New Saponins from the Starfish Certonardoa semiregularis

Abstract

Ten new saponins designated as certonardosides A-J (1-5, 7-11) and the known halityloside D (6) were isolated from the brine shrimp active fraction of the MeOH extract of the starfish Certonardoa semiregularis. The structures were determined on the basis of spectral analysis and chemical manipulation. The compounds were evaluated for antiviral activity against HIV, HSV, CoxB, EMCV, and VSV and displayed insignificant activity within the range of noncytotoxic concentrations.

Chemical Constituents and Bioactivities of Starfish

“…The absolute configurations of the side chains of certonardosides A -E (301 -305, resp.) and certonardoside H (306) [92] were established by the 1 H-NMR analysis of their MTPA esters (cf. Table 2).…”

“…Steroidal glycosides 301 -321 and certonardosides F, G, I, and J (343 -346, resp.) [92], and certonardoside I 3 (347) [94] were isolated from the starfish Certonardoa semiregularis, collected off the coast of Komun Island, Korea. Compounds 343 -346 were evaluated for antiviral properties towards HIV, HSV, CoxB, EMCV, and VSV (for abbreviations, cf.…”

Marine natural products

“…565 The new sulfated steroid 730 was isolated from both Leptasterias alaskensis asiatica and L. fisheri, starfish collected at the Kiril Islands. 569 The absolute configurations of the side chains were secured by the 1 H NMR analysis of MTPA esters. 567 Lysastroside A 732, a new steroidal glycoside was isolated from the starfish Lysastrosoma anthosticta, collected in the Sea of Japan.…”

Convenient and Inexpensive Synthesis of (1R,2R)‐ trans‐1‐Amino‐6‐nitroindan‐2‐ol

“…[15] Adopting this protocol, the nitration of rac-9 could be performed in quantitative yield, however, the product was obtained as the betain-type monosulfate ester rac-10 (Scheme 2). The zwitterionic nature of rac-10 caused its low solubility in most organic solvents, and this probably is the reason, why the hydroxy group in rac-10 could not be deprotected applying established methods [16] such as heating in a pyridine/dioxane mixture, [16a] stirring in dioxane in the presence of p-TsOH [16b] or stirring in THF in the presence of sulfuric acid.…”