Five new anthraquinone derivatives, auxarthrols D-H (1-5), along with two known analogues (6-7), were obtained from the culture of the marine-derived fungus Sporendonema casei. Their structures, including absolute configurations, were established on the basis of NMR, HRESIMS, and circular dichroism (CD) spectroscopic techniques. Among them, compound 4 represents the second isolated anthraquinone derivative with a chlorine atom, which, with compound 6, are the first reported anthraquinone derivatives with anticoagulant activity. Compounds 1 and 3 showed cytotoxic activities with IC50 values from 4.5 μM to 22.9 μM, while compounds 1, 3-4, and 6-7 showed promising antibacterial activities with MIC values from 12.5 μM to 200 μM. In addition, compound 7 was discovered to display potential antitubercular activity for the first time.
Keywords: Sporendonema casei; anthraquinone derivatives; antibacterial activities; cytotoxic activities; marine-derived fungus.