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1.
Food Chem ; 442: 138411, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38271901

RESUMO

Seeds of ten Andean lupin (Lupinus mutabilis Sweet) ecotypes were collected from different regions of Peru and treated with an aqueous debittering method. Both untreated and treated seeds were analyzed by using LC-MS to investigate flavonoid profiles of different ecotypes and impact of debittering process on these compounds. Thirteen isoflavones (mainly as glycosides of genistein and methoxy-genistein) and eight flavones (glycosylated apigenins and methyl-luteolins) were characterized as the main flavonoids in the seed samples. The untreated lupin seeds contained 187-252 mg/100 g (dry weight) of flavonoids. The main difference among lupin ecotypes was observed in the levels of genistein-malonylhexoside, methoxy-genistein-malonylhexoside, and methyl-luteolin-malonylhexoside. After the debittering treatment, the total flavonoid content in the seeds was decreased to 125-203 mg/100 g dry weight, the aglycones of genistein, methoxy-genistein, and methyl-luteolin being the key distinguishing compounds of ecotypes. The aqueous treatment was effective in degrading flavonoid glycosides and releasing the corresponding aglycones.


Assuntos
Lupinus , Flavonoides , Genisteína , Luteolina , Sementes , Glicosídeos
2.
Food Chem ; 387: 132882, 2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-35398685

RESUMO

DHA is most often used in supplements either in its triacylglycerol or ethyl ester form. Currently, there is only little published data on the differences in the oxidative stability and α-tocopherol response between the two lipid structures, as well as on the oxidation patterns of pure DHA. This study investigated the oxidative stability, α-tocopherol response and oxidation pattern of DHA incorporated in triacylglycerols and as ethyl esters with an untargeted approach after oxidation at 50 °C in the dark. Liquid and gas chromatographic methods with mass spectrometric detection and nuclear magnetic resonance spectroscopy were applied. DHA was more stable in triacylglycerols than as ethyl esters without α-tocopherol addition. With α-tocopherol added the opposite was observed. The oxidation products formed during triacylglycerol and ethyl ester oil oxidation were mostly similar, but also some structure-related differences were detected in both volatile and non-volatile oxidation products.


Assuntos
Ácidos Docosa-Hexaenoicos , Ésteres , Ácidos Docosa-Hexaenoicos/química , Ésteres/química , Cromatografia Gasosa-Espectrometria de Massas , Oxirredução , Estresse Oxidativo , Triglicerídeos/química , alfa-Tocoferol
3.
Molecules ; 27(6)2022 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-35335249

RESUMO

Triterpenoids are among the bioactive components of Chaga, the sterile conk of the medicinal fungus Inonotus obliquus. Supercritical fluid extraction of Chaga triterpenoids was carried out with supercritical CO2, while a modified Folch method was used as a comparison. Three temperature-pressure combinations were tested varying between 314-324 K (40-50 °C) and 281-350 bars, using time- and volume-limited extractions. Six triterpenoids were identified with GC-MS and quantified with GC-FID: ergosterol, lanosterol, ß-sitosterol, stigmastanol, betulin, and inotodiol. The Folch extraction resulted in recovery of trametenolic acid, which was not extracted by supercritical CO2. Inotodiol was the major triterpenoid of all the extracts, with a yield of 87-101 mg/100 g and 139 mg/100 g, for SFEs and the Folch method, respectively. The contents of other major triterpenoids, lanosterol and ergosterol, varied in the ranges 59-63 mg/100 g and 17-18 mg/100 g by SFE, respectively. With the Folch method, the yields were 81 mg/100 g and 40 mg/100 g, respectively. The highest recovery of triterpenoids with SFE in relation to Folch was 56% and it was obtained at 324 K (50 °C) and 350 bar, regardless of extraction time or volume of CO2. The recoveries of lanosterol and stigmastanol were unaffected by SFE conditions. Despite the lower yield, SFE showed several advantages including shorter extraction time and less impact on the environment. This work could be a starting point for further studies on green extraction methods of bioactive triterpenoids from Chaga.


