RESUMEN
Two varieties of common beans (Phaseolus vulgaris L.), Bayo Victoria and Negro 8025, were evaluated to determine the effect on cellular viability and mechanisms involved in apoptosis pathways, using a cellular model with HT-29 cells. Aqueous methanolic (50:50) extracts from cooked beans were analyzed for phenolic composition, identifying greater diversity of phenolic compounds in Bayo Victoria extracts. However, Negro 8025 showed greater phenolic content and cytotoxicity effects at lower media inhibitory concentrations, and greater effectiveness to activate apoptotic pathways. Proteins related to the arrest of cell cycle were modulated by both bean cultivars. Qualitative analysis by HPLC-PAD and HPLC-MS systems of phenolic compounds in common bean extracts showed mainly hydroxybenzoic and hydroxycinnamic acids, flavonols, and monomeric flavan-3-ols. Bioactive phenolics such as catechin, kaempferol, and ferulic acid were found in both cultivars as well anticancer phytochemicals such as quercetin, protocatechuic acid, myricetin, naringenin and their derivatives, and procyanidins. PRACTICAL APPLICATIONS: Polyphenols in common beans (Phaseolus vulgaris L.) cultivars processed by canning display chemoprotective potential as they activate mechanisms involved in apoptosis pathways. Phenolics in common beans modulate 28 proteins related to apoptotic processes. Therefore, a diet including canned beans (particularly darker varieties) might represent health benefits and cancer-preventive effects.
Asunto(s)
Línea Celular Tumoral/efectos de los fármacos , Phaseolus/química , Extractos Vegetales/farmacología , Antioxidantes/análisis , Apoptosis , Cromatografía Líquida de Alta Presión/métodos , Flavonoles/análisis , Células HT29 , Humanos , Neoplasias/prevención & control , Fenoles/análisis , Fitoquímicos/análisis , Extractos Vegetales/análisis , Polifenoles/análisis , Semillas/químicaRESUMEN
Mung beans (Vigna radiata [L] Wilczek) purchased from a Spanish company as "green soybeans", showed a different phenolic composition than yellow soybeans (Glycine max cv. Merit). Isoflavones were predominant in yellow soybeans, whereas they were completely absent in the green seeds on which flavanones were predominant. In order to enhance their health benefits, both types of bean were subjected to technological processes, such as soaking and fermentation. Soaking increased malonyl glucoside isoflavone extraction in yellow beans and produced an increase in apigenin derivatives in the green beans. Lactobacillus plantarum CECT 748 T fermentation produced an increase in the bioactivity of both beans since a conversion of glycosylated isoflavones into bioactive aglycones and an increase of the bioactive vitexin was observed in yellow and green beans, respectively. In spite of potential consumer confusion, since soybean and "green soybean" are different legumes, the health benefits of both beans were enhanced by lactic fermentation.
Asunto(s)
Fabaceae , Fermentación , Manipulación de Alimentos/métodos , Isoflavonas/metabolismo , Lactobacillus , Fenoles/metabolismo , Semillas/metabolismo , Antioxidantes/metabolismo , Apigenina/metabolismo , Dieta , Glucósidos/metabolismo , Salud , Humanos , Glycine max , AguaRESUMEN
Legumes are the basés diet in several countries. They hold a high nutritional value, but other properties related to human health are nowadays being studied. The aim of this work was to study the influence of processes (boiling or germination) on the phenolic composition of dark beans (Phaseolus vulgaris L. c.v. Tolosana) and their effect on their antioxidant, neuroprotective and anticancer ability. Phenolic composition of raw and processed dark beans was analysed by HPLC-PAD and HPLC-ESI/MS. The antioxidant activity was evaluated by ORAC. Astrocytes cultures (U-373) have been used to test their neuroprotective effect. Anticancer activities were evaluated on three different cell lines (renal adenocarcinoma (TK-10), breast adenocarcinoma (MCF-7) and melanoma (UACC-62)) by sulphorhodamine B method. Qualitative and quantitative differences in phenolic composition have been observed between raw and processed dark beans that influence the antioxidant activity, mainly for germinated samples which show a decrease of antioxidant capacity. Although every assayed extracts decreased reactive oxygen species release and exhibited cytotoxicity activities on cancer cell lines, raw beans proved to be the most active in neuroprotective and antitumoral effects; this sample is especially rich in phenolic compounds, mainly anthocyanins. This study further demonstrated that phenolic composition of dark beans is related with cooking process and so with their neuroprotective and anticancer activity; cooking of dark beans improves their digestion and absorption at intestinal level, while maintaining its protective ability on oxidative process at cellular level.
