Complexation of resveratrol by native and modified cyclodextrins: Determination of complexation constant by enzymatic, solubility and fluorimetric assays

The complexation of resveratrol with native a-, b- and c-cyclodextrins (CDs) and modified CDs (hydroxypropyl-b-(HP-b-CDs), maltosyl-b-(G2-b-CDs), methyl-b-, carboxymethyl-b- and acetyl-b-cyclodextrins) was studied, and the complexation constants (Kc) were compared. The complexation constant between resveratrol and each type of CD was calculated using three different methods: enzymatic, solubility and fluorimetric. The Kc values obtained showed that HP-b-CDs with their very high Kc of 18,048 ± 625 M 1, were the most effective for complexing resveratrol. Moreover, comparison of the results obtained by the three methods revealed that the fluorimetric method undervalued the Kc between resveratrol and all cyclodextrins, while the enzymatic and solubility methods were more precise for calculating the Kc between resveratrol and CDs, as demonstrated by the cyclodextrin-assay.This work was partially supported by Fundación Séneca (03025/PPC/05) and Ministerio de Educación y Ciencia (AGL2006-08702/ALI). C.L.A. is a holder of a research grant from the Programa Nacional de Formación de Personal Investigador (FPI), Ministerio de Educación y Ciencia (Spain) (BES-2007-16082).Ciencias de la Alimentació

Influencia de la densidad de la masa adulta y el tratamiento del suelo sobre la regeneración del pino laricio (Pinus nigra Arn. ssp. Salzmannii) en España

Satisfactory results relating to the natural regeneration of the Spanish black pine (Pinus nigra Arn ssp. salzmannii) is generally difficult to achieve. The natural regeneration of this pine was studied comparing two types of soil treatment and various overstory densities in six experimental forests. These studies were conducted from 1999 to 2002 and seed rain and germination, as well as seedling survival were observed in a number of specific plots: Brushing, scalping and control plots. In addition various overstory densities were used (measured as base area (square m/ha). Soil and air temperature together with soil moisture were continuously recorded throughout this summer period. The results showed that seed germination was higher in plots using the scalping technique, as opposed to the brushed or controlled plots. The best seedling survival percentage was found in scalped plots together with a larger basal area. It was also found that seedling survival was lower during the first year than during the second one. The results have practical implications for management of Spanish black pine forests as well as valuable information which could improve the conditions for regeneration.Generalmente es difícil conseguir una regeneración natural satisfactoria del pino laricio (Pinus nigra Arn ssp. salzmannii). Esta ha sido estudiada en dos tipos de tratamiento del suelo y bajo diferentes rangos de densidad de masa en seis montes de la Provincia de Cuenca. Entre 1999 y 2000 se ha seguido la lluvia de semillas, germinación y supervivencia de plántulas en las parcelas en las que se realizaron los tratamientos de suelo y bajo diferentes rangos de densidad de masa adulta, medida como área basimétrica (m cuadrados/ha). La temperatura del suelo y aire y la humedad del suelo han sido registradas durante el verano y para las dos primeras épocas de crecimiento de las plántulas. En las zonas decapadas la germinación fue superior a la encontrada en las zonas desbrozadas o testigo. El mejor porcentaje de supervivencia se calculó para las zonas decapadas en combinación con el mayor nivel de área basimétrica medido. La mortalidad de plántulas fue superior durante el primer periodo de crecimiento. Los resultados tienen implicaciones prácticas especialmente en lo relativo a una gestión forestal que mejore las condiciones para la regeneración natural de los bosques de pino laricio

Impact of the cultivation strategy on resveratrol production from glucose in engineered Corynebacterium glutamicum

The health benefits of polyphenols such as stilbenes and flavonoids for humans are increasingly attracting attention. Resveratrol is awell-characterized naturally-occurring stilbeneandpotentanti-oxidant, which isused as food supplement and cosmetic ingredient. Several microorganisms including Corynebacterium glutamicum were engineered for resveratrol production from glucose. Based on the cultivation of a resveratrol-producing C. glutamicum strain in shake flasks, different strategies for improving production under controlled conditions at bioreactor scale were tested. To this end, different cultivation parameters including substrate concentration and operation modes (batch and fed-batch) were evaluated. Whereas the highest biomass concentration was observed during fed-batch fermentation, the maximum resveratrol production was achieved in batch mode. The maximal titer obtained was 12 mg L−1 of resveratrol without the addition of the fatty acid synthase inhibitor cerulenin, which was previously shown to be crucial for production with C. glutamicum. The specific growth rate duringproductionseemstohaveasignificanteffectinresveratrolproductionandapparentlylowspecificgrowth rates may redirect the metabolic bottleneck from p-coumaric acid formation to malonyl-CoA or ATP availability. We also show that high oxygen concentrations in the bioreactor negatively affected the obtained resveratrol titerswithC.glutamicum,whichismost likelydueto thestrongtendency ofresveratrol tooxidizeoroligomerize. Thus, up-scaling of the resveratrol production process is technically challenging and individual process parameters have to be optimized cautiously.We would like to thank the European Union Framework Program 7 "BacHBerry" (www.bachberry.eu), Project No. FP7- 613793 for financial support, the PortugueseFoundation forScience andTechnology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit, COMPETE 2020 (POCI-01-0145-FEDER-006684) and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 − Programa Operacional Regional do Norte.info:eu-repo/semantics/publishedVersio

