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1.
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2.
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   

3.
Concerning the requirements of effective drug candidates to combat against high rising multidrug resistant pathogens, we isolated three new linear lipopeptides, gageostatins A–C (1–3), consisting of hepta-peptides and new 3-β-hydroxy fatty acids from the fermentation broth of a marine-derived bacterium Bacillus subtilis. Their structures were elucidated by analyzing a combination of extensive 1D, 2D NMR spectroscopic data and high resolution ESIMS data. Fatty acids, namely 3-β-hydroxy-11-methyltridecanoic and 3-β-hydroxy-9,11-dimethyltridecanoic acids were characterized in lipopeptides 1 and 2, respectively, whereas an unsaturated fatty acid (E)-7,9-dimethylundec-2-enoic acid was assigned in 3. The 3R configuration of the stereocenter of 3-β-hydroxy fatty acids in 1 and 2 was established by Mosher’s MTPA method. The absolute stereochemistry of amino acid residues in 1–3 was ascertained by acid hydrolysis followed by Marfey’s derivatization studies. Gageostatins 1–3 exhibited good antifungal activities with MICs values of 4–32 µg/mL when tested against pathogenic fungi (R. solani, B. cinerea and C. acutatum) and moderate antibacterial activity against bacteria (B. subtilis, S. aeureus, S. typhi and P. aeruginosa) with MICs values of 8–64 µg/mL. Futhermore, gageostatins 1–3 displayed cytotoxicity against six human cancer cell lines with GI50 values of 4.6–19.6 µg/mL. It is also noteworthy that mixed compounds 1+2 displayed better antifungal and cytotoxic activities than individuals.  相似文献   

4.
A new chrysolaminarin, named CL2, with a molecular mass of 7.75 kDa, was purified from the marine diatom, Odontella aurita, using DEAE-52 cellulose anion-exchange chromatography and Sephadex G-200 gel-filtration chromatography. The monosaccharide and structural analysis revealed that CL2 was a glucan mainly composed of glucose, which was linked by the β-d-(1→3) (main chain) and β-d-(1→6) (side chain) glycosidic bond, demonstrated by infrared spectroscopy (IR) and nuclear magnetic resonance (NMR). The antioxidant activity tests revealed that the CL2 presented stronger hydroxyl radical scavenging activity with increasing concentrations, but less was effective on reducing power analysis and scavenging 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical. The influences of nitrogen concentration and light intensity on chrysolaminarin production of O. aurita were further investigated in a glass column photobioreactor, and a record high chrysolaminarin productivity of 306 mg L−1 day−1 was achieved. In conclusion, the chrysolaminarin CL2 from O. aurita may be explored as a natural antioxidant agent for application in aquaculture, food and pharmaceutical areas.  相似文献   

5.
We recently found that dietary supplementation with the seaweed Sargassum fusiforme, containing the preferential LXRβ-agonist 24(S)-saringosterol, prevented memory decline and reduced amyloid-β (Aβ) deposition in an Alzheimer’s disease (AD) mouse model without inducing hepatic steatosis. Here, we examined the effects of 24(S)-saringosterol as a food additive on cognition and neuropathology in AD mice. Six-month-old male APPswePS1ΔE9 mice and wildtype C57BL/6J littermates received 24(S)-saringosterol (0.5 mg/25 g body weight/day) (APPswePS1ΔE9 n = 20; C57BL/6J n = 19) or vehicle (APPswePS1ΔE9 n = 17; C57BL/6J n = 19) for 10 weeks. Cognition was assessed using object recognition and object location tasks. Sterols were analyzed by gas chromatography/mass spectrometry, Aβ and inflammatory markers by immunohistochemistry, and gene expression by quantitative real-time PCR. Hepatic lipids were quantified after Oil-Red-O staining. Administration of 24(S)-saringosterol prevented cognitive decline in APPswePS1ΔE9 mice without affecting the Aβ plaque load. Moreover, 24(S)-saringosterol prevented the increase in the inflammatory marker Iba1 in the cortex of APPswePS1ΔE9 mice (p < 0.001). Furthermore, 24(S)-saringosterol did not affect the expression of lipid metabolism-related LXR-response genes in the hippocampus nor the hepatic neutral lipid content. Thus, administration of 24(S)-saringosterol prevented cognitive decline in APPswePS1ΔE9 mice independent of effects on Aβ load and without adverse effects on liver fat content. The anti-inflammatory effects of 24(S)-saringosterol may contribute to the prevention of cognitive decline.  相似文献   