Asunto(s)
Antineoplásicos Fitogénicos/análisis , Antioxidantes/análisis , Germinación , Fármacos Neuroprotectores/análisis , Phaseolus/química , Fenoles/análisis , Extractos Vegetales/análisis , Antineoplásicos Fitogénicos/metabolismo , Antineoplásicos Fitogénicos/farmacología , Antioxidantes/metabolismo , Antioxidantes/farmacología , Línea Celular , Culinaria , Humanos , Neuronas/efectos de los fármacos , Fármacos Neuroprotectores/metabolismo , Fármacos Neuroprotectores/farmacología , Valor Nutritivo , Phaseolus/crecimiento & desarrollo , Phaseolus/metabolismo , Fenoles/metabolismo , Fenoles/farmacología , Extractos Vegetales/metabolismo , Extractos Vegetales/farmacología , Semillas/química , Semillas/crecimiento & desarrollo , Semillas/metabolismoRESUMEN
The phenolic composition of heartwood extracts from Fraxinus excelsior L. and F. americana L., both before and after toasting in cooperage, was studied using LC-DAD/ESI-MS/MS. Low-molecular weight (LMW) phenolic compounds, secoiridoids, phenylethanoid glycosides, dilignols and oligolignols compounds were detected, and 48 were identified, or tentatively characterized, on the basis of their retention time, UV/Vis and MS spectra, and MS fragmentation patterns. Some LMW phenolic compounds like protocatechuic acid and aldehyde, hydroxytyrosol and tyrosol, were unlike to those for oak wood, while ellagic and gallic acid were not found. The toasting of wood resulted in a progressive increase in lignin degradation products with regard to toasting intensity. The levels of some of these compounds in medium-toasted ash woods were much higher than those normally detected in toasted oak, highlighting vanillin levels, thus a more pronounced vanilla character can be expected when using toasted ash wood in the aging wines. Moreover, in seasoned wood, we found a great variety of phenolic compounds which had not been found in oak wood, especially oleuropein, ligstroside and olivil, along with verbascoside and isoverbascoside in F. excelsior, and oleoside in F. americana. Toasting mainly provoked their degradation, thus in medium-toasted wood, only four of them were detected. This resulted in a minor differentiation between toasted ash and oak woods. The absence of tannins in ash wood, which are very important in oak wood, is another peculiar characteristic that should be taken into account when considering its use in cooperage.
