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991.
Yamazaki H Wewengkang DS Nishikawa T Rotinsulu H Mangindaan RE Namikoshi M 《Marine drugs》2012,10(2):349-357
Two new tryptamine-derived alkaloids, named as leptoclinidamide (1) and (-)-leptoclinidamine B (2), were isolated from an Indonesian ascidian Leptoclinides dubius together with C2-α-D-mannosylpyranosyl-L-tryptophan (3). The structure of 1 was assigned on the basis of spectroscopic data for 1 and its N-acetyl derivative (4). Compound 1 was an amide of tryptamine with two β-alanine units. Although the planar structure of 2 is identical to that of the known compound (+)-leptoclinidamine B (5), compound 2 was determined to be the enantiomer of 5 based on amino acid analysis using HPLC methods. Compounds 1 to 4 were evaluated for cytotoxicity against two human cancer cell lines, HCT-15 (colon) and Jurkat (T-cell lymphoma) cells, but none of the compounds showed activity. 相似文献
992.
Three new eremophilane sesquiterpenes (1–3) were isolated from the mangrove endophytic fungus Xylaria sp. BL321 together with 07H239-A (4), a known analogue of the new compounds. The structures of these compounds were elucidated by analysis of their MS, 1D and 2D NMR spectroscopic data. Compound 4 showed activation activity on α-glucosidase at 0.15 μM (146%), and then, 4 gradually produced inhibitory activity on α-glucosidase with increasing concentration, and the IC50 value is 6.54 μM. 相似文献
993.
Genoveffa Nuzzo Maria Letizia Ciavatta Robert Kiss V��ronique Mathieu Helene Leclercqz Emiliano Manzo Guido Villani Ernesto Mollo Florence Lefranc Lisette D��Souza Margherita Gavagnin Guido Cimino 《Marine drugs》2012,10(8):1799-1811
The first chemical study of the Indo-Pacific dorid nudibranch Aldisa andersoni resulted in the isolation of five chlorinated phenyl-pyrrolyloxazoles belonging to the phorbazole series. Two new molecules, 9-chloro-phorbazole D and N1-methyl-phorbazole A, co-occurring with known phorbazoles A, B and D, have been characterized. Phorbazoles were found to be present mainly in the external part of the mollusc. The structures of the new compounds were determined by interpretation of spectroscopic data, mainly NMR and mass spectrometry and by comparison with the literature data. Evaluation of feeding-deterrence activity as well as in vitro growth inhibitory properties in human cancer cells was also carried out. 相似文献
994.
Trypanocidal Action of (?)-Elatol Involves an Oxidative Stress Triggered by Mitochondria Dysfunction
Vania Cristina Desoti Danielle Lazarin-Bid��ia Daniela Bueno Sudatti Renato Crespo Pereira Antonio Alonso Tania Ueda-Nakamura Benedito Prado Dias Filho Celso Vataru Nakamura Sueli de Oliveira Silva 《Marine drugs》2012,10(8):1631-1646
Natural compounds have shown good potential for the discovery of new chemotherapeutics for the treatment of Chagas’ disease. Recently, our group reported the effective trypanocidal activity of (−)-elatol, extracted from the red macroalgae Laurencia dendroidea present in the Brazilian coast against Trypanosoma cruzi. However, the mechanism of action of this compound has remained unclear. There are only hypotheses concerning its action on mitochondrial function. Here, we further investigated the mechanisms of action of (−)-elatol on trypomastigotes of T. cruzi. For this, we evaluated some biochemical alterations in trypomastigotes treated with (−)-elatol. Our results show that (−)-elatol induced depolarization of the mitochondrial membrane, an increase in the formation of mitochondrial superoxide anion and loss of cell membrane and DNA integrity. Additionally, (−)-elatol induced formation of autophagic vacuoles and a decrease in cell volume. All together, these results suggest that the trypanocidal action of (−)-elatol involves multiple events and mitochondria might be the initial target organelle. Our hypothesis is that the mitochondrial dysfunction leads to an increase of ROS production through the electron transport chain, which affects cell membrane and DNA integrity leading to different types of parasite death. 相似文献
995.
Nednaldo Dantas-Santos Jailma Almeida-Lima Arthur Anthunes Jacome Vidal Dayanne Lopes Gomes Ruth Medeiros Oliveira Silvia Santos Pedrosa Paula Pereira Francisco Miguel Gama Hugo Alexandre Oliveira Rocha 《Marine drugs》2012,10(9):2002-2022
Sulfated fucans comprise families of polydisperse natural polysaccharides based on sulfated L-fucose. Our aim was to investigate whether fucan nanogel induces cell-specific responses. To that end, a non toxic fucan extracted from Spatoglossum schröederi was chemically modified by grafting hexadecylamine to the polymer hydrophilic backbone. The resulting modified material (SNFuc) formed nanosized particles. The degree of substitution with hydrophobic chains was close to 100%, as estimated by elemental analysis. SNFfuc in aqueous media had a mean diameter of 123 nm and zeta potential of −38.3 ± 0.74 mV, as measured by dynamic light scattering. Nanoparticles conserved their size for up to 70 days. SNFuc cytotoxicity was determined using the MTT assay after culturing different cell lines for 24 h. Tumor-cell (HepG2, 786, H-S5) proliferation was inhibited by 2.0%–43.7% at nanogel concentrations of 0.05–0.5 mg/mL and rabbit aorta endothelial cells (RAEC) non-tumor cell line proliferation displayed inhibition of 8.0%–22.0%. On the other hand, nanogel improved Chinese hamster ovary (CHO) and monocyte macrophage cell (RAW) non-tumor cell line proliferation in the same concentration range. The antiproliferative effect against tumor cells was also confirmed using the BrdU test. Flow cytometric analysis revealed that the fucan nanogel inhibited 786 cell proliferation through caspase and caspase-independent mechanisms. In addition, SNFuc blocks 786 cell passages in the S and G2-M phases of the cell cycle. 相似文献
996.
