title: Biological and taxonomic perspective of triterpenoid glycosides of sea cucumbers of the family Holothuriidae (Echinodermata, Holothuroidea).
abstract: Since the discovery of saponins in sea cucumbers, more than 150 triterpene glycosides have been described for the class Holothuroidea. The family Holothuriidae has been increasingly studied in search for these compounds. With many species awaiting recognition and formal description this family currently consists of five genera and the systematics at the species-level taxonomy is, however, not yet fully understood. We provide a bibliographic review of the triterpene glycosides that has been reported within the Holothuriidae and analyzed the relationship of certain compounds with the presence of Cuvierian tubules. We found 40 species belonging to four genera and 121 compounds. Holothurin A and B are the most common saponins for Actinopyga, Holothuria, and Pearsonothuria. The genus Bohadschia presents mainly bivittoside C and D. Actinopyga has only sulfated saponins mainly oxidized, Bohadschia non-sulfated ones mainly non-oxidized, Holothuria and Pearsonothuria contain both types of compounds, mainly oxidized. Within the genus Holothuria, the subgenus Panningothuria only has non-sulfated saponins. The presence of sulfated and non-sulfated compounds seemingly relates to the expellability or the absence of Cuvierian tubules and the temporal or permanent concealing habits of the species. Our study concludes that better insights into the systematic distribution of saponins in Holothuriidae will only be possible if the identifications of the investigated species are confirmed by a taxonomist, especially in this group wherein cryptic species and variation between life-history stages are common and yet poorly understood. Understanding of saponin distribution within the Holothuriidae would also benefit from a stabilization of triterpene glycoside nomenclature.
authors.affiliation: Departamento de Química de Biomacromoléculas, Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior s/n, Ciudad Universitaria, C.P. 04510 México, D. F., Mexico. Electronic address: mbihoney@hotmail.com.
authors.forename: Magali
authors.initials: M
authors.lastname: Honey-Escandón
authors.affiliation: Departamento de Química de Biomacromoléculas, Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior s/n, Ciudad Universitaria, C.P. 04510 México, D. F., Mexico.
authors.forename: Roberto
authors.initials: R
authors.lastname: Arreguín-Espinosa
authors.affiliation: Laboratorio de Sistemática y Ecología de Equinodermos, Instituto de Ciencias del Mar y Limnología, Universidad Nacional Autónoma de México, Apartado Postal 70-350, C.P. 04510 México, D. F., Mexico.
authors.forename: Francisco Alonso
authors.initials: FA
authors.lastname: Solís-Marín
authors.affiliation: Scientific Service of Heritage, Invertebrates Collections, Royal Belgian Institute of Natural Sciences, Vautierstraat 29, B-1000 Brussels, Belgium.
authors.forename: Yves
authors.initials: Y
authors.lastname: Samyn
mesh_terms: D000818:Animals; D006027:Glycosides / Q000737:chemistry / Q000145:classification*; D012503:Saponins / Q000737:chemistry / Q000145:classification; D012616:Sea Cucumbers / Q000737:chemistry*; D014315:Triterpenes / Q000737:chemistry / Q000145:classification*
chemical_list: D006027:Glycosides; D012503:Saponins; D014315:Triterpenes
keywords: Cuvierian tubules; Saponins; Taxonomy; family Holothuriidae