Assuntos
Cromatografia com Fluido Supercrítico , Triterpenos , Dióxido de Carbono , Cromatografia com Fluido Supercrítico/métodos , Ergosterol , Inonotus
4.
Plant Foods Hum Nutr ; 75(2): 184-191, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32009208

RESUMO

The evaluation of the level of alkaloids in edible Lupinus species is crucial from a food safety point of view. Debittering of lupin seeds has a long history; however, the control of the level of alkaloids after processing the seeds is typically only evaluated by changes in the bitter taste. The aim of this study was to evaluate the profile and residual levels of quinolizidine alkaloids (QA) in (Lupinus mutabilis Sweet) after aqueous debittering process. Samples from 10 ecotypes from different areas of Peru were analyzed before and after the process. Based on results obtained by gas chromatography and mass spectrometry, from eight alkaloids identified before the debittering process, only small amounts of lupanine (avg. 0.0012 g/100 g DM) and sparteine (avg. 0.0014 g/100 g DM) remained in the seeds after the debittering process, and no other alkaloids were identified. The aqueous debittering process reduced the content of alkaloids to levels far below the maximal level allowed by international regulations (≤ 0.2 g/kg DM).


Assuntos
Alcaloides , Lupinus , Ecótipo , Cromatografia Gasosa-Espectrometria de Massas , Sementes , Paladar
5.
Food Res Int ; 122: 318-329, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31229085

RESUMO

Oil deterioration during deep-frying influences the quality of fried foods to a great extent. In this study, the frying performance of six vegetable oils, i.e., hemp, lupin, oat, rapeseed, soy, and sunflower, was evaluated following short-term (60 min) deep-frying of French fries at 180 °C. The frying oils were investigated for fatty acid profile, volatile compound composition, and parameters of oxidative stability, such as iodine, peroxide, and p-anisidine values. The examination showed that the content of Æ©PUFA in hemp oil decreased significantly (p < 0.05) after 60 min of deep-frying, although the degree of change was relatively small (close to 1.5%). Similarly, soy oil presented a fatty acid profile prone to oxidation, and generated the highest level of peroxides at the end of the thermal treatment (PV = 16.6 ±â€¯2.3 mEq O2 kg-1). As for the volatile compound composition of the oils, sunflower oil was extensively affected by the deep-frying treatment with a significant decrease (p > 0.05) in total terpenes, accompanied by a considerable rise in total aldehydes. Oppositely, the proportions of MUFA and PUFA of lupin and oat oils remained stable (p > 0.05) during the short-term deep-frying, indicating high stability of these oils. The research provided new data for evaluating the suitability of these oils for household food preparations.


Assuntos
Culinária , Ácidos Graxos/análise , Peroxidação de Lipídeos/fisiologia , Óleos de Plantas/análise , Compostos Orgânicos Voláteis/análise , Ácidos Graxos/química , Temperatura Alta , Óleos de Plantas/química , Análise de Componente Principal
6.
J Agric Food Chem ; 66(13): 3426-3434, 2018 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-29529370

RESUMO

The potential for using extracts of press residues from black, green, red, and white currants and from sea buckthorn berries as sources of antioxidants for foods use was investigated. Press residues were extracted with ethanol in four consecutive extractions, and total Folin-Ciocalteu (F-C) reactive material and authentic phenolic compounds were determined. Radical quenching capability and mechanisms were determined from total peroxyl radical-trapping antioxidant capacity (TRAP) and oxygen radical absorbance capacity (ORAC) assays and from diphenylpicrylhydrazyl (DPPH) kinetics, respectively; specific activities were normalized to F-C reactive concentrations. Levels of total F-C reactive materials in press residue extracts were higher than in many fruits and showed significant radical quenching activity. Black currant had the highest authentic phenol content and ORAC, TRAP, and DPPH reactivity. Sea buckthorn grown in northern Finland showed extremely high total specific DPPH reactivity. These results suggest that berry press residues offer attractive value-added products that can provide antioxidants for use in stabilizing and fortifying foods.


