was obtained from the sea cucumber Stichopus japonicus that was collected from
Lingshan Island, Qingdao, Shandong Province. Liquid GYM medium fermentation
of A. fumigatus yielded seven prenylated indole diketopiperazines (419–425). Compound 422 was active against the MOLT-4, HL-60, and A-549 cell lines with IC 50
values of 3.1, 2.3, and 3.1 μM, respectively. Compound 423 was active against two
further cell lines, HEL-60 and BEL-7402, with IC 50 values of 3.4 and 7.0 μM,
respectively. Compounds 424 and 425 were active against the HL-60 cell line with
IC 50 values of 5.4 and 1.9 μM (Fig. 23) [133].
The fungal strain Penicillium janthinellum was isolated from the soft coral
Dendronephthya sp. collected in the South China Sea. Two 2,5-piperazinediones,
janthinolides A and B (426 and 427) (Fig. 24), were obtained from the mycelium of
liquid potato extract medium fermentation of P. janthinellum [134]. The fungus
Dichotomomyces cejpii from the soft coral Lobophytum crassum collected from the
N
NH
O
OH
OH
O
OH
O
O
426 (janthinolide A)
N
NH
O
OH
OH
O
O
HO
427 (janthinolide B)
N
N
S
O
O
428 ((±)-dichocerazine A)
N
N
O
HO
S
OH
S
O
O
OAc
429 (dichocerazine B)
S
OH
O
O
N
H
H
N
433 (pseuboydone C)
N
N
OAc
S
O
O
S
HO
434 (pseuboydone D)
S
O
N
H
O
O
N
NH
S
O
N
H
O
O
N
NH
430 (pseudellone A)
431 (pseudellone B)
H
N
NH
HN
O
O
S
432 (pseudellone D)
HN
N
O
O
OH
435 cyclo-(2-hydroxy-Pro-Gly)
N
N
O
O
R 2
R 1
436 R
1 = Me, R
2 = OMe (neosartin A)
437 R
1
= CH 2 OH, R
2 = OMe (neosartin B)
438 R
1
= Me, R
2 = H
N
N
O
O
439
N
N
O
O
R 1 S
OR 3
SR 2
OH
440 R
1 = R
2 = R 3 = H
441 R 1 = R 2 = Me, R 3 = Ac
N
N
O
O
S
S
OH
442
Fig. 24 Structures of diketopiperazines (part 2)
120
Z. Liu et al.