Guías Latinoamericanas de Infecciones Congénitas y Perinatales de la Sociedad Latinoamericana de Infectología Pediátrica (SLIPE). Parte II

Las infecciones perinatales son una causa de morbilidad, tanto fetal como neonatal, y que compromete la salud de la mujer embarazada, por lo que su diagnóstico, tratamiento, e intento de eliminación son una prioridad en América Latina y el Caribe. Este documento representa la segunda entrega realizada por expertos en la región dentro de la Sociedad Latinoamericana de Infectología Pediátrica (SLIPE), brindando una mirada actualizada en el manejo de las infecciones congénitas y entrega herramientas para detectar posibles momentos estratégicos de intervención y cambio en el manejo de las infecciones congénitas.

Perinatal infections are a major cause of morbidity and mortality in the fetus, neonate, and the health of the pregnant woman. Diagnosis, treatment, and the search for elimination of these diseases are a priority in Latin America and the Caribbean. This document represents the second delivery by a group of experts in the region inside the Latin-American Society of Pediatric Infectious Diseases (SLIPE), presenting a up-to-date look into the management of congenital infectious diseases and give a tool to detect possible strategic sceneries and a change in the management of congenital infections in our region.

Antifungal Activity Enhancement of Cell-Free Streptomyces griseus Extract Obtained by Fermentation with Magnetic Manganese Ferrite Nanoparticles.

The present study aims to obtain manganese ferrite nanoparticles functionalized with chitosan (C-MNP) or ethylenediamine (E-MNP) by coprecipitation and polyol one-step methods, characterize their interaction with S. griseus demonstrating cell immobilization, and evaluate the antimicrobial activity of the free cell extracts obtained from immobilized S. griseus fermentation in the presence of different concentrations of MNP. The adsorption isotherms were analyzed mathematically using Langmuir and Freundlich models. The highest coefficient of determination (R2) for the S. griseus cell adsorption isotherm with C-MNP was observed with a linear function of the Langmuir model. The adsorption isotherm of S. griseus cells with E-MNP was better fitted to the Freundlich model. Cell immobilization by adsorption on magnetic nanoparticles was demonstrated in both cases. Different concentrations of C-MNP and E-MNP were used in fermentations to prepare cell-free extracts with antifungal activity. The best results were obtained with E-MNP, with a 91.5% inhibition of radial fungal growth. Magnetic nanoparticles offer potential applications in different fields and easy biomass separation.

Self-Standing Metal Foam Catalysts for Cathodic Electro-Organic Synthesis.

Although electro-organic synthesis is currently receiving renewed interest because of its potential to enable sustainability in chemical processes to value-added products, challenges in process development persist: For reductive transformations performed in protic media, an inherent issue is the limited choice of metallic cathode materials that can effectively suppress the parasitic hydrogen evolution reaction (HER) while maintaining a high activity toward the targeted electro-organic reaction. Current development trends are aimed at avoiding the previously used HER-suppressing elements (Cd, Hg, and Pb) because of their toxicity. Here, this work reports the rational design of highly porous foam-type binary and ternary electrocatalysts with reduced Pb content. Optimized cathodes are tested in electro-organic reductions using an oxime to nitrile transformation as a model reaction relevant for the synthesis of fine chemicals. Their electrocatalytic performance is compared with that of the model CuSn7Pb15 bronze alloy that has recently been endorsed as the best cathode replacement for bare Pb electrodes. All developed metal foam catalysts outperform both bare Pb and the CuSn7Pb15 benchmark in terms of chemical yield and energetic efficiency. Moreover, post-electrolysis analysis of the crude electrolyte mixture and the cathode's surfaces through inductively coupled plasma mass spectrometry (ICP-MS) and scanning electron microscopy (SEM), respectively, reveal the foam catalysts' elevated resistance to cathodic corrosion.

Anti-allodynic and anti-hyperalgesic activity of (±)-licarin A in neuropathic rats via NO-cyclic-GMP-ATP-sensitive K+ channel pathway.

