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Updated: Nov 1, 2025
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Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions
Published on: July 17, 2020
Hyperdioxanes, dibenzo-1,4-dioxane derivatives from the roots of Hypericum ascyron
Kanji Niwa1, Naonobu Tanaka2, Yusei Shimomoto1
1Graduate School of Pharmaceutical Sciences, Tokushima University, Tokushima, 770-8505, Japan.
Abstract:
Six dibenzo-1,4-dioxane derivatives (1-6) were isolated from the roots of a Hypericaceous plant Hypericum ascyron. Spectroscopic analyses revealed 2 and 4-6 to be new compounds. The partial racemic natures of 1-3 were concluded by chiral HPLC analyses, while 5 was confirmed to be a racemate. The absolute configurations 1-4 were deduced on the basis of ECD calculations. Biological activity evaluation of the dibenzo-1,4-dioxane derivatives along with two related compounds: hyperdioxanes A (7) and B (8), previously isolated from the same plant material by our group demonstrated that 7 exhibit an anti-HIV activity (IC50 5.3 μM, TI 7.2) while 8 showed an inhibitory effect on IL-1β production (inhibition rate: 72.3% at 6.3 μM) from LPS-stimulated microglial cells.
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