Asunto(s)
Cromatografía Liquida/métodos , Fraxinus/química , Fenoles/análisis , Espectrometría de Masas en Tándem/métodos , Árboles/química , Madera/química , Glicósidos/análisis , Glicósidos/química , Calor , Iridoides/análisis , Iridoides/química , Lignanos/análisis , Lignanos/química , Fenoles/química , Quercus/química , Espectrometría de Masa por Ionización de ElectrosprayRESUMEN
Although oak wood is the main material used in cooperage, other species are being considered as possible sources of wood for the production of wines and their derived products. In this work we have compared the phenolic composition of acacia (Robinia pseudoacacia), chestnut (Castanea sativa), cherry (Prunus avium) and ash (Fraxinus excelsior and F. americana) heartwoods, by using HPLC-DAD/ESI-MS/MS (some of these data have been showed in previous paper), as well as the changes that toasting intensity at cooperage produce in each polyphenolic profile. Before toasting, each wood shows a different and specific polyphenolic profile, with both qualitative and quantitative differences among them. Toasting notably changed these profiles, in general, proportionally to toasting intensity and led to a minor differentiation among species in toasted woods, although we also found phenolic markers in toasted woods. Thus, methyl syringate, benzoic acid, methyl vanillate, p-hydroxybenzoic acid, 3,4,5-trimethylphenol and p-coumaric acid, condensed tannins of the procyanidin type, and the flavonoids naringenin, aromadendrin, isosakuranetin and taxifolin will be a good tool to identify cherry wood. In acacia wood the chemical markers will be the aldehydes gallic and ß-resorcylic and two not fully identified hydroxycinnamic compounds, condensed tannins of the prorobinetin type, and when using untoasted wood, dihydrorobinetin, and in toasted acacia wood, robinetin. In untoasted ash wood, the presence of secoiridoids, phenylethanoid glycosides, or di and oligolignols will be a good tool, especially oleuropein, ligstroside and olivil, together verbascoside and isoverbascoside in F. excelsior, and oleoside in F. americana. In toasted ash wood, tyrosol, syringaresinol, cyclolovil, verbascoside and olivil, could be used to identify the botanical origin. In addition, in ash wood, seasoned and toasted, neither hydrolysable nor condensed tannins were detected. Lastly, in chestnut wood, gallic and ellagic acids and hydrolysable tannins of both the gallotannin and ellagitannin type, can be used as chemical markers.
Asunto(s)
Polifenoles/química , Vino/análisis , Madera/química , Cromatografía Líquida de Alta Presión , Flavonoides/química , Espectrometría de Masa por Ionización de Electrospray , Taninos/química , Factores de TiempoRESUMEN
Polyphenolic composition of two Syrah wines aged during 6 or 12 months in medium toasting acacia and oak 225L barrels was studied by LC-DAD-ESI/MS. A total of 43 nonanthocyanic phenolic compounds were found in all wines, and other 15 compounds only in the wines from acacia barrels. Thus, the nonanthocyanic phenolic profile could be a useful tool to identify the wines aged in acacia barrels. Among all of them the dihydrorobinetin highlights because of its high levels, but also robinetin, 2,4-dihydroxybenzaldehyde, a tetrahydroxydihydroflavonol, fustin, butin, a trihydroxymethoxydihydroflavonol and 2,4-dihydroxybenzoic acid were detected at appreciable levels in wines during aging in acacia barrels, and could be used as phenolic markers for authenticity purposes. Although longer contact time with acacia wood mean higher concentrations of phenolic markers found in wines, the identification of these wines will also be easy after short aging times due the high levels reached by these compounds, even after only 2 months of aging.
Asunto(s)
Acacia/química , Polifenoles/análisis , Quercus/química , Vino/análisis , Cromatografía Líquida de Alta Presión , Espectrometría de Masa por Ionización de Electrospray , Factores de TiempoRESUMEN
Avocado processing by the food and cosmetic industries yields a considerable amount of phenolic-rich byproduct such as peels and seeds. Utilization of these byproducts would be favorable from an economic point of view. Methanolic (80%) extracts obtained from lyophilized ground peels and seeds of avocado (Persea americana Mill.) of the Hass and Shepard varieties were characterized for their phenolic compound profiles using the HPLC-PAD technique. The structures of the identified compounds were subsequently unambiguously confirmed by ESI-MS. Compositional analysis revealed that the extracts contained four polyphenolic classes: flavanol monomers, proanthocyanidins, hydroxycinnamic acids, and flavonol glycosides. The presence of 3-O-caffeoylquinic acid, 3-O-p-coumaroylquinic acid, and procyanidin A trimers was identified in seeds of both varieties. Intervarietal differences were apparent in the phenolic compound profiles of peels. Peels of the Shepard variety were devoid of (+)-catechin and procyanidin dimers, which were present in the peels of the Hass variety. Peels of both varieties contained 5-O-caffeoylquinic acid and quercetin derivatives. The differences in the phenolic profiles between varietals were also apparent in the different antioxidant activity of the extracts. The peel extracts had a higher total phenolic compound content and antioxidant activity when compared to the seed extracts. The highest TEAC and ORAC values were apparent in peels of the Haas variety in which they amounted to 0.16 and 0.47 mmol Trolox/g DW, respectively. No significant (p > 0.05) differences were apparent between the TEAC values of seeds of the two varieties but the ORAC values differed significantly (p < 0.05). Overall these findings indicate that both the seeds and peel of avocado can be utilized as a functional food ingredient or as an antioxidant additive.
