Bioactive Compounds and Antioxidant Capacity of Pulp, Peel and Seeds from Jeriva (Syagrus romanzoffiana).

Jeriva (Syagrus romanzoffiana) is a fruit from palm trees of the Arecaceae family, widely distributed in tropical and subtropical areas of Latin America. It has low production costs and high productivity throughout the year; however, its consumption is very low, and the production goes almost entirely to feed animals or to waste. To improve its consumption, a good characterization of the whole fruit is necessary. The objective of this work was to evaluate the jeriva pulp, peel and seeds according to carotenoids, phenolic compounds, vitamin C, tocopherols and antioxidant potential using HPLC, microplate readers and spectrophotometric methods. Every part of the fruit exhibited antioxidant capacity in the ORAC and TEAC tests, which can be attributed to its high concentration of polyphenols. Carotenoids were more present in the pulp and peel and almost absent in the seeds. Vitamin C ranged from 12 ± 1 for the seeds up to 92 ± 3 mg/100 g for the pulp. The total phenolic content was quantified between 473 ± 39 for the seeds and 1089 ± 32 mg of gallic acid equivalents (GAEs)/100 g for the pulp. These results demonstrate that all parts of this fruit have important bioactive nutrients, with promising perspectives for further scientific approaches and for composing formulations of food products to enhance functional properties.

Chemical Composition, Antioxidant Properties, and Antibacterial Activity of Essential Oils of Satureja macrostema (Moc. and Sessé ex Benth.) Briq.

Satureja macrostema is a plant that is located in various regions of Mexico and is used in a traditional way against illness. Essential oils (EOs) were obtained from leaves Satureja macrostema and the chemical composition was evaluated by gas chromatography-mass spectrometry (GC-MS). The antioxidant effect of the oil was assayed by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and by Trolox Equivalent Antioxidant Capacity (TEAC). In vitro antibacterial activity against Escherichia coli and Staphylococcus aureus was determined using a broth microdilution assay and thin layer chromatography-direct bioautography (TLC-DB) to identify active antibacterial compounds. The EOs analysis showed 21 compounds, 99% terpenes, and 96% oxygenated monoterpenes, with trans-piperitone epoxide (46%), cis-piperitone epoxide (22%), and piperitenone oxide (11%) as more abundant compounds. Likewise, S. macrostema EOs showed an antioxidant activity of DPPH = 82%, with 50% free radical scavenging (IC50) = 7 mg/mL and TEAC = 0.005, an antibacterial effect against E. coli of 73% inhibition, and 81% over S. aureus at dose of 100 µL of undiluted crude oil. The TLC-DB assay showed that the most active compounds were derived from piperitone. The comparison with other studies on S. macrostema shows variability in the compounds and their abundances, which can be attributed to climatic factors and the maturity of plants with similar antioxidant and antibacterial activities.

Effect of Instant Controlled Pressure Drop (DIC) on Polyphenols, Flavonoids and Antioxidant Capacity of Green Lentils (Lens culinaris).

Instant controlled pressure drop (DIC) is one of the emerging technologies in food processing; it can be used for drying, freezing and the extraction of bioactive molecules without damaging their properties. Legumes, such as lentils, are one of the most consumed foods in the world; however, they are mainly cooked by boiling, which causes the loss of antioxidant compounds. This work evaluated the effect of 13 different DIC treatments (with pressure ranges of 0.1-0.7 MPa and times of 30-240 s) on the content of polyphenols (Folin-Ciocalteu and High Performance Liquid Chromatography HPLC) and flavonoids (2-aminoethyl diphenylborinate) as well as the antioxidant activity (DPPH and TEAC) of green lentils. The DIC 11 treatment (0.1 MPa, 135 s) obtained the best release of polyphenols, which in turn are related to antioxidant capacity. The abiotic stress generated by DIC could lead to the breakdown of the cell wall structure, which favors the availability of antioxidant compounds. Finally, the most efficient conditions for DIC to promote the release of phenolic compounds and maintain antioxidant capacity were found under low pressures (<0.1 MPa) and short times (<160 s).

