RESUMEN

The present work reports the inhibitory effect of amides derived from gallic acid (gallamides) against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) main protease (Mpro), along with cytotoxicity evaluation and molecular docking studies. In addition to gallamides, other relevant compounds were also synthesized and evaluated against Mpro, making a total of 25 compounds. Eight compounds presented solubility issues during the inhibitory assay and one showed no inhibitory activity. Compounds 3a, 3b, and 3f showed the highest enzymatic inhibition with IC50 = 0.26 ± 0.19 µM, 0.80 ± 0.38 µM, and 2.87 ± 1.17 µM, respectively. Selenogallamide 6a exhibited IC50 values of 5.42 ± 2.89 µM and a comparison with its nonselenylated congener 3c shows that the insertion of the chalcogen moiety improved the inhibitory capacity of the compound by approximately 10 times. Regarding the cellular toxicity in THP-1 and Vero cells, compounds 3e and 3g, showed moderate cytotoxicity in Vero cells, while for THP-1 both were nontoxic, with CC50 > 150 µM. Derivative 3d showed moderate cytotoxicity against both cell lines, whereas 6d was moderatly toxic to THP-1. Other compounds analyzed do not induce substantial cellular toxicity at the concentrations tested. The molecular docking results for compounds 3a, 3b, and 3f show that hydrogen bonding interactions involving the hydroxyl groups (OH) of the gallate moiety are relevant, as well as the carbonyl group.

Asunto(s)

Amidas , Antivirales , Proteasas 3C de Coronavirus , Ácido Gálico , Simulación del Acoplamiento Molecular , Inhibidores de Proteasas , SARS-CoV-2 , Humanos , Células Vero , Chlorocebus aethiops , Ácido Gálico/farmacología , Ácido Gálico/síntesis química , Ácido Gálico/química , Ácido Gálico/análogos & derivados , Proteasas 3C de Coronavirus/antagonistas & inhibidores , Proteasas 3C de Coronavirus/metabolismo , SARS-CoV-2/efectos de los fármacos , SARS-CoV-2/enzimología , Antivirales/farmacología , Antivirales/síntesis química , Antivirales/química , Animales , Relación Estructura-Actividad , Amidas/farmacología , Amidas/síntesis química , Amidas/química , Inhibidores de Proteasas/farmacología , Inhibidores de Proteasas/síntesis química , Inhibidores de Proteasas/química , Simulación por Computador , Tratamiento Farmacológico de COVID-19 , Concentración 50 Inhibidora , Supervivencia Celular/efectos de los fármacos

RESUMEN

Gallic acid (GA) is a powerful antioxidant extracted from plants of the Brazilian Cerrado. Oxidative stress plays an important role in the occurrence of radiation-induced osteonecrosis in patients treated for head and neck cancer. There is a need to develop research aimed at developing complementary therapies to prevent or reverse bone damage. The aim of the present study was to investigate the effect of GA in preosteoblasts exposed to therapeutic ionizing radiation. MC3T3-E1 preosteoblast cells were treated with 10 µM GA and exposed to 6 Gy ionizing radiation. We performed in vitro assays of cell proliferation, oxidative stress analysis by detection of reactive oxygen species, and alkaline phosphatase assay. GA at lower concentrations was able to significantly increase proliferation and inhibit radiation-induced generation of reactive oxygen species in osteoblast precursor cells, despite ionizing radiation-induced injury. Furthermore, GA significantly increased alkaline phosphatase at a dose of 6 Gy. The findings suggested that GA could attenuate ionizing radiation-induced injuries in osteoblast precursor cells. Moreover, in vivo studies are needed to better investigate the role of GA in osteonecrosis, especially in cancer patients undergoing radiotherapy or taking antiresorptive drugs.

