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1.
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.  相似文献   

2.
Pure compound screening has identified the dioxothiazino-quinoline-quinone ascidian metabolite ascidiathiazone A (2) to be a moderate growth inhibitor of Trypanosoma brucei rhodesiense (IC50 3.1 μM) and Plasmodium falciparum (K1 dual drug resistant strain) (IC50 3.3 μM) while exhibiting low levels of cytotoxicity (L6, IC50 167 μM). A series of C-7 amide and Δ2(3) analogues were prepared that explored the influence of lipophilicity and oxidation state on observed anti-protozoal activity and selectivity. Little variation in anti-malarial potency was observed (IC50 0.62–6.5 μM), and no correlation was apparent between anti-malarial and anti-T. brucei activity. Phenethylamide 7e and Δ2(3)-glycine analogue 8k exhibited similar anti-Pf activity to 2 but with slightly enhanced selectivity (SI 72 and 93, respectively), while Δ2(3)-phenethylamide 8e (IC50 0.67 μM, SI 78) exhibited improved potency and selectivity towards T. brucei rhodesiense compared to the natural product hit. A second series of analogues were prepared that replaced the quinoline ring of 2 with benzofuran or benzothiophene moieties. While esters 10a/10b and 15 were once again found to exhibit cytotoxicity, carboxylic acid analogues exhibited potent anti-Pf activity (IC50 0.34–0.035 μM) combined with excellent selectivity (SI 560–4000). In vivo evaluation of a furan carboxylic acid analogue against P. berghei was undertaken, demonstrating 85.7% and 47% reductions in parasitaemia with ip or oral dosing respectively.  相似文献   

3.
The marine sponge, Axinyssa djiferi, collected on mangrove tree roots in Senegal, was investigated for glycolipids. A mixture containing new glycosphingolipids, named axidjiferoside-A, -B and -C, accounted for 0.07% of sponge biomass (dry weight) and for 2.16% of total lipids. It showed a significant antimalarial activity, with a 50% inhibitory concentration (IC50) of 0.53 ± 0.2 μM against a chloroquine-resistant strain of Plasmodium falciparum. They were identified as homologous β-galactopyranosylceramides composed of 2-amino-(6E)-octadec-6-en-1,3,4-triol, and the major one, axidjiferoside-A (around 60%), contained 2-hydroxytetracosanoic acid. Cytotoxicity was studied in vitro on human cancer cell lines (multiple myeloma, colorectal adenocarcinoma, glioblastoma and two lung cancer NSCLC-N6 and A549). Results of this investigation showed that axidjiferosides are of interest, because they proved a good antiplasmodial activity, with only a low cytotoxicity against various human cell lines and no significant antitrypanosomal and antileishmanial activity. Thus, it seems that galactosylceramides with a β anomeric configuration may be suitable in searching for new antimalarial drugs.  相似文献   

4.
The fungus Aspergillus tubingensis (strain OY907) was isolated from the Mediterranean marine sponge Ircinia variabilis. Extracellular extracts produced by this strain were found to inhibit the growth of several fungi. Among the secreted extract components, a novel anhydride metabolite, tubingenoic anhydride A (1) as well as the known 2-carboxymethyl-3-hexylmaleic acid anhydride, asperic acid, and campyrone A and C were purified and their structure elucidated. Compound 1 and 2-carboxymethyl-3-hexylmaleic acid anhydride inhibited Neurospora crassa growth (MIC = 330 and 207 μM, respectively) and affected hyphal morphology. We produced a N. crassa mutant exhibiting tolerance to 1 and found that a yet-uncharacterized gene, designated mas-1, whose product is a cytosolic protein, confers sensitivity to this compound. The ∆mas-1 strain showed increased tolerance to sublethal concentrations of the chitin synthase inhibitor polyoxin D, when compared to the wild type. In addition, the expression of chitin synthase genes was highly elevated in the ∆mas-1 strain, suggesting the gene product is involved in cell wall biosynthesis and the novel anhydride interferes with its function.  相似文献   

