A glucosylceramide with a novel ceramide and three novel ceramides from the basidiomycete Cortinarius umidicola

Two New Cerebroside Metabolites from the Marine Fungus Hortaea werneckii

Two new cerebroside metabolites were isolated from the fermented sponge-derived fungus extract of Hortaea werneckii. They were hortacerebroside A (1) ((2R,3E)-N-[(2S,3R,4E,8E)-1-(β-D-glucopyranosyloxy)-3-hydroxy-9-methylhenicosa-4,8-dien-2-yl]-2-hydroxypentadec-3-enamide) and hortacerebroside B (2) ((2R)-N-[(2S,3R,4E,8E)-1-(β-D-glucopyranosyloxy)-3-hydroxy-9-methylhenicosa-4,8-dien-2-yl]-2-hydroxypentadecanamide). Their structures were elucidated by spectroscopic analysis and by comparison of the spectroscopic data with those of related cerebroside analogs. These two compounds showed significant inhibitory effect on NO produced by lipopolysaccharide (LPS) stimulated RAW 264.7 macrophages. The IC₅₀ values of hortacerebroside A (1) and hortacerebroside B (2) were 7 and 5 μM, respectively. These results suggested the potential application of these cerebrosides as drug leads targeting inflammatory-related disorders.

First report of isolation of antibacterial ceramides from the leaves of Euclinia longiflora Salisb

Two phytosphingosine-type ceramides (euclinide A (1) and B (2)) were isolated alongside one fatty acid (geddic acid (3)), one fatty acid-1-glyceride ((2 S)-1- O-hentriacontanoyl glycerol (4)), ten triterpenes ( α-amyrin (5), α-amyrin acetate (6), ursolic acid (7), β-amyrin (8), β-amyrin acetate (9), β-amyrin palmitate (10), oleanic acid (11), maslinic acid (12), betulinic acid (13) and cylicodiscic acid (14)) and four sterols ( β -sitosterol (15), stigmasterol (17), and their glucosylated derivatives β-sitosterol-3-O- β-glucopyranoside (16) and stigmasterol-3-O- β-glucopyranoside (18)) from the methanol extract of the leaves of Euclinia longiflora Salisb. using routine chromatographic methods. The structures of the new ceramides and known compounds were determined by analyses of HR-FAB-MS, 1D and 2D NMR (HSQC, HMBC, and NOESY) data and confirmed, where applicable, by comparison with data reported in literature. The methanolic extract and the ceramides were evaluated for their antibacterial activities against different bacterial strains using microdilution method and the MIC values ranged from 6.25 to 50 μg/mL and were considered as moderate activity compared to ciprofloxacin. It is the first report of ceramides in Euclinia longiflora.

A new cerebroside from the twigs of Lindera glauca (Sieb. et Zucc.) Blume

Lindera glauca (Sieb. et Zucc.) Blume (Lauraceae) has been used to treat rheumatic arthritis, stroke, and cardiac pain. Phytochemical investigation of twigs of L. glauca (Sieb. et Zucc.) Blume resulted in the isolation and identification of a new cerebroside, glaucerebroside (1). The structure of 1 was elucidated by a combination of extensive spectroscopic analyses, including extensive 2D NMR, HR-MS, chemical reactions, and LC/MS analysis. Compound 1 is a relatively rare cerebroside with l-threo-configuration of the sphingosine part. This is the second example of identification of a cerebroside from the family Lauraceae. Compound 1 significantly inhibited nitric oxide (NO) production in lipopolysaccharide (LPS)-stimulated BV-2 cells, with an IC₅₀ value of 23.84μM without inducing cell toxicity. This study suggests that glaucerebroside (1) can be an excellent candidate for development of novel anti-neuroinflammatory agents.

