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Updated: Aug 1, 2025
09:33
Determination of the Photoisomerization Quantum Yield of a Hydrazone Photoswitch
Published on: February 7, 2022
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CBD hydroxyquinone photo-isomerises to a highly reactive intermediate
Brodie J Thomson1, Summer Hanna2, Adrian Schwarzenberg2
1Department of Chemistry, University of British Columbia, Vancouver, Canada.
Scientific Reports
|April 28, 2023
Summary
Cannabidiol (CBD) impurity, HU-331, transforms under light into reactive compounds. These by-products, not HU-331, cause the purple color in aged CBD solutions, highlighting contamination concerns.
Area of Science:
- Organic Chemistry
- Photochemistry
- Cannabinoid Science
Background:
- The widespread availability of cannabidiol (CBD) products follows hemp legalization.
- Common impurities like CBD-hydroxyquinone (HU-331) are present in CBD isolates.
Purpose of the Study:
- To investigate the photo-induced transformations of HU-331 in CBD solutions.
- To identify the source of color changes in light-exposed CBD products.
Main Methods:
- Photochemical reactions of HU-331 were studied.
- Computational calculations were employed to support experimental findings.
- Spectroscopic analysis was used to characterize reaction products.
Main Results:
- HU-331 undergoes photo-isomerization to a reactive intermediate.
- This intermediate rapidly reacts with oxygen, forming numerous cannabinoid derivatives.
- The purple color in aged CBD solutions is attributed to anions of these by-products, not HU-331 anions.
Conclusions:
- Light exposure generates uncharacterized cannabinoid derivatives from HU-331 impurities.
- These findings are relevant for CBD-containing e-liquids and solutions stored under light.
- Enhanced quality control is needed to manage HU-331 contamination in CBD products.
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