RESUMEN

Glycosyltransferases catalyze the transfer of a glycoside group to a wide range of acceptor compounds to produce glycoconjugates with diverse biological and pharmacological activities. The present work reports the identification and biochemical characterization of Nicotiana tabacum UGT89A2 glycosyltransferase (NtUGT89A2). The enzyme is a monomer in solution that catalyzes the O-ß-glucosylation of di- and tri-hydroxylated and chlorinated derivatives of benzoic acid. NtUGT89A2 has a preference for 2,5-dihydroxybenzoic acid (2,5-DHBA) over 2,3-dihydroxybenzoic acid (2,3-DHBA) and 2,4-dihydroxybenzoic acid (2,4-DHBA). Other substrates that can be used by NtUGT89A2 include 3,4,5-trihydroxybenzoic acid and chlorinated derivatives such as 2-chloro-5-hydroxybenzoic acid (2-Cl-5-HBA). The substrates of NtUGT89A2 were identified by thermal stability experiments, where we observed a maximum increase of the thermal denaturation midpoint (Tm) of 10 °C in the presence of 2,5-DHBA and UDP-glucose. On the other hand, the highest specific activity was obtained with 2,5-DHBA (225 ± 1.7 nkat/mg). Further characterization revealed that the enzyme has a micromolar affinity for its substrates. Notably, the enzyme retains full activity after incubation at 70 °C for 1 h. These results provide a basis for future functional and structural studies of NtUGT89A2.

Asunto(s)

Glicosiltransferasas , Nicotiana , Nicotiana/enzimología , Glicosilación , Glicosiltransferasas/metabolismo , Glicosiltransferasas/química , Estructura Molecular , Ácido Benzoico/química , Ácido Benzoico/metabolismo , Benzoatos/química , Benzoatos/metabolismo , Biocatálisis

RESUMEN

Obesity and overweight are multifactorial diseases affecting more than one-third of the world's population. Physical inactivity contributes to a positive energy balance and the onset of obesity. Exercise combined with a balanced diet is an effective non-pharmacological strategy to improve obesity-related disorders. Gallic acid (GA), is a natural endogenous polyphenol found in a variety of fruits, vegetables, and wines, with beneficial effects on energetic homeostasis. The present study aims to investigate the effects of exercise training on obese mice supplemented with GA. Animal experimentation was performed with male Swiss mice divided into five groups: ST (standard control), HFD (obese control), HFD + GA (GA supplement), HFD + Trained (training), and HFD + GA + Trained (GA and training). The groups are treated for eight weeks with 200 mg/kg/body weight of the feed compound and, if applicable, physical training. The main findings of the present study show that GA supplementation improves liver fat, body weight, adiposity, and plasma insulin levels. In addition, animals treated with the GA and a physical training program demonstrate reduced levels of anxiety. Gene expression analyses show that Sesn2 is activated via PGC-1α independent of the GATOR2 protein, which is activated by GA in the context of physical activity. These data are corroborated by molecular docking analysis, demonstrating the interaction of GA with GATOR2. The present study contributes to understanding the metabolic effects of GA and physical training and demonstrates a new hepatic mechanism of action via Sestrin 2 and PGC-1α.

Asunto(s)

Ácido Gálico , Hígado , Ratones Obesos , Obesidad , Coactivador 1-alfa del Receptor Activado por Proliferadores de Peroxisomas gamma , Condicionamiento Físico Animal , Animales , Ratones , Ácido Gálico/farmacología , Masculino , Hígado/metabolismo , Hígado/efectos de los fármacos , Obesidad/metabolismo , Obesidad/genética , Obesidad/tratamiento farmacológico , Coactivador 1-alfa del Receptor Activado por Proliferadores de Peroxisomas gamma/metabolismo , Coactivador 1-alfa del Receptor Activado por Proliferadores de Peroxisomas gamma/genética , Ansiedad/tratamiento farmacológico , Proteínas Nucleares/metabolismo , Proteínas Nucleares/genética , Dieta Alta en Grasa/efectos adversos , Regulación de la Expresión Génica/efectos de los fármacos , Sestrinas