5.
Experiments were performed, feeding Calanus pacificus seston and a food consisting of seston and microcapsules (μ-caps), i.e., protein and lipid μ-caps to test for potential biochemical limitation. Seston was collected off Scripps Pier (La Jolla, CA, USA). Whereas protein μ-caps were too small to be efficiently ingested, lipid μ-caps rich in ω3-highly-unsaturated fatty acids (ω3-HUFA) were ingested similarly to natural seston and lipids were assimilated. However, egg production experiments exhibited that animals fed with lipid μ-caps didn’t produce significantly more eggs than with seston of equal carbon concentration and egg production even declined when the diet consisted of 50% lipid μ-caps. Thus, the content of certain ω3-HUFA seemed to have been sufficiently high in seston to prevent limitation. Algal counts revealed that seston consisted mainly of plankton rich in those fatty acids, such as cryptophytes, dinoflagellates, diatoms, and ciliates in the edible size range. This might be characteristic for upwelling systems like the area off Southern California which are known for high trophic transfer efficiency.  相似文献   

6.
Pure compound screening has previously identified the indolglyoxylamidospermidine ascidian metabolites didemnidine A and B (2 and 3) to be weak growth inhibitors of Trypanosoma brucei rhodesiense (IC50 59 and 44 μM, respectively) and Plasmodium falciparum (K1 dual drug resistant strain) (IC50 41 and 15 μM, respectively), but lacking in selectivity (L6 rat myoblast, IC50 24 μM and 25 μM, respectively). To expand the structure–activity relationship of this compound class towards both parasites, we have prepared and biologically tested a library of analogues that includes indoleglyoxyl and indoleacetic “capping acids”, and polyamines including spermine (PA3-4-3) and extended analogues PA3-8-3 and PA3-12-3. 7-Methoxy substituted indoleglyoxylamides were typically found to exhibit the most potent antimalarial activity (IC50 10–92 nM) but with varying degrees of selectivity versus the L6 rat myoblast cell line. A 6-methoxyindolglyoxylamide analogue was the most potent growth inhibitor of T. brucei (IC50 0.18 μM) identified in the study: it, however, also exhibited poor selectivity (L6 IC50 6.0 μM). There was no apparent correlation between antimalarial and anti-T. brucei activity in the series. In vivo evaluation of one analogue against Plasmodium berghei was undertaken, demonstrating a modest 20.9% reduction in parasitaemia.  相似文献   

7.
Two new indole-diterpenoids (1 and 2) and a new isocoumarin (3), along with the known β-aflatrem (4), paspalinine (5), leporin B (6), α-cyclopiazonic acid (7), iso-α-cyclopiazonic acid (8), ditryptophenaline (9), aflatoxin B1 (10), 7-O-acetylkojic acid (11) and kojic acid (12), were isolated from the fermentation broth of the marine-derived fungus, Aspergillus flavus OUCMDZ-2205. The structures of Compounds 1–12 were elucidated by spectroscopic analyses, quantum ECD calculations and the chemical method. New Compound 1 exhibited antibacterial activity against Staphylococcus aureus with a MIC value of 20.5 μM. Both new Compounds 1 and 2 could arrest the A549 cell cycle in the S phase at a concentration of 10 μM. Compound 1 showed PKC-beta inhibition with an IC50 value of 15.6 μM. In addition, the absolute configurations of the known compounds, 4–6 and leporin A (6a), were also determined for the first time.  相似文献   

8.
Two unusual pyridones, trichodin A (1) and trichodin B (2), together with the known compound, pyridoxatin (3), were extracted from mycelia and culture broth of the marine fungus, Trichoderma sp. strain MF106 isolated from the Greenland Seas. The structures of the new compounds were characterized as an intramolecular cyclization of a pyridine basic backbone with a phenyl group. The structure and relative configuration of the new compounds were established by spectroscopic means. The new compound 1 and the known compound 3 showed antibiotic activities against the clinically relevant microorganism, Staphylococcus epidermidis, with IC50 values of 24 μM and 4 μM, respectively.  相似文献   

