fermentation of this fungus in liquid medium containing sea salt [34]. Three xanthone derivatives, yicathins AÀC (57–59), were isolated from the liquid potato
dextrose broth (PDB) medium fermentation of Aspergillus wentii pt-1, an endophyte
obtained from the marine red alga Gymnogongrus flabelliformis that was collected
from the coast of Pingtan Island. In antibacterial and antifungal bioassays, yicathin B
(58) was active against Escherichia coli (inhibition diameter 9 mm) while yicathin C
(59) inhibited Escherichia coli, Staphylococcus aureus, and Colletotrichum
O
O
HO
OH
OH
O
O
O
56
O
O
O
OH
57 (yicathin A)
O
O
O
O
O
OH
O
O
O
OH
O
O
O
OH
58 (yicathin B)
59 (yicathin C)
O
OH
HO
OH
OH
60
O
OH
O
OH
OH
61
O
O
OH
OH
HO
62
O
O
O
O
O
OH
OH
O
O
O
O
O
OH
OAc
O
O
O
O
O
OH
O
65 (5-methoxydihydrosterigmatocystin)
O
O
O
OH
OH
O
O
O
O
O
OH
O
OH
O
O
O
OH
OH
OH
O
O
O
HO
O
O
OH
OH
O
O
66 (nigerasperone A)
67 (nigerasperone B)
68 (nigerasperone C)
O
O
O
O
OH
O
O
O
O
OH
O
O
O
O
69 (paecilin C)
O
OH
HO
O
OH
OH
71 (penimethavone A)
O
O
OH
HO
OH
OH
70
63 (sterigmatocystin hemiacetal)
64 (sterigmatocystin
acetyl hemiacetal)
Fig. 4 Structures of γ-pyrones including xanthones and chromones (part 1)
Secondary Metabolites from Marine-Derived Fungi from China
89