Chemoinformatic modelling of the antioxidant activity of phenolic compounds.

BACKGROUND: Antioxidants are chemicals used to protect foods from deterioration by neutralizing free radicals and inhibiting the oxidative process. One approach to investigate the antioxidant activity is to develop quantitative structure-activity relationships (QSARs). RESULTS: A curated database of 165 structurally heterogeneous phenolic compounds with the Trolox equivalent antioxidant capacity (TEAC) was developed. Molecular geometries were optimized by means of the GFN2-xTB semiempirical method and diverse molecular descriptors were obtained afterwards. For model development, V-WSP unsupervised variable reduction was used before performing the genetic algorithms-variable subset selection (GAs-VSS) to construct the best five-descriptor multiple linear regression model. The coefficient of determination and the root mean square error were used to measure the performance in calibration (R2 = 0.789 and RMSEC = 0.381), and test set prediction (Q2 = 0.748 and RMSEP = 0.416), along several cross-validation criteria. To thoroughly understand the TEAC prediction, a fully explained mechanism of action of the descriptors is provided. In addition, the applicability domain of the model defined a theoretical chemical space for reliable predictions of new phenolic compounds. CONCLUSION: This in silico model conforms to the five principles stated by the Organisation for Economic Co-operation and Development. The model might be useful for virtual screening of the antioxidant chemical space and for identifying the most potent molecules related to an experimental measurement of TEAC activity. In addition, the model could assist chemists working on computer-aided drug design for the synthesis of new targets with improved activity and potential uses in food science. © 2023 Society of Chemical Industry.

Gallic Acid Mitigates 5-Hydroxymethylfurfural Formation while Enhancing or Preserving Browning and Antioxidant Activity Development in Glucose/Arginine and Sucrose/Arginine Maillard Model Systems.

The current trend of lowering 5-hydroxymethylfurfural (5-HMF) dietary exposure is challenging since its formation is parallel with the development of food color, flavor and aroma. We aimed to investigate the effect of gallic acid (GA) addition on 5-HMF formation, color development and antioxidant activity (AA) in a series of Maillard Reaction (MR) model systems. The effects of GA addition on browning and AA development were not uniform for all model systems, but always occurred in the same direction, indicating that these phenomena were interconnected. GA mitigated 5-HMF development in four of the nine tested systems, possibly by preventing the oxidation of MR intermediates. Correlation analysis indicated that when GA addition mitigated 5-HMF formation, browning was either promoted or not affected. The proposed strategy was effective for glucose/arginine and sucrose/arginine systems, since GA mitigated 5-HMF formation (49% and 54%, respectively) in addition to increasing color development and antioxidant activity.

Antioxidant activity optimization and GC-MS profile of aqueous extracts of Vernonanthura patens (Kunth) H. Rob. leaves.

The temperature and extraction time of aqueous extracts of Vernonanthura patens (Kunth) H. Rob. (AEVP) leaves obtained by decoction were optimized for maximum recovery of DPPH radical scavenging activity, ABTS+ inhibition activity, total phenolic content (TPC) and total flavonoids content (TFC) using response surface methodology (RSM). A central composite design (CCD) of 13 experimental runs was applied and second order polynomial models were used to describe the responses of the assessed extraction parameters. The optimized conditions: 79.79 °C and 126.23 minutes were found using the composite desirability function. The scavenging activity of assessed extracts could be correlated mostly to the presence of malic acid, succinic acid, α-ketoglutaric acid, citric acid, m-hydroxybenzoic acid, caffeic acid, inositol, and ß-amyrin detected by gas chromatography-mass spectrometry (GC-MS). These results have not been reported and support the potential application of AEVP as natural source of antioxidants.

Analysis of Phenolic Composition of Byproducts (Seeds and Peels) of Avocado (Persea americana Mill.) Cultivated in Colombia.

