Conservation of commercial quality and bioactive compounds of guava pieces by application of an alginate-acemannan coating

The objective of this study was to evaluate the effect of an edible coating based on alginate and acemannan on the commercial quality and concentration of bioactive compounds of guava pieces stored in refrigeration. Pieces of guava were coated with an alginate film enriched with acemannan (A-Ac), with samples without cover used as a control. The fruit pieces with and without the A-Ac coating were stored for 12 days at 6 ± 2 °C. Analyses of colour, firmness, ethylene production, ascorbic acid, total polyphenols, antioxidant potential, and polyphenol profile were performed at 0, 3, 6, 9, and 12 days of storage. In addition, a sensory analysis was carried out after nine days of refrigeration. The coated guava pieces retained firmness at 2.8 N, while in the uncoated pieces, firmness decreased to 1.3 N. Similarly, the coated pieces showed better colour retention (ΔE<9) and lower ethylene emission during storage. Also, the content of ascorbic acid, total polyphenols, antioxidant capacity, and the concentration of individually identified polyphenols were higher in the pieces of guava coated with the A-Ac film. In addition, coated guava pieces, stored for nine days in refrigeration, showed greater sensory acceptability compared to uncoated samples. Therefore, applying the A-Ac cover could be a good alternative for conserving sensory attributes and bioactive compounds of guava pieces stored at low temperatures

Nutritional quality, fatty acids content and antioxidant capacity of pecan nut fruits from Criolla and Improved walnut varieties

In the current study were evaluated the nutrimental quality, fatty acid and mineral content, and antioxidant capacity of pecan nut of Criolla and Improved walnut varieties. Nut fruit samples of three Criolla walnut varieties (‘Nazas I’, ‘Nazas II’ and ‘Norteña’), and two Improved varieties (‘Western’ and ‘Wichita’) were collected in La Laguna (Nazas, Durango) in Northern Mexico. The analyses run in nut samples were: bromatological and mineral content, fatty acids profile and antioxidant capacity. The results showed that Criolla and Improved varieties had similar bromatological content except ‘Nazas I’, which had the lowest protein and fat content. Furthermore, nuts from Criolla varieties had a higher mineral content, including iron (~38 mg/100 g dw), zinc (~51 mg/100 g dw) and manganese (25 mg/100 g dw). Besides, the fatty acid profile indicates a higher rate of oleic acid (71%) in nut oil of Criolla varieties than in Improved varieties (61%). Regarding antioxidant capacity (AC) the obtained values were similar in all varieties, with ‘Norteña’ variety (850 µM trolox equivalent/g of oil) in Criolla, and ‘Western’ (800 µM trolox equivalent/g of oil) in Improved as the highest values of AC among all varieties. Hence, pecan nut fruits of Criolla varieties are good nutrients and beneficial health compounds source for consumers, and their production and marketing represent interesting opportunity areas for nut producers

Benzimidazole derivatives as new and selective inhibitors of arginase from leishmania mexicana with biological activity against promastigotes and amastigotes

17 pags, 6 figs, 3 tabs, 2 schs. -- Supplementary materials are available online at https://www.mdpi.com/article/10 .3390/ijms222413613/s1.Leishmaniasis is a disease caused by parasites of the Leishmania genus that affects 98 countries worldwide, 2 million of new cases occur each year and more than 350 million people are at risk. The use of the actual treatments is limited due to toxicity concerns and the apparition of resistance strains. Therefore, there is an urgent necessity to find new drugs for the treatment of this disease. In this context, enzymes from the polyamine biosynthesis pathway, such as arginase, have been considered a good target. In the present work, a chemical library of benzimidazole derivatives was studied performing computational, enzyme kinetics, biological activity, and cytotoxic effect characterization, as well as in silico ADME-Tox predictions, to find new inhibitors for arginase from Leishmania mexicana (LmARG). The results show that the two most potent inhibitors (compounds 1 and 2) have an I50 values of 52 μM and 82 μM, respectively. Moreover, assays with human arginase 1 (HsARG) show that both compounds are selective for LmARG. According to molecular dynamics simulation studies these inhibitors interact with important residues for enzyme catalysis. Biological activity assays demonstrate that both compounds have activity against promastigote and amastigote, and low cytotoxic effect in murine macrophages. Finally, in silico prediction of their ADME-Tox properties suggest that these inhibitors support the characteristics to be considered drug candidates. Altogether, the results reported in our study suggest that the benzimidazole derivatives are an excellent starting point for design new drugs against leishmanisis.This research was funded by the Consejo Nacional de Ciencia y Tecnología (CONACyT), grants 257848 (A.T.-V.) and 258694 (C.A.-D.). The work in Spain was funded by a grant from the Spanish Ministry of Science, Innovation and Competitiveness PID2020-115331GB-100 to J.A.-H.Peer reviewe

