fungus in PDB medium gave asperversin A (394) [121]. Isocyathisterol (395) was
produced in a PDB culture of Aspergillus ustus that was isolated from the marine
green alga Codium fragile collected from Zhoushan Island. Isocyathisterol (395)
exhibited antibacterial activity in a Petri dish assay against Escherichia coli and
Staphylococcus aureus with inhibitory diameters of 7 and 6 mm, respectively, at a
dose of 30 μg/disk [122]. The endophytic fungal strain Eurotium rubrum cf-14 was
isolated from the marine green alga Codium fragile collected off the coast of Yantai.
390 (ergosterimide)
O
HO
O
HO
R
O
391 (7-nor-ergosterolide)
392 R = OH
393 R = H
O
O
O
O
OH
O
O
O
O
O
394 (asperversin A)
404
HO
O
O
399
HO
O
400
HO
O
R
HO
O
O
403
HO
O
O
O
405
HO
NH
O
O
396
HO
OAc
OH
395 (isocyathisterol)
O
OH
397
HO
O
398
HO
O
OH
O
401 R = -OH
402 R = -OH
Fig. 22 Structures of steroids
Secondary Metabolites from Marine-Derived Fungi from China
117
produced in a PDB culture of Aspergillus ustus that was isolated from the marine
green alga Codium fragile collected from Zhoushan Island. Isocyathisterol (395)
exhibited antibacterial activity in a Petri dish assay against Escherichia coli and
Staphylococcus aureus with inhibitory diameters of 7 and 6 mm, respectively, at a
dose of 30 μg/disk [122]. The endophytic fungal strain Eurotium rubrum cf-14 was
isolated from the marine green alga Codium fragile collected off the coast of Yantai.
390 (ergosterimide)
O
HO
O
HO
R
O
391 (7-nor-ergosterolide)
392 R = OH
393 R = H
O
O
O
O
OH
O
O
O
O
O
394 (asperversin A)
404
HO
O
O
399
HO
O
400
HO
O
R
HO
O
O
403
HO
O
O
O
405
HO
NH
O
O
396
HO
OAc
OH
395 (isocyathisterol)
O
OH
397
HO
O
398
HO
O
OH
O
401 R = -OH
402 R = -OH
Fig. 22 Structures of steroids
Secondary Metabolites from Marine-Derived Fungi from China
117