Aragusterols E-H, new 26,27-cyclosterols from the Okinawan marine sponge of the genus Xestospongia and absolute configurations of xestokerols A and B

Miyaoka, Hiroaki; Shinohara, Masakazu; Shimomura, Masako; Mitome, Hidemichi; Yano, Akiko; Iguchi, Kazuo; Yamada, Yasuji

doi:10.1016/s0040-4020(97)00231-7

Cited by 38 publications

(45 citation statements)

References 16 publications

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“…The proton signal of H-3 at δ H 3.50 (1H, m, J 1/2 =11.0 Hz) is indicative for its α-orientation 12) (versus t, J=2.5 or 3.0 Hz for β-orientation of H-3 without a large J value attributable to a diaxial coupling 13,14) ). This was further confirmed by the 13 C-NMR chemical shift for C-3 of 2 at δ C 72.1 7,12,15) and a NOESY correlation of H-3 (δ H 3.50) with H-5 (δ H 1.06). The β-orientation for both H-6 and H-15 was assigned by NOESY correlations of H-6 (δ H 3.66) with H-19 (δ H 1.05) and H-15 (δ H 4.96) with H-18 (δ H 1.19).…”

Section: Resultsmentioning

confidence: 54%

Further Highly Hydroxylated Steroids from the Vietnamese Starfish Archaster typicus

Hạnh

Vien

Vinh

et al. 2016

CHEMICAL & PHARMACEUTICAL BULLETIN

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Key words Archaster typicus; starfish; polyhydroxylated steroidThe phylum Echinodermata is divided into five classes: Crinoidea (sea lilies and feather stars), Holoturoidea (sea cucumbers or holothurians), Echinoidea (sea urchins), Asteroidea (starfish or sea stars), and Ophiuroidea (brittle stars). Of which, starfish are benthic organisms widely found in all oceans. Starfish have attracted organic chemists, biochemists, and pharmacologists as a fascinating source of bioactive secondary metabolites especially polyhydroxylated steroids and steroidal glycosides.1,2) Polyhydroxylated steroids from starfish comprise four to nine hydroxy groups in steroidal nucleus and side chains. It is of special interest that all the groups were found only in limited positions. The majority of polyhydroxylated steroids possess a 3β,6α(or β), 8,15α(or β),16β-pentahydroxycholestane skeleton, sometimes with additional OH groups at positions 4β,5α,7α(or β), and occasionally at 14α. The side chains of these compounds are very diverse, but (25S)-26-hydroxy structure is a common feature; the less common side chain is hydroxylated at C-24 with (S)-configuration. Polyhydroxylated steroids are also found in sulfated forms, with the sulfate group located at position 3β, 6α, 15α or 24. 1-3)The starfish Archaster typicus is abundantly found in Vietnamese seas. Previous studies on this species yielded nine unique polyhydroxylated steroids in the 1980s. [4][5][6] Recently, several polyhydroxylated steroids of this type 7,8) and asterosaponins 9,10) were reported from this species. In continuation of our recent investigations on Vietnamese starfish, 11) this paper deals with the isolation and structure elucidation of eight highly hydroxylated steroids (1-8, Fig. 1), including three new compounds 1-3, from A. typicus.

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Section: Resultsmentioning

confidence: 54%

Further Highly Hydroxylated Steroids from the Vietnamese Starfish Archaster typicus

Hạnh

Vien

Vinh

et al. 2016

CHEMICAL & PHARMACEUTICAL BULLETIN

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“…The HRFABMS showed a pseudomolecular ion peak at m/z 437.3390 [M + Na]. The 1 H NMR spectrum of 3 showed characteristic steroid signals: two methyl singlets at δ 1.02 (s, H 3 -19) 10,11 The strong H-16/ H 3 -18/H-20 NOE correlations indicated that the hydroxy group at C-16 occurred on the α side of the molecule. A careful comparison of the 1 H and 13 C NMR data with those of natural steroids with OH-16α (e.g., aragusterols F−H) and OH-16β functionalities further corroborated the assignments.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

Monanchosterols A and B, Bioactive Bicyclo[4.3.1]steroids from a Korean Sponge Monanchora sp.

et al. 2014

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Chemical investigation of a Korean marine sponge, Monanchora sp., led to the isolation of three new steroids (1-3). Compounds 1 and 2, designated as monanchosterols A and B, respectively, represent the first examples of steroids possessing the bicyclo[4.3.1] A/B ring system from a natural source. Compounds 1-3 were investigated for their anti-inflammatory activity by evaluating their inhibitory effects on the mRNA expression of IL-6, TNF-α, and COX-2 in the LPS-stimulated murine RAW264.7 macrophage cells. Compounds 2 and 3 exhibited significant inhibitory effects on the mRNA expression of IL-6 without notable cytotoxicity to the cells in a dose-dependent manner.

