Four New Steroidal Glycosides, Protolinckiosides A – D, from the Starfish Protoreaster lincki

Abstract

Four new steroidal glycosides, protolinckiosides A - D (1 - 4, resp.), were isolated along with four previously known glycosides, 5 - 8, from the MeOH/EtOH extract of the starfish Protoreaster lincki. The structures of 1 - 4 were elucidated by extensive NMR and ESI-MS techniques as (3β,4β,5α,6β,7α,15α,16β,25S)-4,6,7,8,15,16,26-heptahydroxycholestan-3-yl 2-O-methyl-β-d-xylopyranoside (1), (3β,5α,6β,15α,24S)-3,5,6,8,15-pentahydroxycholestan-24-yl α-l-arabinofuranoside (2), sodium (3β,6β,15α,16β,24R)-29-(β-d-galactofuranosyloxy)-6,8,16-trihydroxy-3-[(2-O-methyl-β-d-xylopyranosyl)oxy]stigmast-4-en-15-yl sulfate (3), and sodium (3β,6β,15α,16β,22E,24R)-28-(β-d-galactofuranosyloxy)-6,8,16-trihydroxy-3-[(2-O-methyl-β-d-xylopyranosyl)oxy]ergosta-4,22-dien-15-yl sulfate (4). The unsubstituted β-d-galactofuranose residue at C(28) or C(29) of the side chains was found in starfish steroidal glycosides for the first time. Compounds 1 - 4 significantly decreased the intracellular reactive oxygen species (ROS) content in RAW 264.7 murine macrophages at induction by proinflammatory endotoxic lipopolysaccharide (LPS) from E. coli.

Marine natural products

“…The remaining metabolites reported from echinoderms were dominated by anthraquinones 1257 and 1258 (crinoid Comatula rotalaria), 403 pyrrole oligoglycosides 1259 and 1260 (starsh Acanthaster planci) 720 and sterols 1261-1263 (starsh Archaster typicus) 721 and their glycosides including 1264-1267 (starsh Protoreaster lincki), 722 1268-1277 (starsh Anthenea aspera), 723 1278 and 1279 (starsh Acanthaster planci), 724 1280-1282 (star-sh Pentaceraster regulus), 725 732 Two synthetic routes to spinamine E 1255 (2-amino-3,6,7-trihydroxynaphthazarin) have been reported 733 as has the rst synthesis of the pentacyclic naphthazarin-derived dimer mirabiquinone A. 734,735 The structure of the complex sialic acid embedded octasaccharide ganglioside GP3 (Asterina pectinfera) 736 has been conrmed by total synthesis.…”

Cytotoxic Polyhydroxysteroidal Glycosides from Starfish Culcita novaeguineae

“…The assignment of the NMR signals associated with the aglycone moiety and side chain ( Table 1 ) was derived from HSQC, 1 H- 1 H COSY, HMBC, and TOCSY experiments. The normally occurring 2- O -methyl-β- d -xylopyranose (2-OMe-Xyl) moiety in the polyhydroxysteroidal glycosides was detected in compound 1 by analyzing the one-dimensional (1D) and two-dimensional (2D) NMR spectra, and by comparing the monosaccharide signals with those co-isolated known compounds and the literature values [ 21 , 22 , 23 ]. This was further confirmed by the demethylation and acid hydrolysis of compound 1 with 2 M trifluoroacetic acid, followed by derivatization with 1-(trimethylsily)-imidazole, gas chromatography (GC) analysis sequentially, and a comparison with the corresponding derivatives of a standard monosaccharide [ 6 , 8 ].…”

Marine Pharmacology in 2016–2017: Marine Compounds with Antibacterial, Antidiabetic, Antifungal, Anti-Inflammatory, Antiprotozoal, Antituberculosis and Antiviral Activities; Affecting the Immune and Nervous Systems, and Other Miscellaneous Mechanisms of Action

“…SF-5976 [192]; a novel halogenated 5α-iodozoanthenamine (171) isolated from the colorful Taiwanese zoanthid Zoanthus kuroshio [193]; two novel steroids klyflaccisteroid J and K (172, 173) isolated from the Taiwanese soft coral Klyxum flaccidum [194,195]; a known lobane diterpenoid (174) isolated from a Taiwanese soft coral Lobophytum varium [196]; two new bioactive steroids petasitosterones B and C (175, 176) isolated from the Taiwanese soft coral Umbellulifera petasites [197]; two new sterols (177,178) [198], and novel 9,11-secosterols pinnigorgiol A (179) [199], pinnigorgiol E (180) [200], pinnisterol A (181) [201] and pinnisterol H (182) [202] isolated from the Taiwanese gorgonian coral Pinnigorgia sp. ; a new pyrrole oligoglycoside plancipyrroside B (183) isolated from an extract of the Vietnamese starfish Acanthaster planci [203]; a novel steroidal glycoside protolinckioside A (184) isolated from an Arabian sea starfish Protoreaster lincki [204]; a known terpenoid sarcophytonolide O (185) isolated from the Chinese soft coral Lobophytum crassum [205]; two novel norcembranoids sinulerectols A and B (186, 187) isolated from South China Sea soft coral Sinularia erecta [206]; a known terpenoid sinubrasolide A (188) and the steroid sinubrasone D (189) isolated from the Taiwanese "cultivation pool" soft coral Sinularia brassica [207,208]; and the novel diterpenes uprolides N, O and P (190)(191)(192) isolated from the Panamanian octocoral Eunicea succinea [209].…”

“…In contrast, for the marine compounds (200)(201)(202)(203)(204)(205) listed in Table 2 and depicted in Figure 2, only the immune bioactivity (IC 50 ) was reported, but no molecular mechanism of action had been described by the time of publication: A novel dimeric nitrophenyl trans-epoxyamide chrysamide C (200) produced by a Indian Ocean deep (3386 m) sedimentderived fungus Penicillium chrysogenum SCSIO41001 [217]; a new dimeric macrolide xylopyranoside cocosolide (201) isolated from the Guamanian marine cyanobacterium Symploca sp. [218]; a new N-acyl dopamine glycoside myxillin A (202) isolated from the Icelandic hydrothermal vent-derived sponge Myxilla incrustans [219]; the known steroidal saponin pectinioside A (203) isolated from the starfish Patiria pectinifera [220]; a new benzophenone polyketide peniphenone (204) obtained from the mangrove Sonneratia apetala endophytic fungus Penicillium sp. ZJ-SY 2 [221]; and a known analog of the antimycin-type depsipeptide somalimycin, named USF-19A (205) isolated from the South China Sea deep (3536 m) sediment-derived Streptomyces somaliensis SCSIO ZH66 [222].…”