The study aimed to examine the effect of intraperitoneal and intrathecal (±)-licarin A in neuropathic pain induced by L5 and L6 spinal nerve ligation (SNL) in male Wistar rats and the possible involvement of the NO-cGMP-ATP-sensitive K+ channel pathway. Neuropathic pain signs (allodynia and hyperalgesia) were evaluated on postoperative Day 14 using von Frey filaments. Single intraperitoneal (0.01, 0.1, 1, and 10 mg/kg) and intrathecal (0.01, 0.1, 1, and 10 µg/rat) administration of (±)-licarin A improved allodynia and hyperalgesia. The (±)-licarin A-induced anti-allodynic and anti-hyperalgesic activity was prevented by the intrathecal injection of  l-NAME (100 µg/rat; nonselective nitric oxide synthase inhibitor), ODQ (10 µg/rat; guanylate cyclase inhibitor), and glibenclamide (50 µg/rat; adenosine triphosphate (ATP)-sensitive K+ channel blocker). The data suggest that (±)-licarin A exerts its anti-allodynic and anti-hyperalgesic activity by activating the NO-cGMP-ATP-sensitive K+ channel pathway.

Are the first 1,000 days of life a neglected vital period to prevent the impact on maternal and infant morbimortality of infectious diseases in Latin America? Proceedings of a workshop of experts from the Latin American Pediatric Infectious Diseases Society, SLIPE.

While the first 1,000 days of life are a critical period in child's development, limited information on the main determinants affecting this period in the Latin America and the Caribbean (LAC) region is available. Therefore, the Latin American Pediatric Infectious Diseases Society (SLIPE) held an ad hoc workshop in May 2022 with an expert panel designed to analyze the main factors impacting the development of childhood in the region during this period and the main causes of maternal infant morbimortality. The aim was to identify priorities, generate recommendations, and advise practical actions to improve this situation. Considerations were made about the challenges involved in bridging the gap that separates the region from more developed countries regarding an optimal early childhood and maternal care. Extensive discussion was conducted to reach consensus recommendations on general strategies intended to reduce maternal and infant mortality associated with infections and immune-preventable diseases during the first 1,000 days of life in LAC.

Anti-Inflammatory and Cytotoxic Activities of Clerodane-Type Diterpenes.

The secondary metabolites of clerodane diterpenoids have been found in several plant species from various families and in other organisms. In this review, we included articles on clerodanes and neo-clerodanes with cytotoxic or anti-inflammatory activity from 2015 to February 2023. A search was conducted in the following databases: PubMed, Google Scholar and Science Direct, using the keywords clerodanes or neo-clerodanes with cytotoxicity or anti-inflammatory activity. In this work, we present studies on these diterpenes with anti-inflammatory effects from 18 species belonging to 7 families and those with cytotoxic activity from 25 species belonging to 9 families. These plants are mostly from the Lamiaceae, Salicaceae, Menispermaceae and Euphorbiaceae families. In summary, clerodane diterpenes have activity against different cell cancer lines. Specific antiproliferative mechanisms related to the wide range of clerodanes known today have been described, since many of these compounds have been identified, some of which we barely know their properties. It is very possible that there are even more compounds than those described today, in such a way that makes it an open field to discover. Furthermore, some diterpenes presented in this review have already-known therapeutic targets, and therefore, their potential adverse effects can be predicted in some way.

Multiplex assay for the simultaneous detection of antibodies against small ruminant lentivirus, Mycobacterium avium subsp. paratuberculosis, and Brucella melitensis in goats.

Background and Aim: Brucellosis, paratuberculosis (PTb), and infections caused by small ruminant lentivirus (SRLV), formerly known as caprine arthritis encephalitis virus (CAEV), adversely affect goat production systems. Nonetheless, commonly used diagnostic tests can only determine one analyte at a time, increasing disease surveillance costs, and limiting their routine use. This study aimed to design and validate a multiplex assay for antibody detection against these three diseases simultaneously. Materials and Methods: Two recombinant proteins from the SRLV (p16 and gp38), the native hapten of Brucella melitensis, and the paratuberculosis-protoplasmic antigen 3 from Mycobacterium avium subsp. paratuberculosis (MAP) were used to devise and assess a multiplex assay. Conditions for the Luminex® multiplex test were established and validated by sensitivity, specificity, repeatability, and reproducibility parameters. Cut-off points for each antigen were also established. Results: The 3-plex assay had high sensitivity (84%) and specificity (95%). The maximum coefficients of variation were 23.8% and 20.5% for negative and positive control samples, respectively. The p16 and gp38 SRLV antigens are 97% and 95%, similar to the CAEV sequence found in GenBank, respectively. Conclusion: The multiplex test can be effectively used for the simultaneous detection of antibodies against SRLV, MAP and B. melitensis in goats.