Asunto(s)
Antioxidantes/análisis , Cinamatos/análisis , Flavonoides/análisis , Persea/química , Fenoles/análisis , Epidermis de la Planta/química , Semillas/química , Antioxidantes/química , Australia , Cinamatos/química , Flavonoides/química , Fenoles/química , Especificidad de la EspecieRESUMEN
This study presents the effects of soaking, cooking and industrial dehydration on the phenolic profile, and antioxidant capacity in two chickpea varieties (Sinaloa and Castellano). Chromatographic analysis identified a total of 24 phenolic components, being isoflavones the main phenolics in raw and processed Sinaloa and Castellano flours. The impact of the industrial dehydration was different depending on the chickpea variety. Although Castellano chickpea exhibited the highest levels of phenolic compounds (103.1 µg/g), significant reductions were observed during processing; in contrast, the dehydration did not cause any further effects in Sinaloa flours. Interestingly, Sinaloa variety showed high thermal stability of isoflavones during processing. As expected, the levels of antioxidant capacity were in accordance with the behavior of phenolic compounds exhibiting noticeable reductions in Castellano chickpea and not relevant changes in Sinaloa chickpea. Thus, the significant occurrence of bioactive phenolic compounds along with the relevant antioxidant capacities of dehydrated chickpea flours make them to be considered functional ingredients for their beneficial health effects, especially in case of Sinaloa.
Asunto(s)
Antioxidantes/química , Antioxidantes/farmacología , Cicer/química , Desecación/métodos , Antioxidantes/análisis , Ácidos Cumáricos/análisis , Ácidos Cumáricos/química , Flavonoles/análisis , Flavonoles/química , Manipulación de Alimentos/métodos , Hidroxibenzoatos/análisis , Hidroxibenzoatos/química , Isoflavonas/análisis , Fenoles/análisis , Fenoles/químicaRESUMEN
The phenolic composition of heartwood from Robinia pseudoacacia, commonly known as false acacia, before and after toasting in cooperage was studied by HPLC-DAD and HPLC-DAD/ESI-MS/MS. A total of 41 flavonoid and nonflavonoid compounds were identified, some tentatively, and quantified. Seasoned acacia wood showed high concentrations of flavonoid and low levels of nonflavonoid compounds, the main compounds being the dihydroflavonols dihydrorobinetin, fustin, tetrahydroxy, and trihydroxymethoxy dihydroflavonol, the flavonol robinetin, the flavanones robtin and butin, and a leucorobinetinidin, none of which are found in oak wood. The low molecular weight (LMW) phenolic compounds present also differed from those found in oak, since compounds with a ß-resorcylic structure, gallic related compounds, protocatechuic aldehyde, and some hydroxycinnamic compounds are included, but only a little gallic and ellagic acid. Toasting changed the chromatographic profiles of extracts spectacularly. Thus, the toasted acacia wood contributed flavonoids and condensed tannins (prorobinetin type) in inverse proportion to toasting intensity, while LMW phenolic compounds were directly proportional to toasting intensity, except for gallic and ellagic acid and related compounds. Even though toasting reduced differences between oak and acacia, particular characteristics of this wood must be taken into account when considering its use in cooperage: the presence of flavonoids and compounds with ß-resorcylic structure and the absence of hydrolyzable tannins.
