Part F | 32.3
772 Part F Marine Derived Metabolites
tion at C-4
0 had no effect on the activity compared to
MPA [32.107].
A new anthraquinone derivative, 6,8-di-O-methylaverantin (84), was isolated together with six known
congeners from a culture of Aspergillus versicolor EN7 derived from the brown alga, Sargassum thunbergii
collected off the Qingdao coastline (China) [32.108].
Compound 84 exhibited only weak inhibition against
E. coli but not against S. aureus or Candida albicans [32.108].
Protulactones A (85) and B (86), two polyketidederived fungal metabolites, were been isolated from
an EtOAc extract of the marine sediment-derived fungus Aspergillus sp. SF-5044 [32.109]. The structures
of 85 and 86 were established based on NMR spectroscopy and mass spectroscopy (MS) data, along with
chemical methods such as Mosher’s method [32.109].
Compounds 85 and 86 represented new polyketide
derivatives, possessing unique ring systems among
the fungal metabolites produced by the genus Aspergillus [32.109].
A new isochroman, (3R,4S)-3,4-dihydro-4,5,8trihydroxy-3-methylisocoumarin (87), was purified
from the marine fungus Phomopsis sp. ZH-111 together
with two known compounds [32.110]. Compound 87
accelerated the growth of subintestinal vessel plexus
(SIV) branches [32.110].
A new xanthone derivative, 8-hydroxy-3-methyl-9oxo-9H-xanthene-1-carboxylic acid methyl ester (88),
was isolated from the co-culture broth of two mangrove-derived fungi (K38 and E33) [32.111]. Primary
bioassays showed that 88 possesses inhibitory activity
against five microorganisms, including Gloeasporium
musae and Peronophthora circhoralearum [32.111].
Porric acid D (89), a new dibenzofuran derivative,
was obtained from the methanolic extract of a marine-derived fungus, Alternaria sp., isolated from the
Bohai Sea [32.112]. Porric acid D exhibited mild antimicrobial activity against S. aureus with a MIC of
100 g mL
1 .
Aspergillumarins A (90) and B (91), two new dihydroisocoumarin derivatives, were isolated from the
marine fungus Aspergillus sp., derived from the Chinese mangrove Bruguiera gymnorrhiza [32.113]. Aspergillumarins A and B revealed weak antibacterial
activity against S. aureus and Bacillus subtilis at a concentration of 50 g mL
1 [32.113].
Three new citrinin derivatives, penicitrinols C–E
(92–94), were isolated along with two known compounds from Penicillium citrinum [32.114]. The structures of the isolated citrinin derivatives were established
based on spectroscopic methods and X-ray crystallographic analyses [32.114]. In the in vitro cytotoxicity
assay against P388 and HL-60 cell lines, only penicitrinols C (92) and E (94) revealed modest antiproliferative
activity against HL-60 cells with IC 50 values of 52:8
and 41:2 M, respectively [32.114].
In addition to a new diketopiperazine (51), a new
anthraquinone derivative, 9-dehydroxyeurotinone (95),
was purified from the fungal strain Eurotium rubrum,
an endophytic fungus isolated from the semi-mangrove
plant Hibiscus tiliaceus [32.94]. Compound 95 revealed
weak antibacterial activity against E. coli with an inhibition zone of 7:0 mm at 100 g=disk compared to
amphotericin B with an inhibition zone of 11:0 mm at
20 g=disk [32.94]. However, in the cytotoxic activity
assay, 9-dehydroxyeurotinone revealed mild but selective activity against human cholangiocarcinoma cell
line SW1990 (IC 50 D 92:0 M) when tested against
seven tumor cell lines [32.94].
Three new sterigmatocystin derivatives, oxisterigmatocystins A–C (96–98), together with the known
compound 5-methoxysterigmatocystin (99), were isolated from the deep sea-derived fungus Aspergillus versicolor [32.115]. All isolated sterigmatocystin derivatives were assessed for cytotoxic activity against A-549
and HL-60 cell lines, and interestingly, only 99 revealed
significant cytotoxicities with IC 50 values of 3:86 and
5:32 M, respectively [32.115]. This result implied that
the double bond between C-3 and C-4 is a crucial pharmacophoric functionality in sterigmatocystins, and the
activity disappeared upon saturation [32.115].
Two new botcinin derivatives, botcinin A (100)
and B (101), were isolated from the fungus Botryotinia sp. SF-5275 derived from an unidentified marine
alga collected off Seongsan Port (Korea) [32.116].
Botcinins A and B were evaluated for their in vitro inhibitory activity against protein tyrosine phosphatase
1B (PTP1B), an insulin-antagonizing protein influencing negative regulation of the insulin pathway,
which is a promising target for the treatment of diabetes and obesity. Results revealed that botcinin A
(100) possesses higher activity than 101 with IC 50
values of 53:6 and 340:7 M, respectively, compared
to ursolic acid that was used as a positive control
(IC 50 D 3:1 M) [32.116]. These data disclosed that the
hexahydropyrano[3,2,b]-pyran-2(3H/-one moiety is an
essential structural feature required for activity.
Acremostrictin (102), a highly oxygenated tricyclic
lactone of an unprecedented skeletal class, was isolated from the culture broth of Acremonium strictum, a marine fungus derived from a Korean Choris-
772 Part F Marine Derived Metabolites
tion at C-4
0 had no effect on the activity compared to
MPA [32.107].