RESUMEN

The bark extract from Endopleura uchi has been widely used in traditional medicine to treat gynecological-related disorders, diabetes, and dyslipidemias albeit without scientific proof. In addition, E. uchi bark extract safety, especially regarding mutagenic activities, is not known. The aim of this study was to determine the chemical composition, antitumor, and toxicological parameters attributed to an E. uchi bark aqueous extract. The phytochemical constitution was assessed by colorimetric and chromatographic analyzes. The antiproliferative effect was determined using sulforhodamine B (SRB) assay using 4 cancer cell lines. Cytotoxic and genotoxic activities were assessed utilizing MTT and comet assays, respectively, while mutagenicity was determined through micronucleus and Salmonella/microsome assays. The chromatographic analysis detected predominantly the presence of gallic acid and isoquercitrin. The antiproliferative effect was more pronounced in human colon adenocarcinoma (HT-29) and human breast cancer (MCF-7) cell lines. In the MTT assay, the extract presented an IC50 = 39.1 µg/ml and exhibited genotoxic (comet assay) and mutagenic (micronucleus test) activities at 20 and 40 µg/ml in mouse fibroblast cell line (L929) and mutagenicity in the TA102 and TA97a strains in the absence of S9 mix. Data demonstrated that E. uchi bark possesses bioactive compounds which exert cytotoxic and genotoxic effects that might be associated with its antitumor potential. Therefore, E. uchi bark aqueous extract consumption needs to be approached with caution in therapeutic applications.

Asunto(s)

Adenocarcinoma , Antineoplásicos , Neoplasias del Colon , Humanos , Ratones , Animales , Extractos Vegetales/química , Corteza de la Planta/química , Daño del ADN , Agua , Mutágenos , Células MCF-7

RESUMEN

BACKGROUND/AIM: Enzyme-mediated grafting of poly (gallic acid) (PGAL) and L-arginine and a-L-lysine onto PGAL produces reactive oxygen species (ROS)-suppressor multiradical molecules with low cytotoxicity, high thermostability and water solubility with cancer treatment potential. This study examined the anticancer effects of these molecules in hepatic (HepG2, ATCC HB-8065), breast (MCF7, ATCC HTB-22), and prostate (PC-3, ATCC CRL-1435 and DU 145, ATCC HTB-81) cancer cell lines, as well as in fibroblasts from healthy human skin as control cells. MATERIALS AND METHODS: PGAL was synthesized by the oxidative polymerization of the naturally abundant GA using laccase from Trametes versicolor. Insertions of amino acids L-arginine and α-L-lysine on the PGAL chain were carried out by microwave. The cells of dermal fibroblast (Fb) were obtained from primary skin cultures and isolated from skin biopsies. The cancer cells lines of hepatic (HepG2), breast (MCF7), and prostate (PC-3, DU 145) were obtained from ATCC. The viability of the cancer cells and the primary culture was obtained by the MTT assay. Proliferation was demonstrated by crystal violet assay. Cell migration was determined by Wound healing assay. Finally, cell cycle analysis was carried out with cells. RESULTS: The results show that 200 µg/ml of PGAL cultured in vitro with prostate cancer cells decreased viability, proliferation, and migration, as well as arrested cells in the G1 and S phases of the cell cycle. In contrast, the dermal fibroblasts and the hepatic line remained unaffected. The random grafting of L-Arg and a-L-Lys onto the PGAL chain also decreased the viability of prostate cancer cells. CONCLUSION: PGAL and PGAL-grafted amino acids are potential adjuvants for prostate cancer treatment, with improved physicochemical characteristics compared to GA.

Asunto(s)

Ácido Gálico , Neoplasias de la Próstata , Salicilatos , Masculino , Humanos , Ácido Gálico/farmacología , Lisina , Trametes , Neoplasias de la Próstata/patología , Células MCF-7 , Arginina/farmacología , Proliferación Celular

RESUMEN

ABSTRACT Cutaneous leishmaniasis, caused by protozoa of the genus Leishmania, presents diverse clinical manifestations, and current therapeutic options have limitations, including long treatment periods, potential hospitalization, and excessive pain during treatment. Methyl gallate, a phenolic compound found in plants such as Libidibia ferrea, presents promising antileishmanial activity. Combining this compound with existing leishmaniasis medications could lead to reduced dosages and the minimization of side effects. This study aimed to assess the efficacy of a microemulsion containing methyl gallate, either on its own or in combination with Glucantime®, for the experimental treatment of cutaneous leishmaniasis in a 30-day in vivo assay using golden hamsters infected with Leishmania (Leishmania) amazonensis. The control groups included an untreated positive control and an uninfected, untreated negative control. After treatment, we evaluated clinical, parasitological, and biochemical parameters. While none of the treatments achieved clinical or parasitological cure, notable improvements were observed in the combined group, with significant reductions in snout skin lesions and parasite load when compared to the control. Biochemical parameters such as creatinine, CK-MB, GOT, and GPT remained unchanged, but urea and CPK levels significantly increased in all the experimental groups relative to the control. In conclusion, the integration of a topical methyl gallate microemulsion with intralesional Glucantime® showed potential as an effective treatment for cutaneous leishmaniasis. Further investigations into optimal dosages and therapeutic schemes are warranted in order to enhance treatment outcomes.

