heptapeptides isolated from the sponge Hymeniacidon sp. have been shown to have
powerful antifungal properties against the fungus Cryptococcus neoformans.
8.2.3 Pharmacologically Active Substances
The red alga Digenea simplex, better known as Corsican weed, has been used over
the years as an insectifuge. Its effective ingredient is L-a-kainic acid, a kind of
amino acid, and it has been used together with santonin as an antihelminthic that
paralyzes parasites (roundworms, whipworms, and tapeworms) by blocking tissue
respiration through suppression of dehydrogenase activity within their bodies
(Fig. 8.9) (Endo et al. 1986).
Fig. 8.8 Substances isolated from marine microorganisms
Fig. 8.9 L-a-kainic acid
from the red alga D. simplex
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8 Developing Functional Materials with Marine Organisms