Antioxidant activity of an Mg(II) compound containing ferulic acid as a chelator: potential application for active packaging and riboflavin stabilisation.

Foods rich in riboflavin (Rf) are susceptible to degradation due to oxidative processes with the formation of radicals. Herein, we describe the features and stability of an Mg(II) complex containing ferulic acid (fer) and 1,10-phenanthroline (phen) as chelators: henceforth called Mg(phen)(fer). The electrochemical behavior of Mg(phen)(fer) is pH dependent and results from the stabilisation of the corresponding phenoxyl radical via complexation with Mg(II). This stabilisation enhances the antioxidant activity of Mg(phen)(fer) with respect to free fer and commercial antioxidants. Mg(phen)(fer) scavenges and neutralizes DPPH˙ (IC50 = 15.6 µmol L-1), ABTS˙+ (IC50 = 5.65 µmol L-1), peroxyl radical (IC50 = 5.64 µg L-1) and 1O2 (IC50 = 0.7 µg m-1). Mg(phen)(fer) effectively protects riboflavin (Rf) against photodegradation by quenching the singlet excited states of Rf regardless of the conditions. Also, the complex Mg(phen)(fer) was effectively incorporated into starch films, broadening its applications, as shown by microbiological studies. Thus, Mg(phen)(fer) has high potential for use in Rf-rich foods and to become a new alternative to the synthetic antioxidants currently used.

Putative Identification of New Phragmaline-Type Limonoids from the Leaves of Swietenia macrophylla King: A Case Study Using Mass Spectrometry-Based Molecular Networking.

Swietenia macrophylla King is a plant commonly known as Brazilian mahogany. The wood from its stem is highly prized for its exceptional quality, while its leaves are valued for their high content of phragmalin-type limonoids, a subclass of compounds known for their significant biological activities, including antimalarial, antitumor, antiviral, and anti-inflammatory properties. In this context, twelve isolated limonoids from S. macrophylla leaves were employed as standards in mass spectrometry-based molecular networking to unveil new potential mass spectrometry signatures for phragmalin-type limonoids. Consequently, ultra-performance liquid chromatography coupled with high-resolution mass spectrometry was utilized for data acquisition. Subsequently, the obtained data were analyzed using the Global Natural Products Social Molecular Networking platform based on spectral similarity. In summary, this study identified 24 new putative phragmalin-type limonoids for the first time in S. macrophylla. These compounds may prove valuable in guiding future drug development efforts, leveraging the already established biological activities associated with limonoids.

Polyaromatic Group Embedded Cd(II)-Coordination Polymers for Microwave-Assisted Solvent-Free Strecker-Type Cyanation of Acetals.

In this work, two new 1D Cd(II) coordination polymers (CPs), [Cd(L1)(NMF)2]n (1) and [Cd(L2)(DMF)(H2O)2]n·n(H2O) (2), have been synthesized, characterized and employed as catalysts for the microwave-assisted solvent-free Strecker-type cyanation of different acetals. Solvothermal reaction between the pro-ligand, 5-{(pyren-1-ylmethyl)amino}isophthalic acid (H2L1) or 5-{(anthracen-9-ylmethyl)amino}isophthalic acid (H2L2), and Cd(NO3)2.6H2O in the presence of NMF or DMF:THF solvent, produces the coordination polymer 1 or 2, respectively. These frameworks were characterized by single-crystal and powder X-ray diffraction analyses, ATR-FTIR, elemental and thermogravimetry analysis. Their structural analysis revealed that both CPs show one-dimensional structures, but CP 1 has a 1D double chain type structure whereas CP 2 is a simple one-dimensional network. In CP 1, the dinuclear {Cd2(COO)4} unit acts as a secondary building unit (SBU) and the assembly of dinuclear SBUs with deprotonated ligand (L12-) led to the formation of a 1D double chain framework. In contrast, no SBU was observed in CP 2. To test the catalytic effectiveness of these 1D compounds, the solvent-free Strecker-type cyanation reactions of different acetals in presence of trimethylsilyl cyanide (TMSCN) was studied with CPs 1 and 2 as heterogenous catalysts. CP 1 displays a higher activity (yield 95%) compared to CP 2 (yield 84%) after the same reaction time. This is accounted for by the strong hydrogen bonding packing network in CP 2 that hampers the accessibility of the metal centers, and the presence of the dinuclear Cd(II) SBU in CP 1 which can promote the catalytic process in comparison with the mononuclear Cd(II) center in CP 2. Moreover, the recyclability and heterogeneity of both CPs were tested, demonstrating that they can be recyclable for at least for four cycles without losing their structural integrity and catalytic activity.