6.
A new antitumor and antioxidant peptide (H3) was isolated from Arca subcrenata Lischke using ion exchange and hydrophobic column chromatography. The purity of H3 was over 99.3% in reversed phase-high performance liquid chromatography (RP-HPLC) and the molecular weight was determined to be 20,491.0 Da by electrospray-ionization mass spectrometry (ESI-MS/MS). The isoelectric point of H3 was measured to be 6.65 by isoelectric focusing-polyacrylamide gel electrophoresis. Partial amino acid sequence of this peptide was determined as ISMEDVEESRKNGMHSIDVNHDGKHRAYWADNTYLM-KCMDLPYDVLDTGGKDRSSDKNTDLVDLFELDMVPDRKNNECMNMIMDVIDTN-TAARPYYCSLDVNHDGAGLSMEDVEEDK via MALDI-TOF/TOF-MS and de novo sequencing. The in vitro antitumor activity of H3 was evaluated by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. The result indicated that H3 exhibited significant antiproliferative activity against HeLa, HepG2 and HT-29 cell lines with IC50 values of 10.8, 10.1 and 10.5 μg/mL. The scavenging percentage of H3 at 8 mg/mL to 2,2-diphenyl-1-picrylhydrazyl (DPPH) and hydroxyl radicals were 56.8% and 47.5%, respectively.  相似文献   

7.
l-Methionine γ-lyase (MGL), a pyridoxal 5′-phosphate-dependent enzyme, possesses anti-tumor activity. However, the low activity of MGL blocks the anti-tumor effect. This study describes an efficient production process for the recombinant MGL (rMGL) from Idiomarina constructed using the overexpression plasmid in Escherichia coli BL21 (DE3), purification, and large-scale production. The enzyme produced by the transformants accounted for 53% of the total proteins and accumulated at 1.95 mg/mL using a 500 L fermentor. The enzyme was purified to approximately 99% purity using a high-pressure mechanical homogenizer and nickel (Ni) Sepharose 6 Fast Flow (FF) chromatography. Then, the enzyme was polished by gel filtration, the endotoxins were removed using diethyl-aminoethanol (DEAE) Sepharose FF, and the final product was lyophilized with a vacuum freeze dryer at −35 °C. The specific activity of rMGL in the lyophilized powder was up to 108 U/mg. Compared to the control, the enzyme significantly inhibited cellular proliferation in a concentration-dependent manner as tested using the MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) assay and induced cellular apoptosis as analyzed by Annexin V-fluorescein isothiocyanate (FITC) with fluorescence-activated cell sorting (FACS) in leukemia cells. This paper demonstrated the cloning, overexpression, and large-scale production protocols for rMGL, which enabled rMGL to be used as a novel anti-leukemic drug.  相似文献   

8.
The toxin-producing cyanobacterium, Moorea producens, is a known causative organism of food poisoning and seaweed dermatitis (also known as “swimmer’s itch”). Two new toxic compounds were isolated and structurally elucidated from an ethyl acetate extract of M. producens collected from Hawaii. Analyses of HR-ESI-MS and NMR spectroscopies, as well as optical rotations and CD spectra indicated two new lyngbyatoxin derivatives, 2-oxo-3(R)-hydroxy-lyngbyatoxin A (1) and 2-oxo-3(R)-hydroxy-13-N-desmethyl-lyngbyatoxin A (2). The cytotoxicity and lethal activities of 1 and 2 were approximately 10- to 150-times less potent than lyngbyatoxin A. Additionally, the binding activities of 1 and 2 possessed 10,000-times lower affinity for the protein kinase Cδ (PKCδ)-C1B peptide when compared to lyngbyatoxin A. These findings suggest that these new lyngbyatoxin derivatives may mediate their acute toxicities through a non-PKC activation pathway.  相似文献   

