Nine polyhydroxy steroids and two steroid glycosides have been isolated from the starfish M. platyacanthum. The novel compds. possess the same 3β,5α,6β,15α-tetrol nucleus but differ in the side chains. Two levels of oxidn. (CH2OH and CO2H) at the side chain methyls were encountered in this class of steroids. The novel compd. I is an asterosaponin assigned as myxodermoside A, consisting of a Δ9(11)-3β,6α-dihydroxysteroidal moiety, a tetrasaccharide portion attached at C-6, and a sulfate group at C-3. The general structure of the novel compds. was detd. from spectral data (1H and 13C NMR and FAB MS), and the stereochem. of the side chains was detd. by correlating the resp. spectral data with those of synthetic models of known configuration. The stereoselective synthesis of the side chain of II is also described.
Novel marine polyhydroxylated steroids from the starfish Myxoderma platyacanthum
RICCIO, Raffaele;
1991-01-01
Abstract
Nine polyhydroxy steroids and two steroid glycosides have been isolated from the starfish M. platyacanthum. The novel compds. possess the same 3β,5α,6β,15α-tetrol nucleus but differ in the side chains. Two levels of oxidn. (CH2OH and CO2H) at the side chain methyls were encountered in this class of steroids. The novel compd. I is an asterosaponin assigned as myxodermoside A, consisting of a Δ9(11)-3β,6α-dihydroxysteroidal moiety, a tetrasaccharide portion attached at C-6, and a sulfate group at C-3. The general structure of the novel compds. was detd. from spectral data (1H and 13C NMR and FAB MS), and the stereochem. of the side chains was detd. by correlating the resp. spectral data with those of synthetic models of known configuration. The stereoselective synthesis of the side chain of II is also described.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
