In this work, a miniaturized version of the QuEChERS (quick, easy, cheap, effective, rugged, and safe) method was optimized, validated, and applied for extracting eight pesticide residues in anuran liver tissue samples. The extracts were quantified by high-performance liquid chromatography with diode array detection, and the detected residues in liver tissue samples were identified by tandem mass spectrometry-liquid chromatography. The optimized extraction method entailed the scale reduction of the QuEChERS method twenty times using 500 mg of liver tissue sample, 200 mg Mg2SO4, 50 mg NaCl, 1.5 mL of acetonitrile, and a mixture of 25 mg C18 + 25 mg PSA (primary-secondary amine) as dispersive solid-phase extraction sorbent. The method was validated using liver tissue samples spiked at two levels of pesticide concentrations according to the SANTE/11312/2021 document. Recoveries ranged from 91-110% with a relative standard deviation < 20%. The method robustness assessed by the Steiner and Youden test resulted in recovery rate variations of less than 2% for all pesticides after deliberated changes in seven variables. The validated method was applied to 72 liver tissue samples from two anuran species, registering residues of some pesticides in 31 samples. The proposed method proved to be efficient, precise, and robust for determining pesticide residues in anuran liver tissues. work quick, quick (quick easy cheap effective rugged safe highperformance high performance detection spectrometryliquid spectrometry sample 20 Mg2SO4 MgSO Mg SO 5 NaCl 15 1 1. acetonitrile 2 C C1 primarysecondary primary secondary amine solidphase solid phase sorbent SANTE113122021 SANTE 11312 2021 SANTE/11312/202 document 91110% 91110 91 110% 110 91-110 20% variables 7 species 3 efficient precise tissues Mg2SO SANTE11312202 1131 202 SANTE/11312/20 9111 9 11 91-11 SANTE1131220 113 SANTE/11312/2 911 91-1 SANTE113122 SANTE/11312/ 91- SANTE11312 SANTE/11312 SANTE1131 SANTE/1131 SANTE113 SANTE/113 SANTE11 SANTE/11 SANTE1 SANTE/1 SANTE/

Acquired immunodeficiency syndrome is an infectious disease caused by human immunodeficiency virus (HIV). Pharmacological antiretroviral therapy, along with therapeutic monitoring of drug plasma concentrations, facilitates adequate and effective follow-up in each patient. Our main objective was to develop and validate a high-performance liquid chromatography with ultraviolet detector (HPLC-UV) bioanalytical method for the simultaneous quantification of plasma concentrations of three commonly used antiretrovirals in Colombia: efavirenz, lopinavir, and ritonavir. This method is intended for therapeutic drug monitoring in persons living with HIV locally or in developing countries. The method is selective, specific, accurate, precise, and stable over the concentration range of 250 and 20,000 ng mL -1 for the drugs. It was successfully applied to measure the plasma levels of efavirenz, lopinavir, and ritonavir in HIV patients, which ranged from 251.0 ± 10.4 to 7186.2 ± 10.2, 8188.2 ± 5.9 to 15,312.5 ± 6.6, and 246.1 ± 6.5 to 1189.0 ± 6.4 ng mL-1, respectively. HIV. . (HIV) therapy followup follow up patient highperformance high performance HPLCUV HPLC UV (HPLC-UV Colombia efavirenz lopinavir countries selective specific accurate precise 25 20000 20 000 20,00 1 - drugs patients 2510 251 0 251. 104 10 4 10. 71862 7186 2 7186. 102 10.2 81882 8188 8188. 59 5 9 5. 153125 15 312 15,312. 66 6 6.6 2461 246 246. 65 6. 11890 1189 1189. 64 mL1, mL1 1, mL-1 respectively (HIV 2000 00 20,0 718 818 15312 31 15,312 24 118 mL- 200 20, 71 81 1531 3 15,31 11 7 8 153 15,3 15,

The exploration of carbon steel corrosion inhibition in 0.5 mol L-1 H2SO4 using extracts from Hymenaea courbaril (HC) has resulted in significant findings. Extracts from the bark, leaves, fruit pulp, and fruit shell have all proven to be effective corrosion inhibitors, as demonstrated through surface studies and electrochemical methods. Infrared spectroscopy and high-performance liquid chromatography have identified the presence of phenolic compounds, which are known to have corrosion-inhibiting potential. UV-Vis spectroscopy has further revealed the adsorption of extract species on the steel surface. Electrochemical studies have confirmed the inhibition of corrosion, allowing to propose mechanisms of both chemisorption and physisorption. X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS) have provided evidence of the formation of an inhibitory layer, further supporting the inhibition of corrosion. Langmuir isotherms have indicated favorable adsorption of the extracts, while reduced surface roughness suggests improved protection of the steel surface. Activation energy calculations have demonstrated an increase in energy barriers, resulting in slower corrosion rates. These findings suggest that extracts from Hymenaea courbaril show promise as eco-friendly corrosion inhibitors, with potential industrial applications. Further research is needed to optimize the extraction process and fully understand the inhibition mechanisms. 05 0 5 0. L1 L 1 L- HSO H SO H2SO HC (HC bark leaves pulp inhibitors methods highperformance high performance compounds corrosioninhibiting inhibiting UVVis UV Vis physisorption Xray X ray XPS (XPS energydispersive dispersive SEMEDS SEM EDS (SEM-EDS layer barriers rates ecofriendly eco friendly applications