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RESUMO A leishmaniose cutânea, causada por protozoários do gênero Leishmania, apresenta diversas manifestações clínicas e as opções terapêuticas atuais têm limitações, incluindo longos períodos de tratamento, possível hospitalização e dor excessiva durante o tratamento. O galato de metila, um composto fenólico encontrado em plantas como Libidibia ferrea, mostra atividade antileishmania promissora. A combinação deste composto com os medicamentos existentes para leishmaniose pode levar a dosagens reduzidas e à minimização dos efeitos colaterais. Este estudo teve como objetivo avaliar a eficácia de uma microemulsão contendo galato de metila, isoladamente ou em combinação com Glucantime®, no tratamento experimental da leishmaniose cutânea em um ensaio in vivo de 30 dias em hamsters sírios infectados com Leishmania (Leishmania) amazonensis. Os grupos de controle incluíram um controle positivo não tratado e um controle negativo não infectado e não tratado. Após o tratamento, avaliamos parâmetros clínicos, parasitológicos e bioquímicos. Embora nenhum dos tratamentos tenha alcançado cura clínica ou parasitológica, melhorias notáveis ​​foram observadas no grupo combinado, com redução significativa nas lesões cutâneas do focinho e na carga parasitária em comparação com o controle. Parâmetros bioquímicos como creatinina, CK-MB, TGO e TGP permaneceram inalterados, os níveis de ureia e CPK aumentaram significativamente em todos os grupos experimentais em relação ao controle. Em conclusão, a integração da microemulsão tópica de galato de metila com Glucantime® intralesional mostrou potencial como um tratamento eficaz para a leishmaniose cutânea. Mais investigações sobre dosagens ideais e esquemas terapêuticos são necessárias para melhorar os resultados do tratamento.

RESUMEN

Sestrins (SESNs) are a family of evolutionarily conserved proteins among mammals. They have several body homeostatic functions such as antioxidant, metabolic, and anti-aging, and are required to regenerate hyperoxidized forms of peroxiredoxins and reactive oxygen species. Sestrin 2 has been studied as a therapeutic agent in obesity treatment. Gallic acid (GA) is a triphenolic compound with beneficial biological activities including anti-inflammatory, antidiabetic, antihypertensive, and antioxidant effects. Recent studies demonstrated the GA's ability to reduce body weight gain and improve glycemic parameters. In this sense, the present study aims to investigate the GA activating potential of Sestrin using the molecular docking method. The 3D structure of gallic acid was retrieved from the NCBI PubChem database and the chemical structure of the Sestrin2 protein from the RCSB Protein Data Bank (5DJ4). The docking calculus was performed via UCSF Chimera and AutoDock Vinaprograms. The results showed that amino acids Arg390, Glu451, Trp444, Thr386, Arg448, Thr374, Tyr375, Asn376, Thr377, Leu389, His454, Ser450, His86, and Val455 are very important for GA stabilization, resembling the interactions that permit Leucine to activate SESN2. In this context, the obesity therapeutic property of GA can be understood from a Sestrin activating process through amino acid metabolism.

Asunto(s)

Ácido Gálico , Sestrinas , Animales , Simulación del Acoplamiento Molecular , Ácido Gálico/farmacología , Ácido Gálico/uso terapéutico , Obesidad/tratamiento farmacológico , Antioxidantes , Mamíferos

RESUMEN

Re-emerging arboviruses represent a serious health problem due to their rapid vector-mediated spread, mainly in urban tropical areas. The 2013-2015 Zika virus (ZIKV) outbreak in South and Central America has been associated with cases of microcephaly in newborns and Guillain-Barret syndrome. We previously showed that the conjugate gallic acid-Hecate (GA-FALALKALKKALKKLKKALKKAL-CONH2)-is an efficient inhibitor of the hepatitis C virus. Here, we show that the Hecate peptide is degraded in human blood serum into three major metabolites. These metabolites conjugated with gallic acid were synthesized and their effect on ZIKV replication in cultured cells was evaluated. The GA-metabolite 5 (GA-FALALKALKKALKKL-COOH) was the most efficient in inhibiting two ZIKV strains of African and Asian lineage at the stage of both virus entry (virucidal and protective) and replication (post-entry). We also demonstrate that GA-metabolite 5 does not affect cell growth after 7 days of continuous treatment. Thus, this study identifies a new synthetic antiviral compound targeting different steps of ZIKV replication in vitro and with the potential for broad reactivity against other flaviviruses. Our work highlights a promising strategy for the development of new antivirals based on peptide metabolism and bioconjugation.

