalin, a type of activity expected from positive allosteric modulators (PAMs). To provide a structural explanation for the observed PAM effect, we conducted molecular docking simulations. These simulations revealed the co-binding potential of CBDP (or CBD) and met-enkephalin to the MOR.<\/jats:p>","DOI":"10.3390\/ijms25147724","type":"journal-article","created":{"date-parts":[[2024,7,15]],"date-time":"2024-07-15T18:17:32Z","timestamp":1721067452000},"page":"7724","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":4,"title":["CBD Versus CBDP: Comparing In Vitro Receptor-Binding Activities"],"prefix":"10.3390","volume":"25","author":[{"given":"Mehdi","family":"Haghdoost","sequence":"first","affiliation":[{"name":"Nalu Bio Inc., 38 Keyes Avenue, Suite 117, San Francisco, CA 94129, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Scott","family":"Young","sequence":"additional","affiliation":[{"name":"Charlotte\u2019s Web, 700 Tech Court, Louisville, CO 80027, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9810-389X","authenticated-orcid":false,"given":"Alisha K.","family":"Holloway","sequence":"additional","affiliation":[{"name":"Phylos Bioscience, 2455 NW Nicolai Street STE B-O6, Portland, OR 97210, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Matthew","family":"Roberts","sequence":"additional","affiliation":[{"name":"Nalu Bio Inc., 38 Keyes Avenue, Suite 117, San Francisco, CA 94129, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ivori","family":"Zvorsky","sequence":"additional","affiliation":[{"name":"Charlotte\u2019s Web, 700 Tech Court, Louisville, CO 80027, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Marcel O.","family":"Bonn-Miller","sequence":"additional","affiliation":[{"name":"Charlotte\u2019s Web, 700 Tech Court, Louisville, CO 80027, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2024,7,15]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"694","DOI":"10.1021\/ja01255a061","article-title":"Tetrahydrocannabinol Homologs and Analogs with Marihuana Activity. XIII1","volume":"64","author":"Adams","year":"1942","journal-title":"J. Am. Chem. Soc."},{"key":"ref_2","unstructured":"Makriyannis, A., Nikas, S.P., and Alapafuja, S.O. (2012). Angiogenic Resorcinol Derivatives. (20120172339A12012), U.S. Patent."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"20335","DOI":"10.1038\/s41598-019-56785-1","article-title":"A Novel Phytocannabinoid Isolated from Cannabis Sativa L. with an in Vivo Cannabimimetic Activity Higher than \u03949-Tetrahydrocannabinol: \u03949-Tetrahydrocannabiphorol","volume":"9","author":"Citti","year":"2019","journal-title":"Sci. Rep."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"531","DOI":"10.1021\/acs.jnatprod.0c01034","article-title":"(\u2212)-Trans-\u03949-Tetrahydrocannabiphorol Content of Cannabis Sativa Inflorescence from Various Chemotypes","volume":"84","author":"Bueno","year":"2021","journal-title":"J. Nat. Prod."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"34","DOI":"10.1186\/s42238-023-00200-0","article-title":"High Levels of Pesticides Found in Illicit Cannabis Inflorescence Compared to Licensed Samples in Canadian Study Using Expanded 327 Pesticides Multiresidue Method","volume":"5","author":"Gagnon","year":"2023","journal-title":"J. Cannabis Res."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"357","DOI":"10.15288\/jsad.23-00008","article-title":"Delta-8, Delta-10, HHC, THC-O, THCP, and THCV: What Should We Call These Products?","volume":"84","author":"Rossheim","year":"2023","journal-title":"J. Stud. Alcohol. Drugs"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"5577","DOI":"10.1002\/chem.202002887","article-title":"Cannabidiol Discovery and Synthesis\u2014A Target-Oriented Analysis in Drug Production Processes","volume":"27","author":"Miranda","year":"2021","journal-title":"Chem. A Eur. J."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"99","DOI":"10.1016\/S0014-2999(02)02624-9","article-title":"(\u2212)-Cannabidiol Antagonizes Cannabinoid Receptor Agonists and Noradrenaline in the Mouse Vas Deferens","volume":"456","author":"Pertwee","year":"2002","journal-title":"Eur. J. Pharmacol."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"2093","DOI":"10.1111\/j.1460-9568.2007.05448.x","article-title":"Interactions of Cannabidiol with Endocannabinoid Signalling in Hippocampal Tissue","volume":"25","author":"Ryan","year":"2007","journal-title":"Eur. J. Neurosci."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"613","DOI":"10.1038\/sj.bjp.0707133","article-title":"Cannabidiol Displays Unexpectedly High Potency as an Antagonist of CB1 and CB2 Receptor Agonists In Vitro","volume":"150","author":"Thomas","year":"2007","journal-title":"Br. J. Pharmacol."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"4790","DOI":"10.1111\/bph.13250","article-title":"Cannabidiol Is a Negative Allosteric Modulator of the Cannabinoid CB1 Receptor","volume":"172","author":"Laprairie","year":"2015","journal-title":"Br. J. Pharmacol."