9.
In the present study, we synthesized and, structurally and functionally characterized a novel α4/7-conotoxin Mr1.7 (PECCTHPACHVSHPELC-NH2), which was previously identified by cDNA libraries from Conus marmoreus in our lab. The NMR solution structure showed that Mr1.7 contained a 310-helix from residues Pro7 to His10 and a type I β-turn from residues Pro14 to Cys17. Electrophysiological results showed that Mr1.7 selectively inhibited the α3β2, α9α10 and α6/α3β2β3 neuronal nicotinic acetylcholine receptors (nAChRs) with an IC50 of 53.1 nM, 185.7 nM and 284.2 nM, respectively, but showed no inhibitory activity on other nAChR subtypes. Further structure-activity studies of Mr1.7 demonstrated that the PE residues at the N-terminal sequence of Mr1.7 were important for modulating its selectivity, and the replacement of Glu2 by Ala resulted in a significant increase in potency and selectivity to the α3β2 nAChR. Furthermore, the substitution of Ser12 with Asn in the loop2 significantly increased the binding of Mr1.7 to α3β2, α3β4, α2β4 and α7 nAChR subtypes. Taken together, this work expanded our knowledge of selectivity and provided a new way to improve the potency and selectivity of inhibitors for nAChR subtypes.  相似文献   

10.
Three different fucoidan fractions were isolated and purified from the brown alga, Sargassum mcclurei. The SmF1 and SmF2 fucoidans are sulfated heteropolysaccharides that contain fucose, galactose, mannose, xylose and glucose. The SmF3 fucoidan is highly sulfated (35%) galactofucan, and the main chain of the polysaccharide contains a →3)-α-l-Fucp(2,4SO3−)-(1→3)-α-l-Fucp(2,4SO3−)-(1→ motif with 1,4-linked 3-sulfated α-l-Fucp inserts and 6-linked galactose on reducing end. Possible branching points include the 1,2,6- or 1,3,6-linked galactose and/or 1,3,4-linked fucose residues that could be glycosylated with terminal β-d-Galp residues or chains of alternating sulfated 1,3-linked α-l-Fucp and 1,4-linked β-d-Galp residues, which have been identified in galactofucans for the first time. Both α-l-Fucp and β-d-Galp residues are sulfated at C-2 and/or C-4 (and some C-6 of β-d-Galp) and potentially the C-3 of terminal β-d-Galp, 1,4-linked β-d-Galp and 1,4-linked α-l-Fucp residues. All fucoidans fractions were less cytotoxic and displayed colony formation inhibition in colon cancer DLD-1 cells. Therefore, these fucoidan fractions are potential antitumor agents.  相似文献   

11.
Influence of amino acid compositions and peptide profiles on antioxidant capacities of two protein hydrolysates from skipjack tuna (Katsuwonus pelamis) dark muscle was investigated. Dark muscles from skipjack tuna were hydrolyzed using five separate proteases, including pepsin, trypsin, Neutrase, papain and Alcalase. Two hydrolysates, ATH and NTH, prepared using Alcalase and Neutrase, respectively, showed the strongest antioxidant capacities and were further fractionated using ultrafiltration and gel filtration chromatography. Two fractions, Fr.A3 and Fr.B2, isolated from ATH and NTH, respectively, showed strong radical scavenging activities toward 2,2-diphenyl-1-picrylhydrazyl radicals (EC50 1.08% ± 0.08% and 0.98% ± 0.07%), hydroxyl radicals (EC50 0.22% ± 0.03% and 0.48% ± 0.05%), and superoxide anion radicals (EC50 1.31% ± 0.11% and 1.56% ± 1.03%) and effectively inhibited lipid peroxidation. Eighteen peptides from Fr.A3 and 13 peptides from Fr.B2 were isolated by reversed-phase high performance liquid chromatography, and their amino acid sequences were determined. The elevated antioxidant activity of Fr.A3 might be due to its high content of hydrophobic and aromatic amino acid residues (181.1 and 469.9 residues/1000 residues, respectively), small molecular sizes (3–6 peptides), low molecular weights (524.78 kDa), and amino acid sequences (antioxidant score 6.11). This study confirmed that a smaller molecular size, the presence of hydrophobic and aromatic amino acid residues, and the amino acid sequences were the key factors that determined the antioxidant activities of the proteins, hydrolysates and peptides. The results also demonstrated that the derived hydrolysates and fractions from skipjack tuna (K. pelamis) dark muscles could prevent oxidative reactions and might be useful for food preservation and medicinal purposes.  相似文献   