A new anthraquinone derivative, 6,8-di-O-methylaverantin (84), was isolated together with six known
congeners from a culture of Aspergillus versicolor EN7 derived from the brown alga, Sargassum thunbergii
collected off the Qingdao coastline (China) [32.108].
Compound 84 exhibited only weak inhibition against
E. coli but not against S. aureus or Candida albicans [32.108].
Protulactones A (85) and B (86), two polyketidederived fungal metabolites, were been isolated from
an EtOAc extract of the marine sediment-derived fungus Aspergillus sp. SF-5044 [32.109]. The structures
of 85 and 86 were established based on NMR spectroscopy and mass spectroscopy (MS) data, along with
chemical methods such as Mosher’s method [32.109].
Compounds 85 and 86 represented new polyketide
derivatives, possessing unique ring systems among
the fungal metabolites produced by the genus Aspergillus [32.109].
A new isochroman, (3R,4S)-3,4-dihydro-4,5,8trihydroxy-3-methylisocoumarin (87), was purified
from the marine fungus Phomopsis sp. ZH-111 together
with two known compounds [32.110]. Compound 87
accelerated the growth of subintestinal vessel plexus
(SIV) branches [32.110].
A new xanthone derivative, 8-hydroxy-3-methyl-9oxo-9H-xanthene-1-carboxylic acid methyl ester (88),
was isolated from the co-culture broth of two mangrove-derived fungi (K38 and E33) [32.111]. Primary
bioassays showed that 88 possesses inhibitory activity
against five microorganisms, including Gloeasporium
musae and Peronophthora circhoralearum [32.111].
Porric acid D (89), a new dibenzofuran derivative,
was obtained from the methanolic extract of a marine-derived fungus, Alternaria sp., isolated from the
Bohai Sea [32.112]. Porric acid D exhibited mild antimicrobial activity against S. aureus with a MIC of
100 g mL
1 .
Aspergillumarins A (90) and B (91), two new dihydroisocoumarin derivatives, were isolated from the
marine fungus Aspergillus sp., derived from the Chinese mangrove Bruguiera gymnorrhiza [32.113]. Aspergillumarins A and B revealed weak antibacterial
activity against S. aureus and Bacillus subtilis at a concentration of 50 g mL
1 [32.113].
Three new citrinin derivatives, penicitrinols C–E
(92–94), were isolated along with two known compounds from Penicillium citrinum [32.114]. The structures of the isolated citrinin derivatives were established
based on spectroscopic methods and X-ray crystallographic analyses [32.114]. In the in vitro cytotoxicity
assay against P388 and HL-60 cell lines, only penicitrinols C (92) and E (94) revealed modest antiproliferative
activity against HL-60 cells with IC 50 values of 52:8
and 41:2 M, respectively [32.114].
In addition to a new diketopiperazine (51), a new
anthraquinone derivative, 9-dehydroxyeurotinone (95),
was purified from the fungal strain Eurotium rubrum,
an endophytic fungus isolated from the semi-mangrove
plant Hibiscus tiliaceus [32.94]. Compound 95 revealed
weak antibacterial activity against E. coli with an inhibition zone of 7:0 mm at 100 g=disk compared to
amphotericin B with an inhibition zone of 11:0 mm at
20 g=disk [32.94]. However, in the cytotoxic activity
assay, 9-dehydroxyeurotinone revealed mild but selective activity against human cholangiocarcinoma cell
line SW1990 (IC 50 D 92:0 M) when tested against
seven tumor cell lines [32.94].
Three new sterigmatocystin derivatives, oxisterigmatocystins A–C (96–98), together with the known
compound 5-methoxysterigmatocystin (99), were isolated from the deep sea-derived fungus Aspergillus versicolor [32.115]. All isolated sterigmatocystin derivatives were assessed for cytotoxic activity against A-549
and HL-60 cell lines, and interestingly, only 99 revealed
significant cytotoxicities with IC 50 values of 3:86 and
5:32 M, respectively [32.115]. This result implied that
the double bond between C-3 and C-4 is a crucial pharmacophoric functionality in sterigmatocystins, and the
activity disappeared upon saturation [32.115].
Two new botcinin derivatives, botcinin A (100)
and B (101), were isolated from the fungus Botryotinia sp. SF-5275 derived from an unidentified marine
alga collected off Seongsan Port (Korea) [32.116].
Botcinins A and B were evaluated for their in vitro inhibitory activity against protein tyrosine phosphatase
1B (PTP1B), an insulin-antagonizing protein influencing negative regulation of the insulin pathway,
which is a promising target for the treatment of diabetes and obesity. Results revealed that botcinin A
(100) possesses higher activity than 101 with IC 50
values of 53:6 and 340:7 M, respectively, compared
to ursolic acid that was used as a positive control
(IC 50 D 3:1 M) [32.116]. These data disclosed that the
hexahydropyrano[3,2,b]-pyran-2(3H/-one moiety is an
essential structural feature required for activity.
Acremostrictin (102), a highly oxygenated tricyclic
lactone of an unprecedented skeletal class, was isolated from the culture broth of Acremonium strictum, a marine fungus derived from a Korean Choris-