9.
This study evaluated the anti-Leishmania amazonensis activity of a lipophilic extract from the brown alga Stypopodium zonale and atomaric acid, its major compound. Our initial results revealed high inhibitory activity for intracellular amastigotes in a dose-dependent manner and an IC50 of 0.27 μg/mL. Due to its high anti-Leishmania activity and low toxicity toward host cells, we fractionated the lipophilic extract. A major meroditerpene in this extract, atomaric acid, and its methyl ester derivative, which was obtained by a methylation procedure, were identified by nuclear magnetic resonance (NMR) spectroscopy. Both compounds inhibited intracellular amastigotes, with IC50 values of 20.2 μM (9 μg/mL) and 22.9 μM (10 μg/mL), and selectivity indexes of 8.4 μM and 11.5 μM. The leishmanicidal activity of both meroditerpenes was independent of nitric oxide (NO) production, but the generation of reactive oxygen species (ROS) may be at least partially responsible for the amastigote killing. Our results suggest that the lipophilic extract of S. zonale may represent an important source of compounds for the development of anti-Leishmania drugs.  相似文献   

10.
The endophytic fungus Fusarium equiseti was isolated from the brown alga Padina pavonica, collected from the Red Sea. The fungus was identified by its morphology and 18S rDNA. Cultivation of this fungal strain in biomalt-peptone medium led to isolation of 12 known metabolites of diketopeprazines and anthraquinones. The organic extract and isolated compounds were screened for their inhibition of hepatitis C virus NS3/4A protease (HCV PR). As a result, the fungal metabolites showed inhibition of HCV protease (IC50 from 19 to 77 μM), and the fungus was subjected to culture on Czapek’s (Cz) media, with a yield of nine metabolites with potent HCV protease inhibition ranging from IC50 10 to 37 μM. The Cz culture extract exhibited high-level inhibition of HCV protease (IC50 27.6 μg/mL) compared to the biomalt culture extract (IC50 56 μg/mL), and the most potent HCV PR isolated compound (Griseoxanthone C, IC50 19.8 μM) from the bio-malt culture extract showed less of an inhibitory effect compared to isolated ω-hydroxyemodin (IC50 10.7 μM) from the optimized Cz culture extract. Both HCV PR active inhibitors ω-hydroxyemodin and griseoxanthone C were considered as the lowest selective safe constituents against Trypsin inhibitory effect with IC50 48.5 and 51.3 μM, respectively.  相似文献   

11.
We have created via metabolic engineering a heterotrophic strain of Phaeodactylum tricornutum that accumulates enhanced levels of the high value omega-3 long chain polyunsaturated fatty acid (LC-PUFAs) docosahexaenoic acid (DHA). This was achieved by generation of transgenic strains in which the Δ5-elongase from Ostreococcus tauri was co-expressed with a glucose transporter from the moss Physcomitrella patens. This double transformant has the capacity to grow in the dark in liquid medium supplemented with glucose and accumulate substantial levels of omega-3 LC-PUFAs. The effects of glucose concentrations on growth and LC-PUFA production of wild type and transformed strains cultivated in the light and dark were studied. The highest omega-3 LC-PUFAs accumulation was observed in cultures grown under mixotrophic conditions in the presence of 1% glucose (up to 32.2% of total fatty acids, TFA). Both DHA and EPA are detected at high levels in the neutral lipids of transgenic cells grown under phototrophic conditions, averaging 36.5% and 23.6% of TFA, respectively. This study demonstrates the potential for P. tricornutum to be developed as a viable commercial strain for both EPA and DHA production under mixo- and heterotrophic conditions.  相似文献   

