Antarctic Marine Metabolites: New Polyhydroxylated Steroidal Glycosides from the Starfish Odontaster validus

• Published in: Liebigs Annalen der Chemie
• Main Authors: Vázquez, M. Jesús, Quiñoá, Emilio, Riguera, Ricardo, Martin, Aurelio San, Darias, José
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 1993
• Subjects: Antarctic; Antarc*
• Online Access: http://dx.doi.org/10.1002/jlac.1993199301205; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fjlac.1993199301205; https://onlinelibrary.wiley.com/doi/full/10.1002/jlac.1993199301205

Abstract Two new asterosaponins, validosides A and B, were isolated from the butanolic extract of the starfish Odontaster validus and their structures established as (24 S )‐24‐ O ‐[2,4‐di‐ O ‐methyl‐β‐xylopyranosyl‐(1→2)‐α‐arabinofuranosyl]‐5α‐cholestane‐3β,4β,6α,8,15β,24‐hexaol 6‐ O ‐sodium sulfate ( 1 ) and (24 S )‐24‐ O ‐(3‐ O ‐methyl‐β‐xylopyranosyl)‐5α‐cholestane‐3β,6α,8,15β,24‐pentaol 2′‐ O ‐sodium sulfate ( 2 ) on the basis of extensive spectroscopic investigations and chemical correlations. Validoside A and B are extremely rarely occurring saponins due to the presence of a sulfated group at C‐6 of the aglycone in 1 and at C‐2′ of a pyranose in 2 . The absolute configuration at C‐24 was found to be S by the application of the Trost‐Mosher methodology.