Asunto(s)
Calor , Fenoles/análisis , Robinia/química , Madera/química , Cromatografía Líquida de Alta Presión , Flavonoides/análisis , Espectrometría de Masa por Ionización de Electrospray , Espectrometría de Masas en Tándem , Vino/análisisRESUMEN
This study presents the effects of soaking, cooking, and industrial dehydration treatments on phenolic profile and also on antioxidant properties in Pardina lentil. HPLC-PAC and HPLC-MS (ESI) analysis identified a total of 35 phenolic compounds in raw and processed lentil flours, corresponding to catechins and procyanidins (69% of the total of identified phenolic compounds), flavonols (17%), flavones, and flavanones (5%), and hydroxybenzoic and hydroxycinnamic compounds (5 and 4%, respectively). During the industrial process, catechins and procyanidins, flavonols, flavones, and flavanones decreased, while hydroxybenzoic compounds exhibited an important increase. In addition, raw lentils showed high values of the antioxidant activity (66.97 µmol Trolox/g); although the thermal processing promotes decreased, the levels of antioxidant activity were still relevant. Thus, the significant occurrence of bioactive phenolic compounds along with the interesting antioxidant capacity of dehydrated lentil flours make them useful for daily inclusion in the human diet as ready-to-use for special meals to specific populations.
Asunto(s)
Antioxidantes/análisis , Desecación , Lens (Planta)/química , Fenoles/análisis , Semillas/química , Antioxidantes/química , Flavonoides/análisis , Flavonoides/química , Conservación de Alimentos , Fenoles/químicaRESUMEN
The phenolic and tannic composition of heartwood extracts from Castanea sativa Mill., before and after toasting in cooperage, were studied using HPLC-DAD and HPLC-DAD/ESI-MS, and some low molecular weight phenolic compounds and hydrolyzable tannins were found. The low molecular weight phenolic compounds were lignin constituents as the acids gallic, protocatechuic, vanillic, syringic, ferulic, and ellagic, the aldehydes protocatechuic, vanillic, syringic, coniferylic, and sinapic, and the coumarin scopoletin. Their patterns were somewhat different those of oak because oak does not contain compounds such protocatechuic acid and aldehyde and is composed of much lower amounts of gallic acid than chestnut. Vescalagin and castalagin were the main ellagitannins, and acutissimin was tentatively identified for the first time in this wood. Moreover, some gallotannins were tentatively identified, including different isomers of di, tri, tetra, and pentagalloyl glucopyranose, and di and trigalloyl-hexahydroxydiphenoyl glucopyranose, comprising 20 different compounds, as well as some ellagic derivatives such as ellagic acid deoxyhexose, ellagic acid dimer dehydrated, and valoneic acid dilactone. These ellagic derivatives as well as some galloyl and hexahydroxydiphenoyl derivatives were tentatively identified for the first time in this wood. The profile of tannins was therefore different from that of oak wood because oak only contains tannins of the ellagitannins type. Seasoned and toasted chestnut wood showed a very different balance between lignin derivatives and tannins because toasting resulted in the degradation of tannins and the formation of low molecular weight phenolic compounds from lignin degradation. Moreover, the different toasting levels provoked different balances between tannins and lignin constituents because the intensity of lignin and tannin degradation was in relation to the intensity of toasting.
