A new 5 alpha,8 alpha-epidioxy sterol from the Okinawan marine sponge of the Axinyssa genus

Isolation and characterization of antiplasmodial constituents from the marine sponge Coscinoderma sp

Six known compounds, namely two halisulfates 1 and 2 and four epidioxy sterols 3-6, were isolated from the marine sponge Coscinoderma sp. The structures of these compounds were confirmed by nuclear magnetic resonance (1H and 13C NMR) spectroscopy, and their antiplasmodial activities were determined against the chloroquine-resistant Dd2 strain of Plasmodium falciparum. The epidioxy steroids 3-6 all showed moderate to weak antiplasmodial activity, with IC50 values of 2.7 μM for (24S)-5α,8α-epidioxy-24-methylcholesta-6-en-3β-ol (3), 11.6 μM for 5α,8α-epidioxycholesta-6,24(28)-dien-3β-o1 (4), 2.33 μM for 5α,8α-epidioxy-24-methylcholesta-6,9(11)-24(28)-trien-3β-ol (5), and between 12 and 24 μM for 5α,8α-epidioxycholesta-6-en-3β-ol (6). In contrast, halisulfate 2 (1) was inactive, and halisulfate 1 (2) had an of IC50 value of about 24 μM.

A new bioactive steroidal ketone from the South China Sea sponge Xestospongia testudinaria

A new steroidal ketone (1), with an ergosta-22,25-diene side chain, was obtained from the South China Sea marine sponge Xestospongia testudinaria. The structure of 1 was determined on the basis of detailed spectroscopic analysis and by comparison with literature. Compound 1 exhibited significant inhibitory activity against protein tyrosine phosphatase 1B (PTP1B), a key target for the treatment of type II diabetes and obesity, with an IC50 value of 4.27 ± 0.55 μM, which is comparable with the positive control oleanolic acid (IC50 = 2.63 ± 0.22 μM).

5α,8α-Epidioxysterols from a Formosan Sponge, Axinyssa sp

One new 5α,8α-epidioxysterol, 3-acetylaxinysterol (1), along with one known sterol, axinysterol (2), were isolated from a Formosan sponge, Axinyssa sp.. The structures of the compounds were determined by spectroscopic methods and the absolute configuration of 2 was further confirmed by single-crystal X-ray diffraction analysis for the first time. Compound 2 exhibited significant cytotoxicity against K562 and Molt 4 cancer cell lines.

Chemical examination of the Sponge Phycopsis sp

Two new compounds 7alpha,8alpha-epoxy theonellin isothiocyanate (1) and 5alpha,8alpha-epidioxyergosta-6Z,22Z,25-trien-3beta-ol (2) along with two known compounds, theonellin isothiocyanate (3) and theonellin formamide (4) have been isolated from the sponge Phycopsis sp. Compound 2 showed cytotoxic activity against HL-60 and U937 human cancer cell lines with IC(50) values of 5.96+/-0.02 and 31.72+/-0.55 microg/ml, respectively.

New biologically active epidioxysterols from Stereum hirsutum

From the fungus Stereum hirsutum have been isolated and identified two new epidioxysterols 1, 4, together with two known ones 2 and 3. Their structures were elucidated on the basis of spectroscopic analysis and chemical reactions. Epidioxysterols 1-4 have been shown to possess a significant activity against Mycobacterium tuberculosis.

5,6:8,9-diepoxy and other cytotoxic sterols from the marine sponge Homaxinella sp

Four new (1, 2, 4, and 5) and 14 known (3 and 6-18) polyoxygenated sterols have been isolated from the MeOH extract of the marine sponge Homaxinella sp. by bioactivity-guided fractionation. The planar structures of the sterols were established by 1D and 2D NMR and MS spectroscopic analysis. 5,6:8,9-Diepoxy sterols (1-3) were isolated from a marine organism for the first time. The isolated sterols were tested against a panel of five human solid tumor cell lines and exhibited varying degrees of cytotoxicity.

Cytotoxic sterol derivatives from a marine sponge Homaxinella sp

A bioactivity-guided fractionation of a marine sponge Homaxinella sp. has led to the isolation of three new (1-3) highly degraded sterols and four new 6-O-alkylated (6-9) sterols, along with known sterol derivatives. The degraded sterols (1-5) belong to the class incisterols, previously isolated from the marine sponge Dictyonella incisa. Mainly NMR and MS spectroscopic analyses established the gross structures of the new compounds. The relationship between the stereoisomerism of the side chain and HPLC retention time has also been discussed. The compounds were tested against a panel of five human solid tumor cell lines, and especially the degraded sterols (1-4) displayed significant cytotoxicity.

New biologically active marine sesquiterpenoid and steroid from the okinawan sponge of the genus Axinyssa

A new bisabolane-type sesquiterpenoid, (E)-3-isocyanobisabolane-7,10-diene (1), and a new epidioxyergostane-type steroid, 9(11)-dehydroaxinysterol (2), were isolated from the Okinawan sponge of the genus Axinyssa. Their structures were elucidated based on the results of spectroscopic analysis and chemical conversion. Epidioxysterol 2 was found to show significant growth inhibitory effects against human cancer cell lines.

New nitrogenous eudesmane-type compounds isolated from the Caribbean sponge Axinyssa ambrosia

Fractionation of an acetone-methanol (1:1) extract of the Caribbean marine sponge Axinyssa ambrosia yielded three new sesquiterpenes whose structures were established by spectroscopic methods as (4R*,5R*,7S*,10R*)-eudesm-11-en-4-ylamine hydrochloride (1), axinyssamine hydrochloride, (4R*,5R*,7S*,10R*)-4-isocyanatoeudesm-11-ene (3), and (4R*,5R*,7S*,10R*)-formamidoeudesm-11-ene (4). Compound 1 exhibited significant cytotoxic activity against cancer cells and was also active in a lethality test using polyps of the scleractinian coral Madracis mirabilis.

Isolation of bioactive 5α,8α-epidioxy sterols from the marine sponge Luffariella cf. variabilis

The lipid extract of the marine sponge Luffariella cf. variabilis from Mayotte (Indian Ocean) has proven to be an extraordinarily rich source of a wide variety of unusual steroids belonging to the 5α,8α-epidioxy sterol family. Ten epidioxy sterols have been identified: 5α,8α-epidioxycholesta-6,22-dien-3β-ol, 5α,8α-epidioxycholest-6-en-3β-ol, 5α,8α-epidioxy-24(ξ)-methylcholesta-6,22-dien-3β-ol, 5α,8α-epidioxy-24(S)-methylcholest-6-en-3β-ol and its epimer (24R), 5α,8α-epidioxy-24(S)-ethylcholesta-6,22-dien-3β-ol and its epimer (24R), 5α,8α-epidioxy-24(S)-ethylcholest-6-en-3β-ol and its epimer (24R), along with 5α,8α-epidioxy-24(ξ)-methylcholesta-6,9(11),22-trien-3β-ol. Their structures were determined by nuclear magnetic resonance (1H, 13C) and electron impact mass spectrometry. The mixture of the 10 steroids showed inhibitive activity against the human T-cell leukemia/lymphotropic virus type I (HTLV-I) and also displayed cytotoxic activity against the human breast cancer cell line (MCF7WT).Key words: Luffariella cf. variabilis, marine sponge, 5α,8α-epidioxy sterols, antitumor and antiviral activities.