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E. Molina Grima A. Robles Medina A. Giménez Giménez M. J. Ibáñez González 《Journal of applied phycology》1996,8(4-5):359-367
Eicosapentaenoic acid (EPA, 20:5n-3) was obtained from the microalgaPhaeodactylum tricornutum following a three-step process: fatty acid extraction by direct saponification of wet biomass, polyunsaturated fatty acid (PUFA) concentration by formation of urea inclusion compounds and EPA isolation by preparative HPLC. Direct saponification of wet biomass was carried out with KOH-ethanol (96% v:v) (1 h, 60 °C), extracting 91% of the EPA. PUFAs were concentrated by the urea method with an urea/fatty acid ratio of 4:1 at a crystallization temperature of 28 °C using methanol as the urea solvent. An EPA concentration ratio of 1.5 (55.2/36.3) and recovery of 79% were obtained. This PUFA concentrate was used to obtain 95.8% pure EPA by preparative HPLC, using a reverse-phase column (C18, 4.7 cm i.d. × 30 cm) and methanol-water (1% AcH) 80:20 w/w as the mobile phase. Ninety-seven per cent of EPA loaded was recovered and 70% EPA present in theP. tricornutum biomass was recovered in a highly pure form by means of this three-step downstream processing. In each of the HPLC preparative runs, 635 mg PUFA concentrate were loaded, obtaining 326 mg of a highly concentrated EPA fraction (2.46 g d–1). Finally, a preliminary cost statement has been calculated. 相似文献
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Induction versus progression of brain tumor development: differential functions for the pRB- and p53-targeting domains of simian virus 40 T antigen. 总被引:10,自引:2,他引:8 下载免费PDF全文
The ability of simian virus 40-encoded large T antigen to disrupt the growth control of a variety of cell types is related to its ability to interfere with certain cellular proteins, such as p53 and the retinoblastoma susceptibility gene product (pRB). We have used wild-type and mutant forms of T antigen in transgenic mice to dissect the roles of pRB, p53, and other cellular proteins in tumorigenesis of different cell types. In this study, using a cell-specific promoter to target expression specifically to brain epithelium (the choroid plexus) and to B and T lymphoid cells, we characterize the tumorigenic capacity of a T-antigen fragment that comprises only the amino-terminal 121 residues. This fragment (dl1137) retains the ability to interact with pRB and p107 but lacks the p53-binding domain. While loss of the p53-binding region results in loss of the capacity to induce lymphoid abnormalities, dl1137 retains the ability to induce choroid plexus tumors that are histologically indistinguishable from those induced by wild-type T antigen. Tumors induced by dl1137 develop much more slowly, however, reaching an end point at around 8 months of age rather than at 1 to 2 months. Analysis of tumor progression indicates that tumor induction by dl1137 does not require secondary genetic or epigenetic events. Rather, the tumor growth rate is significantly slowed, indicating that the T-antigen C-terminal region contributes to tumor progression in this cell type. In contrast, the pRB-binding region appears essential for tumorigenesis as mutation of residue 107, known to disrupt pRB and p107 binding to wild-type T antigen, abolishes the ability of the dl1137 protein to induce growth abnormalities in the brain. 相似文献
4.
Glycoprotein was isolated from a purified thymocyte membrane preparation by two methods: lithium diiodosalicylate-phenol extraction and hot 75% ethanol extraction. A higher yield of membrane sialic acid was obtained by the latter method. The preparations had similar apparent molecular weights on sodium dodecyl sulfate gel electrophoresis. Both had similar receptor activities against a panel of hemagglutinins, although the 75% ethanol extract was more active on a weight basis. However, there were significant differences in carbohydrate and amino acid compositions of the two thymocyte extracts. The lithium diiodosalicylate-extracted material had much more glucose, ribose, and glycine than the ethanol extract. The glycoprotein preparations from thymocytes were quite distinct from the glycoprotein of bovine erythrocytes in both composition and receptor properties. 相似文献
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Delgado Naranjo Juan Martin Jiménez Callejón Maria José Peñuela Vásquez Mariana Rios Luis Alberto Robles Medina Alfonso 《Journal of applied phycology》2021,33(4):2031-2045
Journal of Applied Phycology - The thraustochytrid Aurantiochytrium limacinum SR21 is a promising source of docosahexaenoic acid (DHA) for human consumption as dietary supplement, replacing... 相似文献
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Anna Grandas Jordi Robles Enrique Pedroso 《Nucleosides, nucleotides & nucleic acids》2013,32(3-5):825-828
Abstract N-acylphosphoramidates can be obtained from the reaction of phosphitylated primary carboxamides and an alcohol in the presence of an acid catalyst such as tetrazole and subsequent oxidation. The reaction is useful for the preparation of peptide-oligonucleotide conjugates. 相似文献
8.
Grijota Francisco Javier Muñoz Diego Bartolomé Ignacio Siquier-Coll Jesús Robles María Concepción Maynar Marcos 《Biological trace element research》2020,195(1):39-45
Biological Trace Element Research - The aim of the present study was to determine changes occurring in the erythrocyte concentrations of arsenic (As), cadmium (Cd) and lead (Pb) in highly trained... 相似文献
9.
Maria Teresa Sáenz Robles Chikdu Shivalila Jeremy Wano Shelly Sorrells Alison Roos James M. Pipas 《Journal of virology》2013,87(24):13499-13509
10.
Viviana Ulloa María García‐Robles Fernando Martínez Katterine Salazar Karin Reinicke Fernando Pérez David F. Godoy Alejandro S. Godoy Francisco Nualart 《Journal of neurochemistry》2013,127(3):403-414
In vitro and in vivo studies suggest that the basolateral membrane of choroid plexus cells, which is in contact with blood vessels, is involved in the uptake of the reduced form of vitamin C, ascorbic acid (AA), through the sodium‐vitamin C cotransporter, (SVCT2). Moreover, very low levels of vitamin C were observed in the brains of SVCT2‐null mice. The oxidized form of vitamin C, dehydroascorbic acid (DHA), is incorporated through the facilitative glucose transporters (GLUTs). In this study, the contribution of SVCT2 and GLUT1 to vitamin C uptake in human choroid plexus papilloma (HCPP) cells in culture was examined. Both the functional activity and the kinetic parameters of GLUT1 and SVCT2 in cells isolated from HCPP were observed. Finally, DHA uptake by GLUT1 in choroid plexus cells was assessed in the presence of phorbol‐12‐myristate‐13‐acetate (PMA)‐activated human neutrophils. A marked increase in vitamin C uptake by choroid plexus cells was observed that was associated with superoxide generation and vitamin C oxidation (bystander effect). Thus, vitamin C can be incorporated by epithelial choroid plexus papilloma cells using the basolateral polarization of SVCT2 and GLUT1. This mechanism may be amplified with neutrophil infiltration (inflammation) of choroid plexus tumors.