title: Qualitative and quantitative saponin contents in five sea cucumbers from the Indian ocean.
abstract: To avoid predation, holothuroids produce feeding-deterrent molecules in their body wall and viscera, the so-called saponins. Five tropical sea cucumber species of the family Holothuriidae were investigated in order to study their saponin content in two different organs, the body wall and the Cuvierian tubules. Mass spectrometry techniques (MALDI- and ESI-MS) were used to detect and analyze saponins. The smallest number of saponins was observed in Holothuria atra, which contained a total of four congeners, followed by Holothuria leucospilota, Pearsonothuria graeffei and Actinopyga echinites with six, eight and ten congeners, respectively. Bohadschia subrubra revealed the highest saponin diversity (19 congeners). Saponin mixtures also varied between the two body compartments within a given animal. A semi-quantitative approach completed these results and showed that a high diversity of saponins is not particularly correlated to a high saponin concentration. Although the complexity of the saponin mixtures described makes the elucidation of their respective biological roles difficult, the comparisons between species and between body compartments give some clues about how these molecules may act as predator repellents.
authors.affiliation: Marine Biology Laboratory, University of Mons, 20 Place du Parc, B-7000 Mons, Belgium. Severinevandyck@hotmail.com
authors.forename: Séverine
authors.initials: S
authors.lastname: Van Dyck
authors.forename: Pascal
authors.initials: P
authors.lastname: Gerbaux
authors.forename: Patrick
authors.initials: P
authors.lastname: Flammang
mesh_terms: D000818:Animals; D002851:Chromatography, High Pressure Liquid; D053878:Hemolytic Agents / Q000032:analysis / Q000737:chemistry; D019156:Indian Ocean; D007536:Isomerism; D008387:Marine Toxins / Q000032:analysis* / Q000737:chemistry*; D015394:Molecular Structure; D009928:Organ Specificity; D012503:Saponins / Q000032:analysis* / Q000737:chemistry*; D012616:Sea Cucumbers / Q000033:anatomy & histology / Q000737:chemistry*; D013045:Species Specificity; D021241:Spectrometry, Mass, Electrospray Ionization; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013463:Sulfuric Acid Esters / Q000032:analysis / Q000737:chemistry; D053719:Tandem Mass Spectrometry; D014315:Triterpenes / Q000032:analysis / Q000737:chemistry
chemical_list: D053878:Hemolytic Agents; D008387:Marine Toxins; D012503:Saponins; D013463:Sulfuric Acid Esters; D014315:Triterpenes