¿La cirugía laparoscópica en el cáncer de colon presenta iguales resultados en pacientes octogenarios? Influencia de factores diferenciales

S'ha realitzat un estudi retrospectiu sobre 593 pacients dividits en tres grups d'edat ( 80 anys), intervinguts de càncer de còlon per laparoscòpia entre 1998 i 2009. S'han analitzat totes les variables preoperatòries, la morbiditat associada a cada grup d'edat tant mèdica como quirúrgica i les dades intraoperatòries, per a obtenir la taxa de complicacions postoperatòries. Després dels resultats s'ha objectivat que l'índex de complicacions en el grup de majors de 80 anys és major a causa del gran nombre de factors de risc pel que fa als més joves.Se ha realizado un estudio retrospectivo sobre 593 pacientes divididos en tres grupos de edad ( 80 años), intervenidos de cáncer de colon por laparoscopia entre 1998 y 2009. Se han analizado todas las variables preoperatorias, la morbilidad asociada en cada grupo de edad tanto médica como quirúrgica y los datos intraoperatorios; para obtener la tasa de complicaciones postoperatorias. Tras los resultados se ha objetivado que el índice de complicaciones en el grupo de mayores de 80 años es mayor debido al mayor número de factores de riesgo con respecto a los más jóvenes

Effect of HP-b-cyclodextrins complexation on the antioxidant activity of flavonols

The beneficial effects from phenolic compounds have been attributed to their antioxidant activity. Differences in the chemical structure of flavonols and their degree of substitution will influence phenoxyl radical stability and, thereby, their antioxidant properties. Cyclodextrins (CDs) can be used as a flavonol complexation agent, since they act as a substrate reservoir in a dose-controlled manner. In the present paper, the effect of complexing flavonols, kaempferol, quercetin and myricetin with HP-b-CDs on their antioxidant capacity is studied by means of the oxygen radical absorbance capacity-fluorescein (ORAC-FL) assay. This complexation phenomenon increased the antioxidant activity of the three flavonols, which reached a maximum level when each flavonol had been complexed in the hydrophobic cavity of CDs. The antioxidant activity increased because of the flavonol was protected against rapid oxidation by free radicals.Ciencias de la Alimentació

Comparative study of different methods to measure antioxidant activity of resveratrol in the presence of cyclodextrins

The antioxidant activity of resveratrol in the absence and presence of increasing concentrations of HPb- CDs was determined using three different methods: ORAC, ABTS and DPPH. The three methods were validated and compared for their linearity, precision and accuracy in measuring resveratrol antioxidant activity. The results indicated that the most sensitive method is the ORAC assay, which can measure the lowest resveratrol concentration (0.15–2 lM) with the highest precision. In the presence of increasing concentrations of HP-b-CDs, the antioxidant activity of resveratrol was seen to increase when it was measured by the ORAC and ABTS assays. However, no increase was observed when the DPPH assay was used. With the ORAC assay, the antioxidant activity increased until all the resveratrol had been included in HP-b-CDs (0.4 mM CDs), whereas in the case of ABTS assay the plateau in antioxidant activity was reached after 2 mM HP-b-CDs, suggesting that the CDs interferences in the measurement method. When the DPPH assay was used, no effect was observed when increasing concentrations of HP-b-CDs, indicating that in a methanolic medium resveratrol is free. Therefore, so this method cannot be used to measure the effect of resveratrol complexation with CDs on its antioxidant activity.Ciencias de la Alimentació

Impact of vulvovaginal atrophy of menopause in Spanish women: prevalence and symptoms according to the EVES Study