Asunto(s)

Fármacos Dermatológicos , Infección por el Virus Zika , Virus Zika , Recién Nacido , Humanos , Antivirales/química , Replicación Viral , Fármacos Dermatológicos/farmacología , Ácido Gálico/farmacología

RESUMEN

Ludwigia octovalvis (Jacq.) P.H. Raven is widely used in traditional medicine for different illnesses, including diabetes and hypertension. However, its impact on lipotoxicity and metabolic syndrome in vivo has not been addressed. Therefore, the aim of this study was to evaluate the effects of this plant on the metabolic syndrome parameters in a C57BL6J mouse hypercaloric diet model. L. octovalvis hydroalcoholic extract and its ethyl acetate fraction (25 mg/kg/day) were used for sub-chronic assessment (10 weeks). Additionally, four subfractions (25 mg/kg) were evaluated in the postprandial triglyceridemia test in healthy C57BL6J mice. The hydroalcoholic extract and ethyl acetate fraction significantly decreased body weight gain (-6.9 g and -1.5 g), fasting glycemia (-46.1 and -31.2 mg/dL), systolic (-26.0 and -22.5 mmHg) and diastolic (-8.1 and 16.2 mmHg) blood pressure, free fatty acid concentration (-13.8 and -8.0 µg/mL) and insulin-resistance (measured by TyG index, -0.207 and -0.18), compared to the negative control. A postprandial triglyceridemia test showed that the effects in the sub-chronic model are due, at least in part, to improvement in this parameter. L. octovalvis treatments, particularly the hydroalcoholic extract, improve MS alterations and decrease free fatty acid concentration. These effects are possibly due to high contents of corilagin and ellagic acid.

RESUMEN

Polygallic acid (PGAL) has been used in vitro to protect synoviocytes from monosodium urate (MSU) crystals due to its anti-inflammatory properties. However, MSU crystals can also activate other cells of the synovial fluid (SF). We studied the impact of PGAL on the phagocytosis of MSU crystals, inflammation, and oxidative stress using an in vitro model with SF leukocytes and THP-1 monocyte cells. SF leukocytes were stimulated with PGAL and MSU crystals, proinflammatory cytokines and phagocytosis were assessed. In THP-1 cells, the effect of PGAL on the phagocytosis of MSU crystals and the levels of IL-1ß, IL-6, TNF-α, and reactive oxygen species (ROS) was evaluated. PGAL was added to THP-1 cultures 24 h before MSU crystal addition as a pre-treatment, and IL-1ß was measured. One-way ANOVA with Tukey's post hoc test was performed, and a P value < 0.05 was considered statistically significant. PGAL (100 µg/mL) decreased phagocytosis in SF leukocytes by 14% compared to cells exposed to crystals without PGAL. In THP-1 cells, 100 and 200 µg/mL PGAL reduced phagocytosis by 17% and 15%, respectively. In SF cells, there was a tendency to decrease IL-1ß and IL-6. In THP-1 cells, decreases in IL-1ß and TNF-α, as well as a slight decrease in ROS, were identified. PGAL pre-treatment resulted in a reduction of IL-1ß. PGAL inhibits MSU phagocytosis by exerting an anti-inflammatory effect on cells exposed to crystals. The use of PGAL before an acute attack of gout suggests an important protective factor to control the inflammation.

