RESUMEN
Oxidative stress and inflammation play a key role in diverse pathological conditions such as cancer and metabolic disorders. The objective of this study was to determine the antioxidant and anti-inflammatory potentials of crude extract (CE) and phenolic-enriched extract (PHE) obtained from the seed coats (SCs) of black bean (BB) and pinto bean (PB) varieties. Delphinidin-3-O-glucoside (46 mg/g SC), malvidin-3-O-glucoside (29.9 mg/g SC), and petunidin-3-O-glucoside (7.5 mg/g SC) were found in major concentrations in the PHE-BB. Pelargonidin (0.53 mg/g SC) was only identified in the PHE-PB. PHE from both varieties showed antioxidant and radical scavenging capacities, with strong correlations associated with total phenolic content (TPC). Polyphenolics, including catechin, myricetin, kaempferol, quercetin, and isorhamnetin glucosides, were identified in the extracts. In terms of the anti-inflammatory potentials, PHE-PB had an IC50 of 10.5 µg dry extract/mL (µg DE/mL) for cyclooxygenase-2 (COX-2) inhibition. The inhibition values for cyclooxygenase-1 (COX-1) ranged from 118.1 to 162.7 µg DE/mL. Regarding inducible nitric oxide synthase (iNOS) inhibition, PHE-BB had an IC50 of 62.6 µg DE/mL. As determined via in silico analysis, pelargonidin showed binding affinities of -7.8 and -8.5 kcal/mol for COX-1 and iNOS, respectively, and catechin had a value of -8.3 kcal/mol for COX-2. Phenolic-enriched extracts from seed coats of black and pinto beans showed good antioxidant and anti-inflammatory potential that warrants in vitro and in vivo studies.
Asunto(s)
Catequina , Phaseolus , Phaseolus/química , Antioxidantes/química , Extractos Vegetales/química , Ciclooxigenasa 2/metabolismo , Catequina/metabolismo , Antiinflamatorios/farmacología , Antiinflamatorios/metabolismo , Fenoles/análisis , Glucósidos/metabolismoRESUMEN
Seeds of tropical pioneer trees have chemical and physical characteristics that determine their capacity to persist in the soil seed bank. These traits allow seeds to survive in the soil despite diverse predators and pathogens, and to germinate and recruit even decades after dispersal. Defenses in seedlings and adult plants often are described in terms of tradeoffs between chemical and physical defense, but the interplay of defensive strategies has been evaluated only rarely for seeds. Here we evaluated whether classes of seed defenses were negatively correlated across species (consistent with tradeoffs in defense strategies), or whether groups of traits formed associations across species (consistent with seed defense syndromes). Using 16 of the most common pioneer tree species in a neotropical lowland forest in Panama we investigated relationships among four physical traits (seed fracture resistance, seed coat thickness, seed permeability, and seed mass) and two chemical traits (number of phenolic compounds and phenolic peak area), and their association with seed persistence. In addition, seed toxicity was assessed with bioassays in which we evaluated the activity of seed extracts against representative fungal pathogens and a model invertebrate. We did not find univariate tradeoffs between chemical and physical defenses. Instead, we found that seed permeability - a trait that distinguishes physical dormancy from other dormancy types - was positively associated with chemical defense traits and negatively associated with physical defense traits. Using a linear discriminant analysis and a hierarchical cluster analysis we found evidence to distinguish three distinct seed defense syndromes that correspond directly with seed dormancy classes (i.e., quiescent, physical, and physiological). Our data suggest that short and long-term persistence of seeds can be achieved via two strategies: having permeable seeds that are well defended chemically, corresponding to the physiologically dormant defense syndrome; or having impermeable seeds that are well defended physically, corresponding to the physically dormant defense syndrome. In turn, transient seeds appear to have a lower degree of chemical and physical defenses, corresponding to the quiescent defense syndrome. Overall, we find that seed defense and seed dormancy are linked, suggesting that environmental pressures on seed persistence and for delayed germination can select for trait combinations defining distinct dormancy-defense syndromes.
