A dolabellane diterpene from the brown alga Dictyota pfaffii as chemical defense against herbivores
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Jussara P. Barbosa
Abstract
Laboratory and field experiments assessed the defensive properties of the crude extract and major secondary metabolite found in the Brazilian brown alga Dictyota pfaffii. Natural concentrations of the crude organic extract of D. pfaffii significantly inhibited feeding by the sea urchin Lytechinus variegatus and generalist herbivore fishes in the field. In contrast, the crude extract did not inhibit feeding by the crab Pachygrapsus transversus. Chemical defensive action against the sea urchin and the generalist fishes was due to the diterpenoid 10,18-diacetoxy-8-hydroxy-2,6-dolabelladiene found as the major natural product in D. pfaffii. However, this compound did not inhibit feeding by P. transversus as readily as the crude extract. This is the first report showing that Dictyota species produce dolabellane diterpenes as chemical defense against herbivory. In addition, these results widen the action spectrum of secondary metabolites found in species of this brown algal genus. Since dolabellanes constitute the major skeleton type found in Dictyota, we suggest that these diterpenes may play an important ecological function as defenses to the Dictyota species worldwide.
Copyright © 2004 by Walter de Gruyter GmbH & Co. KG
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Artikel in diesem Heft
- Spatial and temporal variability of Mediterranean macroalgal coralligenous assemblages in relation to habitat and substratum inclination
- Nutrient capital in different aged forests of the mangrove Rhizophora apiculata
- Seasonal and geographical variation in the chemical composition of the red alga Palmaria palmata (L.) Kuntze
- Season influence on lipid composition of marine macrophytes
- Antibacterial activity in marine algae from the coast of Yucatan, Mexico
- A dolabellane diterpene from the brown alga Dictyota pfaffii as chemical defense against herbivores
- Gymnodinium chlorophorum (Dinophyceae) in the Adriatic Sea: electron microscopical observations
- Aphanocladia ecorticata nov. sp. (Rhodophyta, Rhodomelaceae) from the South African south coast
- Meetings