Assuntos
Antioxidantes/química , Hippophae/química , Fenóis/química , Extratos Vegetais/isolamento & purificação , Ribes/química , Antioxidantes/isolamento & purificação , Cor , Frutas/química , Fenóis/isolamento & purificação , Extratos Vegetais/química , Resíduos
7.
J Agric Food Chem ; 66(11): 2900-2908, 2018 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-29478323

RESUMO

Finland is the second largest oat producer in Europe. Despite the existing knowledge of phenolics in oat, there is little information on the phenolic composition of oats from Finland. The aim of the study was to investigate the concentrations of free and bound phenolic acids, as well as avenanthramides in eight Finnish cultivars of husked oat ( Avena sativa L.). Seven phenolic acids and one phenolic aldehyde were identified, including, in decreasing order of abundance: p-coumaric, ferulic, cinnamic, syringic, vanillic, 2,4-dihydroxybenzoic, and o-coumaric acids and syringaldehyde. Phenolic acids were mostly found as bound compounds. Significant varietal differences ( p < 0.05) were observed in the cumulative content of phenolic acids, with the lowest level found in cv. 'Viviana' (1202 ± 52.9 mg kg-1) and the highest in cv. 'Akseli' (1687 ± 80.2 mg kg-1). Avenanthramides (AVNs) 2a, 2p, and 2f were the most abundant. Total AVNs levels ranged from 26.7 ± 1.44 to 185 ± 12.5 mg kg-1 in cv. 'Avetron' and 'Viviana', respectively.


Assuntos
Alcaloides/química , Avena/química , Hidroxibenzoatos/química , Avena/classificação , Cromatografia Líquida de Alta Pressão , Grão Comestível/química , Finlândia , Espectrometria de Massas , Extratos Vegetais/química , Sementes/química , Sementes/classificação
8.
Lipids ; 52(10): 849-855, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28861716

RESUMO

This study examined the effect of substituting vegetable oil for fish oil in feed, with subsequent re-introduction of fish oil-rich feed (finishing feeding) in late stages of growth, on the fatty acids of cultivated European whitefish (Coregonus lavaretus). Restorative finishing feeding with fish oil-rich feed for 15 and 25 weeks was sufficient to change the total content of nutritionally valuable long-chain n-3 fatty acids, eicosapentaenoic acid (20:5n-3) and docosahexaenoic acid (22:6n-3), to correspond to that of fish fed the fish oil-rich feed throughout their lifespan. Under natural conditions, 15 and 25 weeks correspond to weight gains of 75% and 100% (i.e. doubling), respectively. Also, the fatty acid profile of the fish was restored after finishing periods of 15 and 25 weeks. Limiting the use of fish oil by lowering the overall fat content of the feed (no vegetable oil added) resulted in a decrease in the long-chain n-3 fatty acids. Based on the results, after receiving a vegetable oil-rich diet, restorative fish oil-rich feeding in the last stages of growth in European whitefish is nutritionally justified in order to balance nutritional gain for consumers with sustainable use of finite marine oils. The results encourage commercial efforts to further utilize and optimize finishing feeding practices.


Assuntos
Ácidos Graxos Ômega-3/análise , Óleos de Peixe/administração & dosagem , Salmonidae/crescimento & desenvolvimento , Ração Animal/análise , Animais , Gorduras na Dieta/administração & dosagem , Salmonidae/metabolismo
9.
Ann Nutr Metab ; 70(3): 184-190, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28301837

RESUMO

BACKGROUND/AIMS: The aim of the present study was to identify and quantify the polyamine levels in human milk obtained from different countries and through different modes of delivery, and to investigate their association with breast milk microbes. METHODS: Mature breast milk samples were obtained from 78 healthy mothers after 1 month of lactation from 4 different geographical locations: Finland, Spain (Europe); South Africa (Africa); and China (Asia). Polyamines were determined using HPLC after dansyl derivatization and milk microbiota was obtained by 16S rRNA gene sequencing. RESULTS: The mean values of polyamines in breast milk were 70.0, 424.2, and 610.0 nmol/dL for putrescine, spermidine and spermine, respectively, and 1,170.9 nmol/dL of total polyamines. The levels of putrescine were significantly higher in Spain (p < 0.05) and spermidine levels were significantly higher in Finland (p < 0.05) compared with other countries. Cesarean delivery had an impact on polyamine levels and it was related to an increase in the putrescine concentration being significant in Spanish samples (p < 0.01). Furthermore, putrescine levels were correlated positively with Gammaproteobacteria (r = 0.46, p < 0.001), especially with Pseudomonas fragi (r = 0.40, p < 0.001). CONCLUSIONS: The results demonstrate significant effect of geographical variations in human milk polyamine concentrations, being correlated with human milk microbiota composition. These differences may have an impact on infant development during lactation.


