AUTHOR=Zhang Dewu , Tao Xiaoyu , Gu Guowei , Wang Yujia , Zhao Wenxia , Zhao Wuli , Ren Yan , Dai Shengjun , Yu Liyan 

TITLE=Microbial Transformation of neo-Clerodane Diterpenoid, Scutebarbatine F, by Streptomyces sp. CPCC 205437

JOURNAL=Frontiers in Microbiology

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2021.662321

DOI=10.3389/fmicb.2021.662321

ISSN=1664-302X

ABSTRACT=<p>Biotransformation of the <italic>neo</italic>-clerodane diterpene, scutebarbatine F (<bold>1</bold>), by <italic>Streptomyces</italic> sp. CPCC 205437 was investigated for the first time, which led to the isolation of nine new metabolites, scutebarbatine F<sub>1</sub>–F<sub>9</sub> (<bold>2</bold>–<bold>10</bold>). Their structures were determined by extensive high-resolution electrospray ionization mass spectrometry (HRESIMS) and NMR data analyses. The reactions that occurred included hydroxylation, acetylation, and deacetylation. Compounds <bold>2</bold>–<bold>4</bold> and <bold>8</bold>–<bold>10</bold> possess 18-OAc fragment, which were the first examples of 13-spiro <italic>neo</italic>-clerodanes with 18-OAc group. Compounds <bold>7</bold>–<bold>10</bold> were the first report of 13-spiro <italic>neo</italic>-clerodanes with 2-OH. Compounds <bold>1</bold>–<bold>10</bold> were biologically evaluated for the cytotoxic, antiviral, and antibacterial activities. Compounds <bold>5</bold>, <bold>7</bold>, and <bold>9</bold> exhibited cytotoxic activities against H460 cancer cell line with inhibitory ratios of 46.0, 42.2, and 51.1%, respectively, at 0.3 μM. Compound <bold>5</bold> displayed a significant anti-influenza A virus activity with inhibitory ratio of 54.8% at 20 μM, close to the positive control, ribavirin.</p>