Elaboración de un protocolo de determinación de micronutrientes para su implamentación en la docencia práctica

Memoria ID-169. Ayudas de la Universidad de Salamanca para la innovación docente, curso 2018-2019

Anthocyanin composition in fig (Ficus carica L.)

[EN] The anthocyanin composition was analysed in fig fruit (Ficus carica L.) from five different varieties (Colar, Cuello de Dama (green), Cuello de Dama (dark purple), Granilla and Bursa Siyahi). Fifteen anthocyanin pigments were detected, most of them containing cyanidin (Cy) as aglycone; some pelargonidin (Pg) derivatives were also found. Rutinose and glucose were present as substituting sugars, as well as acylation with malonic acid. Minor levels of peonidin 3-rutinose (Pn 3-rutinoside) in the pulp were also detected. Other noticeable aspects in the pigment composition of the fig were the detection of anthocyanidin-derived pigments, namely 5-carboxypyranocyanidin-3-rutinoside, a cyanidin 3-rutinose dimer and five condensed pigments containing C–C linked anthocyanins (Cy and Pg) and flavanol (catechin and epicatechin) residues. Total anthocyanin content in the skin ranged between 32 and 97 mgg 1 and between 1.5 and 15 mgg 1 in the pulp. The main anthocyanin in both parts of the fruit was Cy 3-rutinoside (48–81% in skin and 68–79% in pulp) usually followed by Cy 3-glucoside (5–18% in skin and 10–15% in pulp). Malonyl derivatives were more abundant in the skin (1.2–6.5%) than in the pulp (1.0–2.6%)

Diseño e implementación de píldoras formativas con autoevaluación mediante Kaltura como una nueva metodología para mejorar el aprendizaje

Memoria ID2022-197 Ayudas de la Universidad de Salamanca para la innovación docente, curso 2022-2023

Betalains and phenolic compounds profiling and antioxidant capacity of pitaya (Stenocereus spp.) fruit from two species (S. Pruinosus and S. stellatus)

[EN] Pitaya fruits (Stenocereus spp.) contain betalains and phenolic compounds that have not been completely characterized. Fruits of two ecotypes of S. pruinosus, red-fleshed (SpR) and orange-fleshed (SpO), and two of S. stellatus, red-fleshed (SsR) and white-fleshed (SsW), were characterized in their betalains and phenolic compounds. The chromatographic profile of betalains was similar in SpR, SpO, and SsR, where indicaxanthin, gomphrenin I, phyllocacthin, and their isomers predominated. Betaxanthins content was higher than betacyanins and ranged from 17,706.7 ± 1128.1 to 22,053.6 ± 328.1 mg/g dry sample. The identified phenolics mostly corresponded to hydroxycinnamoyl derivatives, flavonols and flavanones. The phenolics content was higher in S. stellatus than in S. pruinosus. The ecotype SsW, that had flesh without color, showed the highest concentration. The antioxidant capacity varied within 9.21 ± 0.84 and 2.41 ± 0.36 lmol Trolox/g fresh sample, as determined by the ABTS assay. By its phytochemical composition, the fruits of pitaya can be a good source of antioxidant compounds

Colour implications of self-association processes of wine anthocyanins

[EN] Copigmentation processes have been indicated to be crucial to stabilise coloured forms of the anthocyanins and explain colour expression in young red wines. Several studies exist about copigmentation between anthocyanins and different phenolics in model solutions, but little information is available about interactions among anthocyanins themselves. In this work, the process of self-association has been investigated in wine-like model solutions containing different grape anthocyanins (the 3-glucosides of malvidin, delphinidin and peonidin). The results obtained confirmed the existence of anthocyanin self-association and its influence on the apparent hydration constant of the anthocyanins with subsequent modification in the colour of the solutions. It was observed that the greater the degree of methoxylation of the anthocyanin B-ring the greater was the magnitude of the self-association. Colour analyses in the CIELAB space showed that self-association produces changes, which are more important in quantitative parameters (chroma, C ab* and lightness, L *) than in qualitative ones (hue, h ab). Self-association leads to an increase in C ab*, indicating a more intense colour of the solutions, and to a decrease in the psychometric index L *, meaning that a darkening is produced. The effects on the colour were more pronounced with the passage of time of storage of the solutions

Studies on the copigmentation between anthocyanins and flavan-3-ols and their influence in the colour expression of red wine

[ES] With the aim of evaluating the importance of the copigmentation process between anthocyanins and flavanols on the colour expression of red wine, assays were carried out in wine model systems with mixtures of compounds obtained from two Vitis vinifera grape varieties (Graciano and Tempranillo). Spectrophotometric and chromatic analyses were performed to evaluate the magnitude of the copigmentation and the modifications induced in the colour of the solutions. Measurement of the changes in the anthocyanin hydration constant (Kh) was also used to determine the strength of the copigmentation process. All the flavanols assayed induced significant changes in the colour, perceptible to the human eye, of the wine-like anthocyanin solutions at concentrations similar to those that can exist in red wines. The percentage contribution of the copigmentation with flavanols to the colour of the anthocyanin solutions was found to range from 2% to 20%. The extent of this effect was related not only to the concentration of flavanols but also to the qualitative composition of the flavanol preparations, as influenced by the part of the grape (either skin or seed) and the variety considered. Divergences were found between the evaluation of the copigmentation based on chromatic parameters in the CIELAB colour space and that based on the measurement at visible kmax, as the latter does not consider the integral colour changes produced in the visible spectrum. The results obtained confirmed the importance of the qualitative phenolic composition, determined in the wine by the type of grape and winemaking practices, to the production of an effective copigmentation process