Limonoids and insecticidal activity on Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) of Trichilia catigua A. Juss. (Meliaceae).

The aim of the study was to evaluate the effects of the seeds, exocarp and aril extracts from Trichilia catigua A. Juss. (Meliaceae) against Spodoptera frugiperda and present the phytochemical study carried out with the aril extract of T. catigua. Limonoids were isolated from the aril of T. catigua through chromatographic techniques and their structures were proposed by spectroscopic analysis and comparison with literature data. The effects of the seeds, exocarp and aril extracts from T. catigua against S. frugiperda were evaluated considering as parameters the duration and mortality of the larval phase, in addition to the pupal weight. Phytochemical investigation of the aril extracts of T. catigua has led to the identification of the limonoids 6α-O-acetyl-7-deacetyl-14,15-dihydro-15-oxo-nimocinol (1), cedrelone (2) and 6α-O-acetyl-7-deacetylnimocinol (3). The hexane and CH2Cl2 extracts of the aril showed a high rate of larval mortality (100 and 90%, respectively). In addition, a prolongation of larval phase and a reduction in the pupal weight were observed for insects treated with hexane, CH2Cl2 and methanol extracts of seeds and with CH2Cl2 extract of exocarp of T. catigua.

MALDI-TOF Mass Spectrometry for the Diagnosis of Citrus Canker Caused by Xanthomonas citri subsp. citri.

Citrus canker, caused by the bacterium Xanthomonas citri subsp. citri (Xcc), is a disease that causes serious problems to the global citrus industry. Matrix-Assisted Laser Desorption/Ionization Time-of-Flight (MALDI-TOF) Mass Spectrometry (MS) has been used in human medicine to diagnose various diseases caused by both fungi and bacteria. In agriculture, this technique has potential for the diagnosis of diseases due to the low cost of large-scale analysis and quickness. This study showed that MALDI-TOF MS combined with chemometric analysis was effective for differentiating the macromolecule profile of orange leaves with canker lesions, healthy leaves, and leaves with phytotoxicity symptoms, proving that this technique may be used for the rapid diagnosis of citrus canker.

Electrocatalytic Behavior of an Amide Functionalized Mn(II) Coordination Polymer on ORR, OER and HER.

The new 3D coordination polymer (CP) [Mn(L)(HCOO)]n (Mn-CP) [L = 4-(pyridin-4-ylcarbamoyl)benzoate] was synthesised via a hydrothermal reaction using the pyridyl amide functionalized benzoic acid HL. It was characterized by elemental, FT-IR spectroscopy, single-crystal and powder X-ray diffraction (PXRD) analyses. Its structural features were disclosed by single-crystal X-ray diffraction analysis, which revealed a 3D structure with the monoclinic space group P21/c. Its performance as an electrocatalyst for oxygen reduction (ORR), oxygen evolution (OER), and hydrogen evolution (HER) reactions was tested in both acidic (0.5 M H2SO4) and alkaline (0.1 M KOH) media. A distinct reduction peak was observed at 0.53 V vs. RHE in 0.1 M KOH, which corresponds to the oxygen reduction, thus clearly demonstrating the material's activity for the ORR. Tafel analysis revealed a Tafel slope of 101 mV dec-1 with mixed kinetics of 2e- and 4e- pathways indicated by the Koutecky-Levich analysis. Conversely, the ORR peak was not present in 0.5 M H2SO4 indicating no activity of Mn-CP for this reaction in acidic media. In addition, Mn-CP demonstrated a noteworthy activity toward OER and HER in acidic media, in contrast to what was observed in 0.1 M KOH.

