Eliseu Rodrigues

Development of a novel micro-assay for evaluation of peroxyl radical scavenger capacity: Application to carotenoids and structure–activity relationship

A micro-assay was developed and validated, using a microplate reader in 96-well format, C(11)-BODIPY(581/591) as fluorescent probe and AIBN as ROO() generator. The structure-activity relationship was established for 15 carotenoid standards, indicating that the opening of the β-ionone ring and the increase of chromophore extension in the carotenoid structure were the major factors leading to the increase of ROO() scavenging capacity. The values for ROO() scavenging capacity were calculated using α-tocopherol as reference compound. Among the studied carotenoids, all-trans-lycopene was the most efficient ROO() scavenger (8.67±0.74) followed by all-trans-astaxanthin (6.50±0.62). All the carotenoids showed to be more effective ROO() scavengers than α-tocopherol and some hydrophilic compounds. Finally, the method was successfully applied to assay the ROO() scavenging capacity of carotenoid extracts from two Amazonian fruits, peach palm (7.83±0.21) and mamey (6.90±0.44).

Phenolic Compounds and Carotenoids from Four Fruits Native from the Brazilian Atlantic Forest

Fruits from the Atlantic Forest have received increasing interest because they contain high levels of bioactive compounds with notable functional properties. The composition of carotenoids and phenolic compounds from fruits found in the Atlantic Forest (jussara, uvaia, araça, and grumixama) was determined by high-performance liquid chromatography coupled to diode array and mass spectrometry detectors. Uvaia showed the highest levels of carotenoids (1306.6 μg/100 g fresh matter (f.m.)). Gallic acid was the major phenolic compound in araça (12.2 mg GAE/100 g f.m.) and uvaia (27.5 mg GAE/100 g f.m.). In grumixama, eight quercetin derivatives were found; the main carotenoids included all-trans-β-cryptoxanthin (286.7 μg/100 g f.m.) and all-trans-lutein (55.5 μg/100 g f.m.). Uvaia and grumixama contain high amounts of carotenoids, while jussara showed greater levels of phenolic compounds (415 mg GAE/100 g f.m.), particularly anthocyanins (cyanidin 3-rutinoside: 179.60 mg/100 g f.m.; cyanidin 3-glucoside: 47.93 mg/100 g f.m.).

Carotenoids and Phenolic Compounds from Solanum sessiliflorum, an Unexploited Amazonian Fruit, and Their Scavenging Capacities against Reactive Oxygen and Nitrogen Species

The composition of carotenoids and phenolic compounds from mana-cubiu (Solanum sessiliflorum), a fruit native to Amazonia, was determined by high-performance liquid chromatography coupled to diode array and mass spectrometry detectors (HPLC-DAD-MS(n)). The antioxidant capacities of the hydrophilic and carotenoid extracts against some reactive oxygen (ROO(•), H(2)O(2), HOCl, and HO(•)) and nitrogen (ONOO(-)) species were also determined. Seventeen carotenoids and three phenolic compounds were found in mana-cubiu. The major carotenoids were (all-E)-β-carotene (7.15 μg/g of dry weight) and (all-E)-lutein (2.41 μg/g of dry weight). The 5-caffeoylquinic acid (1351 μg/g of dry weight) was the major phenolic compound, representing more than 78% (w/w) of the total phenolic compounds. Moreover, two dihydrocaffeoyl spermidines were found in the hydrophilic extract. Both mana-cubiu extracts were able to scavenge all the tested reactive species. The carotenoid extract was shown to be a potent scavenger of peroxyl radical, while the hydrophilic extract was a potent hydrogen peroxide and hypochlorous acid scavenger.

Identification of carotenoids with high antioxidant capacity produced by extremophile microorganisms

In this study, the carotenoids produced by the extremophile microorganisms Halococcus morrhuae, Halobacterium salinarium and Thermus filiformis were separated and identified by high-performance liquid chromatography connected to a diode array detector and a tandem mass spectrometer. The in vitro scavenging capacity of the carotenoid extracts against radical and non-radical species was evaluated. In halophilic microorganisms, the following carotenoids were identified: bacterioruberin, bisanhydrobacterioruberin, trisanhydrobacterioruberin and their derivatives. In the thermophilic bacterium, the carotenoids all-trans-zeaxanthin, zeaxanthin monoglucoside, thermozeaxanthins and thermobiszeaxanthins were identified. The antioxidant capacities of the carotenoid extracts of H. morrhuae (trolox equivalent antioxidant capacityxa0=xa05.07 and IC50xa0=xa00.85xa0μgxa0mL−1) and H. salinarium (trolox equivalent antioxidant capacityxa0=xa05.28 and IC50xa0=xa00.84xa0μgxa0mL−1) were similar and higher than those of the bacterium T. filiformis (trolox equivalent antioxidant capacityxa0=xa02.87 and IC50xa0=xa02.41xa0μgxa0mL−1). This difference is related to the presence of acyclic carotenoids with both large numbers of conjugated double bounds and of hydroxyl groups in the major carotenoid of the halophilic microorganisms.