Compuestos bioactivos de legumbres. Evaluación y efecto del proceso de adición de enzimas

Tesis Doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Química Agrícola, Geología y Geoquímica. Fecha de lectura: 24-06-200

Exploring Target Genes Involved in the Effect of Quercetin on the Response to Oxidative Stress in Caenorhabditis elegans

[EN] Quercetin is one the most abundant flavonoids in the human diet. Although it is well known that quercetin exhibits a range of biological activities, the mechanisms behind these activities remain unresolved. The aim of this work is to progress in the knowledge of the molecular mechanisms involved in the biological effects of quercetin using Caenorhabditis elegans as a model organism. With this aim, the nematode has been used to explore the ability of this flavonoid to modulate the insulin/insulin-like growth factor 1(IGF-1) signaling pathway (IIS) and the expression of some genes related to stress response. Different methodological approaches have been used, i.e., assays in knockout mutant worms, gene expression assessment by RT-qPCR, and C. elegans transgenic strains expressing green fluorescent protein (GFP) reporters. The results showed that the improvement of the oxidative stress resistance of C. elegans induced by quercetin could be explained, at least in part, by the modulation of the insulin signaling pathway, involving genes age-1, akt-1, akt-2, daf-18, sgk-1, daf-2, and skn-1. However, this effect could be independent of the transcription factors DAF-16 and HSF-1 that regulate this pathway. Moreover, quercetin was also able to increase expression of hsp-16.2 in aged worms. This observation could be of particular interest to explain the effects of enhanced lifespan and greater resistance to stress induced by quercetin in C. elegans, since the expression of many heat shock proteins diminishes in aging worms

Nitric oxide plays a role in stem cell niche homeostasis through its interaction with auxin

[EN]Nitric oxide (NO) is a unique reactive nitrogen molecule with an array of signaling functions that modulates plant developmental processes and stress responses. To explore the mechanisms by which NO modulates root development, we used a pharmacological approach and NO-deficient mutants to unravel the role of NO in establishing auxin distribution patterns necessary for stem cell niche homeostasis. Using the NO synthase inhibitor and Arabidopsis (Arabidopsis thaliana) NO biosynthesis mutants (nitric oxide-associated1 [noa1], nitrate reductase1 [nia1] and nia2, and nia1 nia2 noa1), we show that depletion of NO in noa1 reduces primary root elongation and increases flavonol accumulation consistent with elevated reactive oxygen species levels. The elevated flavonols are required for the growth effect, because the transparent testa4 mutation reverses the noa1 mutant root elongation phenotype. In addition, noa1 and nia1 nia2 noa1 NO-deficient mutant roots display small root meristems with abnormal divisions. Concomitantly, auxin biosynthesis, transport, and signaling are perturbed. We further show that NO accumulates in cortex/endodermis stem cells and their precursor cells. In endodermal and cortical cells, the noa1 mutant acts synergistically to the effect of the wuschel-related homeobox5 mutation on the proximal meristem, suggesting that NO could play an important role in regulating stem cell decisions, which has been reported in animals

Influence of processing in the phenolic composition and health-promoting properties of lentils (Lens culinaris L.)

'Lentils (Lens culinaris L.) are a source of polyphenolic compounds with health-promoting properties, but cooking processes before consumption cause hydrolytic reactions, endogenous enzymes and biochemical metabolism activation which could interfere with their positive physiological effects. The aim of this study was to assess the influence of boiling and germination in the phenolic content and composition of marketed lentils by liquid chromatography analysis and thus, to evaluate its impact on the neuroprotective and anticancer properties through cell culture assays. The protective effect toward astrocyte culture when submitted to an oxidant injury remained after processing while a decrease in the antioxidant activity by oxygen radical absorbing capacity assay and DPPH methods was detected. Every sample was cytotoxic on the assayed cancer cell lines, the strongest antiproliferative activity being for germinated lentils on melanoma cell line. In conclusion, processing of lentils led to significant chemical modifications in the polyphenolic content without significant influence on its healthy properties’PRACTICAL APPLICATIONS This study assesses the influence of two cooking processes for legumes, boiling and germination, in the phenolic content and composition of lentils and its impact on health promoting properties mainly mediated by antioxidant activity. Both processes caused significant changes in the chemical composition which was reflected as a decrease in the antioxidant in vitro activity while neuroprotective effect remained. Every sample showed antitumoral activity toward the assayed cell lines, the strongest antiproliferative activity being obtained for germinated lentils on melanoma cell line. In conclusion, processing lentils before human consumption does not decrease the health-promoting properties of this legume. Further studies to obtain food derivatives with a right balance among palatability, digestibility and antioxidant ability are desirableMinisterio de Educación y Ciencia (España)Depto. de Farmacología, Farmacognosia y BotánicaFac. de FarmaciaTRUEpu