The byproducts (seeds and peels) of an avocado cultivated in the south of Colombia were extracted with aqueous acetone and their antioxidant properties were measured with ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) and DPPH (2,2-diphenyl-1-picrylhydrazyl) assays, and total polyphenol content was determined by Folin-Ciocalteu method. A bioguided fractionation was performed, first by SPE (solid phase extraction) on Amberlite XAD-7, and then by size exclusion chromatography on Sephadex LH-20. The polyphenolic-rich extracts and their fractions were analyzed by ultra-performance liquid chromatography-electrospray ionization-mass spectrometry (UPLC-ESI-MS/MS), finding the presence of organic acids, hydroxycinnamic acids, catechins, free and glycosylated flavonoids, and dimeric and trimeric procyanidins. Catechin, epicatechin, six quercetin derivatives, four dimeric procyanidins (three type B and one type A), and three trimeric procyanidins (two type B and one type A) were detected in the most active fractions of avocado peel and seeds. The most antioxidant fractions contain the higher molecular weight phenolic compounds (condensed tannins).

Reactive oxygen species and antioxidant properties from mushrooms.

Preventive medicine and food industry have shown an increased interest in the development of natural antioxidants, since those most commonly used synthetic antioxidants may have restricted use in food. This could explain why there is currently much research on the antioxidant properties from natural products such as mushrooms. Many mushrooms have been reported to possess antioxidant properties, which enable them to neutralize free radicals. The oxygen molecule is a free radical, which lead to the generation of the reactive oxygen species and can damage the cells. Cell damage caused by free radicals appears to be a major contributor to aging and degenerative diseases. Mushrooms antioxidant components are found in fruit bodies, mycelium and culture both, which include polysaccharides, tocopherols, phenolics, carotenoids, ergosterol and ascorbic acid among others. Fruit bodies or mycelium can be manipulated to produce active compounds in a relatively short period of time, which represent a significant advantage in antioxidant compounds extraction from mushrooms. Antioxidant compounds may be extracted to be used as functional additives or mushrooms can be incorporated into our food regime, representing an alternative source of food to prevent damage caused by oxidation in the human body.

Influence of ßS allele in the lipid peroxidation and antioxidant capacity parameters.

INTRODUCTION: The oxidative process plays a fundamental role in the pathophysiology of sickle cell anemia (SCA), and population and environmental characteristics may influence redox balance. The aim of this study was to evaluate lipid peroxidation and antioxidant capacity in Brazilian Hb S carriers undergoing different therapies. METHODS: Blood samples from 270 individuals were analyzed (Hb SS, n = 68; Hb AS, n = 53, and Hb AA, n = 149). Hemoglobin genotypes were assessed through cytological, electrophoretic, chromatographic, and molecular methods. Plasma lipid peroxidation and antioxidant capacity were measured by spectrophotometric methods. RESULTS: Patients with SCA who used iron-chelating drugs combined with hydroxyurea, associated with regular transfusions, showed lower levels of TBARS (P ≤ 0.05), higher levels of TEAC (P ≤ 0.01), and lower TBARS/TEAC ratio (R = 255.8). The redox profile of Hb AS subjects was not statistically different (P > 0.05) from that of Hb AA subjects. CONCLUSION: The data suggest that oxidative stress is lower in the patients with SCA who received regular blood transfusions associated with the combined use of HU and iron chelators than the group received only HU. The redox system of the Hb AS carriers is compatible with the control group.

Biological evaluation of morin and its new oxovanadium(IV) complex as antioxidant and specific anti-cancer agents.