Introduction: The prevalence of menopausal women with confirmed vulvovaginal atrophy (VVA) oscillates between 67e98%. Aim: To assess the prevalence of postmenopausal women with VVA confirmed by gynecologic clinical assessment among all women attending menopause centers in Spain, as well as to describe the impact of VVA on quality of life and sexual functioning. Methods: Women aged 45e75 years old with the last menstrual period >12 months before were included in a cross-sectional study. Main Outcome Measures: Women with 1 VVA symptoms filled out a number of questionnaires, including EuroQoL, Day-to-Day Impact of Vaginal Aging, Female Sexual Function Index, and Female Sexual Distress Scale-revised. A gynecologic examination was performed to confirm diagnosis. Results: 1,177 evaluable patients were included. VVA was confirmed in 87.3% of the patients. Almost 80% of women who acknowledged being sexually active (n ¼ 717) presented pain during intercourse. As compared with patients without confirmed VVA (n ¼ 66), patients with confirmed VVA (n ¼ 1,028) were significantly older (P < .0001), had lower rates of sexual activity (P < .05), and used more VVA treatments (P < .05). Severe vaginal atrophy and severe vulvar atrophy were more prevalent in VVA-confirmed women (P < .0001, in both cases). No differences regarding the confirmation of VVA were observed for EuroQoL andDay-to-Day Impact of Vaginal Aging quality-oflife questionnaires. Sexual function measured through the Female Sexual Function Index score was significantly reduced in sexually-active patients with confirmed VVA (P < .05). Conclusion: VVA signs and symptoms are highly prevalent in Spanish postmenopausal women. Confirmation of VVA diagnosis was associated with impaired sexual function. The early recognition of VVA symptoms should be actively promoted in medical practice, instead of waiting until signs appear to exclude other reasons for VVA and to manage treatment effectively

Effect of temperature, pH, β- and HP-β-CDs on the solubility and stability of flavanones: naringenin and hesperetin

Naringenin and hesperetin are two of the most abundant flavanones found in citrus with beneficial effects on human health. However, their poor water solubility imposes considerable limitations to their use in functional foods or nutraceuticals development. In order to increase their aqueous solubility and find a new stable system, the effect of different factors as temperature, pH or complexation agents as cyclodextrins has been studied. The solubility of both flavanones increased exponentially with temperature (25-90 ºC): 10-fold in the case of naringenin and 20-fold for hesperetin. The solubility of both flavanones also increased with the media pH (3.5-8.5): 314-fold in the case of naringenin and 3.5-fold for hesperetin. Flavanones solubility also increased with β- or HP-β-CDs concentration. By the addition of β-CDs 13 mM naringenin solubility increased 9.3-fold and hesperetin solubility 30-fold. Using HP-β-CDs 100 mM naringenin solubility increased 143-fold and hesperetin 467-fold. In summary, the higher increase in naringenin solubility was reached by increasing pH up 8.5. However, in the case of hesperetin, the higher increase was obtained by complexation with HP-β-CDs 100 mM. Moreover, the presence of CDs, not only increased the aqueous solubility of flavanones, but also improved the stability of hesperetin at pHs 3.5 and 6.5.Ciencias de la Alimentació

Protective effect of cyclodextrins on the quality parameters of roast preserved pepper

Total phenolics (TP), vitamin C, antioxidant activity and colour of preserved peppers were evaluated at 4, 25 and 50 C storage during 30-day intervals. Except for 4 C, TP decreased during storage at 25 C and 50 C, being softer for fortified samples with b-CDs. The protective effect was evident, since 50 C samples containing b-CDs exhibited lower TP loss (19%) than control samples (38%) for 5 months storage. A decrease in the vitamin C content was observed for both samples as time and temperature progressed. In samples stored at 50 C the protective effect of b-CD only was evident at the first month, since fortified samples showed lower vitamin C loss (10%) than control samples. The fortified samples with b-CDs exhibited lowest antioxidant activity loss (40%) during 90-day storage at 50 C, than control samples (64%). The colour changes were in line with those observed for total phenolics and at the end of study, the presence of 1% b-CDs delayed the darkening of samples at both (25 and 50 C) storage conditions.Ciencias de la Alimentació

Pulsed light for a cleaner dyeing industry: azo dye degradation by an advanced oxidation process driven by pulsed light

Water pollution by wastewater containing dyes is an environmental issue that can be mitigated by the use of advanced oxidation processes (AOP). Pulsed light (PL) is an emerging food processing technology that uses eco-friendly lamps and can potentially be adapted as light source of an UV-based AOP. In the present work, a PL/H2O2 process was tested for the decolourization of two azo dyes, and a pulsed light/H2O2/ferrioxalate process was tested for the decolourization of one azo dye. The efficiency of the PL/H2O2 process in a batch reactor under different parametric values: dye concentration, pH, H2O2 and salt doses was followed by spectrophotometry and fitted to first-order kinetics; and several degradation products were detected. In the PL/H2O2 process, decolourization rates increased at low dye concentrations and high H2O2 doses, were pH-dependent and were inhibited by the addition of NaCl, Na2SO3 or Na2CO3. More than 50 % decolouration was achieved with the PL/H2O2 process for both dyes after applying 54 J/cm2 (25 light pulses). The PL/H2O2/ferrioxalate process achieved > 95 % decolouration for Methyl orange when applying 21 J/cm2 (10 pulses); that level of energy can be supplied by PL commercial systems in nine and four seconds respectively. No known toxic degradation products were detected. Results show that a PL/H2O2 process has potential to be used for the efficient degradation of dyes from wastewater. Furthermore, the efficacy of this process can be improved by the use of ferrioxalate. PL technology could become an alternative light source to contribute to decrease the environmental impact of wastewater produced by the dyeing industry.Ciencias de la Alimentació