Asunto(s)

Gota , Factor de Necrosis Tumoral alfa , Humanos , Especies Reactivas de Oxígeno , Interleucina-6 , Ácido Úrico/farmacología , Inflamación , Antiinflamatorios

RESUMEN

BACKGROUND: Chia oil represents the vegetable source with the highest content of omega-3 fatty acids. However, the incorporation of polyunsaturated fatty acids into food is limited due to their susceptibility toward oxidation. This investigation aimed to study the microencapsulation of chia oil (CO), using gallic acid (GA) crosslinked-soy protein isolate (SPI) as a wall material and its effect on its oxidative stability. RESULTS: Microcapsules presented a moisture content, water activity, and encapsulation efficiency of around 2.95-4.51% (wet basis); 0.17 and 59.76-71.65%, respectively. Rancimat tests showed that with higher GA content, the induction period increased up to 27.9 h. The storage test demonstrated that the microencapsulated oil with crosslinked wall material has lower values of hydroperoxides and higher induction times concerning the non-crosslinked oil. Finally, the fatty acid profile at this storage time indicated that microcapsules with GA did not have significant changes. In vitro digestion exhibited a reduction in the percentage of bioavailable oil for crosslinked microcapsules, but with no variations in its chemical quality, and an increase in the total polyphenols amount and antioxidant activity. CONCLUSION: The results obtained demonstrated that the microencapsulation of CO using SPI crosslinked with GA as wall material exerted a very important protective effect since a synergistic effect could be described between the microencapsulation effect and the antioxidant power of GA. © 2023 Society of Chemical Industry.

Asunto(s)

Salvia , Proteínas de Soja , Ácido Gálico , Salvia/química , Cápsulas/química , Aceites de Plantas/química , Antioxidantes/química

RESUMEN

The encapsulation of gallic acid (GA) through several methods has enhanced its shelf life and facilitated industrial applications. Polymeric matrices made of alginate and pectin were evaluated to encapsulate GA via spray drying. The pH-responsive release mechanism was monitored to validate the matrices' performances as wall materials and extend the bioactive compound stability. The microcapsules produced were characterized via scanning electron microscopy (SEM), dynamic light scattering (DLS), Fourier-transform infrared spectroscopy (FTIR), and cyclic voltammetry (CV). The retention and encapsulation efficiency ranges were 45-82% and 79-90%, respectively. The higher values were reached at 3 and 0.75% (w/v) pectin and sodium alginate, respectively. The scanning electron microscopy showed smooth spherical capsules and the average particle size ranged from 1327 to 1591 nm. Their performance and stability were evaluated with optimal results at a pH value of 7 throughout the investigation period. Therefore, this work demonstrated the suitability of gallic acid encapsulation via spray drying using pectin and alginate, which are biopolymers that can be obtained from circular economy processes starting from agro-industrial biomass. The developed formulations provide an alternative to protecting and controlling the release of GA, promoting its application in the food, pharmaceutical, and cosmetic industries and allowing for the release of compounds with high bioactive potential.

RESUMEN

A model (sucrose and gallic acid) solution was concentrated by block freeze concentration (BFC) at three centrifugation cycles, and the solutions were encapsulated in calcium alginate and corn starch calcium alginate hydrogel beads. Static and dynamic tests determined the rheological behavior, differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR) established thermal and structural properties, and the release kinetics was evaluated under in vitro simulated digestion experiment. The highest efficiency encapsulation value was close to 96%. As the concentrated solution increased in terms of solutes and gallic acid, the solutions were fitted to the Herschel-Bulkley model. Moreover, from the second cycle, the solutions exhibited the highest values of storage modulus (G') and loss modulus (G″), contributing to form a more stable encapsulation. The FTIR and DSC results demonstrated strong interactions between corn starch and alginate, establishing a good compatibility and stability in the bead formation. The kinetic release model under in vitro conditions was fitted to the Korsmeyer-Peppas model, demonstrating the significant stability of the model solutions inside the beads. Therefore, the present study proposes a clear and precise definition for the elaboration of liquid foods obtained by BFC and its incorporation inside an edible material that facilitates the controlled release in specific sites.

RESUMEN

Campomanesia xanthocarpa leaves are a byproduct of fruit production without studies on antioxidant activity. Thus, this study aimed to identify the antioxidant compounds of C. xanthocarpaleaves by ultra-high performance liquid chromatography coupled with electrospray ionization-quadrupole-time of flight-mass spectrometry (UHPLC-ESI/qTOF) and by different in vitro antioxidant methods. The crude extract of C. xanthocarpa leaves had a yield of 15.2% and only five out of 37 fractions of the crude extract had antioxidant activity. The crude extract presented greater antioxidant activity than the isolated fractions. The identified antioxidant compounds were phenolic acids (gallic acid and chlorogenic acid), flavonoids (quercetin and naringenin 7,4'-dimethoxy) and an organic acid (quinic acid). Leaves of C. xanthocarpa have high concentration of antioxidant compounds and it is a promising plant for the development of applications in the food, cosmetic, and pharmaceutical fields. The extraction of antioxidant compounds can add value to the productive chain of this plant.