Recovery of Naringin-Rich Flavonoid Extracts from Agroresidues with Anxiolytic- and Antidepressant-like Effects in Mice.

Citrus paradisi species belong to the Rutaceae family, and it is commonly known as grapefruit. Grapefruit consumption involves a large amount of waste that goes to landfills and produces significant pollution affecting the human health. To examine this phenomenon, we designed an efficient chemical method that recovers naringin-rich flavonoid extracts from the fresh waste of grapefruits, by using the solvent impregnation resin method (SIR) with XAD-4 amberlite and either methanol or water as elution systems. Additionally, we focused on evaluating these extracts' anxiolytic- and antidepressant-like effects in behavioral predictive paradigms in mice. According to direct Principal Component Analysis (PCA) by NMR, and Direct Injection Electrospray Ionization-Mass Spectrometry (DIESI-MS), methanol extracts obtained after resin treatment were free of coumarin compounds and evinced had a high content of naringin. Poncirin, phenylalanine, chrysin 5,7-dimethyl ether, 5,7-dimethoxy-4'-hydroxyflavanone, 2,3-dihydro-2-(4-hydroxyphenyl)-5,6,7,8-tetramethoxy-4H-1-benzopyran-4-one, tetrahydrocurcumin, corchoionoside C, 6'-coumaroyl-1'-O-[2-(3,4-dihydroxyphenyl) ethyl]-ß-D-glucopyranoside were also detected. Naringin-rich methanol extract caused a clear anxiolytic-like effect in the Elevated Plus Maze (EPM) and the Hole-Board (HBT) Tests, increasing oral doses of this extract did not produce a sedative effect. A single oral dose caused an antidepressant-like effect in the Tail Suspension Test (TST), while repeated administrations of the methanol extract elicited a robust antidepressant effect in the Forced Swimming Test (FST) in mice. Our evidence highlights the importance of bioprospecting studies of organic waste with therapeutic potentials, such as anxiety and depression disorders.

Infección tardía por Streptococcus agalactiae asociada a la leche humana: reporte de 3 casos clínicos / Streptococcus agalactiae late onset infection associated with human milk: three cases report

La infección por estreptococo ß-hemolítico del grupo B o Streptococcus agalactiae puede causar morbilidad grave y mortalidad en los recién nacidos, especialmente en prematuros. Las estrategias de prevención actuales han sido eficaces en reducir la frecuencia de sepsis neonatal temprana ocasionada por transmisión vertical. La incidencia de sepsis tardía por dicho microrganismo no se ha modificado y la vía de infección es menos clara. En niños amamantados, la transmisión a través de la leche materna es posible. Se presentan tres casos de infección tardía por estreptococo ß-hemolítico del grupo B en recién nacidos prematuros alimentados con leche materna cuyas madres tenían mastitis. En todos los casos, tanto en el cultivo de la leche materna como en los hemocultivos de los neonatos se desarrolló el mismo microrganismo.

Group B ß-hemolytic Streptococcus or Streptococcus agalactiae is a major cause of morbidity and mortality in neonates, especially in premature infants. Current prevention strategies have been effective in reducing the frequency of early onset neonatal sepsis caused by vertical transmission. The incidence of late onset sepsis due to this microorganism has not changed and the route of infection is less clear. In breastfed infants, transmission through breast milk is possible. We report three cases of late group B ß-hemolytic streptococcal infection in breastfed preterm infants whose mothers had mastitis. In all cases, both the breast milk culture and the blood cultures of the neonates developed the same microorganism.

Synthesis and Biological Activities of Dehydrodiisoeugenol: A Review.

Dehydrodiisoeugenol (DHIE) is a neolignan found in more than 17 plant species, including herbs, fruit, and root. DHIE was, for the first time, isolated from Myristica fragrans bark in 1973. Since then, many methodologies have been used for the obtention of DHIE, including classical chemistry synthesis using metal catalysts and biocatalytic synthesis; employing horseradish peroxidase; peroxidase from Cocos nucifera; laccase; culture cells of plants; and microorganisms. Increasing evidence has indicated that DHIE has a wide range of biological activities: anti-inflammatory, anti-oxidant, anti-cancerogenic, and anti-microbial properties. However, evidence in vivo and in human beings is still lacking to support the usefulness potential of DHIE as a therapeutic agent. This study's review was created by searching for relevant DHIE material on websites such as Google Scholar, PubMed, SciFinder, Scholar, Science Direct, and others. This reviews the current state of knowledge regarding the different synthetical routes and biological applications of DHIE.