12.
The wblAso gene functions as a global regulatory gene in a negative manner in deepsea-derived Streptomyces somaliensis SCSIO ZH66. A new dioic acid (1) as well as two known butenolides (2 and 3) were isolated from the ΔwblAso mutant strain of S. somaliensis SCSIO ZH66. The structure of 1 was elucidated by a combination of spectroscopic analyses, including MS and NMR techniques. In the cell growth inhibitory evaluation, compound 3 exhibited moderate activity against the human hepatic carcinoma cell line (Huh7.5) with an IC50 value of 19.4 μg/mL, while compounds 1 and 2 showed null activity up to 100 μg/mL.  相似文献   

13.
Algae contain a number of anti-inflammatory bioactive compounds such as omega-3 polyunsaturated fatty acids (n-3 PUFA) and chlorophyll a, hence as dietary ingredients, their extracts may be effective in chronic inflammation-linked metabolic diseases such as cardiovascular disease. In this study, anti-inflammatory potential of lipid extracts from three red seaweeds (Porphyra dioica, Palmaria palmata and Chondrus crispus) and one microalga (Pavlova lutheri) were assessed in lipopolysaccharide (LPS)-stimulated human THP-1 macrophages. Extracts contained 34%–42% total fatty acids as n-3 PUFA and 5%–7% crude extract as pigments, including chlorophyll a, β-carotene and fucoxanthin. Pretreatment of the THP-1 cells with lipid extract from P. palmata inhibited production of the pro-inflammatory cytokines interleukin (IL)-6 (p < 0.05) and IL-8 (p < 0.05) while that of P. lutheri inhibited IL-6 (p < 0.01) production. Quantitative gene expression analysis of a panel of 92 genes linked to inflammatory signaling pathway revealed down-regulation of the expression of 14 pro-inflammatory genes (TLR1, TLR2, TLR4, TLR8, TRAF5, TRAF6, TNFSF18, IL6R, IL23, CCR1, CCR4, CCL17, STAT3, MAP3K1) by the lipid extracts. The lipid extracts effectively inhibited the LPS-induced pro-inflammatory signaling pathways mediated via toll-like receptors, chemokines and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling molecules. These results suggest that lipid extracts from P. lutheri, P. palmata, P. dioica and C. crispus can inhibit LPS-induced inflammatory pathways in human macrophages. Therefore, algal lipid extracts should be further explored as anti-inflammatory ingredients for chronic inflammation-linked metabolic diseases.  相似文献   

14.
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15.
Three new polyhydroxylated sterol derivatives topsensterols A–C (1–3) have been isolated from a marine sponge Topsentia sp. collected from the South China Sea. Their structures were elucidated by detailed analysis of the spectroscopic data, especially the NOESY spectra. Topsensterols A–C (l–3) possess novel 2β,3α,4β,6α-tetrahydroxy-14α-methyl Δ9(11) steroidal nuclei with unusual side chains. Compound 2 exhibited cytotoxicity against human gastric carcinoma cell line SGC-7901 with an IC50 value of 8.0 μM. Compound 3 displayed cytotoxicity against human erythroleukemia cell line K562 with an IC50 value of 6.0 μM.  相似文献   

16.
Further chemical investigation of the fruits of the mangrove, Avicennia marina, afforded three new phenylethyl glycosides, marinoids J–L (1–3), and a new cinnamoyl glycoside, marinoid M (4). The structures of isolates were elucidated on the basis of extensive spectroscopic analysis and by comparison of the data with those of related secondary metabolites. The antioxidant activity of the isolates was evaluated using the cellular antioxidant assay (CAA), and compounds 1–4 showed antioxidant activities, with EC50 values ranging from 23.0 ± 0.71 μM to 247.8 ± 2.47 μM.  相似文献   

