Four New Saponins from the Starfish Certonardoa semiregularis.

Abstract

Four new saponins, designated as certonardosides K-N (1-3, 5), were isolated, along with culcitoside C(6) (4), from the brine shrimp active fraction of the starfish Certonardoa semiregularis. The structures were determined on the basis of spectral analysis and chemical derivatization. These compounds were evaluated for cytotoxicity and antibacterial activity.

Isolation and structural characterisation of five new and 14 known metabolites from the commercial starfish Archaster typicus

“…According to the reported references, in the R-MTPA esters, the H 2 -26 signals of the 25R isomer were closely spaced, while those of the 25R isomer were well-separated. The reverse was observed in the S-MTPA esters (Finamore, Minale, Riccio, Rinaldo, & Zollo, 1991;Wang et al, 2004). Therefore, the 25R configuration was established unambiguously.…”

Tirucallane triterpenes from the roots of Ozoroa insignis

“…The molecular formula of 5 was assigned as C 32 H 54 O 5 by positive HRESIMS. Comparison of its NMR data with those of compounds described above, revealed the characteristic signals for a 3a-hydroxy-D 8 tetracyclic nucleus, but relevant differences were observed for the side chain proton and carbon resonances: an oxygenated quaternary carbon at d C 73.1 showing HMBC correlations with two methyl groups at d 1.13 and 1.19; a low-field methylene group (d 4.14; d C 60.0) exhibiting COSY cross-peaks with two protons at d 1.25, in agreement with a fragment [-CH 2 -CH 2 OH] (Wang et al, 2004); the signals for the methyl ester were absent, although a carbonyl resonance was displayed at d C 176.2. The above spectral data indicated a side chain bearing a hydroxyethyl group at C-24, a C-21 carboxyl, and an ending segment [-C(CH 3 ) 2 -OH], which was corroborated by the mass fragmentation recorded in the EI mode (see Section 3), consistent with the structure of 3a,25-dihydroxy-24-(2-hydroxyethyl)-tirucall-8-en-21-oic acid (5).…”

Cytolytic and antinociceptive activities of starfish Protoreaster linckii (Blainvilli, 1893)

“…Among them, the sea stars have variety of chemical constituents such as steroids, glycosides consisting of astrosaponins, steroids cyclic glycosides, steroid monoglycosides and diglycosides, saponins, astrosaponins and carotenoids. Moreover, the echinoderm tissue extracts have demonstrated cytotoxic (Wang et al, 2003), hemolytic (Ivanchina et al, 2006), antifungal (Chludil and Maier, 2005), antimicrobial (Haug et al, 2002), feeding deterrent (McClintock et al, 2003), antifouling (Iorizzi et al, 1995;Bryan et al, 1996;Greer et al, 2006) activities. Hence, the present investigation was made from sea star Protoreaster linckii demonstrated the hemolytic, cytotoxic and antinociceptive properties.…”