[Streptococcus agalactiae late onset infection associated with human milk: three cases report]. / Infección tardía por Streptococcus agalactiae asociada a la leche humana: reporte de 3 casos clínicos.

Group B ß-hemolytic Streptococcus or Streptococcus agalactiae is a major cause of morbidity and mortality in neonates, especially in premature infants. Current prevention strategies have been effective in reducing the frequency of early onset neonatal sepsis caused by vertical transmission. The incidence of late onset sepsis due to this microorganism has not changed and the route of infection is less clear. In breastfed infants, transmission through breast milk is possible. We report three cases of late group B ß-hemolytic streptococcal infection in breastfed preterm infants whose mothers had mastitis. In all cases, both the breast milk culture and the blood cultures of the neonates developed the same microorganism.

La infección por estreptococo ß-hemolítico del grupo B o Streptococcus agalactiae puede causar morbilidad grave y mortalidad en los recién nacidos, especialmente en prematuros. Las estrategias de prevención actuales han sido eficaces en reducir la frecuencia de sepsis neonatal temprana ocasionada por transmisión vertical. La incidencia de sepsis tardía por dicho microrganismo no se ha modificado y la vía de infección es menos clara. En niños amamantados, la transmisión a través de la leche materna es posible. Se presentan tres casos de infección tardía por estreptococo ß-hemolítico del grupo B en recién nacidos prematuros alimentados con leche materna cuyas madres tenían mastitis. En todos los casos, tanto en el cultivo de la leche materna como en los hemocultivos de los neonatos se desarrolló el mismo microrganismo.

Bilingual Supports for Clinicians: Where Do We Go From Here?

Purpose The purpose of this study was to identify and define the support needs of bilingual speech-language pathologists working in one urban school district and to investigate the experiences of the clinicians engaged in a professional learning community (PLC) format within their public school system. Method Twenty-three bilingual speech-language pathologists met in a PLC over the course of 5 months, with a total of four sessions that were a mix of in person and virtual. The participants engaged in group discussions and activities alongside their peers to address self-identified areas of support and need. Additionally, initial and final focus group and exit slip data following the PLC were collected to inform the discussion topics of the PLC and gather final impressions. Constant comparative analysis was utilized to analyze focus group and exit slip data. Results When looking across the experiences of the clinicians in the district, the three themes that emerged from the data were systemic obstacles, professional obstacles, and supports. The three themes that emerged from the speech-language pathologists' experiences in the PLC included their positive experiences, the challenges with participation, and the positive outcomes from exposure to new techniques and earning platforms. Conclusion The findings of this study suggest that bilingual clinicians benefit from a PLC model when addressing specific areas of need.

Role of aromatase activation on sodium arsenite-induced proliferation, migration, and invasion of MDA-MB-231 and MDA-MB-453 breast cancer cell lines.

Arsenic is an endocrine disruptor that promotes breast cancer (BCa) development. Estrogen synthesis, through aromatase activation, is essential for BCa promotion and progression through activating the G-coupled estrogen receptor 1 (GPER1), regulating rapid nongenomic effects involved in cell proliferation and migration of BCa cells. Herein, was studied the role of aromatase activation and the GPER1 pathway on sodium arsenite-induced promotion and progression of MDA-MB-231 and MDA-MB-453 BCa cell lines. Our results demonstrated that 0.1 µM of sodium arsenite induces cell proliferation, migration, invasion, and stimulates aromatase activity of BCa cell lines MDA-MB-231, MDA-MB-453, MCF-7, but not in a nontumorigenic breast epithelial cell line (MCF-12A). Using letrozole (an aromatase inhibitor) and G-15 (a GPER1-selective antagonist), we demonstrated that sodium arsenite-induced proliferation and migration is mediated by induction of aromatase enzyme and, at least in part, by GPER1 activation in MDA-MB-231 and MDA-MB-453 cells. Sodium arsenite induced phosphorylation of Src that participated in sodium arsenite-induced aromatase activity, and -cell proliferation of MDA-MB-231 cell line. Overall, data suggests that sodium arsenite induces a positive-feedback loop, resulting in the promotion and progression of BCa cells, through induction of aromatase activity, E2 production, GPER1 stimulation, and Src activation.

Evaluation of clinically asymptomatic high risk infants with congenital cytomegalovirus infection.