Assuntos
Parto Obstétrico/métodos , Leite Humano/química , Leite Humano/microbiologia , Poliaminas/análise , Adulto , China , Feminino , Finlândia , Voluntários Saudáveis , Humanos , Masculino , Microbiota , África do Sul , Espanha
10.
Food Chem ; 197 Pt B: 1031-7, 2016 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-26675838

RESUMO

The effect of variation in origin and season on the lipids and sensory quality of European whitefish (Coregonus lavaretus) was studied. The proportion of docosahexaenoic acid (22:6n-3) of the total phospholipid fatty acids in fillets was considerably higher in spring compared with autumn. Farmed fish contained 3-4 times more lipids than wild fish. Combined, the fillets of farmed fish contained 2-3 times more eicosapentaenoic acid (20:5n-3) and docosahexaenoic acid than the fillets of wild fish. Contents of vitamin D were high both in farmed and wild fish. Aroma of raw farmed whitefish was less algae-like than wild one. Raw farmed whitefish was harder, less springy, and lighter in flesh color than wild whitefish. Cooked, farmed fish had slightly stronger flavor than wild fish. There was no significant difference in pleasantness between whitefish of different origin in any of the evaluated characteristics. Both farmed and wild European whitefish caught in autumn and spring proved to have a high content of n-3 fatty acids and vitamin D, and hence they serve as a good source of nutritionally important lipids.


Assuntos
Ácidos Graxos , Produtos Pesqueiros/análise , Qualidade dos Alimentos , Salmonidae , Estações do Ano , Animais , Vitamina D
11.
J Agric Food Chem ; 62(49): 12015-26, 2014 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-25408277

RESUMO

Leaves of bilberry (Vaccinium myrtillus L.) and lingonberry (Vaccinium vitis-idaea L.) are potential raw materials for food and health care products. Targeted (HPLC-DAD, HPLC-MS, and GC-FID) and nontargeted ((1)H NMR) approaches were applied to study the metabolomic profiles of these leaves. Chlorogenic acid was the major phenolic compound in bilberry leaves and arbutin in lingonberry leaves. Flavonol glycosides were another major group of phenolics in bilberry [5-28 mg/g DM (dry mass)] and lingonberry (15-20 mg/g DM) leaves. Contents of fatty acids were analyzed using GC-FID. The changes in the metabolomics profile during the season were apparent in bilberry but not lingonberry leaves. Negative correlation was found between the contents of lipids and phenolics. The consistency between the key results obtained by targeted and nontargeted analyses suggests nontargeted metabolomic analysis is an efficient tool for fast screening of various leaf materials.


Assuntos
Fenóis/química , Extratos Vegetais/química , Folhas de Planta/química , Vaccinium myrtillus/química , Vaccinium vitis-Idaea/química , Cromatografia Líquida de Alta Pressão , Espectrometria de Massas , Metabolômica , Fenóis/metabolismo , Extratos Vegetais/metabolismo , Folhas de Planta/metabolismo , Vaccinium myrtillus/metabolismo , Vaccinium vitis-Idaea/metabolismo
12.
Am J Clin Nutr ; 98(4): 941-51, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23945716

