Marine-Derived Fungal Metabolites 32.3 Marine Organic Compounds 771
Part F | 32.3
68
74
69
70
71
72
79
80
86
85
92
93
94
102
84
83
87
95
88
89
97
99
73
HO
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
8
O
O
O
O
O
O R
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
R
O
O
O
O
4'
3'
O
O
O
O
O
O
O
O
O
R
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
7
2'
4'
3'
O
O
O
O
O
O
(S)
O
O
R
O
O
O
OH OH
OH
OH
OH
HO
OH
OH
OH
HO
HO
OH
OH
OH
OH
OH
HO
OH
OH
OH
OH
OH
OH
OH
OH
OH
OH
OR 1
R 2
R 2
R 2
HO
HO
OH
OH
OH OH
OH
OH
OH
OH
OH
OH
OH
HO
OH
OH
HO
OH
OH
OH
HO
OH
OH
OH
75: R =
76: R = H
77: R =
78: R = H
90: R 1 and R 2 = O
91: R 1 = OH, R 2 = H
96: R = OCH 3
98: R = H
100: R = n-Butyl
101: R = n-Hexyl
81: R 1 = CH 3 , R 2 = OH
82: R 1 = H, R 2 = OGlu
Fig. 32.7 Chemical structures of compounds 68–102
lected in the South China Sea [32.107]. All compounds
were assessed for their inhibitory activity against inosine 5
0 -monophosphate dehydrogenase (IMPDH), revealing IC 50 values between 0:63 and 73 M [32.107].
IMPDH is an essential rate-limiting enzyme controlling the guanine nucleotide pool which, in turn, controls
replication, transcription, signaling, and translocation.
Hydroxylation at C-4
0 , methylation at C-7-OH, or dual
hydroxylation at the C-2
0 /C-3
0 double bond of MPA
diminished bioactivity, whereas glucosyl hydroxyla-