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1455","DOI":"10.1111\/bph.14440","article-title":"Allosteric and Orthosteric Pharmacology of Cannabidiol and Cannabidiol-Dimethylheptyl at the Type 1 and Type 2 Cannabinoid Receptors","volume":"176","author":"Tham","year":"2019","journal-title":"Br. J. Pharmacol."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"191","DOI":"10.1089\/can.2019.0052","article-title":"Use of Cannabidiol for the Treatment of Anxiety: A Short Synthesis of Pre-Clinical and Clinical Evidence","volume":"5","author":"Wright","year":"2020","journal-title":"Cannabis Cannabinoid Res."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"12137","DOI":"10.1021\/acs.jmedchem.0c00724","article-title":"The Essential Medicinal Chemistry of Cannabidiol (CBD)","volume":"63","author":"Nelson","year":"2020","journal-title":"J. Med. Chem."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"1037","DOI":"10.1007\/s11064-005-6978-1","article-title":"Agonistic Properties of Cannabidiol at 5-HT1a Receptors","volume":"30","author":"Russo","year":"2005","journal-title":"Neurochem. Res."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"410","DOI":"10.1016\/j.euroneuro.2013.10.012","article-title":"Effects of Intra-Prelimbic Prefrontal Cortex Injection of Cannabidiol on Anxiety-like Behavior: Involvement of 5HT1A Receptors and Previous Stressful Experience","volume":"24","author":"Reis","year":"2014","journal-title":"Eur. Neuropsychopharmacol."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"136","DOI":"10.1097\/j.pain.0000000000001386","article-title":"Cannabidiol Modulates Serotonergic Transmission and Reverses Both Allodynia and Anxiety-like Behavior in a Model of Neuropathic Pain","volume":"160","author":"McLaughlin","year":"2019","journal-title":"Pain"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"393","DOI":"10.1093\/jat\/bkab026","article-title":"Safety, Pharmacokinetics and Pharmacodynamics of Spectrum Yellow Oil in Healthy Participants","volume":"46","author":"Peters","year":"2022","journal-title":"J. Anal. Toxicol."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"405","DOI":"10.1002\/phar.2512","article-title":"Food Effects on the Formulation, Dosing, and Administration of Cannabidiol (CBD) in Humans: A Systematic Review of Clinical Studies","volume":"41","author":"Silmore","year":"2021","journal-title":"Pharmacotherapy"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"5131","DOI":"10.2174\/138161212802884681","article-title":"A Critical Review of the Antipsychotic Effects of Cannabidiol: 30 Years of a Translational Investigation","volume":"18","author":"Zuardi","year":"2012","journal-title":"Curr. Pharm. Des."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"e920","DOI":"10.1038\/tp.2016.195","article-title":"Cannabidiol Is a Partial Agonist at Dopamine D2High Receptors, Predicting Its Antipsychotic Clinical Dose","volume":"6","author":"Seeman","year":"2016","journal-title":"Transl. Psychiatry"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"1366","DOI":"10.1016\/j.bbrc.2020.10.021","article-title":"Involvement of Dopamine Receptor in the Actions of Non-Psychoactive Phytocannabinoids","volume":"533","author":"Shrader","year":"2020","journal-title":"Biochem. Biophys. Res. Commun."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"7731","DOI":"10.1073\/pnas.95.13.7731","article-title":"Prominence of the Dopamine D2 Short Isoform in Dopaminergic Pathways","volume":"95","author":"Khan","year":"1998","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"4305","DOI":"10.1073\/pnas.0730708100","article-title":"Distinct Roles of Dopamine D2L and D2S Receptor Isoforms in the Regulation of Protein Phosphorylation at Presynaptic and Postsynaptic Sites","volume":"100","author":"Lindgren","year":"2003","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"27","DOI":"10.1007\/BF02246947","article-title":"Comparison of in Vitro Binding Properties of a Series of Dopamine Antagonists and Agonists for Cloned Human Dopamine D2S and D2L Receptors and for D2 Receptors in Rat Striatal and Mesolimbic Tissues, Using [125I] 2\u2032-Iodospiperone","volume":"110","author":"Leysen","year":"1993","journal-title":"Psychopharmacology"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"354","DOI":"10.1007\/s00210-006-0033-x","article-title":"Cannabidiol Is an Allosteric Modulator at Mu- and Delta-Opioid Receptors","volume":"372","author":"Kathmann","year":"2006","journal-title":"Naunyn Schmiedebergs Arch. Pharmacol."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"9466","DOI":"10.1021\/acs.jmedchem.3c00061","article-title":"Structure\u2013Activity Relationship Study of Cannabidiol-Based Analogs as Negative Allosteric Modulators of the \u03bc-Opioid Receptor","volume":"66","author":"Gudorf","year":"2023","journal-title":"J. Med. Chem."