Environmental Engineering Reference
In-Depth Information
A polycyclic compound, bis(deacetyl)solenolide D
731
was obtained from
themarinesponge
Psammaplysilla purpurea
. It inhibited the biofilm forma-
tion [47].
Isothiocyanates isolated from a Japanese horse-radish,
Wasabi japonicas
,
showed the moderate inhibition of settlement of the blue mussels
Mytilus
edulis
,especially,PhCH
2
CH
2
NCS
741
showed the highest value in the isoth-
iocyanates. The mixture of PhCH
2
CH
2
NCS
741
and CH
3
S(CH
2
)
6
NCS showed
much higher synergistic antifouling activities [49].
Recently, a screening of antifouling activity from plant extracts led to the
selection and further study of Myrsinaceae (
Maesa lanceolata
Forssk). Two
p
-benzoquinone compounds (maesanin
761
,maesanol
762
)wereisolated
from its fruits. They were found to be active against a representative marine
crustaceans
Artemia salina
as shown in Table 18 [70]. Maesanin
761
and mae-
sanol
762
showed the highest activity against
Artemia salina
among all the
extracts, and were more active than 6-pentadecylsalicylic acid (PSA) isolated
from
Ozoroa insignis
, but were less potent than TBTO. Hence, they are ac-
tive against marine fouling organisms. The chemical modifications of these
compounds were undertaken in order to obtain more active derivatives [70].
8
Conclusions
Five kinds of compounds, i.e., terpenes, nitrogen-containing compounds,
phenols, steroids and others, were isolated as natural products antifouling
substances. Of these substances, many compounds showed the same level
of antifouling properties as CuSO
4
, and some compounds also showed the
same level of activities with the organotin antifoulants. However, these natu-
ral products showed generally no or very low toxicity, and are biodegradable
in marine environment. Many simple natural products such as trigonelline,
nicotinamide and ethyl
N
-(2-phenylethylcarbamate) and their synthetic
derivatives had also high antifouling properties. Many of them showed syner-
gistic properties. We expect to utilize some natural products, their synthetic
derivatives or their mixtures as environmentally friendly antifouling agents in
near future.
Acknowledgements
I should like to express my sincere appreciation to Dr. Sumio
Chubachi for reading the full manuscript, which enhanced its accuracy and clarity, and
for providing much valuable constructive criticism.
References
1. Omae I (2003) Chem Rev 103:3431
2. Kishihara M (1998) Kagaku Kogyo 49:458