Inhibitors of BRD4 Protein from a Marine-Derived Fungus Alternaria sp. NH-F6

• Main Authors: Hui Ding, Dashan Zhang, Biao Zhou, Zhongjun Ma
• Format: Article
• Language: English
• Published: MDPI AG 2017-03-01
• Series: Marine Drugs
• Subjects: marine-derived fungus; Alternaria sp. NH-F6; secondary metabolites
• Online Access: http://www.mdpi.com/1660-3397/15/3/76

Bromodomains (BRD) are readers of the epigenetic code that regulate gene transcription through their recognition of acetyl-lysine modified histone tails. Recently, bromodomain-containing proteins such as BRD4 have been demonstrated to be druggable through the discovery of potent inhibitors. These protein–protein interaction inhibitors have the potential to modulate multiple diseases by their profound anti-inflammatory and antiproliferative effects. In order to explore new BRD4 inhibitors as well as lead compounds for the development of new drugs, the secondary metabolites of Alternaria sp. NH-F6, a fungus isolated from deep-sea sediment samples, were analyzed systematically. Five new compounds including two new perylenequinones (1–2), one new alternaric acid (3), 2-(N-vinylacetamide)-4-hydroxymethyl-3-ene-butyrolactone (4), one new cerebroside (5), together with 19 known compounds (6–24) were isolated from the ethyl acetate extracts of this strain. Their structures were elucidated using nuclear magnetic resonance (NMR) and high resolution electrospray ionization mass spectrometry (HR-ESI-MS) analyses. Finally, all these compounds were evaluated for their inhibitory activity against BRD4 protein, and compound 2 exhibited a potent inhibition rate of 88.1% at a concentration of 10 µM. This research provides a new BRD4 inhibitor which may possess potential antitumoral, antiviral, or anti-inflammatory pharmaceutical values.