It is known that flavonoids possess, among others, antioxidant and antitumoral properties that depend on their molecular structure. The central objective if this study was to investigate the potential antioxidant and antiproliferative properties of the flavonol morin and its new oxovanadium(IV) complex (VOmor) that was synthesized in order to modify the morin chemical structure. Two osteoblast (UMR106 and MC3T3E1), two breast tumor (T47D and SKBR3) and breast epithelial cell lines in culture were used for the antitumoral determinations. Additionally, a comparative study of their antioxidant capacities using different radicals (DPPH, ABTS(+), OH, O2(-), ROO) was performed. Selected mechanisms of action were studied using the breast cancer cell lines. Results obtained show that morin and its complex behaved as good antioxidant agents for some of the radicals and that the complexation improved the behavior with respect to OH and O2(-) radicals being morin more effective as ROO scavenger. A considerable variation in sensitivity was observed in the breast cancer cells but non-specificity was found for the treatment of osteosarcoma. Moreover, the compounds did not affect the normal proliferation of the breast epithelial mammal cells. The mechanistic studies demonstrated that the complex did not generate reactive oxygen species in the cells (confirming the in vitro studies) and did not produce any damage of DNA. The plasmatic membrane was observed to be damaged only in the SKBR3 cell line. In contrast, the perturbation of the mitochondrial membrane potential and the activation of caspase 3/7 for the breast tumor cells revealed an apoptotic cell death process. All these results collectively suggested that VOmor complex could serve as promising pharmacologically active substance against breast cancer treatment.

Total Phenolic Content and Antioxidant Activity of Some Malvaceae Family Species.

The antioxidant activity of four species of the Malvaceae family (Sidastrum micranthum (A. St.-Hil.) Fryxell, Wissadula periplocifolia (L.) C. Presl, Sida rhombifolia (L.) E. H. L and Herissantia crispa L. (Brizicky)) were studied using the total phenolic content, DPPH radical scavenging activity and Trolox equivalent antioxidant capacity (TEAC) assays. The antioxidant activity of the crude extract, phases and two isolated flavonoids, kaempferol 3,7-di-O-α-l-rhamnopyranoside (lespedin) and kaempferol 3-O-ß-d-(6''-E-p-coumaroil) glucopyranoside (tiliroside) was determined. The results showed that there is a strong correlation between total polyphenol contents and antioxidant activity of the crude extract of Sidastrum micranthum and Wissadula periplocifolia; however, this was not observed between Sida rhombifolia and Herissantia crispa. The ethyl acetate (EaF) phase showed the best antioxidant effect in the total phenolics, DPPH and TEAC assays, followed by the chloroform (CfF) phase, in most species tested. Lespedin, isolated from the EaF phase of W. periplocifolia and H. crispa may not be responsible for the antioxidant activity due to its low antioxidant activity (IC50: DPPH: 1,019.92 ± 68.99 mg/mL; TEAC: 52.70 ± 0.47 mg/mL); whereas tiliroside, isolated from W. periplocifolia, H. crispa and S. micrantum presented a low IC50 value (1.63 ± 0.86 mg/mL) compared to ascorbic acid in the TEAC assay.

Quantitative stuucture-activity relationships t predict in vitro teac and ec500 of synthetic anilines / Relacionescuantiitativas actividad-estructura para predeci la teac y la eec50 de anilinas sintéticas / Relaçõs quantitaativas atividade - estrutura para a predição a teaceaec50 da anilinas sintéticas

Quantitative Structure-Activity Relationships (QSAR) are useful in understanding how chemical structure relates to the biological activity of natural or synthetic compounds and for designing newer and better compounds. In the present study, 22 N-arylmethyl substituted anilines were treated with ABTS (2,2'-azinobis- (3-ethylbenzothiazoline-6-sulfonic-acid)) and DPPH (2,2-diphenyl-1-picrylhy-dracyl) radicals in order to evaluate their TEAC (mmol trolox/mmol antioxidant, Trolox Equivalent Antioxidant Capacity) and EC50 (mmol antioxidant/mmol initial DPPH, Antioxidant Equivalent Concentration to decrease the initial DPPH concentration by 50 %) values, respectively. Different QSARs were developed based on these data, using theoretical descriptors derived from geometry-optimized molecular structures. A model with electronic energy (EE), total charge weighted partial positively charged surface area (PPSA-2), and exact polarizability (αzz) as descriptors showed satisfactory predictive TEAC performance according to internal and external validation procedures. It can be useful in predicting data and setting a testing priority for those compounds not yet synthesized or for which experimental data are not available.