Neritinaceramides A-E, new ceramides from the marine bryozoan Bugula neritina inhabiting South China Sea and their cytotoxicity

Five new ceramides, neritinaceramides A (1), B (2), C (3), D (4) and E (5), together with six known ceramides (6–11), two known alkyl glycerylethers (12 and 13) and a known nucleoside (14), were isolated from marine bryozoan Bugula neritina, which inhabits the South China Sea. The structures of the new compounds were elucidated as (2S,3R,3′S,4E,8E,10E)-2-(hexadecanoylamino)-4,8,10-octadecatriene-l,3,3′-triol (1), (2S,3R,2′R,4E,8E,10E)-2-(hexadecanoylamino)-4,8,10-octadecatriene-l,3,2′-triol (2), (2S,3R,2′R,4E,8E,10E)-2-(octadecanoylamino)-4,8,10-octadecatriene-l,3,2′-triol (3), (2S,3R,3′S,4E,8E)-2-(hexadecanoylamino)-4,8-octadecadiene-l,3,3′-triol (4) and (2S,3R,3′S,4E)-2-(hexadecanoylamino)-4-octadecene-l,3,3′-triol (5) on the basis of extensive spectral analysis and chemical evidences. The characteristic C-3′S hydroxyl group in the fatty acid moiety in compounds 1, 4 and 5, was a novel structural feature of ceramides. The rare 4E,8E,10E-triene structure in the sphingoid base of compounds 1–3, was found from marine bryozoans for the first time. The new ceramides 1–5 were evaluated for their cytotoxicity against HepG2, NCI-H460 and SGC7901 tumor cell lines, and all of them exhibited selective cytotoxicity against HepG2 and SGC7901 cells with a range of IC₅₀ values from 47.3 μM to 58.1 μM. These chemical and cytotoxic studies on the new neritinaceramides A–E (1–5) added to the chemical diversity of B. neritina and expanded our knowledge of the chemical modifications and biological activity of ceramides.

New ceramides from Rantherium suaveolens

A mixture of five new ceramides was isolated from the aerial parts of Rantherium suaveolens and characterized by spectroscopic and chemical methods. Their structures were elucidated by spectroscopic and chemical methods as (2S,3S, 4R,2'R, 14E)-2-(2'-hydroxydocosanoylamino) - 14 - octadecene -1,3,4-triol (1), (2S,3S,4R,2'R, 14E)-2-(2'-hydroxytricosanoylamino)-14-octadecene-1,3,4-triol (2), (2S,3S,4R,2'R, 14E)-2-(2'-hydroxytetracosanoylamino)- 14 - octadecene - 1,3,4 - triol (3), (2S, 3S,4R,2'R, 14E) - 2 - (2'- hydroxypentacosanoylamino) - 14 - octadecene - 1,3,4-triol (4), and (2S,3S,4R,2'R,14E)-2-(2'-hydroxyhexacosanoylamino)-14-octadecene-1,3,4-triol (5).

Molecular species of ceramides from the ascomycete truffle Tuber indicum

The ceramide fractions were isolated from the chloroform/methanolic extractable of the fruiting bodies of Tuber indicum and separated into three kinds of molecular species TI-1, TI-2, and TI-3 by normal and reverse phase silica gel-column chromatography. By means of (1)H NMR and (13)C NMR spectroscopy, fast atom bombardment mass spectrometry (FAB-MS), and chemical degradation experiment, their component sphingoid base for TI-1 and TI-2 was uniformly (2S,3S,4R)-2-amino-1,3,4-octadecantriol, while the sphingoid of TI-3 was d-erythro-sphingosine, and their structures have been determined unequivocally to be (2S,2'R,3S,4R)-2-(2'-d-hydroxyalkanoylamino) octadecane-1,3,4-triol, the fatty acid composition of which consists of 2-hydroxydocosanoic, 2-hydroxytetracosanoic, and 2-hydroxytricosanoic acids (from major to minor); (2S,3S,4R)-2-(alkanoylamino)octadecane-1,3,4-triol, the fatty acid composition of which is unusual and consists of docosanoic, hexadecanoic, tricosanoic, octadecanoic and nonadecanoic acids (from major to minor); and (2S,3R,4E)-2-(alkanoylamino)-4-octadecene-1,3-diol, the component fatty acids of which were hexadecanoic (predominant) and octadecanoic acids, respectively.

Two new steryl esters from the basidiomycete Tricholomopsis rutilans

Two new steryl esters with a polyhydroxylated ergostane-type nucleus, 3beta,5alpha-dihydroxy-(22E,24R)-ergosta-7,22-dien-6beta-yl oleate (1) and 3beta,5alpha-dihydroxy-(22E,24R)-ergosta-22-en-7-one-6beta-yl oleate (2), were isolated from the fruiting bodies of the basidiomycete Tricholomopsis rutilans along with three known sterols (3, 4, and 5). The structures of compounds 1 and 2 were established on the basis of spectroscopic means and chemical methods.