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Las hojas de Campomanesia xanthocarpa son un subproducto de la producción de frutos sin estudios sobre la actividad antioxidante. Así, este estudio tuvo como objetivo identificar los compuestos antioxidantes de las hojas de C. xanthocarpa mediante cromatografía líquida de ultra alta resolución acoplada con espectrometría de ionización-cuadrupolo-tiempo de vuelo-masa por electropulverización (UHPLC-ESI / qTOF) y mediante diferentes métodos antioxidantes in vitro. El extracto crudo de hojas de C. xanthocarpa tuvo un rendimiento del 15,2% y solo cinco de las 37 fracciones del extracto crudo tuvieron actividad antioxidante. El extracto crudo presentó mayor actividad antioxidante que las fracciones aisladas. Los compuestos antioxidantes identificados fueron ácidos fenólicos (ácido gálico y ácido clorogénico), flavonoides (quercetina y naringenina 7,4'-dimetoxi) y un ácido orgánico (ácido quínico). Las hojas de C. xanthocarpa tienen una alta concentración de compuestos antioxidantes y es una planta prometedora para el desarrollo de aplicaciones en los campos alimentario, cosmético y farmacéutico. La extracción de compuestos antioxidantes puede agregar valor a la cadena productiva de esta planta.

Asunto(s)

Plantas Medicinales , Myrtaceae/química , Mezclas Complejas/química , Antioxidantes/farmacología , Aceites Volátiles/farmacología , Aceites Volátiles/química

RESUMEN

Polygonum hydropiperoides Michx. is an Asian native plant species that is also widely distributed in the Americas. Despite its traditional uses, P. hydropiperoides is scarcely scientifically exploited. This study aimed to chemically characterize and investigate the antioxidant and antibacterial activities of hexane (HE-Ph), ethyl acetate (EAE-Ph), and ethanolic (EE-Ph) extracts from aerial parts of P. hydropiperoides. The chemical characterization was performed through HPLC-DAD-ESI/MSn. The antioxidant activity was assessed by the phosphomolybdenum reducing power, nitric oxide inhibition, and the ß-carotene bleaching assays. The antibacterial activity was determined by the minimal inhibitory concentration (MIC) and the minimal bactericidal concentration followed by the classification of the antibacterial effect. Chemical characterization revealed the expressive presence of phenolic acids and flavonoids in EAE-Ph. An increased antioxidant capacity was revealed in EAE-Ph. Regarding antibacterial activity, EAE-Ph showed weak to moderate property against 13 strains tested with MIC values ranging from 625 to 5000 µg/mL, with bactericidal or bacteriostatic effects. Glucogallin and gallic acid stand out as the most relevant bioactive compounds. These results suggest that P. hydropiperoides is a natural source of active substances, supporting this species' traditional use.

RESUMEN

Diverse reducing mediators have often been used to increase the degradation of emerging pollutants (EPs) and dyes through the Fenton reaction (Fe2+ + H2O2 → Fe3+ + HO● + HO-). Adding reductants can minimize the accumulation of Fe3+ in a solution, leading to accelerated Fe2+ regeneration and the enhanced generation of reactive oxygen species, such as the HO● radical. The present study consisted in reviewing the effects of gallic acid (GA), a plant-extracted reductant, on the Fenton-based oxidation of several EPs and dyes. It was verified that the pro-oxidant effect of GA was not only reported for soluble iron salts as a catalyst (homogeneous Fenton), but also iron-containing solid materials (heterogeneous Fenton). The most common molar proportion verified in the studies was catalyst:oxidant:GA equal to 1:10-20:1. This shows that the required amount of both catalyst and GA is quite low in comparison with the oxidant, which is generally H2O2. Interestingly, GA has proven to be an effective mediator at pH values well above the ideal range of 2.5-3.0 for Fenton processes. This allows treatments to be carried out at the natural pH of the wastewater. The use of plant extracts or wood barks containing GA and other reductants is suggested to make GA-mediated Fenton processes easier to apply for treating real wastewater.

