title: Terpenes from the red alga Sphaerococcus coronopifolius inhibit the settlement of barnacles.
abstract: In this study, we screened eight terpenes isolated from the organic extract of Sphaerococcus coronopifolius for their antifouling activity in order to find possible new sources of non-toxic or less toxic bioactive antifoulants. The anti-settlement activity (EC₅₀) and the degree of toxicity (LC₅₀) of S. coronopifolius metabolites was evaluated using larvae of the cirriped crustacean Amphibalanus (Balanus) amphitrite (cyprids and nauplii) as model organism. For five of eight tested metabolites EC₅₀ was lower than 5 mg/L. The most promising results were observed for bromosphaerol (3), which expressed an EC₅₀ value of 0.23 mg/L, in combination with low toxicity levels (LC₅₀ > 100 mg/L). The therapeutic ratio--an index used to estimate whether settlement inhibition is due to toxicity or other mechanisms--is also calculated and discussed.
authors.affiliation: Institute of Marine Science (ISMAR) CNR, via De Marini 6, 16149 Genoa, Italy. veronica.piazza@ge.ismar.cnr.it
authors.forename: Veronica
authors.initials: V
authors.lastname: Piazza
authors.forename: Vassilios
authors.initials: V
authors.lastname: Roussis
authors.forename: Francesca
authors.initials: F
authors.lastname: Garaventa
authors.forename: Giuliano
authors.initials: G
authors.lastname: Greco
authors.forename: Vangelis
authors.initials: V
authors.lastname: Smyrniotopoulos
authors.forename: Constantinos
authors.initials: C
authors.lastname: Vagias
authors.forename: Marco
authors.initials: M
authors.lastname: Faimali
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D007814:Larva / Q000187:drug effects; D007928:Lethal Dose 50; D015394:Molecular Structure; D010936:Plant Extracts / Q000302:isolation & purification / Q000633:toxicity*; D000461:Rhodophyta / Q000737:chemistry*; D013729:Terpenes / Q000737:chemistry / Q000302:isolation & purification / Q000633:toxicity*; D001468:Thoracica / Q000187:drug effects*
chemical_list: D010936:Plant Extracts; D013729:Terpenes