RESUMO

BACKGROUND: Berries are associated with health benefits. Little is known about the effect of baseline metabolome on the overall metabolic responses to berry intake. OBJECTIVE: We studied the effects of berries on serum metabolome. DESIGN: Eighty overweight women completed this randomized crossover study. During the interventions of 30 d, subjects consumed dried sea buckthorn berries (SBs), sea buckthorn oil (SBo), sea buckthorn phenolics ethanol extract mixed with maltodextrin (SBe+MD) (1:1), or frozen bilberries. Metabolic profiles were quantified from serum samples by using (1)H nuclear magnetic resonance spectroscopy. RESULTS: All interventions induced a significant (P < 0.001-0.003) effect on the overall metabolic profiles. The effect was observed both in participants who had a metabolic profile that reflected higher cardiometabolic risk at baseline (group B: P = 0.001-0.008) and in participants who had a lower-risk profile (group A: P < 0.001-0.009). Although most of the changes in individual metabolites were not statistically significant after correction for multiplicity, clear trends were observed. SB-induced effects were mainly on serum triglycerides and very-low-density lipoprotein (VLDL) and its subclasses, which decreased in metabolic group B. SBo induced a decreasing trend in serum total, intermediate-density lipoprotein (IDL), and low-density lipoprotein (LDL) cholesterol and subfractions of IDL and LDL in group B. During the SBe+MD treatment, VLDL fractions and serum triglycerides increased. Bilberries caused beneficial changes in serum lipids and lipoproteins in group B, whereas the opposite was true in group A. CONCLUSION: Berry intake has overall metabolic effects, which depend on the cardiometabolic risk profile at baseline. This trial was registered at clinicaltrials.gov as NCT01860547.


Assuntos
Frutas/química , Hippophae , Metaboloma/efeitos dos fármacos , Sobrepeso/sangue , Extratos Vegetais/administração & dosagem , Vaccinium myrtillus , Adulto , Biomarcadores , Doenças Cardiovasculares/sangue , Proteínas de Transporte/sangue , Colesterol/sangue , LDL-Colesterol/sangue , Estudos Cross-Over , Dieta , Suplementos Nutricionais , Feminino , Alimentos em Conserva , Humanos , Lipoproteínas/sangue , Lipoproteínas IDL/sangue , Lipoproteínas VLDL/sangue , Espectroscopia de Ressonância Magnética , Pessoa de Meia-Idade , Óleos de Plantas/administração & dosagem , Fatores de Risco , Triglicerídeos/sangue
13.
Food Chem ; 135(3): 1210-9, 2012 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-22953845

RESUMO

The hedonic response of 104 healthy children, recruited from day-care centres and schools, to 12 different berry products with varying content of added sugar was studied. The berries used as ingredients were blackcurrant (Ribes nigrum), sea buckthorn (Hippophaë rhamnoides), bilberry (Vaccinium myrtillus), and lingonberry (Vaccinium vitis-idaea). Another aim of the study was to study the effects of the chemical composition of berries as well as children's hTAS2R38 taste receptor genotypes on liking. The most liked product was bilberry with yoghurt, followed by bilberry juice, dried bilberries, and lingonberry rye bread. The most disliked products were sea buckthorn juice, sea buckthorn berries with yoghurt, and oatmeal with blackcurrant powder and berry oil. High total organic acid concentration was strongly related with a poor average liking score of the berries/berry products. A total of four different alleles of hTAS2R38 gene were observed in the study. Of the genotyped children, 45% were bitter taste insensitive individuals of the genotype AVI/AVI, and 40% were of the genotype PAV/AVI. Children of the genotype PAV/AVI were reported using more vegetables, but not berries, than the AVI/AVI children. The results also show that the liking scores of the children of the AVI/AVI, PAV/AVI, and PAV/PAV genotypes differed from each other, and that the familiarity of a berry product is likely to be an important factor in liking.


Assuntos
Preferências Alimentares , Frutas/química , Magnoliopsida/química , Receptores Acoplados a Proteínas G/genética , Criança , Pré-Escolar , Feminino , Genótipo , Hippophae/química , Humanos , Masculino , Ribes/química , Paladar , Vaccinium myrtillus/química , Vaccinium vitis-Idaea/química
14.
J Agric Food Chem ; 60(14): 3564-79, 2012 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-22433015