RESUMEN

Agro-industrial by-products are a sustainable source of natural additives that can replace the synthetic ones in the food industry. Grape pomace is an abundant by-product that contains about 70% of the grape's polyphenols. Polyphenols are natural antioxidants with multiple health-promoting properties. They are secondary plant metabolites with a wide range of solubilities. Here, a novel extraction process of these compounds was developed using enzymes that specifically liberates target polyphenols in the appropriate hydroalcoholic mixture. Tannase, cellulase, and pectinase retained 22, 60, and 52% of their activity, respectively, in ethanol 30% v/v. Therefore, extractions were tested in ethanol concentrations between 0 and 30% v/v. Some of these enzymes presented synergistic effects in the extraction of specific polyphenols. Maximum yield of gallic acid was obtained using tannase and pectinase enzymes in ethanol 10% v/v (49.56 ± 0.01 mg L-1 h-1); in the case of p-coumaric acid, by cellulase and pectinase treatment in ethanol 30% v/v (7.72 ± 0.26 mg L-1 h-1), and in the case of trans-resveratrol, by pectinase treatment in ethanol 30% v/v (0.98 ± 0.04 mg L-1 h-1). Also, the effect of enzymes and solvent polarity was analysed for the extraction of malvidin-3-O-glucoside, syringic acid, and quercetin. Previous studies were mainly focused on the maximization of total polyphenols extraction yields, being the polyphenolic profile the consequence but not the driving force of the optimization. In the present study, the basis of a platform for a precise extraction of the desire polyphenols is provided. KEY POINTS: • Enzymes can be used up to ethanol 30% v/v. • The specific enzymes' action determines the polyphenolic profile of the extracts. • The yields obtained of target polyphenols are competitive.

Asunto(s)

Celulasas , Polifenoles , Poligalacturonasa , Solventes , Etanol , Extractos Vegetales , Antioxidantes

RESUMEN

Gallic acid is a powerful antioxidant with multiple therapeutic applications, usually obtained from the acidic hydrolysis of tannins produced by many plants. As this process generates a considerable amount of toxic waste, the use of tannases or tannase-producing microorganisms has become a greener alternative over the last years. However, their high costs still impose some barriers for industrial scalability, requiring solutions that could be both greener and cost-effective. Since Pseudomonas putida KT2440 is a powerful degrader of gallic acid, its metabolism offers pathways that can be engineered to produce it from cheap and renewable carbon sources, such as the crude glycerol generated in biodiesel units. In this study, a synthetic operon with the heterologous genes aroG4, quiC and pobA* was developed and expressed in P. putida, based on an in silico analysis of possible metabolic routes, resulting in no production. Then, the sequences pcaHG and galTAPR were deleted from the genome of this strain to avoid the degradation of gallic acid and its main intermediate, the protocatechuic acid. This mutant was transformed with the vector containing the synthetic operon and was finally able to convert glycerol into gallic acid. Production assays in shaker showed a final concentration of 346.7 ± 0.004 mg L-1 gallic acid after 72 h.

Asunto(s)

Pseudomonas putida , Pseudomonas putida/genética , Pseudomonas putida/metabolismo , Glicerol/metabolismo , Ácido Gálico/metabolismo

RESUMEN

Tejuino, is a Mexican fermented beverage prepared by germination-fermentation or nixtamalization-fermentation (artisanal and commercial mode respectively) of maize. The aim of this study was to evaluate the gut metabolites, volatile, and phenolic compounds (PC) produced by the indigestible fraction (IF) of Tejuino during an in vitro colonic fermentation. Twenty-six PC in the IF were identified; the hydroxycinnamic acids (30-40 %) were the most abundant. In the IF of Tejuino pyrogallol, and urolithins were identified. Some of the representative PC of maize as maysin derivatives (apimaysin and 3-methoxymaysin) (flavonoids). The quantification of acetic and butyric acid become notable after 6 h of the colonic fermentation of IF of Tejuino. Ninety-seven volatile compounds were found, and the PCA shows the predominant compounds as short chain fatty acids, esters of organic acids and indole derivatives. These results suggest that Tejuino could be an important source of metabolites with high biological value.