biostudies-literatureUnknown11Shen LSix previously undescribed ophiobolin-type sesterterpenes, namely, bipolatoxins A-F (<b>1</b>-<b>6</b>); and one previously undescribed pimarane-type diterpene, namely, 1β-hydroxy momilactone A (<b>7</b>); together with three known compounds, namely, 25-hydroxyophiobolin I (<b>8</b>), ophiobolin I (<b>9</b>), and ophiobolin A lactone (<b>10</b>); were isolated and identified from the endophytic fungus <i>Bipolaris</i> species TJ403-B1. Their structures with absolute configurations were elucidated on the basis of extensive spectroscopic analyses (including 1D and 2D nuclear magnetic resonance (NMR) and high-resolution electrospray ionization mass spectroscopy data), single-crystal X-ray diffraction analyses, and comparison of experimental circular dichroism data. All compounds (except for <Frontiers in microbiology856https://www.ebi.ac.uk/biostudies/studies/S-EPMC7273749biostudies-literatureNovel Antimicrobial Compounds as Ophiobolin-Type Sesterterpenes and Pimarane-Type Diterpene From <i>Bipolaris</i> Species TJ403-B1.PMC7273749Shen LLi HHe YLin SLiu MHu ZZhang YChai CAl Anbari WHWang JfalseNovel Antimicrobial Compounds as Ophiobolin-Type Sesterterpenes and Pimarane-Type Diterpene From <i>Bipolaris</i> Species TJ403-B1.Six previously undescribed ophiobolin-type sesterterpenes, namely, bipolatoxins A-F (<b>1</b>-<b>6</b>); and one previously undescribed pimarane-type diterpene, namely, 1β-hydroxy momilactone A (<b>7</b>); together with three known compounds, namely, 25-hydroxyophiobolin I (<b>8</b>), ophiobolin I (<b>9</b>), and ophiobolin A lactone (<b>10</b>); were isolated and identified from the endophytic fungus <i>Bipolaris</i> species TJ403-B1. Their structures with absolute configurations were elucidated on the basis of extensive spectroscopic analyses (including 1D and 2D nuclear magnetic resonance (NMR) and high-resolution electrospray ionization mass spectroscopy data), single-crystal X-ray diffraction analyses, and comparison of experimental circular dichroism data. All compounds (except for <2020-01-01T00:00:00Z20202026-04-30T22:53:28.248Z2020-06-20T07:04:54ZS-EPMC72737493254749810.3389/fmicb.2020.00856