Asunto(s)
Fagaceae/química , Fenoles/análisis , Cromatografía Líquida de Alta Presión , CalorRESUMEN
The phenolic and tannic composition of heartwood extracts from Prunus avium , commonly known as cherry tree, before and after toasting in cooperage were studied using HPLC-DAD and HPLC-DAD/ESI-MS. Nonflavonoid (16 compounds) and flavonoid (27 compounds) polyphenols were identified, 12 of them in only a tentative way. The nonflavonoids found were lignin constituents, and their pattern is different compared to oak, since they include compounds such as protocatechuic acid and aldehyde, p-coumaric acid, methyl vanillate, methyl syringate, and benzoic acid, but not ellagic acid, and only a small quantity of gallic acid. In seasoned wood we found a great variety of flavonoid compounds which have not been found in oak wood for cooperage, mainly, in addition to the flavan-3-ols (+)-catechin, a B-type procyanidin dimer, and a B-type procyanidin trimer, the flavanones naringenin, isosakuranetin, and eriodictyol and the flavanonols aromadendrin and taxifolin. Seasoned and toasted cherry wood showed different ratios of flavonoid to nonflavonoid compounds, since toasting results in the degradation of flavonoids, and the formation of nonflavonoids from lignin degradation. On the other hand, the absence of hydrolyzable tannins in cherry wood, which are very important in oak wood, is another particular characteristic of this wood that should be taken into account when considering its use in cooperage.
Asunto(s)
Fenoles/análisis , Prunus/química , Cromatografía Líquida de Alta Presión , Espectrometría de Masa por Ionización de ElectrosprayRESUMEN
Phenolic composition of wine depends not only on the grape variety from which it is made, but on some external factors such as winemaking technology. Red wine possesses the most antioxidant effect because of its high polyphenolic content. The aim of this work is to study for the first time, the neuroprotective activity of four monovarietal Spanish red wines (Merlot (ME), Tempranillo (T), Garnacha (G) and Cabernet-Sauvignon (CS)) through its antioxidant ability, and to relate this neuroprotection to its polyphenolic composition, if possible. The wine effect on neuroprotection was studied through its effect as free radical scavenger against FeSO4, H2O2 and FeSO4 + H2O2. Effect on cell survival was determined by 3(4,5-dimethyltiazol-2-il)-2,5-diphenyltetrazolium reduction assay (MTT) and lactate dehydrogenase (LDH) release assay on astrocytes cultures. Results showed that most of the studied wine varieties induced neuroprotection through their antioxidant ability in astrocytes, Merlot being the most active; this variety is especially rich in phenolic compounds, mainly catechins and oligomeric proanthocyanidins. Our results show that red wine exerts a protection against oxidative stress generated by different toxic agents and that the observed neuroprotective activity is related to their polyphenolic content.
Asunto(s)
Antioxidantes/farmacología , Astrocitos/efectos de los fármacos , Flavonoides/farmacología , Fármacos Neuroprotectores/farmacología , Fenoles/farmacología , Extractos Vegetales/farmacología , Vitis/química , Vino , Astrocitos/metabolismo , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Frutas , Humanos , L-Lactato Deshidrogenasa/metabolismo , PolifenolesRESUMEN
OBJECTIVE: We compared the effects of grapefruit flavonoids and inulin, as single dietary components or in a combination, on cecal fermentation in rats adapted to a semipurified diet. METHODS: The experimental diets contained 0.3% flavonoid extract and 5% or 10% inulin and a combination of both supplements. The large bowel metabolism assessment was based on cecal parameters: bulk effect, pH, microbial enzymes activity, and short-chain fatty acid production. RESULTS: Both supplements induced significant enlargement of the cecal digesta weight. Acidification of cecal digesta was more pronounced, with a higher inulin addition to the diet. Cecal pH was the highest with the flavonoid-rich diets and lowest in the case of a simultaneous addition of flavonoids and a high content of inulin. The flavonoid extract applied as a single dietary supplement was observed to decrease the activity of bacterial beta-glucosidase and beta- and alpha-galactosidases in the cecal digesta. In contrast, addition of the grapefruit extract to inulin-containing diets increased the activity of alpha-glucosidase, alpha-galactosidase, and beta-galactosidase. Great accumulation of cecal digesta in rats consuming the flavonoid-diet caused a considerable increase in the short-chain fatty acid pool, mainly acetic acid. Inulin added to the diet decreased the excessive enlargement of digesta caused by dietary flavonoids. Dietary addition of inulin to the flavonoid-diet also normalized hydration of cecal digesta and significantly decreased the pH of digesta. The presence of polyphenols in the inulin-containing diets did not change total short-chain fatty acid production in the cecum of rats. CONCLUSION: Our results suggested that simultaneous intake of inulin and polyphenols can decrease the detrimental effects of the latter on cecal fermentation.