Glyphosate excessive use chronically disrupts the shikimate pathway and can affect photosynthesis and yield in citrus trees.

Glyphosate excessive use is reported in Brazilian citrus orchards, whereas there is speculation about its consequences and the published studies are contradictory and inconclusive. This study aimed to describe the possible harmful effects by simulating glyphosate drift directly to the leaves of ∼4-yr-old citrus plants. As major results, glyphosate doses >360 g ae ha-1 increased the shikimate accumulation in leaves (up to 2.3-times above control), which was increased after a second glyphosate application (up to 3.5-times above control), even after a 240-d interval. Interestingly, shikimate accumulation was occasionally related to a dose-response of the herbicide at specific times; however, the doses had their accumulation peak on determined dates. These accumulations were directly correlated to reduced net photosynthesis even months after the glyphosate sprays. Quantum productivity based on electron transport through the photosystem II and apparent electron transport reductions up to 17% were also observed during the entire experiment course. Similarly, quantum productivity based on CO2 assimilation of glyphosate sprayed leaves decreased up to four times compared to the control after the second application. Glyphosate doses >360 g ae ha-1 increased stomatal conductance and transpiration as the carboxylation efficiency decreased, evidencing a carbon drainage in the Calvin-Benson cycle. These metabolic and physiological disturbances suggest possible photooxidative damage and an increase in photorespiration, which may be a mitigation strategy by the citrus plants to glyphosate effects, by the cost of reducing the citrus fruit yield (up to 57%). It is concluded that glyphosate phytotoxicity damages citrus plants over time due to chronic disturbances in the shikimate pathway and photosynthesis, even when there are no symptoms. This study is the first report to demonstrate how glyphosate damages citrus trees beyond the shikimate pathway.

Exploring chemical diversity in Glycine max cultivars: A multivariate approach in the search for bioactive compounds against Spodoptera cosmioides.

Soybean crop is regulated by abiotic and biotic stresses with great potential in reducing grain yield and quality. The selection of resistant cultivars is a promising approach for mitigating these damages. We evaluated the chemical profile of Glycine max leaves from different cultivars in order to explore their defense mechanisms against Spodoptera cosmioides caterpillars. We optimized solid-liquid extraction techniques using ultrasound bath and static headspace extraction. Additionally, we developed an approach based on liquid and gas chromatography for analyzing the chemical profile of G. max cultivars. The principal component analysis allowed the classification of transgenic cultivars, which are classified as susceptible to S. cosmioides, from those obtained by genetic improvement and resistant to the insect. Differences were observed in the abundance of phenolic glycosides, lipids, aldehydes, and alcohols. More specifically, S. cosmioides resistant cultivars presented molecules related to the jasmonic and salicylic acid pathways. Such data can contribute to a molecular understanding of phenotypic diversity in soybean cultivars, from plant quality to resistance mechanisms and adaptation, to environmental stress and herbivory.

Metabolomic Investigation of Citrus latifolia and the Putative Role of Coumarins in Resistance to Black Spot Disease.

Citrus black spot (CBS) is a disease caused by the fungus Phyllosticta citricarpa that affects citrus plants, causing fruit blemish and premature drop that result in severe economic losses in commercial citrus orchards. However, CBS symptoms and effects may vary depending on the citrus species: Citrus limon (lemon) is susceptible and highly affected by the disease, while no CBS-related damage has ever been observed for Citrus latifolia (Tahiti lime), implying that it must be resistant to the disease. The difference in the response to this disease provided the opportunity to gain insight into the metabolites responsible for the resistance by comparison of the metabolomic profiles of these two citrus species. Metabolic variations of C. limon and C. latifolia inoculated with P. citricarpa were analyzed using various metabolomic-based platforms including 1H NMR for overall metabolic profiling, and LC-MS and HPTLC for targeted analysis. The 1H NMR spectra of the samples demonstrated that certain phenolics were strongly induced after pathogenic inoculation, especially in the resistant species. The induced phenolics were identified from C. latifolia by further 1H NMR, LCMS and HPTLC analysis yielding six prenylated and methoxy coumarins, i.e., 5,7-dimethoxycoumarin, 5-geranyloxy-7-methoxycoumarin, 7-geranyloxycoumarin, 8-methoxypsoralen, 5,8-dimethoxypsoralen and 5-geranyloxypsoralen. These isolated coumarins and a coumarin-rich fraction were tested against the fungal pathogen, P. citricarpa, to evaluate their activity. None of the individual coumarins exhibited a significant inhibition, while the coumarin fraction exhibited a strong antifungal activity suggesting a synergistic interaction of its components. To obtain further insight into the roles of these compounds in the plant defense, the possible mechanisms of the individual coumarins were tested using an in-silico model, the PASS Online Tool; the analysis showed that each coumarin appeared to have a unique defense mechanism, even with very slight variations in the chemical structures. The results could provide evidence of the existence of a complex plant defense mechanism consisting in a multitude of synergistic interactions between compounds.

