Summary: | A new indole diketopiperazine alkaloid, named penilline D ( 1 ), together with five known indole alkaloid analogues ( 2 – 5 , 11 ), two meroterpenoids ( 6 and 12 ), and four butenolide derivatives ( 7 – 10 ), were isolated from the Antarctic fungus Penicillium sp. SCSIO 05705. Extensive spectroscopic analysis and electronic circular dichroism (ECD) calculation were used to elucidate the structure of penilline D ( 1 ), including its absolute configuration. All isolated compounds ( 1 – 12 ) were evaluated for their cytotoxic, antibacterial and enzyme inhibitory activities against acetylcholinesterase (AChE) and pancreatic lipase (PL). Among them, compound 5 exhibited moderate in vitro cytotoxic activity against the 143B cell line with IC 50 value of 12.64 ± 0.78 μM. Compound 6 showed strong inhibitory activity against AChE with IC 50 value of 0.36 nM (IC 50 18.7 nM for Tacrine), while compounds 6 and 11 showed weak PL enzyme inhibitory activity. Furthermore, an in silico molecular docking study was also performed between 6 and AChE.
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