Asunto(s)
Latencia en las Plantas , Semillas , Germinación , Humanos , Panamá , Suelo , SíndromeRESUMEN
Black beans contain anthocyanins that could be used as colorants in foods with associated health benefits. The objective was to optimize anthocyanins extraction from black bean coats and evaluate their physicochemical stability and antidiabetes potential. Optimal extraction conditions were 24% ethanol, 1:40 solid-to-liquid ratio and 29°C (P<0.0001). Three anthocyanins were identified by MS ions, delphinidin-3-O-glucoside (465.1m/z), petunidin-3-O-glucoside (479.1m/z) and malvidin-3-O-glucoside (493.1m/z). A total of 32mg of anthocyanins were quantified per gram of dry extract. Bean anthocyanins were stable at pH 2.5 and low-temperature 4°C (89.6%), with an extrapolated half-life of 277days. Anthocyanin-rich extracts inhibited α-glucosidase (37.8%), α-amylase (35.6%), dipeptidyl peptidase-IV (34.4%), reactive oxygen species (81.6%), and decreased glucose uptake. Black bean coats are a good source of anthocyanins and other phenolics with the potential to be used as natural-source food colorants with exceptional antidiabetes potential.
Asunto(s)
Antocianinas/química , Colorantes de Alimentos/química , Hipoglucemiantes/uso terapéutico , Phaseolus/química , Extractos Vegetales/química , Fenómenos QuímicosRESUMEN
Soybean contains constituents that have antinutritional and bioactive properties. Enzymatic hydrolysis and germination can enhance the biological activity of these compounds in soybean. The objective of this study was to investigate the effect of germination, Alcalase (protease) hydrolysis, and their combination on the concentrations of antinutritional and bioactive compounds in Brazilian soybean cultivar BRS 133. A combination of germination and Alcalase hydrolysis resulted in the degradation of Bowman-Birk inhibitor (BBI), Kunitz trypsin inhibitor (KTI), and lunasin by 96.9, 97.8, and 38.4%. Lectin was not affected by any of the processing treatments when compared to nongerminated and nonhydrolyzed soy protein extract. Total isoflavones (ISF) and total saponins (SAP) increased by 16.2 and 28.7%, respectively, after 18 h of germination, while Alcalase hydrolysis led to the reduction of these compounds. A significant correlation was found between concentrations of BBI and KTI, BBI and lunasin, BBI and ISF, KTI and lunasin, KTI and ISF, KTI and SAP, lunasin and ISF, and ISF and SAP. Germination and Alcalase hydrolysis interacted in reducing BBI, ISF, and SAP. This study presents a process of preparing soy flour ingredients with lower concentrations of antinutritional factors and with biologically active constituents, important for the promotion of health associated with soybean consumption. In conclusion, 18 h of germination and 3 h of Alcalase hydrolysis is recommended for elimination of protease inhibitors, while bioactives are maintained by at least 50% of their original concentrations.
Asunto(s)
Germinación/fisiología , Glycine max , Semillas/enzimología , Semillas/crecimiento & desarrollo , Inhibidor de la Tripsina de Soja de Bowman-Birk/metabolismo , Inhibidor de la Tripsina de Soja de Kunitz/metabolismo , Brasil , Hidrólisis , Isoflavonas/análisis , Saponinas/análisis , Semillas/química , Especificidad de la Especie , Subtilisinas/metabolismo , Inhibidor de la Tripsina de Soja de Bowman-Birk/análisis , Inhibidor de la Tripsina de Soja de Kunitz/análisisRESUMEN
The adulteration of coffee with cereals, coffee twigs, etc. is apparently widespread in Brazil with corn being considered the most widely used. No adequate methods are available to detect such contamination in commercial coffee. A new method, based on high-performance liquid chromatography (HPLC) tocopherol determination was developed to detect coffee adulteration by corn. Percentages of alpha-, beta-, gamma-, and delta-tocopherol determined by HPLC in six coffee varieties were 29.0, 61.7, 3.3, and 6.0, respectively. Similar values were obtained in six popular coffee brands. The percentages of alpha-, gamma-, and delta-tocopherol in six corn samples were 3.6, 91.3, and 5.1, respectively. These differences could be applied to detect corn in a pure coffee sample intentionally contaminated with corn with the best result obtained with gamma-tocopherol. With this methodology, one coffee brand was apparently adulterated (8.9%), most likely with corn. Tocopherol fingerprinting offers the potential to detect adulteration.