RESUMO

A normal diet contains large quantities of oxidized fatty acids, glycerolipids, cholesterol, and their cytotoxic degradation products because many foods in the diet are fried, heated, or otherwise processed and consumed often after long periods of storage. There is also evidence that the acid medium of the stomach promotes lipid peroxidation and that the gastrointestinal tract is a major site of antioxidant action, as demonstrated by various colorimetric methods. The identity and yields of specific products of lipid transformation have seldom been determined. The present study describes the molecular species profiles of all major gastrointestinal lipids formed during digestion of autoxidized rapeseed oil in an artificial digestion model in the presence of L-ascorbic acid, 6-palmitoyl-O-L-ascorbic acid, 3,5-di-tert-butyl-4-hydroxytoluene (BHT), DL-α-tocopherol, and DL-α-tocopheryl acetate. Differences in oxidized lipid profiles were detected in the samples digested in the presence of different antioxidants, but none of them could prevent the formation of oxidized lipids or promote their degradation in a gastric digestion model. The lack of effect is attributed to the inappropriate nature of the gastrointestinal medium for the antioxidant activity of these vitamins and BHT. A fast ultrahigh performance liquid chromatographic-electrospray ionization-mass spectrometric method was developed for the analysis of lipolysis products, including epoxy, hydroperoxy, and hydroxy fatty acids, and acylglycerols, utilizing lithium as ionization enhancer.


Assuntos
Antioxidantes/farmacologia , Cromatografia Líquida de Alta Pressão/métodos , Digestão , Óleos de Plantas/química , Espectrometria de Massas por Ionização por Electrospray/métodos , Ácidos Graxos Monoinsaturados , Ácidos Graxos não Esterificados/análise , Ácidos Graxos não Esterificados/química , Glicerídeos/análise , Glicerídeos/química , Peroxidação de Lipídeos/efeitos dos fármacos , Lítio , Modelos Biológicos , Oxirredução , Óleo de Brassica napus
15.
J Agric Food Chem ; 59(15): 8095-100, 2011 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-21702477

RESUMO

Detailed studies on the regioisomeric structures of oxidized species of triacylglycerols (TAG), formed in food during storage and processing, have not been published thus far. In this study, an analytical approach based on efficient ultra-high-performance liquid chromatographic (UHPLC) separation of different isomers of oxidized TAG species and their tandem mass spectrometric analysis was created. A linear solvent gradient based on acetonitrile and acetone was used in the UHPLC method. A novel method utilizing positive ion ESI using ammonia supplemented in the nebulizer gas was used to produce ammonium adduct ions for mass spectrometric analysis. With the UHPLC method used, different regioisomers of TAG species containing oxidized linoleic or oleic acid could be efficiently resolved. Differences in the fragmentation patterns of many of the oxidized TAG isomers could be demonstrated by the tandem mass spectrometric method. On the basis of the results, the approach enables regiospecific analysis of oxidized TAG molecules.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Espectrometria de Massas em Tandem/métodos , Triglicerídeos/química , Isomerismo , Oxirredução
16.
Biochemistry ; 50(24): 5535-43, 2011 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-21595438

RESUMO

A simplified model system composed of a NADPH-dependent flavoprotein hydroxylase PgaE and a short-chain alcohol dehydrogenase/reductase (SDR) CabV was used to dissect a multistep angucycline modification redox cascade into several subreactions in vitro. We demonstrate that the two enzymes are sufficient for the conversion of angucycline substrate 2,3-dehydro-UWM6 to gaudimycin C. The flavoenzyme PgaE is shown to be responsible for two consecutive NADPH- and O(2)-dependent reactions, consistent with the enzyme-catalyzed incorporation of oxygen atoms at C-12 and C-12b in gaudimycin C. The two reactions do not significantly overlap, and the second catalytic cycle is initiated only after the original substrate 2,3-dehydro-UWM6 is nearly depleted. This allowed us to isolate the product of the first reaction at limiting NADPH concentrations and allowed the study of the qualitative and kinetic properties of the separated reactions. Dissection of the reaction cascade also allowed us to establish that the SDR reductase CabV catalyzes the final biosynthetic step, which is closely coupled to the second PgaE reaction. In the absence of CabV, the complete PgaE reaction leads invariably to product degradation, whereas in its presence, the reaction yields the final product, gaudimycin C. The result implies that the C-6 ketoreduction step catalyzed by CabV is required for stabilization of a reactive intermediate. The close relationship between PgaE and CabV would explain previous in vivo observations: why the absence of a reductase gene may result in the lack of C-12b-oxygenated species and, vice versa, why all C-12b-oxygenated angucyclines appear to have undergone reduction at position C-6.