The Symbiotic Fungus Leucoagaricus gongylophorus (Möller) Singer (Agaricales, Agaricaceae) as a Target Organism to Control Leaf-Cutting Ants.

Atta and Acromyrmex are the main genera of leaf-cutting ants present in North and South America, causing extensive damage to agroforestry. Control of the ants requires high handling costs with few effective methods available to decrease the losses. The symbiosis between the leaf-cutting ants and the fungus Leucoagaricus gongylophorus is essential for ant nest survival. Therefore, L. gongylophorus may be a key target in controlling leaf-cutting ants, since its reduction may cause an imbalance in the symbiosis necessary to maintain the nest. Among the options for natural fungal control, plant species are considered important sources of compounds belonging to several classes of natural products that show potential as antifungal agents. This review also presents studies that establish that the antagonist fungi from the Escovopsis and Trichoderma genera effectively reduce the development of L. gongylophorus. The development of nanostructured delivery systems, which have shown advantages over conventional formulations, is suggested for ant control; no commercial nanotechnology-based product has yet been developed, and this appears to be a new approach for future studies.

Insecticidal activity of copper (II) complexes with flavanone derivatives.

In this work, we describe the insecticidal activity against Spodoptera frugiperda of flavanone derivatives (naringin, naringenin and hesperidin) complexed to copper (II). For the assays, the compounds were incorporated into an artificial diet and offered to S. frugiperda during its larval period. The duration of larval and pupal phases, the weight of pupae and the percentage of dead insects at the end of the larval phase were evaluated. Among the tested compounds, the free flavanones 1 and 3 and the complexes 4 and 6 showed a shortening of the larval phase when compared to the control. Complex 9 showed the highest toxicity, with 96.66% larval mortality. This is the first report on the insecticidal activity of the Cu2+ complexes of the flavanones naringin, naringenin and hesperidin.[Formula: see text].

Encapsulation of B. bassiana in Biopolymers: Improving Microbiology of Insect Pest Control.

The fungus Beauveria bassiana is widely used for pest control; however, biostability and dispersion for broth pulverization are limiting factors for its application in the field. In this context, formulation techniques such as microencapsulation are viable alternatives. The aim of this work is to optimize B. bassiana formulations by spray dryer and evaluate its stability and biological activity against Spodoptera cosmioides compared to ionic gelatinization formulations. The fungus was biocompatible with all evaluated biopolymers (lignin, cellulose, starch, humic substances, and alginate). The encapsulation by spray drying was optimized by factorial design in an inlet and outlet air temperature of 120°C and 68°C, respectively; aspirator rate of 35 m3·h-1, feed flow rate of 12 mL·min-1; and drying gas flow at 35 L·h-1. The ionic gelation capsules were obtained using a 0.5% quantity of conidia in a 1% sodium alginate solution dropped into a 0.5 mol·L-1 CaCl2 solution using a peristaltic pump. Spray drying provided smaller microcapsules than those by ionic gelation. Both techniques produced more stable conidia when exposed to temperature and UV-radiation than non-formulated B. bassiana. The formulations prepared by spray drying showed gains at aqueous dispersion. Biological assays against Spodoptera cosmioides showed a mortality rate of up to 90%. These results demonstrate the suitability of encapsulating B. bassiana conidia stably in aqueous dispersion without loss of viability and virulence.

