Diverse Secondary Metabolites from the Coral-Derived Fungus Aspergillus hiratsukae SCSIO 5Bn 1 003.

Three new metabolites, including a cyclic tetrapeptide asperhiratide ( 1 ), an ecdysteroid derivative asperhiratine ( 2 ), and a sesquiterpene lactone asperhiratone ( 3 ), were isolated and identified from the soft coral-derived fungus Aspergillus hiratsukae SCSIO 5Bn 1 003, together with 10 known compounds. Their structures were elucidated via spectroscopic analysis, X-ray diffraction analysis, and electronic circular dichroism calculations. In addition, the absolute configuration of 1 was determined by Marfey's technique and an analysis of the acid hydrolysates using a chiral phase HPLC column. Among all the compounds, 6 and 8 showed medium cytotoxic activities against four tumor cell lines (SF-268, HepG-2, MCF-7, and A549), with IC 50 values ranging from 31.03 ± 3.04 to 50.25 ± 0.54 µM. Meanwhile, they strongly inhibited α-glucosidase activities, with IC 50 values of 35.73 ± 3.94 and 22.00 ± 2.45 µM, which were close to and even stronger than the positive control acarbose (IC 50 = 32.92 ± 1.03 µM). Compounds 6 - 8 showed significant antibacterial activities against Bacillus subtilis , with MIC values of 10.26 ± 0.76 µM, 17.00 ± 1.25 µM, and 5.30 ± 0.29 µM, respectively. Compounds 9 and 12 exhibited potent radical scavenging activities against DPPH, with IC 50 values of 12.23 ± 0.78 µM and 7.38 ± 1.16 µM. In addition, asperhiratide ( 1 ) was evaluated for anti-angiogenic activities in the in vivo zebrafish model, which showed a weak inhibitory effect on intersegmental vessel (ISV) formation.