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"756","DOI":"10.1124\/mol.110.066613","article-title":"\u03bc-Opioid Receptors: Correlation of Agonist Efficacy for Signalling with Ability to Activate Internalization","volume":"78","author":"McPherson","year":"2010","journal-title":"Mol. Pharmacol."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"1147","DOI":"10.1021\/acschemneuro.7b00090","article-title":"Recent Advances in the Realm of Allosteric Modulators for Opioid Receptors for Future Therapeutics","volume":"8","author":"Remesic","year":"2017","journal-title":"ACS Chem. Neurosci."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"547","DOI":"10.1038\/s41586-018-0219-7","article-title":"Structure of the \u039c-Opioid Receptor-Gi Protein Complex","volume":"558","author":"Koehl","year":"2018","journal-title":"Nature"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"3891","DOI":"10.1021\/acs.jcim.1c00203","article-title":"AutoDock Vina 1.2.0: New Docking Methods, Expanded Force Field, and Python Bindings","volume":"61","author":"Eberhardt","year":"2021","journal-title":"J. Chem. Inf. Model."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"3544","DOI":"10.1038\/s41467-024-47792-6","article-title":"Structural and Dynamic Insights into the Activation of the \u03bc-Opioid Receptor by an Allosteric Modulator","volume":"15","author":"Kaneko","year":"2024","journal-title":"Nat. Commun."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"e2121918119","DOI":"10.1073\/pnas.2121918119","article-title":"Activation Mechanism of the \u03bc-Opioid Receptor by an Allosteric Modulator","volume":"119","author":"Kaneko","year":"2022","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_34","unstructured":"Eurofins DiscoverX (2024, April 06). User Manual: PathHunter\u00ae b-Arrestin Assay for GPCR Cell Lines. Available online: https:\/\/www.discoverx.com\/content\/uploads\/2023\/07\/70-247-PathHunter-Beta-Arrestin-Assay-for-GPCR-Cell-Lines_REV5-1.pdf."},{"key":"ref_35","unstructured":"Eurofins DiscoverX (2024, April 06). User Manual: cAMP Hunter\u2122: G\u03b1s and G\u03b1i Cell Line. Available online: https:\/\/www.discoverx.com\/content\/uploads\/2023\/07\/70-233-cAMP-Hunter-Gs-and-Gi-Cell-Lines_REV10-1.pdf."},{"key":"ref_36","unstructured":"Eurofins DiscoverX (2024, April 06). User Manual: PathHunter\u00ae Total GPCR Internalization Assay. Available online: https:\/\/www.discoverx.com\/content\/uploads\/2023\/07\/70-260-PathHunter-Total-GPCR-Internalization-Assay_REV6-1.pdf."},{"key":"ref_37","doi-asserted-by":"crossref","unstructured":"(2011). A Smoothed Backbone-Dependent Rotamer Library for Proteins Derived from Adaptive Kernel Density Estimates and Regressions. Structure, 19, 844\u2013858. Available online: https:\/\/www.ncbi.nlm.nih.gov\/pmc\/articles\/PMC3118414\/.","DOI":"10.1016\/j.str.2011.03.019"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"3836","DOI":"10.1021\/ct100481h","article-title":"Performance of Molecular Mechanics Force Fields for RNA Simulations: Stability of UUCG and GNRA Hairpins","volume":"6","author":"Hollas","year":"2010","journal-title":"J. Chem. Theory Comput."},{"key":"ref_39","unstructured":"(2016). Vinardo: A Scoring Function Based on Autodock Vina Improves Scoring, Docking, and Virtual Screening. PLoS ONE, 11, Available online: https:\/\/journals.plos.org\/plosone\/article?id=10.1371\/journal.pone.0155183."},{"key":"ref_40","doi-asserted-by":"crossref","unstructured":"(2022). Improving Ligand-ranking of AutoDock Vina by Changing the Empirical Parameters. J. Comput. Chem., 43, 160\u2013169. Available online: https:\/\/onlinelibrary.wiley.com\/doi\/10.1002\/jcc.26779.","DOI":"10.1002\/jcc.26779"},{"key":"ref_41","doi-asserted-by":"crossref","unstructured":"(2021). A Practical Guide to Large-Scale Docking. Nat. Protoc., 16, 4799\u20134832. Available online: https:\/\/www.nature.com\/articles\/s41596-021-00597-z.","DOI":"10.1038\/s41596-021-00597-z"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"6582","DOI":"10.1021\/jm300687e","article-title":"Directory of Useful Decoys, Enhanced (DUD-E): Better Ligands and Decoys for Better Benchmarking","volume":"55","author":"Mysinger","year":"2012","journal-title":"J. Med. Chem."}],"container-title":["International Journal of Molecular Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1422-0067\/25\/14\/7724\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T15:16:59Z","timestamp":1760109419000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1422-0067\/25\/14\/7724"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,7,15]]},"references-count":42,"journal-issue":{"issue":"14","published-online":{"date-parts":[[2024,7]]}},"alternative-id":["ijms25147724"],"URL":"https:\/\/doi.org\/10.3390\/ijms25147724","relation":{},"ISSN":["1422-0067"],"issn-type":[{"value":"1422-0067","type":"electronic"}],"subject":[],"published":{"date-parts":[[2024,7,15]]}}}