The known LMA-P1 (73) displayed the strongest cytotoxicity Akt inhibitor drugs with an IC50 value of 0.041 μM, whereas benquoine had a lower activity (IC50 0.21 μM) (Adelin et al. 2011). Eleven new polyketides, including five new hydroanthraquinone derivatives, tetrahydroaltersolanols C–F (74–77), dihydroaltersolanol A (78), and five new alterporriol-type anthranoid dimers, alterporriols N–R (79–83), along with seven known analogues were produced
by Alternaria sp. ZJ-2008003. This strain was isolated from inner tissues of the soft coral Sarcophyton sp. (GX-WZ-20080011) (alcyoniidae) collected from the Weizhou coral reef in the South China Sea. The structures and the relative configurations of the isolated compounds were elucidated using comprehensive GW2580 nmr spectroscopic methods (NMR and MS) as well as single-crystal X-ray crystallography. Furthermore, the absolute configuration
of 80 was assigned by using the modified Mosher’s method. Compounds 74–81 were evaluated for their cytotoxic activity against human colon carcinoma (HCT-116), human breast cancer (MCF-7/ADR), human prostatic cancer (PC-3), and human hepatoma (HepG2 and Hep3B) cells. The known altersolanol C (84) was the most active metabolite among the monomeric anthranoids, exhibiting IC50 values between 2.2 and 8.9 μM, while the other monomers which lack the paraquinone moiety were inactive (IC50 > 100 μM). These Nec-1s results indicated that the paraquinone moiety was important for cytotoxic activity, as described previously (Debbab
et al. 2009). In addition, 81 was found to inhibit the growth of PC-3 and HCT-116 cells with IC50 values of 6.4 and 8.6 μM, respectively (Zheng et al. 2012). Anti-infective secondary metabolites Fermentation broth of the marine-derived fungus Aspergillus sp., isolated from the sponge Xestospongia testudinaria (Petrosiidae) collected from the South China Sea, yielded four new bisabolane-type sesquiterpenoids, including aspergiterpenoid A (85), (−)-sydonol Endonuclease (86), (−)-sydonic acid (87), and (−)-5-(hydroxymethyl)-2-(2′,6′,6′-trimethyltetrahydro-2Hpyran-2-yl)phenol (88) together with the known (Z)-5-(hydroxymethyl)-2-(6′-methylhept-2′-en-2′-yl)phenol. The structures were established by NMR spectroscopic techniques and mass spectrometric analysis, and the absolute configurations were assigned by measuring optical rotation and comparison with related known analogues. The antibacterial activity of 85–88 was studied, using microplate assay, against eight bacterial strains, e.g. six pathogenic bacteria Staphylococcus albus, Bacillus subtilis, Bacillus cereus, Sarcina lutea, Escherichia coli, Micrococcus tetragenus, and two marine bacterial strains Vibrio Parahaemolyticus and Vibrio anguillarum. Compound 85 exhibited weak antibacterial activity against E. coli and M. tetragenus. Compound 86 exhibited strong inhibitory activity against S. albus and M. tetragenus with MIC (minimum inhibiting concentrations) values of 5.0 and 1.