title: Amaroxocanes A and B: sulfated dimeric sterols defend the Caribbean coral reef sponge Phorbas amaranthus from fish predators.
abstract: Two new dimeric steroids, amaroxocanes A (1) and B (2), were isolated from Phorbas amaranthus collected on shallow coral reefs off Key Largo, Florida. The two compounds are comprised of two sulfated sterol cores bridged by an oxocane formed by different oxidative side-chain fusions. The structures were characterized by interpretation of MS and NMR spectroscopic data. The compounds are the primary components of a fraction that deters feeding of the bluehead wrasse, Thalassoma bifasciatum, in aquarium assays. When the pure compounds were assayed at eight times the natural concentration, amaroxocane B (2) was found to be an effective antifeedant, but A (1) was not.
authors.affiliation: Department of Chemistry and Biochemistry and Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California 92093-0358, USA.
authors.forename: Brandon I
authors.initials: BI
authors.lastname: Morinaka
authors.forename: Joseph R
authors.initials: JR
authors.lastname: Pawlik
authors.forename: Tadeusz F
authors.initials: TF
authors.lastname: Molinski
mesh_terms: D000818:Animals; D005247:Feeding Behavior / Q000187:drug effects*; D005399:Fishes; D015394:Molecular Structure; D011161:Porifera / Q000737:chemistry*; D013261:Sterols / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D013463:Sulfuric Acid Esters / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*
chemical_list: D013261:Sterols; D013463:Sulfuric Acid Esters; C550395:amaroxocane A; C550396:amaroxocane B