Computational Methods in Cooperation with Experimental Approaches to Design Protein Tyrosine Phosphatase 1B Inhibitors in Type 2 Diabetes Drug Design: A Review of the Achievements of This Century

Protein tyrosine phosphatase 1B (PTP1B) dephosphorylates phosphotyrosine residues and is an important regulator of several signaling pathways, such as insulin, leptin, and the ErbB signaling network, among others. Therefore, this enzyme is considered an attractive target to design new drugs against type 2 diabetes, obesity, and cancer. To date, a wide variety of PTP1B inhibitors that have been developed by experimental and computational approaches. In this review, we summarize the achievements with respect to PTP1B inhibitors discovered by applying computer-assisted drug design methodologies (virtual screening, molecular docking, pharmacophore modeling, and quantitative structure–activity relationships (QSAR)) as the principal strategy, in cooperation with experimental approaches, covering articles published from the beginning of the century until the time this review was submitted, with a focus on studies conducted with the aim of discovering new drugs against type 2 diabetes. This review encourages the use of computational techniques and includes helpful information that increases the knowledge generated to date about PTP1B inhibition, with a positive impact on the route toward obtaining a new drug against type 2 diabetes with PTP1B as a molecular target

Effects of Moringa oleifera Leaf Extract on Diabetes-Induced Alterations in Paraoxonase 1 and Catalase in Rats Analyzed through Progress Kinetic and Blind Docking

In our study, we aimed to evaluate the effects of Moringa oleifera leaves extract on rat paraoxonase 1 (rPON1) and catalase (rCAT) activities in alloxan-induced diabetic rats. Our study included three groups; group C (control, n = 5); group D (diabetic, n = 5); and group DM (M. oleifera extract-supplemented diabetic rats, n = 5). Daily oral administration of M. oleifera extract at 200 mg/kg doses produced an increase in endogenous antioxidants. Serum rPON1 (lactonase) and liver cytosol catalase activities were determined by a spectrophotometric assay using progress curve analysis. We found a decrease in the Vm value of rPON1 in diabetic rats, but dihydrocoumarin (DHC) affinity (Km) was slightly increased. The value of Vm for the DM group was found to be reduced approximately by a factor of 3 compared with those obtained for group C, whereas Km was largely changed (96 times). Catalase activity was significantly higher in the DM group. These data suggest that the activation of rPON1 and rCAT activities by M. oleifera extracts may be mediated via the effect of the specific flavonoids on the enzyme structure. In addition, through molecular blind docking analysis, rPON1 was found to have two binding sites for flavonoids. In contrast, flavonoids bound at four sites in rCAT. In conclusion, the data suggest that compounds from M. oleifera leaves extract were able to influence the catalytic activities of both enzymes to compensate for the changes provoked by diabetes in rats

Characterization of Different Capsicum Varieties by Evaluation of Their Capsaicinoids Content by High Performance Liquid Chromatography, Determination of Pungency and Effect of High Temperature

The chili pepper is a very important plant used worldwide as a vegetable, as a spice, and as an external medicine. In this work, eight different varieties of Capsicum annuum L. have been characterized by their capsaicinoids content. The chili pepper fruits were cultivated in the Comarca Lagunera region in North of Mexico. The qualitative and quantitative determination of the major and minor capsaicinoids; alkaloids responsible for the pungency level, has been performed by a validated chromatographic procedure (HPLC-DAD) after a preliminary drying step and an opportune extraction procedure. Concentrations of total capsaicinoids varied from a not detectable value for Bell pepper to 31.84 mg g−1 dried weight for Chiltepín. Samples were obtained from plants grown in experimental field and in greenhouse without temperature control, in order to evaluate temperature effect. Analysis of the two principal capsaicinoids in fruits showed that the amount of dihydrocapsaicin was always higher than capsaicin. In addition, our results showed that the content of total capsaicinoids for the varieties Serrano, Puya, Ancho, Guajillo and Bell pepper were increased with high temperature, while the content of total capsaicinoids and Scoville heat units (SHU) for the varieties De árbol and Jalapeño decreased. However, the pungency values found in this study were higher for all varieties analyzed than in other studies

Characterization of Different Capsicum Varieties by Evaluation of Their Capsaicinoids Content by High Performance Liquid Chromatography, Determination of Pungency and Effect of High Temperature

The chili pepper is a very important plant used worldwide as a vegetable, as a spice, and as an external medicine. In this work, eight different varieties of Capsicum annuum L. have been characterized by their capsaicinoids content. The chili pepper fruits were cultivated in the Comarca Lagunera region in North of Mexico. The qualitative and quantitative determination of the major and minor capsaicinoids; alkaloids responsible for the pungency level, has been performed by a validated chromatographic procedure (HPLC-DAD) after a preliminary drying step and an opportune extraction procedure. Concentrations of total capsaicinoids varied from a not detectable value for Bell pepper to 31.84 mg g−1 dried weight for Chiltepín. Samples were obtained from plants grown in experimental field and in greenhouse without temperature control, in order to evaluate temperature effect. Analysis of the two principal capsaicinoids in fruits showed that the amount of dihydrocapsaicin was always higher than capsaicin. In addition, our results showed that the content of total capsaicinoids for the varieties Serrano, Puya, Ancho, Guajillo and Bell pepper were increased with high temperature, while the content of total capsaicinoids and Scoville heat units (SHU) for the varieties De árbol and Jalapeño decreased. However, the pungency values found in this study were higher for all varieties analyzed than in other studies

