in GPY medium gave the anthraquinone derivative 6,8-di-O-methylaverantin (84)
(Fig. 6). Compound 84 showed weak antibacterial activity against Escherichia coli
with an inhibition diameter of 7 mm at 20 μg/disk [44]. The fungal strain
Talaromyces islandicus EN-501 was obtained from the marine red alga Laurencia
okamurai collected at Qingdao. Fermentation of this fungus on seawater-containing
solid
rice
medium
yielded
five
hydroanthraquinone
derivatives,
O
O
OH
OH
O
O
OH
84 (6,8-di-O-methylaverantin)
OH
O
OH
R 2
OH
R 1
85 R
1 = OH, R
2 = H
(8-hydroxyconiothyrinone B)
86 R
1 = OH, R
2 = OH
(8,11-dihydroxyconiothyrinone B)
OH
O
O
O
OH
OH
OH
88 R
1 = H, R
2 = 
4R),8-dihydroxyconiothyrinone B
89 R
1 = OH, R
2 = 
((4S),8-dihydroxyconiothyrinone B)
OH
OH
OH
OH
87 ((4S),8-dihydroxy-10-O-methyldendryol E)
OH
O
OH
O
OH
OH
OH
94 (dihydroaltersolanol A)
R 2 R 1
O
HO
HO
OH
O
OH
O
O
HO
OH
OH
OH
100 (nigrodiquinone A)
O
O
O
O
O
O
OH
OH
OH
OH
OH
OH
OH
OH
95 (alterporriol N)
O
O
O
O
OH
O
OH
O
OH
OH
OH
HO
HO
OH
96 (alterporriol O)
O
O
O
O
O
OH
OH
O
OH
HO
OH
OH
97 (alterporriol P)
O
O
O
O
OH
OH
O
OH
OH
O
98 (alterporriol Q)
O
O
O
O
O
OH
O
OH
HO
OH
99 (alterporriol R)
O
OH
O
R 4
R 1
R 2
OH
R 3
90 R
1 = R
4 = OH, R
2 = R 3 = H (tetrahydroaltersolanol C)
92 R
1 = R
4 = H, R
2 = R 3 = OH (tetrahydroaltersolanol E)
93 R
1 = OAc, R
2 = R
4 = H, R 3 = OH (tetrahydroaltersolanol F)
91 (tetrahydroaltersolanol D)
O
OH
O
OH
OH
OH
4
4’
9
7’
Fig. 6 Structures of anthraquinones and hydroanthraquinones
92
Z. Liu et al.