12.
Two purified proteins G-6 and G-4-2 were obtained from Arca subcrenata Lischke using the homogenization, salting-out with ammonium sulfate, ion-exchange chromatography and gel filtration chromatography techniques. The purity of G-6 and G-4-2 was over 96%, as measured by RP-HPLC. G-6 and G-4-2 were measured by SDS-PAGE and IEF-PAGE to have molecular weights of 8.2 kDa and 16.0 kDa, and isoelectric points of 6.6 and 6.1, respectively. The amino acid constituents of G-6 and G-4-2 were also determined. The existence of saccharides in G-6 was demonstrated by the phenol-sulfuric acid method. G-6 and G-4-2 inhibited the proliferation of human tumor cells in vitro. By MTT assay, the IC50 values of G-4-2 were 22.9 μg/mL, 46.1 μg/mL and 57.7 μg/mL against Hela, HL-60 and KB cell lines, respectively, and the IC50 value of G-6 against HL-60 cell line was measured to be 123.2 μg/mL.  相似文献   

13.
We examined the inhibitory activity of angiotensin I converting enzyme (ACE) in protein hydrolysates from dulse, Palmaria palmata. The proteins extracted from dulse were mainly composed of phycoerythrin (PE) followed by phycocyanin (PC) and allophycocyanin (APC). The dulse proteins showed slight ACE inhibitory activity, whereas the inhibitory activity was extremely enhanced by thermolysin hydrolysis. The ACE inhibitory activity of hydrolysates was hardly affected by additional pepsin, trypsin and chymotrypsin treatments. Nine ACE inhibitory peptides (YRD, AGGEY, VYRT, VDHY, IKGHY, LKNPG, LDY, LRY, FEQDWAS) were isolated from the hydrolysates by reversed-phase high-performance liquid chromatography (HPLC), and it was demonstrated that the synthetic peptide LRY (IC50: 0.044 μmol) has remarkably high ACE inhibitory activity. Then, we investigated the structural properties of dulse phycobiliproteins to discuss the origin of dulse ACE inhibitory peptides. Each dulse phycobiliprotein possesses α-subunit (Mw: 17,477–17,638) and β-subunit (Mw: 17,455–18,407). The sequences of YRD, AGGEY, VYRT, VDHY, LKNPG and LDY were detected in the primary structure of PE α-subunit, and the LDY also exists in the APC α- and β-subunits. In addition, the LRY sequence was found in the β-subunits of PE, PC and APC. From these results, it was suggested that the dulse ACE inhibitory peptides were derived from phycobiliproteins, especially PE. To make sure the deduction, we carried out additional experiment by using recombinant PE. We expressed the recombinant α- and β-subunits of PE (rPEα and rPEβ, respectively), and then prepared their peptides by thermolysin hydrolysis. As a result, these peptides showed high ACE inhibitory activities (rPEα: 94.4%; rPEβ: 87.0%). Therefore, we concluded that the original proteins of dulse ACE inhibitory peptides were phycobiliproteins.  相似文献   

14.
Bin Wu  Xiaodan Wu  Min Sun  Minhui Li 《Marine drugs》2013,11(8):2713-2721
Two new sesquiterpenes, 1β,5α,6α,14-tetraacetoxy-9α-benzoyloxy-7βH-eudesman-2β,11-diol (1) and 4α,5α-diacetoxy-9α-benzoyloxy-7βH-eudesman-1β,2β,11,14-tetraol (2), were produced as stress metabolites in the cultured mycelia of Pestalotiopsis sp. Z233 isolated from the algae Sargassum horneri in response to abiotic stress elicitation by CuCl2. Their structures were established by spectroscopic means. New compounds 1 and 2 showed tyrosinase inhibitory activities with IC50 value of 14.8 µM and 22.3 µM.  相似文献   

15.
Bioassay-guided fractionation using different chromatographic and spectroscopic techniques in the analysis of the Red Sea soft coral Litophyton arboreum led to the isolation of nine compounds; sarcophytol M (1), alismol (2), 24-methylcholesta-5,24(28)-diene-3β-ol (3), 10-O-methyl alismoxide (4), alismoxide (5), (S)-chimyl alcohol (6), 7β-acetoxy-24-methylcholesta-5-24(28)-diene-3,19-diol (7), erythro-N-dodecanoyl-docosasphinga-(4E,8E)-dienine (8), and 24-methylcholesta-5,24(28)-diene-3β,7β,19-triol (9). Some of the isolated compounds demonstrated potent cytotoxic- and/or cytostatic activity against HeLa and U937 cancer cell lines and inhibitory activity against HIV-1 protease (PR). Compound 7 was strongly cytotoxic against HeLa cells (CC50 4.3 ± 0.75 µM), with selectivity index of SI 8.1, which was confirmed by real time cell electronic sensing (RT-CES). Compounds 2, 7, and 8 showed strong inhibitory activity against HIV-1 PR at IC50s of 7.20 ± 0.7, 4.85 ± 0.18, and 4.80 ± 0.92 µM respectively. In silico docking of most compounds presented comparable scores to that of acetyl pepstatin, a known HIV-1 PR inhibitor. Interestingly, compound 8 showed potent HIV-1 PR inhibitory activity in the absence of cytotoxicity against the cell lines used. In addition, compounds 2 and 5 demonstrated cytostatic action in HeLa cells, revealing potential use in virostatic cocktails. Taken together, data presented here suggest Litophyton arboreum to contain promising compounds for further investigation against the diseases mentioned.  相似文献   