OBJECTIVE: To determine the frequency of abnormal findings on evaluation of neonates with congenital CMV infection who have a normal physical examination STUDY DESIGN: Retrospective, 2-center study (1996-2017) that reviewed results of complete blood cell count and platelets, serum alanine aminotransferase (ALT) and bilirubin concentrations, eye examination, cranial ultrasonography or other neuroimaging, and brainstem evoked responses performed on neonates with congenital CMV infection and a normal physical examination RESULTS: Of 34 infants with congenital CMV infection and a normal physical examination, 56% (19/34) had ≥1 abnormality: 39%, elevated ALT concentration; 45%, abnormal neuroimaging (five, lenticulostriate vasculopathy; six, intraventricular hemorrhage; four, calcifications); 12%, anemia; 16%, thrombocytopenia; and 3%, chorioretinitis. Seven (21%) infants had sensorineural hearing loss, and 18 infants received antiviral therapy. CONCLUSION: Some infants with congenital CMV infection and a normal physical examination had abnormalities on laboratory or neuroimaging evaluation, which in some cases prompted antiviral treatment.

Parálisis fláccida aguda por enterovirus con resolución completa del cuadro neurológico. A propósito de un caso pediátrico / Acute flaccid paralysis related to enterovirus with complete resolution of the neurological symptoms. A pediatric case report

Desde la eliminación de la circulación del virus polio salvaje, disminuyeron los casos de parálisis fláccida aguda. Sin embargo, continúan ocurriendo casos asociados a otros enterovirus no polio y virus neurotropos. Se presenta el caso de una paciente de 9 años con diagnóstico de meningitis y mielitis con compromiso motor en los miembros inferiores y vejiga neurogénica asociado a enterovirus, con resolución completa del cuadro neurológico posterior a la administración de gammaglobulina hiperinmune.

Since the wild poliovirus no longer circulates, the number of cases of acute flaccid paralysis decreased. However, cases related to non-polio enteroviruses and neurotrope viruses continue to occur. We present a nine-year-old patient with meningitis and myelitis with motor involvement in the lower limbs and neurogenic bladder associated with enterovirus, with complete resolution of the neurological symptoms following the administration of hyperimmune gammaglobulin.

[Acute flaccid paralysis related to enterovirus with complete resolution of the neurological symptoms. A pediatric case report]. / Parálisis fláccida aguda por enterovirus con resolución completa del cuadro neurológico. A propósito de un caso pediátrico.

Since the wild poliovirus no longer circulates, the number of cases of acute flaccid paralysis decreased. However, cases related to non-polio enteroviruses and neurotrope viruses continue to occur. We present a nine-year-old patient with meningitis and myelitis with motor involvement in the lower limbs and neurogenic bladder associated with enterovirus, with complete resolution of the neurological symptoms following the administration of hyperimmune gammaglobulin.

Desde la eliminación de la circulación del virus polio salvaje, disminuyeron los casos de parálisis fláccida aguda. Sin embargo, continúan ocurriendo casos asociados a otros enterovirus no polio y virus neurotropos. Se presenta el caso de una paciente de 9 años con diagnóstico de meningitis y mielitis con compromiso motor en los miembros inferiores y vejiga neurogénica asociado a enterovirus, con resolución completa del cuadro neurológico posterior a la administración de gammaglobulina hiperinmune.

Preparative scale extraction of mangiferin and lupeol from mango (Mangifera indica L.) leaves and bark by different extraction methods.

High biological value compounds are very important in the food and pharmaceutical sectors. The leading research interests are seeking efficient methods for extracting these substances. The objective of this study was to evaluate different extraction methods to obtain mangiferin and lupeol at preparative scale from leaves and bark of mango tree varieties Ataulfo and Autochthonous from Nayarit, Mexico. Four extraction techniques were evaluated such as maceration, Soxhlet, sonication (UAE) and microwave (MAE). Sonication gave the highest concentration of mangiferin and lupeol, demonstrating that extraction assisted by ultrasound could be an effective alternative to conventional extraction techniques because it is a low cost, simple and reliable process. Finally, mangiferin and lupeol were obtained at preparative scale with a higher concentration of bioactive compounds, 1.45 g 100 g-1 y 0.92 mg 100 g-1 sample on (d.b.), respectively. The barks from Ataulfo and Autochthonous mango trees turned out to be favourable sources for obtaining mangiferin and lupeol.

Effect of mice Taenia crassiceps WFU cysticerci infection on the ovarian folliculogenesis, enzyme expression, and serum estradiol.

