lagenarium with inhibition diameters of 12, 8, and 11 mm, respectively, at a
concentration of 10 μg/disk [35].
Solid rice culture fermentation of Talaromyces islandicus EN-501, isolated from
the marine red alga Laurencia okamurai collected off the coast at Qingdao, yielded
two diphenylketones, 2,2
0 ,3,5
0 -tetrahydroxy-3
0 -methylbenzophenone (60) and
2,2
0 ,5
0 -trihydroxy-3-methoxy-3
0 -methylbenzophenone (61), as well as a xanthone,
1,4,7-trihydroxy-6-methylxanthone (62). The joint isolation of benzophenones and
xanthones from the same fungal strain supports the biogenesis of xanthones via a
benzophenone intermediate. Compounds 60–62 exhibited potent antioxidative activities against DPPH (1,1-diphenyl-2-picrylhydrazyl) and ABTS (2,2
0 -azino-bis
(3-ethylbenzothiazoline-6-sulfonate)) radicals with IC 50 values ranging from 3 to
27 μM, more potent than the positive controls BHT (butylated hydroxytoluene) and
ascorbic acid. Compound 60 also showed moderate inhibitory activities against
several pathogenic bacteria (Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Vibrio alginolyticus, V. harveyi, and V. parahaemolyticus) with MIC
values ranging from 15 to 30 μM [36]. The fungus Aspergillus versicolor MF359
was obtained from the marine sponge Hymeniacidon perleve collected from the
Bohai Sea. Cultivation of A. versicolor on solid rice medium containing artificial
seawater gave the hemiacetal sterigmatocystin (63), the acetyl-hemiacetal
sterigmatocystin (64), and 5-methoxydihydrosterigmatocystin (65). Compound 63
represented the first example of a sterigmatocystin hemiacetal in Nature. Compound
65 exhibited antibacterial activities against Staphylococcus aureus and Bacillus
subtilis with MIC values of 35 and 9 μM, respectively [37].
Three naphtho-γ-pyrones, nigerasperones AÀC (66–68), were isolated from a
liquid GPY medium culture of Aspergillus niger EN-13, an endophytic fungus
obtained from the marine brown alga Colpomenia sinuosa collected at the Qingdao
coastline. Nigerasperone C (68) showed antifungal activity against Candida
albicans with an inhibition diameter of 9 mm, which was compared with a positive
control, amphotericin B, having an inhibition diameter of 12 mm. Nigerasperone C
(68) also showed weak DPPH-scavenging activity with a scavenging ratio of 41.6%
at a concentration 50 μg/cm
3 , compared to 80.4% by the positive control BHT
[38]. The fungus Penicillium sp. SCSGAF 0023 was obtained from the gorgonian
Dichotella gemmacea that was collected from Sanya, Hainan Province. Culturing
this fungus on liquid potato dextrose agar medium yielded paecilin C (69) and
6,8,5
0 6
0 -tetrahydroxy-3
0 -methylflavone (70). Compound 70 showed antifouling
activity against Balanus amphitrite larval settlement with an EC 50 value of 22 μM
and low toxicity with LC 50 /EC 50 ratio > 14.9 [39]. A novel flavone, penimethavone
A (71), possessing a rare methyl group in ring B, was isolated from the solid rice
medium fermentation of Penicillium chrysogenum, and was obtained from the
gorgonian Carijoa sp. collected from the South China Sea. Penimethavone A (71)
showed selective and moderate cytotoxicity against cervical cancer (HeLa) and
rhabdomyosarcoma cell lines with IC 50 values of 8.4 and 8.2 μM (Fig. 4) [40].
The fungus Penicillium oxalicum SCSGAF 0023 was isolated from the gorgonian
Muricella flexuosa collected from Sanya, Hainan Province. PDA liquid medium
fermentation of this fungus yielded five chromones including four
90
Z. Liu et al.
concentration of 10 μg/disk [35].
Solid rice culture fermentation of Talaromyces islandicus EN-501, isolated from
the marine red alga Laurencia okamurai collected off the coast at Qingdao, yielded
two diphenylketones, 2,2
0 ,3,5
0 -tetrahydroxy-3
0 -methylbenzophenone (60) and
2,2
0 ,5
0 -trihydroxy-3-methoxy-3
0 -methylbenzophenone (61), as well as a xanthone,
1,4,7-trihydroxy-6-methylxanthone (62). The joint isolation of benzophenones and
xanthones from the same fungal strain supports the biogenesis of xanthones via a
benzophenone intermediate. Compounds 60–62 exhibited potent antioxidative activities against DPPH (1,1-diphenyl-2-picrylhydrazyl) and ABTS (2,2
0 -azino-bis
(3-ethylbenzothiazoline-6-sulfonate)) radicals with IC 50 values ranging from 3 to
27 μM, more potent than the positive controls BHT (butylated hydroxytoluene) and
ascorbic acid. Compound 60 also showed moderate inhibitory activities against
several pathogenic bacteria (Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Vibrio alginolyticus, V. harveyi, and V. parahaemolyticus) with MIC
values ranging from 15 to 30 μM [36]. The fungus Aspergillus versicolor MF359
was obtained from the marine sponge Hymeniacidon perleve collected from the
Bohai Sea. Cultivation of A. versicolor on solid rice medium containing artificial
seawater gave the hemiacetal sterigmatocystin (63), the acetyl-hemiacetal
sterigmatocystin (64), and 5-methoxydihydrosterigmatocystin (65). Compound 63
represented the first example of a sterigmatocystin hemiacetal in Nature. Compound
65 exhibited antibacterial activities against Staphylococcus aureus and Bacillus
subtilis with MIC values of 35 and 9 μM, respectively [37].
Three naphtho-γ-pyrones, nigerasperones AÀC (66–68), were isolated from a
liquid GPY medium culture of Aspergillus niger EN-13, an endophytic fungus
obtained from the marine brown alga Colpomenia sinuosa collected at the Qingdao
coastline. Nigerasperone C (68) showed antifungal activity against Candida
albicans with an inhibition diameter of 9 mm, which was compared with a positive
control, amphotericin B, having an inhibition diameter of 12 mm. Nigerasperone C
(68) also showed weak DPPH-scavenging activity with a scavenging ratio of 41.6%
at a concentration 50 μg/cm
3 , compared to 80.4% by the positive control BHT
[38]. The fungus Penicillium sp. SCSGAF 0023 was obtained from the gorgonian
Dichotella gemmacea that was collected from Sanya, Hainan Province. Culturing
this fungus on liquid potato dextrose agar medium yielded paecilin C (69) and
6,8,5
0 6
0 -tetrahydroxy-3
0 -methylflavone (70). Compound 70 showed antifouling
activity against Balanus amphitrite larval settlement with an EC 50 value of 22 μM
and low toxicity with LC 50 /EC 50 ratio > 14.9 [39]. A novel flavone, penimethavone
A (71), possessing a rare methyl group in ring B, was isolated from the solid rice
medium fermentation of Penicillium chrysogenum, and was obtained from the
gorgonian Carijoa sp. collected from the South China Sea. Penimethavone A (71)
showed selective and moderate cytotoxicity against cervical cancer (HeLa) and
rhabdomyosarcoma cell lines with IC 50 values of 8.4 and 8.2 μM (Fig. 4) [40].
The fungus Penicillium oxalicum SCSGAF 0023 was isolated from the gorgonian
Muricella flexuosa collected from Sanya, Hainan Province. PDA liquid medium
fermentation of this fungus yielded five chromones including four
90
Z. Liu et al.