Microcapsules containing antioxidant molecules as scavengers of reactive oxygen and nitrogen species

The antioxidant capacities of gum arabic and maltodextrin microcapsules containing antioxidant molecules (trolox, α-tocopherol, β-carotene, apo-8-carotenal and apo-12-carotenal) against reactive oxygen and nitrogen species were evaluated. The scavenging capacities were influenced by the wall material, the reactive species, namely ROO(), H(2)O(2), HO(), HOCl and ONOO(-), and the antioxidant molecule. In general, a more pronounced enhancement of the antioxidant capacity due to incorporation of antioxidant molecules was observed in gum arabic microcapsules. The empty microcapsules showed capacity to scavenge all the studied ROS and RNS, being gum arabic a more potent antioxidant than maltodextrin. Apo-8-carotenal incorporation promoted the highest increase in the scavenging capacities among the evaluated antioxidants, varying from 50% to 132% and from 39% to 85% for gum arabic and maltodextrin microcapsules, respectively, suggesting that this carotenoid presented the best balance between the molecule localization inside the microcapsules and the reactivity against the specific reactive species.

Identification of Bioactive Compounds From Vitis labrusca L. Variety Concord Grape Juice Treated With Commercial Enzymes: Improved Yield and Quality Parameters

In this work, the effects of eight different enzymatic preparations were compared in terms of the extraction of bioactive compounds as well as the yield and quality of grape juice from Vitis labrusca L. variety Concord. Juices were prepared by enzymatic treatment and the used preparations were characterized through five enzymatic activities: total pectinase (PE), polygalacturonase (PG), pectinlyase (PL), pectin methyl esterase (PME), and cellulase (CE). Quality parameters such as color, total soluble solids (°Brix), reducing sugars, titratable acidity, pH, and antioxidant capacity were determined for all samples. Phenolic compounds and anthocyanins were identified and quantified by HPLC-DAD-MS. Juice yield was improved by preparations with high activities of PG, PME, and PL, up to 9xa0% higher than the control, when used Pectinex Ultra Clear. For the extraction of bioactive compounds, the highest values were found for preparations with high CE activity. Regarding the phenolic compounds, 15 compounds were identified. The content of caftaric acid and total anthocyanins was improved up to 300 and 60xa0%, respectively, using Lallzyme Beta. It was possible to understand the role of each enzyme in the extraction of yield, quality parameters, and bioactive compounds. Pectinex Ultra Clear was the preparation that provided the highest yield and Lallzyme Beta the highest bioactive compounds concentration. For a good quality juice and high yields for the industry, it is important to have a good balance of pectinases and cellulases.

Correlation, by multivariate statistical analysis, between the scavenging capacity against reactive oxygen species and the bioactive compounds from frozen fruit pulps

The contents of total phenolic compounds (TPC), total flavonoids (TF), and ascorbic acid (AA) of 18 frozen fruit pulps and their scavenging capacities against peroxyl radical (ROO•), hydrogen peroxide (H2O2), and hydroxyl radical (•OH) were determined. Principal Component Analysis (PCA) showed that TPC (total phenolic compounds) and AA (ascorbic acid) presented positive correlation with the scavenging capacity against ROO•, and TF (total flavonoids) showed positive correlation with the scavenging capacity against •OH and ROO• However, the scavenging capacity against H2O2 presented low correlation with TF (total flavonoids), TPC (total phenolic compounds), and AA (ascorbic acid). The Hierarchical Cluster Analysis (HCA) allowed the classification of the fruit pulps into three groups: one group was formed by the acai pulp with high TF, total flavonoids, content (134.02 mg CE/100 g pulp) and the highest scavenging capacity against ROO•, •OH and H2O2; the second group was formed by the acerola pulp with high TPC, total phenolic compounds, (658.40 mg GAE/100 g pulp) and AA , ascorbic acid, (506.27 mg/100 g pulp) contents; and the third group was formed by pineapple, cacao, caja, cashew-apple, coconut, cupuacu, guava, orange, lemon, mango, passion fruit, watermelon, pitanga, tamarind, tangerine, and umbu pulps, which could not be separated considering only the contents of bioactive compounds and the scavenging properties.