The murine infection with Taenia crassiceps WFU (T. crassiceps WFU) cysticerci has been widely used as an experimental model to better understand human cysticercosis. Several reports have established that the host hormonal environment determines the susceptibility and severity of many parasite infections. Female mice are more susceptible to infection with T. crassiceps cysticerci suggesting that a rich estrogen environment facilitates their reproduction. Ovarian androgens and estrogens are synthesized by key enzymes as P450-aromatase and 17α-hydroxilase/17, 20 lyase (P450C17). The aim of this study was to determine the effect of chronic intraperitoneal infection of T. crassiceps WFU cysticerci on mice ovarian follicular development, ovulation, the expression of ovarian P450-aromatase and P450C17, and serum 17ß-estradiol, key enzymes of the ovarian steroidogenic pathway. To perform this study ovaries and serum were obtained at two, four and six months from T. crassiceps WFU cysticerci infected mice, and compared to those of healthy animals. The ovaries were fixed and processed for histology or lysed in RIPA buffer for Western blot using specific antibodies for P450C17 and P450-aromatase. 17ß-estradiol serum concentration was measured by ELISA. The results showed that the infection with T. crassiceps WFU cysticerci significantly reduced the number of primordial and primary follicles after two months of infection. Through the course of the study, the corpus luteum number began to decrease, whereas atretic follicles increased. The expression of ovarian P450C17 and P450-aromatase as well as serum E2 concentration were significantly increased in the infected group compared to control. These findings show that chronic infection with Taenia crassiceps WFU may alter the reproductive functions of the female mice host.

Extraction and Identification of Anthocyanins in Corn Cob and Corn Husk from Cacahuacintle Maize.

Pigmented maize has been extensively studied due to its high anthocyanin content. This study has been focused mainly on kernel, although the whole plant of purple corn is a potential source of anthocyanins. First, general parameters of extraction (solvent system, solvent-to-solid ratio, number of extractions, and acid type) were established depending on the total anthocyanins content. Then, three extraction methods to access anthocyanins were compared: maceration extraction (ME), ultrasound-assisted extraction (UAE), and microwave-assisted extraction (MAE). Since the residual material still possessed an intense color, a further treatment was performed by application of enzymatic-assisted extraction (EAE). Three enzymatic cocktails (Xylanases, Celluclast, and Depol), pH, and temperature were evaluated to establish optimal reaction conditions. Subsequent analysis and identification of the anthocyanins obtained by four different extraction techniques were performed using HPLC and HPLC-mass spectrometry, respectively. The most efficient method was UAE using 20 min of ultrasound (100 W) preceded by sample treatment in the following conditions: ethanol/water/lactic acid mixture (80:19:1), two extractions, 1:10 solvent-to-solid ratio. As a result, anthocyanins from corn cob and corn husk were extracted at concentrations of 24.32 and 25.80 mg/gDW, respectively. No difference in the anthocyanins profile for samples extracted by three different methods was observed. However, an enhanced presence of cyanidin-3-(6''malonyl)glucoside was detected in the sample corresponding to the EAE method. Therefore, the Cahuacintle corn husk can be considered as a competitive source of anthocyanins with the available commercial sources. PRACTICAL APPLICATION: The by-products obtained from Cacahuacintle purple corn can be potentially used as natural colorants thanks to their anthocyanins content. In this work, we established the most efficient extraction method of anthocyanins from corn husk and corn cob, and demonstrated that their anthocyanins profile is comparable to other Peruvian purple corns, which are currently used as natural colorants. Therefore, the extraction procedure described in this study might be scaled-up in an industrial process to get access to anthocyanins from undervalued wastes.

Waste residues from Opuntia ficus indica for peroxidase-mediated preparation of phenolic dimeric compounds.

A methodology to detect peroxidase activity in Opuntia ficus indica cladodes waste extracts was performed and then used towards phenolic compounds. The extracts were able to dimerize three different molecules. Dimeric compounds were produced with yields ranging from 11% to 55%. The influence of H2O2 concentration was also tested, finding better yields when the peroxide-to-substrate ratio was 1:1. Some water-miscible solvents were used trying to increase overall yields, but no-significant positive results were found. In fact, one of them, THF, seemed to inhibit dimerization reaction. Hence, we have tested an alternative natural peroxidase source obtained from the wastes of a local highly-consumed vegetable and studied their enzymatic activity towards the preparation of biologically active, valuable compounds.