1. Photoinduced Irreversible Intramolecular Proton Transfer of Arnebinones B, D, and E: The Case of Photoenolization at the p-Benzoquinone-CH2/CH-π System
- Author
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Ya-Nan Yang, Xu Zhang, Hai-Wei Yan, Xiang Yuan, Pei-Cheng Zhang, and Ling-Hao Zhao
- Subjects
Pharmacology ,chemistry.chemical_classification ,Double bond ,Proton ,Organic Chemistry ,Pharmaceutical Science ,Planar chirality ,Photochemistry ,Benzoquinone ,Analytical Chemistry ,Complementary and alternative medicine ,chemistry ,Intramolecular force ,Drug Discovery ,Molecular Medicine ,Common key ,Moiety ,Epimer - Abstract
Arnebinones B, E, and D (1-3) have been found to be sensitive to light, generating complex and diverse proton transfer products when triggered by light. A unique two-step irreversible intramolecular proton transfer of 1 produced five scalemic mixtures, of which four possessed intriguing dual planar chirality. The unprecedented orientation epimerization equilibrium of the intra-annular double bond was first observed and researched in the homologous meroterpenoids by HPLC monitoring and DFT calculations. A "p-benzoquinone-CH2/CH-π" moiety in the structure was the common key feature for the occurrence of this type of photoenolization reaction. The product transformation processes and universality of this photoinduced irreversible proton transfer reaction were analyzed together with the cytotoxic activities of arnebinones B, D, and E, and their photoreaction products.
- Published
- 2021