The Amazonian fruit Byrsonima crassifolia effectively scavenges reactive oxygen and nitrogen species and protects human erythrocytes against oxidative damage

A hydrophilic extract of murici (Byrsonima crassifolia), a fruit native to the North and Northeast regions of Brazil, was evaluated in relation to its phenolic composition and in vitro antioxidant potential against some physiologically relevant reactive oxygen and nitrogen species. Additionally, the protective effect of murici extract against peroxyl radical (ROO)-induced toxicity to human erythrocytes was also determined. The major phenolic compound, determined by HPLC-DAD-MSn, was quercetin (2.72±0.35μg/mL). The extract was able to scavenge ROO (0.30±0.04μmoltroloxequivalent/mg), hypochlorous acid (IC50=10.0±0.1μg/mL), hydroxyl radical (IC50=7±1μg/mL) and peroxynitrite anion (IC50=21.0±0.6μg/mL and 17.0±1.6μg/mL, respectively, in absence and presence of NaHCO3). Human erythrocytes were subjected to oxidative damage, but murici extract was not able to inhibit hemolysis, even at the highest tested concentration. On the other hand, the extract inhibited hemoglobin oxidation (IC50=271±44μg/mL), lipid peroxidation (1000μg/mL) by 48±5%, depletion of glutathione (100μg/mL) by 49±2% and formation of its oxidized form (100μg/mL) by 96±4%.

Composição de ácidos graxos de óleo de semente de uva (Vitis vinifera L. e Vitis labrusca L.)

O bagaço é caracterizado como subproduto da vinificação, contendo principalmente sementes e cascas. As sementes contêm a maior parte do óleo da uva, entre 14 e 17%, conforme a variedade. Neste trabalho, foi determinado o perfil de ácidos graxos do óleo obtido a partir das sementes do bagaço de oito variedades de uva (Pinot Noir, Regente, Ancelota, Tannat, Merlot, Bordô, Isabel e Cabernet Sauvignon), coletadas na cidade de Videira-SC. Os ácidos graxos encontrados com maior abundância foram o linoleico (47,63 a 60,02%), oleico (9,48 a 16,81%), palmítico (6,17 a 8,46%) e o esteárico (2,89 a 4,08%). Os resultados obtidos demonstram que o óleo das sementes das diferentes variedades analisadas é similar e apresenta alto teor de ácidos graxos poli-insaturados.

Chemical composition of microalgae Heterochlorella luteoviridis and Dunaliella tertiolecta with emphasis on carotenoids

BACKGROUNDnMicroalgae have been used as food supplements owing to their high protein, polyunsaturated fatty acid and carotenoid contents. As different carotenoids have distinct properties and the carotenoid composition of microalgae has been poorly explored in the literature, this study determined the complete carotenoid composition of two microalgae species, Heterochlorella luteoviridis and Dunaliella tertiolecta, using high-performance liquid chromatography coupled with diode array detection and tandem mass spectrometry (HPLC-DAD/MS2 ). Additionally, the proximate composition and major minerals were evaluated.nnnRESULTSnThe carotenoid composition of the two microalgae was similar, with 13 carotenoids being found in H. luteoviridis and 12 in D. tertiolecta. The major carotenoids were all-trans-lutein (1.18u2009mgu2009g-1 in H. luteoviridis and 1.59u2009mgu2009g-1 in D. tertiolecta), all-trans-violaxanthin (0.52u2009mgu2009g-1 in H. luteoviridis and 0.45u2009mgu2009g-1 in D. tertiolecta) and all-trans-β-carotene (0.50u2009mgu2009g-1 in H. luteoviridis and 0.62u2009mgu2009g-1 in D. tertiolecta). All-trans-lutein was the predominant carotenoid in both microalgae, representing around 40% (mass fraction) of the total carotenoids. The lutein content found in these microalgae was significantly higher (2-40 times) than that in other important food sources of lutein (e.g. parsley, carrot, red pepper and broccoli).nnnCONCLUSIONnThe microalgae H. luteoviridis and D. tertiolecta are excellent sources of lutein that could be commercially exploited by the food and pharmaceutical industries. Moreover, it was confirmed that both microalgae are good sources of protein, lipids and calcium.