AUTHOR=Guo Xing-Chen , Xu Lan-Lan , Yang Rui-Yun , Yang Meng-Yue , Hu Lian-Dong , Zhu Hua-Jie , Cao Fei 

TITLE=Anti-Vibrio Indole-Diterpenoids and C-25 Epimeric Steroids From the Marine-Derived Fungus Penicillium janthinellum

JOURNAL=Frontiers in Chemistry

VOLUME=7

YEAR=2019

URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2019.00080

DOI=10.3389/fchem.2019.00080

ISSN=2296-2646

ABSTRACT=<p>A systematic chemical exploration of the marine-derived fungus <italic>Penicillium janthinellum</italic> led to the isolation of four indole-diterpenoid derivatives (<bold>1</bold>–<bold>4</bold>), including new penijanthines C and D (<bold>1</bold> and <bold>2</bold>), and a pair of new steroidal epimers, penijanthoids A and B (<bold>5</bold> and <bold>6</bold>). The calculated ECD spectra and Snatzke's method for the new compound <bold>1</bold> were carried out to determine its absolute configuration. The absolute configuration of <bold>3</bold> was established by X-ray diffraction and calculated ECD methods for the first time. DP4plus approach was used to elucidate the absolute configurations of the C-25 epimeric steroids <bold>5</bold> and <bold>6</bold>. 25-Epimeric <bold>5</bold> and <bold>6</bold> represent the first examples of steroids forming a five-membered lactone between C-23 and C-27 from marine fungi. Compounds <bold>1</bold>, <bold>2</bold>, <bold>5</bold>, and <bold>6</bold> displayed significant anti-<italic>Vibrio</italic> activity (Minimum inhibitory concentration, MIC values ranging from 3.1 to 50.0 μM) against three pathogenic <italic>Vibrio</italic> spp.</p>