Assuntos
Antraquinonas/metabolismo , Oxigenases de Função Mista/metabolismo , Álcool Desidrogenase/metabolismo , Oxirredutases do Álcool/metabolismo , Sequência de Bases , DNA Bacteriano/genética , Flavoproteínas/metabolismo , Cinética , Oxigênio/metabolismo , Streptomyces/genética , Streptomyces/metabolismo , Especificidade por Substrato
17.
Lipids ; 45(11): 1061-79, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20872182

RESUMO

Rapeseed oil was oxidized chemically and thermally to produce two distinct oxidized oils. These oils, along with unoxidized oils, were subjected to an artificial digestion model to simulate the digestive processes in humans. Lipid digestion involves lipases that break down the intact triacylglycerol (TAG) molecules first to diacylglycerols, and eventually to sn-2-monoacylglycerols (MAG) and free fatty acids. A high performance liquid chromatography-evaporative light scattering detector-electrospray ionization-mass spectrometric (HPLC-ELSD-ESI-MS) method was developed to monitor the lipolysis and the presence of oxidized lipids. The HPLC-ELSD-ESI-MS analysis enabled the separation and detection of nearly all the lipid species present in the sample after TAG hydrolysis. The HPLC-MS analyses of digestion products revealed that oxidized triacylglycerols are hydrolyzed by the digestive enzymes in a manner similar to that of native, unoxidized molecules. Significant amounts of sn-1(3)-MAG were found in all the samples after lipolysis, however, more of these were found in unoxidized rapeseed oil samples than in the oxidized oils. Several oxidized molecules were identified with the aid of synthesized oxylipids. This novel method is scalable to small-scale preparative fractionation of oxidized lipid molecules from a complex digestion sample. Also, the fingerprint-like, diagnostic, MS profiles of oxidized oils, reference compounds, and digestion products may be a great aid in comprehensive analysis of lipid oxidation and lipolysis.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Digestão/fisiologia , Óleos de Plantas/química , Óleos de Plantas/metabolismo , Espalhamento de Radiação , Espectrometria de Massas por Ionização por Electrospray/métodos , Líquidos Corporais/metabolismo , Líquidos Corporais/fisiologia , Fracionamento Químico/métodos , Cromatografia Líquida de Alta Pressão/instrumentação , Ácidos Graxos Monoinsaturados , Humanos , Técnicas In Vitro , Luz , Lipólise/fisiologia , Modelos Biológicos , Oxirredução , Óleo de Brassica napus , Espectrometria de Massas por Ionização por Electrospray/instrumentação
18.
Ann Med ; 42(7): 521-9, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20718696

RESUMO

BACKGROUND: Serum lipoproteins, the carriers of cholesterol and other lipophilic substances in blood, are known to contain variable amounts of lipid peroxides. We investigated the transport of food-derived and endogenously formed lipid peroxides by serum lipoproteins under physiological conditions. METHODS: Five independent trials were conducted in which different groups of healthy volunteers either consumed a test meal (a standard hamburger meal rich in lipid peroxides) or underwent strenuous physical exercise. The transport function was characterized by analyzing the kinetics of lipid peroxides in lipoprotein fractions. For evaluation of their potential involvement, indicators of oxidative stress (8-isoprostanes, malondialdehyde, 8-oxo-deoxyguanosine), antioxidant functions (total antioxidant potential, paraoxonase activity), and serum lipids were also analyzed. RESULTS: We found that food lipid peroxides are incorporated into serum triglyceride-rich lipoproteins and low-density lipoprotein, directing the flow of lipid peroxides towards peripheral tissues. High-density lipoprotein appears to have an opposite and protective function, and is able to respond to oxidative stress by substantially increasing the reverse transport of lipid peroxides. CONCLUSIONS: We propose that the specific atherosclerosis-related effects of serum lipoproteins are not explained by cholesterol transport alone and may rather result from the transport of the more directly atherogenic lipid peroxides.