Asunto(s)
Ciego/metabolismo , Citrus paradisi/química , Digestión/efectos de los fármacos , Fermentación/efectos de los fármacos , Flavonoides/farmacología , Inulina/farmacología , Fenoles/farmacología , Adaptación Fisiológica , Animales , Ciego/química , Ciego/microbiología , Suplementos Dietéticos , Digestión/fisiología , Relación Dosis-Respuesta a Droga , Combinación de Medicamentos , Ácidos Grasos Volátiles/biosíntesis , Fermentación/fisiología , Flavonoides/administración & dosificación , Galactosidasas/metabolismo , Concentración de Iones de Hidrógeno , Inulina/administración & dosificación , Masculino , Fenoles/administración & dosificación , Polifenoles , Distribución Aleatoria , Ratas , Ratas Wistar , beta-Glucosidasa/metabolismoRESUMEN
Lentils (Lens culinaris L.) are a popular food in many countries. However, little is known about their phenolic composition. Because polyphenols in lentils are located essentially in their seed coat, the objective of this work was to study the composition of proanthocyanidins, the major group of polyphenols, in this part of the tissue. The use of C(18) Sep-Pak cartridges permitted the fractionation of lentil seed coat extract into monomer, oligomer, and polymer proanthocyanidin fractions. Subsequent thiolysis of oligomer and polymer fractions followed by HPLC analysis allowed the mean degree of polymerization (mDP) and the structural composition of proanthocyanidins to be determined. A fractionation of lentil seed coat extracts on a polyamide column followed by HPLC and HPLC-DAD-MS analyses was used to identify the individual proanthocyanidins. The results showed that the major monomeric flavan-3-ol was (+) catechin-3-glucose, with lesser amounts of (+)-catechin and (-)-epicatechin. In the oligomer fraction, various dimer, trimer, and tetramer proanthocyanidins constituted of catechin, gallocatechin, and catechin gallate units were identified, and several procyanidins and prodelphinidins from pentamers to nonamers constitute the polymer fraction. The most abundant proanthocyanidins in the seed coat of lentils are the polymers (65-75%), with a mDP of 7-9, followed by the oligomers (20-30%), with a mDP of 4-5.
Asunto(s)
Lens (Planta)/química , Proantocianidinas/análisis , Semillas/química , Benzaldehídos/análisis , Catequina/análisis , Cromatografía Líquida de Alta Presión , Polímeros/análisis , Proantocianidinas/química , Espectrometría de Masa por Ionización de ElectrosprayRESUMEN
Inhibition of α-amylase and trypsin by phenolic extracts of various fruit and vegetable foodstuffs (pears [ Pyrus communis ], lentils [ Lens esculenta ], and cocoa beans [ Theobroma cacao ]) was studied. An appropriate methodology for determining the percentage of inhibition of each enzyme was developed. A concomitant study carried out using standard substances (gallic acid, (+)-catechin, tannic acid, and condensed tannins) showed that polymeric phenols were more potent inhibitors than the simple forms, all of them having different behaviors towards the enzymes, depending on their chemical characteristics. The inhibitory potency of the extracts varied according to the phenolic composition of each and was intermediate between that of the simple and that of the more complex phenolic compounds. Inhibition of α-amylase by the phenolic extracts (at equal concentrations) was of the same order of magnitude, even though the phenolic nature and content in the three foodstuffs differed substantially. In contrast, in the case of trypsin, the lentil and cocoa extracts displayed inhibition 10 times greater than that of the pear extract.