Chemistry Reference
In-Depth Information
highly unusual cytotoxic metabolite of the tunicate
Diazona angulata
. It inhibits
tubulin polymerization (2).
2.3.6 Guanidine Alkaloids
Many guanidine-containing compounds have been reported from diverse marine
organisms (31). No doubt exists that the most well-known guanidine alkaloid is
tetrodotoxin (
94
), which is a causative agent of puffer fish poisoning (14). It is
highly toxic because of inhibition of voltage-gated Na
+
channels. Production of
tetrodotoxin by bacteria of such genera as
Pseudoalteromonas
and
Vibrio
was
reported. Similarly, saxitoxin (
95
) causes paralytic shellfish poisoning. Bivalves
accumulate the toxin from dinoglagellates, for example,
Alexandrium catenella,
A. tamarense
,and
Gymnodinium catenatum
. Its mode of action is similar to that
of tetrodotoxin. More than 30 saxitoxin derivatives are known to date.
O
HN
H
2
N
O
O
−
+
H
N
HN
O
N
HO
O
+
O
HN
+
NH
2
H
2
N
H
2
N
O
H
2
N
+
H
OH
H
H
2
N
N
N
O
HN
HO
OH
OH
OH
OH
9
994
995
996
Ptilomycalin A (
96
) is a novel polycyclic guanidine alkaloid isolated from the
sponge
Ptilocaulis spiculifer
(31). It is highly cytotoxic, antifungal, and antivi-
ral. The related alkaloids were reported from the Mediterranean sponge
Crambe
crambe
that also contains other types of guanidine alkaloids such as crambescin
A(
97
). Batzelladines are a similar class of alkaloids isolated from a sponge
Batzella
sp.; batzelladine A (
98
) shows anti-HIV activity.
NH
NH
2
NH
2
N
NH
N
N
N
N
OH
O
O
9
7
O
O
N
N
O
O
N
N
+
HN
N
N
NH
N
NH
2
Cl
−
3
NH
2
HN
NH
2
999
997
998
Variolin B (
99
), which is a pyridopyrropyrimidine alkaloid isolated from the
sponge
Kirkpatrichia varialosa
, is strongly cytotoxic, antifungal, and antiviral
(30). It inhibits cyclin-dependent kinases (12).