Las relaciones cuantitativas actividad-estructura (QSAR) son útiles para entender la forma en que la estructura química de sustancias sintéticas y naturales se relaciona con la actividad biológica, y para el diseño de nuevos y mejores compuestos. En el presente estudio fueron evaluadas las capacidades de 22 anilinas N-arylmetil sustituidas para la captura de los radicales ABTS (ácido 2,2'-azino-bis(3-etilbenzo-tiazolino-6-sulfónico) y DPPH (2,2-difenil-1-picrilhidracilo), relacionadas con los valores de TEAC (mmol trolox/mmol antioxidante, capacidad antioxidante equivalente al Trolox) y EC50 (concentración equivalente de antioxidante para disminui r la concentración inicial de DPPH enun 50%), respectivamente. Las TEAC, las EC50 y los descriptores teóricos derivados de las estructuras moleculares optimizadas fueron utilizados para elaborar las diferentes QSAR. Los modelos TEAC con descriptores como EE (energía electrónica), PPSA-2 (carga total pesada con el área superficial cargada positivamente) y αzz (polarizabilidad exacta) mostraron una capacidad de predicción satisfactoria por procedimientos de validación interna y externa, por lo que pueden ser útiles para la predicción de actividades de compuestos que aún no han sido sintetizados o con datos experimentales no disponibles.

Relaçãos quantitativa atividade - estrutura tem sido empregado para estabelecer se a estrutura química está relacionada com a atividade biológica dos químicos naturais e sintéticos e para o desenho de novos e melhores compostos. No presente estudo foram avaliadas as capacidades de 22 anilinas N-arylmetil sustituidas para a captura dos radicais de ABTS (ácido-2,2'-azino-bis(3-etilo-benzo-tiazolino-6-sulfônic o) e DPPH (2,2-difenilo-1-picrilhidracilo), relacionadas com os valores de TEAC (mmol trolox/mmol antioxidante, capacidade antioxidante equivalente ao Trolox) yEC50 (concentração equivalente de antioxidante para a diminuição da concentração inicial de DPPH para um 50 %) respectivamente. As TEAC, as EC50 eos descritores teóricos derivados das estruturas moleculares otimizadas foram empregados para elaborar as diferentes QSARs. Os modelos TEAC com descritores como EE (Energia Eletrônica), PPSA-2 (carga total pesada com a área superficial carregada positivamente) y αzz (polarizabilidade exata) mostraram uma satisfatória capacidade de predição pelos procedimentos de validação interna e externa, e por tanto podem ser úteis para a predição da capacidade antioxidante de compostos que ainda no tem sido sintetizados com dados experimentais não disponíveis.

Atividade antioxidante de xantonas isoladas de espécies de Leiothrix (Eriocaulaceae) / Antioxidant effects of xanthones isolated from Leiothrix species (Eriocaulaceae)

Leiothrix (Eriocaulaceae) é um gênero exclusivo da América do Sul, com 37 espécies restritas ao Brasil. Leiothrix flavescens (Bong.) Ruhland e Leiothrix curvifolia (Bong.) Ruhland, são espécies endêmicas em áreas dos Estados de Minas Gerais e Bahia. Existem na literatura poucos estudos químicos e biológicos realizados com espécies desse gênero. Neste trabalho, foi estudada a atividade antioxidante pelo ensaio TEAC (Trolox Equivalent Antioxidant Capacity) e de autoxidação, utilizando ácido linoléico, de xantonas isoladas dos extratos etanólicos de L. curvifolia e L. flavescens. As substâncias apresentaram moderada atividade antioxidante, quando comparadas com padrões de quercetina e de BHT (2, 6 - ditercbutil - 4 - metóxifenil).

Leiothrix (Eriocaulaceae) is an exclusively South American genus of which 37 species are restricted to Brazil. Leiothrix flavescens (Bong.) Ruhland and Leiothrix curvifolia (Bong.) Ruhland, are species endemic to areas of Minas Gerais and Bahia States. Chemical and biological investigations of this genus are scarse. The objective of this work was to investigate the antioxidant effect using TEAC and linoleic acid assays of the xanthones isolated from the ethanolic extract of these species. These substances showed a moderate antioxidant activity when compared to quercetin and to BHT.