Anthenosides L–U, Steroidal Glycosides with Unusual Structural Features from the Starfish <i>Anthenea aspera</i>

Abstract

Ten new polyhydroxysteroidal glycosides, anthenosides L–U ( 1 – 10 ), with rare positions of carbohydrate fragment attachments, were isolated from the starfish Anthenea aspera . The structures of 1 – 10 were established by NMR and ESIMS techniques as well as by chemical transformations. The unoxidized Δ 22 -24-nor-cholestane ( 1 ), (24 S )-Δ 22 -24-methylcholestane ( 2 – 5 ), and Δ 22 -cholestane ( 7 ) side chains of the steroidal aglycons, 3- O -methyl-β- d -galactofuranosyl residue ( 2, 8 ), and 5α-cholest-8(14)-ene-3α,7β,16α-trihydroxysteroidal nucleus ( 9, 10 ) have not been found previously in starfish polar steroidal compounds. The mixture of glycosides 9 and 10 showed hemolytic activity with an EC 50 = 8 μM. Compound 4 at a dose of 10 μM exhibited a potential immunomodulatory action, decreasing by 24% the intracellular ROS content in RAW 264.7 murine macrophages, induced by pro-inflammatory endotoxic lipopolysaccharide from E. coli .