Chemical investigation of the cave sponge Xestospongia sp. resulted in the isolation of three new polyacetylenic long chain compounds along with two known metabolites. The structures of the new metabolites were established by NMR and MS analyses. The antibacterial activity of the new metabolites was also evaluated. 相似文献
997.
A novel 15C compound, pseudoalteromone B (1), possessing a novel carbon skeleton, was obtained from a marine bacterium Pseudoalteromonas sp. CGH2XX. This bacterium was originally isolated from a cultured-type octocoral Lobophytum crassum, that was growing in cultivating tanks equipped with a flow-through sea water system. The structure of 1 was established by spectroscopic methods. Pseudoalteromone B (1) displayed a modestly inhibitory effect on the release of elastase by human neutrophils. 相似文献
998.
Pine wilt disease (PWD), a destructive disease for pine trees, is caused by the pine wood nematode (PWN), Bursaphelenchus xylophilus and additional bacteria. In this study, extracts of Zostera marina showed a high nematicidal activity against PWN and some of the bacteria that it carries. Light yellow crystals were obtained from extracts of Z. marina through solvent extraction, followed by chromatography on AB-8 resin and crystallization. The NMR and HPLC analysis showed that the isolated compound was rosmarinic acid (RosA). RosA showed effective nematicidal activity, of which the LC50 (50% lethal concentration) to PWN at 24 h, 48 h and 72 h was 1.18 mg/g, 1.05 mg/g and 0.95 mg/g, respectively. To get a high yield rate of RosA from Z. marina, single factor experiments and an L9 (34) orthogonal experiment were performed. This extraction process involved 70% ethanol for 3 h at 40 °C. The extraction dosage was 1:50 (w/v). The highest yield of RosA from Zostera was 3.13 mg/g DW (dried weight). The crude extracts of Zostera marina (10 mg/mL) and RosA (1 mg/mL) also showed inhibitory effects to some bacterial strains carried by PWN: Klebsiella sp., Stenotrophomonas maltophilia, Streptomyces sp. and Pantoea agglomerans. The results of these studies provide clues for preparing pesticide to control PWD from Z. marina. 相似文献
999.
Federico Ferreres Graciliana Lopes Angel Gil-Izquierdo Paula B. Andrade Carla Sousa Teresa Mouga Patrícia Valent?o 《Marine drugs》2012,10(12):2766-2781
Purified phlorotannin extracts from four brown seaweeds (Cystoseira nodicaulis (Withering) M. Roberts, Cystoseira tamariscifolia (Hudson) Papenfuss, Cystoseira usneoides (Linnaeus) M. Roberts and Fucus spiralis Linnaeus), were characterized by HPLC-DAD-ESI-MSn. Fucophloroethol, fucodiphloroethol, fucotriphloroethol, 7-phloroeckol, phlorofucofuroeckol and bieckol/dieckol were identified. The antioxidant activity and the hyaluronidase (HAase) inhibitory capacity exhibited by the extracts were also assessed. A correlation between the extracts activity and their chemical composition was established. F. spiralis, the species presenting higher molecular weight phlorotannins, generally displayed the strongest lipid peroxidation inhibitory activity (IC50 = 2.32 mg/mL dry weight) and the strongest HAase inhibitory capacity (IC50 = 0.73 mg/mL dry weight). As for superoxide radical scavenging, C. nodicaulis was the most efficient species (IC50 = 0.93 mg/mL dry weight), followed by F. spiralis (IC50 = 1.30 mg/mL dry weight). These results show that purified phlorotannin extracts have potent capabilities for preventing and slowing down the skin aging process, which is mainly associated with free radical damage and with the reduction of hyaluronic acid concentration, characteristic of the process. 相似文献
1000.
Capoamycin-type antibiotics (2–5) and polyene acids (6, 7) were isolated from marine Streptomyces fradiae strain PTZ0025. Their structures were established by extensive nuclear magnetic resonance (NMR) and high resolution electron spray ionization mass spectroscopy (HRESIMS) analyses and chemical degradation. Compounds 3, 4, 6, 7 were found to be new and named as fradimycins A (3) and B (4), and fradic acids A (6) and B (7). Compounds 3–5 showed in vitro antimicrobial activity against Staphylococcus aureus with a minimal inhibitory concentration (MIC) of 2.0 to 6.0 μg/mL. Interestingly, Compounds 3–5 also significantly inhibited cell growth of colon cancer and glioma with IC50 values ranging from 0.13 to 6.46 μM. Fradimycin B (4), the most active compound, was further determined to arrest cell cycle and induce apoptosis in tumor cells. The results indicated that fradimycin B (4) arrested the cell cycle at the G0/G1 phase and induced apoptosis and necrosis in colon cancer and glioma cells. Taken together, the results demonstrated that the marine natural products 3–5, particularly fradimycin B (4), possessed potent antimicrobial and antitumor activities. 相似文献