Asperlones A and B, dinaphthalenone derivatives from a mangrove endophytic fungus Aspergillus sp. 16-5C

• Published in: Marine drugs Vol. 13; no. 1; pp. 366 - 378
• Main Authors: Xiao, Ze'en, Lin, Shao'e, Tan, Chunbing, Lu, Yongjun, He, Lei, Huang, Xishan, She, Zhigang
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 13-01-2015; MDPI
• Subjects: Aspergillus; Aspergillus - chemistry; Aspergillus sp; asperlones; azaphilones; Bacterial Proteins - antagonists & inhibitors; Heterocyclic Compounds, 4 or More Rings - chemistry; Heterocyclic Compounds, 4 or More Rings - isolation & purification; Magnetic Resonance Spectroscopy; Marine; marine fungi; Molecular Structure; MptpB inhibitor; Mycobacterium tuberculosis; Naphthols - chemistry; Naphthols - isolation & purification; Protein Tyrosine Phosphatases - antagonists & inhibitors; X-Ray Diffraction
• ISSN: 1660-3397; 1660-3397
• DOI: 10.3390/md13010366

Racemic dinaphthalenone derivatives, (±)-asperlone A (1) and (±)-asperlone B (2), and two new azaphilones, 6'-hydroxy-(R)-mitorubrinic acid (3) and purpurquinone D (4), along with four known compounds, (-)-mitorubrinic acid (5), (-)-mitorubrin (6), purpurquinone A (7) and orsellinic acid (8), were isolated from the cultures of Aspergillus sp. 16-5C. The structures were elucidated using comprehensive spectroscopic methods, including 1D and 2D NMR spectra and the structures of 1 further confirmed by single-crystal X-ray diffraction analysis, while the absolute configuration of 3 and 4 were determined by comparing their optical rotation and CD with those of the literature, respectively. Compounds 1, 2 and 6 exhibited potent inhibitory effects against Mycobacterium tuberculosis protein tyrosine phosphatase B (MptpB) with IC50 values of 4.24 ± 0.41, 4.32 ± 0.60 and 3.99 ± 0.34 μM, respectively.