Aplicación de una película de HPMC- parafina sobre melón: efecto sobre aromáticos y actividad de la pectinmetilesterasa

The melon is a fruit appreciated for its aroma and flavor, but it has a short storage period. An alternative to extend this period is the use of edible films. In the present study,the effect of the application of an edible film of hydroxypropylmethylcellulose-paraffin (HPMC-PAR) on aromatic components and the activity of melon pectinmethylteterase stored in refrigeration was evaluated. Cantaloupe melon fruits were covered with an edible film of HPMC-PAR and non-covered melons were taken as control. The melons were stored for 20 days at 8 ºC and 80% relative humidity. Every four days, the fruits were subjected to analysis of the concentration of ethylbutyrate, ethylcaproate, butylacetate, benzyl alcohol, methylbutanol and pectylmethylteterase activity (PME).The results showed that melons with film had a higher concentration of the analyzed esters, as well as a lower activity of PME compared to samples without film. However, the alcoholic compounds were not affected by the treatments. Therefore, the application of the film based on HPMC-paraffin promotes the increase of ester compounds during the first days of storage in refrigeration. In addition, the activity of PME can influence the amount of these aromatic compounds of the Cantaloupe melon pulp. Keywords:aromas, hydroxypropylmethylcellulose, melon, pectinmetillesteraseEl melón es un fruto apreciado por su aroma y sabor, pero tiene un corto periodo de almacenamiento. Una alternativa para extender este periodo es el uso de películas comestibles. En el presente estudio se evaluó el efecto de la aplicación de una película comestible de hidroxipropilmetilcelulosa-parafina (HPMC-PAR) sobre componentes aromáticos y la actividad de la pectinmetilesterasa de melón almacenado en refrigeración. Frutos de melón Cantaloupe se cubrieron con una película comestible de HPMC-PAR y melones no cubiertos se tomaron como control. Los melones se almacenaron por 20 días a 8 ºC y 80% de humedad relativa. Cada cuatro días, los frutos se sometieron a análisis de concentración de etilbutirato, etilcaproato, butilacetato, benzilalcohol, metilbutanol y actividad de pectilmetilesterasa (PME). Los resultados mostraron que los melones con película tuvieron una mayor concentración de los ésteres analizados, así como una menor actividad de PME en comparación a muestras sin película. Sin embargo, los compuestos alcohólicos no fueron afectados por los tratamientos. Por lo que, la aplicación de la película a base de HPMC-parafina promueve el aumento de compuestos ésteres durante los primeros días de almacenamiento en refrigeración. Además, la actividad de la PME puede influir en la cantidad de estos compuestos aromáticos de la pulpa del melón Cantaloupe. Palabras clave: aromas, hidroxipropilmentilcelulosa, melón, pectinmetilesterasa

Measurement of Capsaicinoids in Chiltepin Hot Pepper: A Comparison Study between Spectrophotometric Method and High Performance Liquid Chromatography Analysis

Direct spectrophotometric determination of capsaicinoids content in Chiltepin pepper was investigated as a possible alternative to HPLC analysis. Capsaicinoids were extracted from Chiltepin in red ripe and green fruit with acetonitrile and evaluated quantitatively using the HPLC method with capsaicin and dihydrocapsaicin standards. Three samples of different treatment were analyzed for their capsaicinoids content successfully by these methods. HPLC-DAD revealed that capsaicin, dihydrocapsaicin, and nordihydrocapsaicin comprised up to 98% of total capsaicinoids detected. The absorbance of the diluted samples was read on a spectrophotometer at 215–300 nm and monitored at 280 nm. We report herein the comparison between traditional UV assays and HPLC-DAD methods for the determination of the molar absorptivity coefficient of capsaicin (ε280=3,410 and ε280=3,720 M−1 cm−1) and dihydrocapsaicin (ε280=4,175 and ε280=4,350 M−1 cm−1), respectively. Statistical comparisons were performed using the regression analyses (ordinary linear regression and Deming regression) and Bland-Altman analysis. Comparative data for pungency was determined spectrophotometrically and by HPLC on samples ranging from 29.55 to 129 mg/g with a correlation of 0.91. These results indicate that the two methods significantly agree. The described spectrophotometric method can be routinely used for total capsaicinoids analysis and quality control in agricultural and pharmaceutical analysis