16.
An apigalacturonan (AGA)-rich polysaccharide, ZCMP, was isolated from the sea grass Zostera caespitosa Miki. The depolymerized fragments derived from ZCMP were obtained by either acidic degradation or pectinase degradation, and their structures were characterized by electrospray ionization collision-induced-dissociation mass spectrometry (ESI-CID-MS2) and nuclear magnetic resonance (NMR) spectroscopy. The average molecular weight of ZCMP was 77.2 kD and it consisted of galacturonic acid (GalA), apiosefuranose (Api), galactose (Gal), rhamnose (Rha), arabinose (Ara), xylose (Xyl), and mannose (Man), at a molar ratio of 51.4꞉15.5꞉6.0꞉11.8꞉4.2꞉4.4꞉4.2. There were two regions of AGA (70%) and rhamnogalacturonan-I (RG-Ι, 30%) in ZCMP. AGA was composed of an α-1,4-d-galactopyranosyluronan backbone mainly substituted at the O-3 position by single Api residues. RG-Ι possessed a backbone of repeating disaccharide units of →4GalAα1,2Rhaα1→, with a few α-l-arabinose and β-d-galactose residues as side chains. The anti-angiogenesis assay showed that ZCMP inhibited the migratory activity of human umbilical vein endothelial cell (HUVECs), with no influence on endothelial cells growth. ZCMP also promoted macrophage phagocytosis. These findings of the present study demonstrated the potential anti-tumor activity of ZCMP through anti-angiogenic and immunoregulatory pathways.  相似文献   

17.
Two new 9,11-secosteroids, 22α-acetoxy-24-methylene-3β,6α,11-trihydroxy-9,11-seco-cholest-7-en-9-one (1) and 11-acetoxy-24-methylene-1β,3β,6α-trihydroxy-9,11-seco-cholest-7-en-9-one (2), as well as two known norcembranoids, 5-epi-sinuleptolide (3) and sinuleptolide (4), were isolated from the soft coral Sinularia nanolobata. The structures of these metabolites were elucidated on the basis of extensive spectroscopic analysis. The anti-HCMV (human cytomegalovirus) activity of 1–4 and its cytotoxicity against selected cell lines were evaluated.  相似文献   

18.
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   

19.
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   

20.
The marine ecosystem has been a key resource for secondary metabolites with promising biological roles. In the current study, bioassay-guided phytochemical investigations were carried out to assess the presence of enzyme inhibitory chemical constituents from the methanolic extract of marine green alga—Codium dwarkense. The bioactive fractions were further subjected to chromatographic separations, which resulted in the isolation of a new triterpenic acid; dwarkenoic acid (1) and the known sterols; androst-5-en-3β-ol (2), stigmasta-5,25-dien-3β,7α-diol (3), ergosta-5,25-dien-3β-ol (4), 7-hydroxystigmasta-4,25-dien-3-one-7-O-β-d-fucopyranoside (5), 7-hydroxystigmasta-4,25-dien-3-one (6), and stigmasta-5,25-dien-3β-ol (7). The structure elucidation of the new compound was carried out by combined mass spectrometry and 1D (1H and 13C) and 2D (HSQC, HMBC, COSY, and NOESY) NMR spectroscopic data. The sub-fractions and pure constituents were assayed for enzymatic inhibition of alpha-glucosidase. Compound 1 showed significant inhibition at all concentrations. Compounds 2, 3, 5, and 7 exhibited a dose-dependent response, whereas compounds 4–6 showed moderate inhibition. Utilizing such marine-derived biological resources could lead to drug discoveries related to anti-diabetics.  相似文献   

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