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“…An oxygenated quaternary carbon was observed at δ C 103.1 (C, C-15) indicating for a dioxygenated carbon. In addition, the oxymethine signal was shifted down-field to δ C 76.9 (CH, C-7)/δ H 4.54 (H-7) [versus δ C 73.6 (CH, C-7)/δ H 4.28 (H-7) of 5α-cholest-8(14)-ene-3β,7β-diol 4) ] and the observation of just two hydroxy proton signals at δ H 4.54 (1H, d, J=4.5 Hz, The relative configuration of astropectenol B (2) was assigned by comparison of the 13 C-NMR data with those reported of similar compounds 4,7,8) and by ROESY. The β-orientation of the hydroxy group at C-3 was indicated by the ).…”

Section: )mentioning

confidence: 96%

Steroidal Constituents from the Starfish Astropecten polyacanthus and Their Anticancer Effects

Thao

Cường

Luyen

et al. 2013

CHEMICAL & PHARMACEUTICAL BULLETIN

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Using various chromatographic methods, four new steroids, astropectenols A-D (1-4), along with three known compounds (5-7) were isolated from a methanol extract of the starfish Astropecten polyacanthus. The structure elucidation was confirmed by spectroscopic methods, including one dimensional (1D)-, 2D-NMR and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS). The CH 2 Cl 2 fraction and compound 7 exhibit potent cytotoxic effects against HL-60 human leukemia cells with the IC 50 of 8.29 µg/mL and 2.70 µM, respectively, comparing to the positive control, mitoxantrone (IC 50 6.80 µM). When HL-60 cells were treated with the CH 2 Cl 2 fraction or compound 7, several apoptosis events like chromatin condensation and the increase of the population of sub-G1 hypodiploid cells were observed. Investigations for the possible mechanism underlying the induction of apoptosis showed that CH 2 Cl 2 fraction or compound 7 induced apoptosis through down-regulation of Bcl-2, up-regulation of Bax, cleavage of caspase-9, cleavage of caspase-3 and cleavage of poly(ADP-ribose) polymerase (PARP) in HL-60 cells. Furthermore, the apoptosis induction of HL-60 cell by CH 2 Cl 2 fraction or compound 7 was attended by the decreasing of phospho-extracellular signal-regulated kinase (ERK) 1/2 and C-myc. These results indicated that the CH 2 Cl 2 fraction and compound 7 could induce the apoptosis of HL-60 cells via the inactivation of ERK 1/2 and the decrease of C-myc. Our finding suggested the potential using of the CH 2 Cl 2 fraction and compound 7 for leukemia treatment. Key words Astropecten polyacanthus; starfish; oxygenated steroid; cytotoxic; apoptosisEchinoderms represent an outstanding source of polar steroids of a great structural diversity, showing various biological activities. Among five living classes of the phylum Echinodermata, two classes Asteroidea (starfish) and Ophiuroidea (brittle stars) are especially rich in polar steroids.1) The research on starfish has expanded rapidly over the past few years, which has been prompted by the discovery of a variety of unique structures and the interest in their pharmacological properties. Starfish have attracted organic chemists, biochemists, and pharmacologists as a fascinating source of bioactive marine natural products, especially steroids and steroidal glycosides. 2)Some polyhydroxylated steroids from starfish exhibited antibacterial and cytotoxic activities. 1)In our screening research for anti-cancer agents from Vietnamese echinoderms, we found the starfish Astropecten polyacanthus to possess significant cytotoxic effects. As part of our continuing investigations on this starfish, we report herein the isolation, structural elucidation, and evaluation of anticancer activity of extracts and seven steroids, including four new compounds 1-4, from the starfish A. polyacanthus.

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Aragusterols E-H, new 26,27-cyclosterols from the Okinawan marine sponge of the genus Xestospongia and absolute configurations of xestokerols A and B

Cited by 38 publications

References 16 publications

Further Highly Hydroxylated Steroids from the Vietnamese Starfish <i>Archaster typicus</i>

Further Highly Hydroxylated Steroids from the Vietnamese Starfish <i>Archaster typicus</i>

Monanchosterols A and B, Bioactive Bicyclo[4.3.1]steroids from a Korean Sponge Monanchora sp.

Steroidal Constituents from the Starfish <i>Astropecten polyacanthus</i> and Their Anticancer Effects

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