17.
Five new diketopiperazine derivatives, (3Z,6E)-1-N-methyl-3-benzylidene-6-(2S-methyl-3-hydroxypropylidene)piperazine-2,5-dione (1), (3Z,6E)-1-N-methyl-3-benzylidene-6-(2R-methyl-3-hydroxypropylidene)piperazine-2,5-dione (2), (3Z,6Z)-3-(4-hydroxybenzylidene)-6-isobutylidenepiperazine-2,5-dione (3), (3Z,6Z)-3-((1H-imidazol-5-yl)-methylene)-6-isobutylidenepiperazine-2,5-dione (4), and (3Z,6S)-3-benzylidene-6-(2S-but-2-yl)piperazine-2,5-dione (5), were isolated from the marine-derived actinomycete Streptomyces sp. FXJ7.328. The structures of 1–5 were determined by spectroscopic analysis, CD exciton chirality, the modified Mosher’s, Marfey’s and the C3 Marfey’s methods. Compound 3 showed modest antivirus activity against influenza A (H1N1) virus with an IC50 value of 41.5 ± 4.5 μM. In addition, compound 6 and 7 displayed potent anti-H1N1 activity with IC50 value of 28.9 ± 2.2 and 6.8 ± 1.5 μM, respectively. Due to the lack of corresponding data in the literature, the 13C NMR data of (3Z,6S)-3-benzylidene-6-isobutylpiperazine-2,5-dione (6) were also reported here for the first time.  相似文献   

18.
Long chain omega-3 polyunsaturated fatty acids (LC n-3 PUFAs) are recommended for management of patients with wide-ranging chronic diseases, including coronary heart disease, rheumatoid arthritis, dementia, and depression. Increased consumption of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) is recommended by many health authorities to prevent (up to 0.5 g/day) or treat chronic disease (1.0 g/day for coronary heart disease; 1.2–4 g/day for elevated triglyceride levels). Recommendations for dietary intake of LC n-3 PUFAs are often provided for α-linolenic acid, and for the combination of EPA and DHA. However, many studies have also reported differential effects of EPA, DHA and their metabolites in the clinic and at the laboratory bench. The aim of this article is to review studies that have identified divergent responses to EPA and DHA, and to explore reasons for these differences. In particular, we review potential contributing factors such as differential membrane incorporation, modulation of gene expression, activation of signaling pathways and metabolite formation. We suggest that there may be future opportunity to refine recommendations for intake of individual LC n-3 PUFAs.  相似文献   

19.
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20.
The culture supernatant of Paenibacillus sp. TKU036, a bacterium isolated from Taiwanese soils, showed high antioxidant activity (85%) when cultured in a squid pen powder (SPP)-containing medium at 37 °C for three days. Homogentisic acid (2,5-dihydroxyphenylacetic acid, HGA) was isolated and found to be the major antioxidant in the culture supernatant of the SPP-containing medium fermented by Paenibacillus sp. TKU036. Tryptophan was also present in the culture supernatant. The results of high-performance liquid chromatography (HPLC) fingerprinting showed that HGA and tryptophan were produced via fermentation but did not pre-exist in the unfermented SPP-containing medium. Neither HGA nor tryptophan was found in the culture supernatants obtained from the fermentation of nutrient broth or other chitinous material, i.e., medium containing shrimp head powder, by Paenibacillus sp. TKU036. The production of HGA via microorganisms has rarely been reported. In this study, we found that squid pen was a potential carbon and nitrogen source for Paenibacillus sp. Tryptophan (105 mg/L) and HGA (60 mg/L) were recovered from the culture supernatant. The isolated HGA was found to have higher antioxidant activity (IC50 = 6.9 μg/mL) than α-tocopherol (IC50 = 17.6 μg/mL). The anti-inflammatory activity of the isolated HGA (IC50 = 10.14 μg/mL) was lower than that of quercetin (IC50 = 1.14 μg/mL). As a result, squid pen, a fishery processing byproduct, is a valuable material for the production of tryptophan and the antioxidant and anti-inflammatory HGA via microbial conversion.  相似文献   

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