Assuntos
Gorduras na Dieta/metabolismo , Metabolismo dos Lipídeos/fisiologia , Peróxidos Lipídicos/sangue , Peróxidos Lipídicos/farmacocinética , Lipoproteínas HDL/sangue , Lipoproteínas LDL/sangue , Estresse Oxidativo , Triglicerídeos/sangue , 8-Hidroxi-2'-Desoxiguanosina , Adulto , Transporte Biológico , Desoxiguanosina/análogos & derivados , Desoxiguanosina/metabolismo , Dinoprosta/análogos & derivados , Dinoprosta/sangue , Exercício Físico/fisiologia , Feminino , Alimentos , Humanos , Lipoproteínas HDL/fisiologia , Lipoproteínas LDL/fisiologia , Masculino , Malondialdeído/sangue , Pessoa de Meia-Idade , Período Pós-Prandial/fisiologia , Triglicerídeos/fisiologia , Adulto Jovem
19.
Endocrinology ; 151(4): 1893-901, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20130115

RESUMO

Hydroxysteroid (17beta) dehydrogenases (HSD17Bs) have a significant role in steroid metabolism by catalyzing the conversion between 17-keto and 17beta-hydroxysteroids. However, several studies in vitro have shown that some of these enzymes may also be involved in other metabolic pathways. Among these enzymes, HSD17B12 has been shown to be involved in both the biosynthesis of estradiol and the elongation of the essential very long fatty acids in vitro and in vivo. To investigate the function of mammalian HSD17B12 in vivo, we generated mice with a null mutation of the Hsd17b12 gene (HSD17B12KO mice) by using a gene-trap vector, resulting in the expression of the lacZ gene of the trapped allele. The beta-galactosidase staining of the heterozygous HSD17B12KO mice revealed that Hsd17b12 is expressed widely in the embryonic day (E) 7.5-E9.5 embryos, with the highest expression in the neural tissue. The HSD17B12KO mice die at E9.5 at latest and present severe developmental defects. Analysis of the knockout embryos revealed that the embryos initiate gastrulation, but organogenesis is severely disrupted. As a result, the E8.5-E9.5 embryos were void of all normal morphological structures. In addition, the inner cell mass of knockout blastocysts showed decreased proliferation capacity in vitro, and the amount of arachidonic acid was significantly decreased in heterozygous HSD17B12 ES cells. This, together with the expression pattern, suggests that in mouse, the HSD17B12 is involved in the synthesis of arachidonic acid and is essential for normal neuronal development during embryogenesis.


Assuntos
17-Hidroxiesteroide Desidrogenases/genética , Ácido Araquidônico/biossíntese , Gastrulação/genética , Organogênese/genética , Alelos , Animais , Morte Fetal/genética , Regulação da Expressão Gênica no Desenvolvimento , Genótipo , Camundongos , Camundongos Knockout
20.
J Agric Food Chem ; 58(1): 620-7, 2010 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-20050706

RESUMO

Glucuronidation and excretion of sea buckthorn and lingonberry flavonols were investigated in a postprandial trial by analyzing the intact forms of flavonol glycosides as well as glucuronides in plasma, urine, and feces. Four study subjects consumed sea buckthorn (study day 1) and lingonberry (study day 2) breakfasts, and blood, urine, and fecal samples were collected for 8, 24, and 48 h, respectively. Both glycosides and glucuronides of the flavonol quercetin as well as kaempferol glucuronides were detected in urine and plasma samples after the consumption of lingonberries; 14% of flavonols in urine were glycosides, and 86% were glucuronidated forms (wt %). After the consumption of sea buckthorn, 5% of flavonols excreted in urine were detected intact, and 95% as the glucuronides (wt %). Solely glucuronides of flavonols isorhamnetin and quercetin were found in plasma after the consumption of sea buckthorn berries. Only glycosides were detected in the feces after each berry trial. Flavonol glycosides and glucuronides remained in blood and urine quite long, and the peak concentrations appeared slightly later than previously described. The berries seemed to serve as a good flavonol supply, providing steady flavonol input for the body for a relatively long time.


Assuntos
Fezes/química , Flavonóis/farmacocinética , Glucuronídeos/metabolismo , Glicosídeos/farmacocinética , Hippophae/química , Extratos Vegetais/farmacocinética , Vaccinium vitis-Idaea/química , Adulto , Disponibilidade Biológica , Feminino , Flavonóis/sangue , Flavonóis/urina , Glicosídeos/sangue , Glicosídeos/urina , Humanos , Masculino , Extratos Vegetais/sangue , Extratos Vegetais/urina , Adulto Jovem
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