Simultaneous changes in visual acuity, cortical population receptive field size, visual field map size, and retinal thickness in healthy human aging.

Healthy human aging is associated with a deterioration of visual acuity, retinal thinning, visual field map shrinkage and increasing population receptive field sizes. Here we ask how these changes are related to each other in a cross-sectional sample of fifty healthy adults aged 20-80 years. We hypothesized that age-related loss of macular retinal ganglion cells may lead to decreased visual field map sizes, and both may lead to increased pRF sizes in the cortical central visual field representation. We measured our participants' perceptual corrected visual acuity using standard ophthalmological letter charts. We then measured their early visual field map (V1, V2 and V3) functional population receptive field (pRF) sizes and structural surface areas using fMRI, and their retinal structure using high-definition optical coherence tomography. With increasing age visual acuity decreased, pRF sizes increased, visual field maps surface areas (but not whole-brain surface areas) decreased, and retinal thickness decreased. Among these measures, only functional pRF sizes predicted perceptual visual acuity, and Bayesian statistics support a null relationship between visual acuity and cortical or retinal structure. However, pRF sizes were in turn predicted by cortical structure only (visual field map surface areas), which were only predicted by retinal structure (thickness). These results suggest that simultaneous disruptions of neural structure and function throughout the early visual system may underlie the deterioration of perceptual visual acuity in healthy aging.

Cineole-containing nanoemulsion: Development, stability, and antibacterial activity.

1,8-cineole is a monoterpene commonly used by the food, cosmetic, and pharmaceutical industries owing to its flavor and fragrances properties. In addition, this bioactive monoterpene has demonstrated bactericidal and fungicidal activities. However, such activities are limited due to its low aqueous solubility and stability. This study aimed to develop nanoemulsion containing cineole and assess its stability and antibacterial activity in this context. The spontaneous emulsification method was used to prepare nanoemulsion (NE) formulations (F1, F2, F3, F4, and F5). Following the development of NE formulations, we chose the F1 formulation that presented an average droplet size (in diameter) of about 100 nm with narrow size distribution (PdI <0.2) and negative zeta potential (∼ - 35 mV). According to the analytical centrifugation method with photometric detection, F1 and F5 formulations were considered the most stable NE with lower droplet migration velocities. In addition, F1 formulation showed high incorporation efficiency (> 80 %) and TEM analyses demonstrated nanosized oil droplets with irregular spherical shapes and without any aggregation tendency. Antibacterial activity assessment showed that F1 NE was able to enhance the cineole action against Staphylococcus aureus, Enterococcus faecalis, and Streptococcus pyogenes. Therefore, using a simple and reproducible method of low energy emulsification we designed a stable nanoemulsion containing 1,8-cineole with improved antibacterial activity against Gram-positive strains.

Octahedral ruthenium and magnesium naringenin 5-alkoxide complexes: NMR analysis of diastereoisomers and in-vivo antibacterial activity against Xylella fastidiosa.

Although many copper-based antimicrobial compounds have been developed to control pathogenic bacteria and fungi in plants and applied for crop protection, there is evidence that several plant pathogens have developed resistance to copper-based antimicrobial compounds, including some Xanthomonas species. Xylella is a bacterial genus belonging to the Xanthomonas family; and X. fastidiosa, which is responsible for citrus variegated chlorosis (CVC) in sweet orange, may develop resistance to one or more copper-based antimicrobials. Because of the time required for the development and approval of new antimicrobials for commercial use, the discovery of novel bactericidal compounds is essential before the development of resistance to the antimicrobials currently in use becomes widespread. Here, we explored the antimicrobial potential of two newly synthesized antimicrobials complexes and one natural compound against X. fastidiosa. Several nuclear magnetic resonance (NMR) assays with high resolution and sensitivity were developed to identify new diastereoisomers in the context of octahedral ruthenium - [Ru(narin)(phen)2]PF6-and magnesium naringenin 5-alkoxide - [Mg(narin)(phen)2]OAc - complexes, obtained in the present work. The NMR assays proved to be powerful tools for the identification of isomers in metal complexes. Moreover, a protocol for the in-vivo determination of the effects of these complexes against X. fastidiosa was developed. The main trunks of X. fastidiosa infected plants were injected with the two complexes as well as with the limonoid azadirachtin using a syringe; the number of bacterial cells in the plants following treatment was estimated via real-time quantitative PCR (qPCR). Importantly, the administration of both complexes and of azadirachtin drastically reduced the number of X. fastidiosa cells in vivo.

