Eleven diketopiperazine and fumiquinazoline alkaloids (1-11) together with a tetracyclic triterpenoid helvolic acid (12) were obtained from the cultures of a deep-sea derived fungus Aspergillus sp. SCSIO Ind09F01. The structures of these compounds (1-12) were determined mainly by the extensive NMR, ESIMS spectra data and by comparison with previously described compounds. Besides, anti-tuberculosis, cytotoxic, antibacterial, COX-2 inhibitory and antiviral activities of these compounds were evaluated. Gliotoxin (3), 12,13-dihydroxy-fumitremorgin C (11) and helvolic acid (12) exhibited very strong anti-tuberculosis activity towards Mycobacterium tuberculosis with the prominent MIC50 values of <0.03, 2.41 and 0.894 μM, respectively, which was here reported for the first time. Meanwhile gliotoxin also displayed significant selective cytotoxicities against K562, A549 and Huh-7 cell lines with the IC50 values of 0.191, 0.015 and 95.4 μM, respectively.
Keywords: Aspergillus sp; Deep sea fungi; alkaloids; anti-tuberculosis.