AUTHOR=Ye Ke , Lv Xiao , Zhang Xian , Wei Pan-Pan , Li Zheng-Hui , Ai Hong-Lian , Zhao Da-Ke , Liu Ji-Kai 

TITLE=Immunosuppressive Isopimarane Diterpenes From Cultures of the Endophytic Fungus Ilyonectria robusta

JOURNAL=Frontiers in Pharmacology

VOLUME=12

YEAR=2022

URL=https://www.frontiersin.org/journals/pharmacology/articles/10.3389/fphar.2021.766441

DOI=10.3389/fphar.2021.766441

ISSN=1663-9812

ABSTRACT=<p>Five new isopimarane diterpenes, robustaditerpene A-E (<bold>1</bold>–<bold>5</bold>), which include 19-nor-isopimarane skeleton and isopimarane skeleton, were isolated from the liquid fermentation of the endophytic fungus <italic>Ilyonectria robusta</italic> collected from <italic>Bletilla striata.</italic> The structure elucidation and relative configuration assignments of all compounds were accomplished by interpretation of NMR and HRESIMS spectrometric analyses and <sup>13</sup>C NMR calculation. And the absolute configuration of <bold>1</bold>-<bold>5</bold> were identified by single-crystal X-ray diffraction and ECD calculation. Compound <bold>3</bold> inhibited lipopolysaccharide-induced B lymphocytes cell proliferation with an IC<sub>50</sub> value at 17.42 ± 1.57 <italic>μ</italic>M while compound <bold>5</bold> inhibited concanavalin A-induced T lymphocytes cell proliferation with an IC<sub>50</sub> value at 75.22 ± 6.10 <italic>μ</italic>M. These data suggested that compounds <bold>3</bold> and <bold>5</bold> may possess potential immunosuppressive prospect.</p>