Chemophenetic Significance of Anomalocalyx uleanus Metabolites are Revealed by Dereplication Using Molecular Networking Tools.

Anomalocalyx uleanus (Pax & K. Hoffm.) Ducke (Euphorbiaceae) is a singular species in the genus and is restricted and exclusive to the Brazilian Amazon. A phytochemical study of A. uleanus leaves was performed, yielding the isolation of five major compounds: catechin/epicatechin, afzelin, quercetin 3-O-α-L-rhamnopyranoside, and astilbin. The phytochemical compositions of the methanolic extracts of leaves, roots, bark, and stem bark were determined using a dereplication approach. Forty-six compounds were annotated from the liquid chromatography-mass spectrometry (LC-MS/MS) data, while four lipids were identified using gas chromatography-mass spectrometry (GC-MS). In total, fifty compounds were detected, and they belonged to the primary metabolism and several classes of natural products such as flavonoids, flavonoids O-glycosides, flavonoids C-glycosides, biflavonoids, procyanidin, triterpene, triterpenes esterified with phenylpropanoids, phenylpropanoid derivatives, flavonolignans, coumarins, quinic acid derivatives, and benzoic acid derivatives. This is the first report on the phytochemical data of the genus Anomalocalyx, and the results of this study will contribute to the chemosystematic knowledge of the Euphorbiaceae family and justify the need for investigation of the pharmacological potential of the species A. uleanus.

Avocado kernels, an industrial residue: a source of compounds with insecticidal activity against silverleaf whitefly.

Fruit processing waste, such as kernels (endocarp + seed) of avocado [Persea americana Mill. (Lauraceae)], could be used as raw material in the preparation of botanical insecticides. In light of this potential, this study assessed the insecticidal action of extracts and fractions from kernels of two avocado cultivars (Breda and Margarida) on Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) biotype B, an important pest species in tropical conditions. Ethanolic and aqueous extracts prepared from kernels of P. americana, regardless of the plant cultivar used, caused promising insecticidal activity to whitefly nymphs. Based on yield in crude extracts [10.32 and 9.85% (w/w), respectively, for cultivars Breda and Margarida], on the bioassay results with crude extracts and on the chemical profiles, the ethanolic extract of kernels of P. americana cv. Breda was chose for the continuation of the study. Thus, the ethanolic extract of kernels of cv. Breda (LC50 = 197.84 ppm and LC90 = 567.19 ppm) was selected and subjected to fractionation by the liquid-liquid partition technique. The hexane and dichloromethane fractions of this extract caused significant mortality of nymphs. The analysis using the ultraviolet (UV) and hydrogen nuclear magnetic resonance (1H NMR) showed the presence of long-chain aliphatic compounds (alkanols or acetogenins of Lauraceae), alkylfurans (or avocadofurans), and unsaturated fatty acids in these fractions, which are possibly related to bioactivity observed in B. tabaci, besides saccharides. The results show that kernels of P. americana are promising sources of compounds with insecticidal action for the control of B. tabaci biotype B, a great opportunity to transform environmental problems into eco-friendly solutions to agriculture.

Potential insecticidal activity of aminonaphthoquinone Mannich bases derived from lawsone and their copper (II) complex derivatives.

The fall armyworm, Spodoptera frugiperda, is a polyphagous pest that causes important damage in different regions of America and mainly affects corn crops in both tropical and subtropical areas. Currently, control relies on both transgenic plants and/or chemical pesticides. In this work, we describe insecticidal activity against the fall armyworm from a series of Mannich bases (1-10), derived from 2-hydroxy-1,4-naphthoquinone (lawsone), substituted benzaldehydes, and two primary amines, and their Cu2+ complexes (11-20). The [Cu(L)2] complexes were more effective in larval mortality compared to the free Mannich bases. Among the tested compounds, complex 11 showed the highest toxicity, with 70.00% larval mortality.

