Eurotiumins A–E, Five New Alkaloids from the Marine-Derived Fungus Eurotium sp. SCSIO F452.

Wang, Jun-Feng; Shi, Xue-Feng; Tian, Xin-Peng; Xiao, Zhi-Hui; Wang, Fa-Zuo; Zhang, Si; Zhong, Wei-Mao; Zeng, Qi; Xiang, Yao; Chen, Xia-Yu; Wei, Xiao-Yi; Chen, Yu-Chan; Zhang, Wei-Min

Three new prenylated indole 2,5-diketopiperazine alkaloids (1–3) with nine known ones (5–13), one new indole alkaloid (4), and one new bis-benzyl pyrimidine derivative (14) were isolated and characterized from the marine-derived fungus Eurotium sp. SCSIO F452. 1 and 2, occurring as a pair of diastereomers, both presented a hexahydropyrrolo[2,3-b]indole skeleton. Their chemical structures, including absolute configurations, were elucidated by 1D and 2D NMR, HRESIMS, quantum chemical calculations of electronic circular dichroism, and single crystal X-ray diffraction experiments. Most isolated compounds were screened for antioxidative potency. Compounds 3, 5, 6, 7, 9, 10, and 12 showed significant radical scavenging activities against DPPH with IC50 values of 13, 19, 4, 3, 24, 13, and 18 µM, respectively. Five new compounds were evaluated for cytotoxic activities.

INDOLE alkaloids; PYRIMIDINES; MARINE fungi; ALKALOIDS; CHEMICAL structure

Marine Drugs, 2018, Vol 16, Issue 4, p136

1660-3397

Academic Journal

10.3390/md16040136