Marine Drugs (Feb 2020)

New Thiodiketopiperazine and 3,4-Dihydroisocoumarin Derivatives from the Marine-Derived Fungus <i>Aspergillus terreus</i>

  • Jing-Shuai Wu,
  • Xiao-Hui Shi,
  • Guang-Shan Yao,
  • Chang-Lun Shao,
  • Xiu-Mei Fu,
  • Xiu-Li Zhang,
  • Hua-Shi Guan,
  • Chang-Yun Wang

DOI
https://doi.org/10.3390/md18030132
Journal volume & issue
Vol. 18, no. 3
p. 132

Abstract

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Aspergillus terreus has been reported to produce many secondary metabolites that exhibit potential bioactivities, such as antibiotic, hypoglycemic, and lipid-lowering activities. In the present study, two new thiodiketopiperazines, emestrins L (1) and M (2), together with five known analogues (3−7), and five known dihydroisocoumarins (8−12), were obtained from the marine-derived fungus Aspergillus terreus RA2905. The structures of the new compounds were elucidated by analysis of the comprehensive spectroscopic data, including high-resolution electrospray ionization mass spectrometry (HRESIMS), one-dimensional (1D) and two-dimensional (2D) nuclear magnetic resonance (NMR), and electronic circular dichroism (ECD) data. This is the first time that the spectroscopic data of compounds 3, 8, and 9 have been reported. Compound 3 displayed antibacterial activity against Pseudomonas aeruginosa (minimum inhibitory concentration (MIC) = 32 μg/mL) and antifungal activity against Candida albicans (MIC = 32 μg/mL). In addition, compound 3 exhibited an inhibitory effect on protein tyrosine phosphatase 1 B (PTP1B), an important hypoglycemic target, with an inhibitory concentration (IC)50 value of 12.25 μM.

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