Evaluation of the microencapsulation of orange essential oil in biopolymers by using a spray-drying process.

Essential oils are volatile compounds commonly used by several industries, easily degradable, which restrains their applications. Therefore, we developed and validated a methodology for producing microcapsules loaded with orange essential oil, using a spray-drying process. The experimental design results showed that the combination between a low flow transfer rate (0.15 L h-1) of the colloidal suspension, a higher drying air flow rate (536 L h-1), and an inlet air temperature of 150 °C to the spray-dryer were the most important parameters for the atomization efficiency. The method optimization resulted in microcapsules with powder recovery between 7.6 and 79.9% (w w-1), oil content ranging from 8.9 to 90.4% (w w-1), encapsulation efficiency between 5.7 and 97.0% (w w-1), and particle sizes with a high frequency of distribution less than 4 µm. In these experiments, gelatin and lignin were evaluated as biopolymers of encapsulation. We also developed an analytical method using headspace gas chromatography. The matrix effects could be addressed by using matrix-matched calibration curves. The chromatographic analysis was linear and selective for D-limonene between 0.025 and 3.00 µg mL-1, with correlation coefficients higher than 0.99. The analytical method had limits of detection and quantitation of 0.024 and 0.073 mg g-1 for gelatin and 0.039 and 0.119 mg g-1 for lignin, respectively.

Estudio observacional de la microbiota intestinal aeróbica / Observational study of the aerobic gut microbiota

El ecosistema microbiano asociado al intestino es el más diverso y complejo, en el ser humano cambia durante las diferentes etapas de la vida. La pérdida del equilibrio de este ecosistema intestinal se conoce como disbiosis. Establecer la posible relación entre la disbiosis aeróbica con diversas enfermedades de interés clínico encontradas. Se estudiaron 377 casos de disbiosis con diferentes patologías como trastorno del espectro autista (TEA), enfermedad inflamatoria intestinal, alergias, intolerancia alimentaria, entre otras; y un grupo control de 497 personas aparentemente sanas. Para el análisis de la información se utilizaron las pruebas de T de Student y regresión logística multinominal, ajustadas a un intervalo de confianza del 95%. Hubo variabilidad en el crecimiento de la microbiota benéfica del grupo de casos de disbiosis respecto al grupo control (p<0,001). La microbiota transitoria causante de disbiosis estuvo conformada principalmente por cocos grampositivos: Streptococcus grupo viridans, Enterococcus faecium y Enterococcus gallinarum; bacilos gramnegativos: Klebsiella pneumoniae, complejo Enterobacter cloacae y Klebsiella oxytoca y especies de Candida albicans, Candida tropicalis y complejo Candida parapsilosis. La población más susceptible con disbiosis fueron niños con edades comprendidas entre 2 y 6 años. Los TEA y la intolerancia alimentaria estuvieron asociados significativamente con la disbiosis (p<0,05)

The microbial ecosystem associated with the intestine is the most diverse and complex in the human being, since it changes during the different stages of life. Losing balance of this intestinal ecosystem is known as dysbiosis. To establish the possible relationship between aerobic dysbiosis and diseases of clinical interest found. Three hundred and seventy-seven (377) cases of dysbiosis with different pathologies such as autism spectrum disorder (ASD), inflammatory bowel disease, allergies, food intolerance, among others; and a control group of 497 apparently healthy people, were studied. For the analysis of the information, multinomial logistic regression and Student's t tests were used, adjusted to a 95% confidence interval. The growth of beneficial microbiota showed variability in the dysbiosis case group compared to the control group (p <0.001). The transient microbiota causing dysbiosis was mainly made up of gram-positive cocci: Streptococcus viridans group, Enterococcus faecium and Enterococcus gallinarum; gram-negative bacilli: Klebsiella pneumoniae, Enterobacter cloacae complex, and Klebsiella oxytoca and Candida albicans, Candida tropicalis and Candida parapsilosis complex species. The most susceptible population with dysbiosis was children aged between 2 and 6 years. The ASD and food intolerance were significantly associated with dysbiosis (p <0.05)