Lisdexamfetamine is a prodrug that is converted to d-amphetamine in the body, mainly used to treat attention deficit hyperactivity disorder in children and adults. Its mechanism involves the enhancement of neurotransmitters such as norepinephrine and dopamine, which are critical for attention and behavioral regulation. With the upcoming patent expiration of Vyvanse®, bioanalytical methods for the quantification of lisdexamfetamine in plasma are needed for use in pharmacokinetic studies. In this work, we developed and validated a sensitive bioanalytical method using liquid chromatography-tandem mass spectrometry (LC-MS/MS) for lisdexamfetamine quantification in human plasma. The method developed was performed for 4 min per sample and using the concentration range of 0.3-100 ng mL-1. Intra-batch, inter-batch and instrument reproducibility, the precision was lower than 10%. The results demonstrated that the method is rapid, sensitive, robust, and suitable for pharmacokinetic studies. damphetamine d amphetamine body adults dopamine regulation Vyvanse Vyvanse® studies work chromatographytandem chromatography tandem LCMS/MS LCMSMS LC MS/MS MS (LC-MS/MS 0.3100 03100 0.3 100 0 3 0.3-10 mL1. mL1 mL 1. 1 mL-1 Intrabatch, Intrabatch Intra batch, batch Intra-batch interbatch inter reproducibility 10 10% rapid robust LCMS MSMS 3100 0.310 0310 03 0. 0.3-1 mL- 310 0.31 031 0.3- 31

Compared to other species, components of Combretum lanceolatum are still with few data reported in the literature. This work describes the compounds identification, antioxidant and antimicrobial activities of C. lanceolatum twigs. Ethanolic extract (EECLT) from C. lanceolatum twigs was submitted to partition obtaining: hexane (HF), diethyl ether (EEF), ethyl acetate (EAF) and hydromethanolic (HMF) fractions. They were analyzed by gas chromatography-mass spectrometry, high performance liquid chromatography coupled to mass spectrometry and direct insertion mass spectrometry and evaluated for antioxidant assay (2,2-diphenyl-1-picrylhydrazyl (DPPH) method) and antimicrobial assay. Fifty-seven compounds were identified in the fractions. In antioxidant assay, EECLT and EAF demonstrated good antioxidant potential (half maximal effective concentration (EC50): 57.9 and 45.4 µg mL–1, respectively), better than the positive control butylated hydroxytoluene (BHT) (EC50: 69.34 µg mL–1). For antimicrobial assay, all fractions presented promising minimal inhibitory concentration (MIC). EECLT presented the best values against Staphylococcus aureus (125 µg mL–1) and Escherichia coli (62.5 µg mL–1) and better than the positive control fluconazole (8 and 16 µg mL–1) against Candida albicans (3.9 µg mL–1) and Candida krusei (15.6 µg mL–1) strains. This study presents relevant chemical and biological information about C. lanceloatum expanding the knowledge of Brazilian flora. species literature identification C (EECLT obtaining HF, HF , (HF) EEF, EEF (EEF) (EAF HMF (HMF chromatographymass 2,2diphenyl1picrylhydrazyl 22diphenyl1picrylhydrazyl diphenylpicrylhydrazyl 2,2 diphenyl 1 picrylhydrazyl 2 DPPH (DPPH method Fiftyseven Fifty seven half EC50 EC (EC50) 579 57 9 57. 454 45 4 45. mL1 mL mL–1 respectively, respectively respectively) BHT (BHT (EC50 6934 69 34 69.3 mL–1. . MIC. MIC (MIC) 125 (12 62.5 625 62 5 (62. 8 ( 3.9 39 3 (3. 15.6 156 15 6 (15. strains flora (HF (EEF 2diphenyl1picrylhydrazyl 22 2, EC5 mL– (EC5 693 69. (MIC 12 (1 62. (62 3. (3 15. (15 (EC (6

Methods used to determine pesticide residues in teas typically require several laborious steps for sample preparation before analysis. In this study, a simple method based on solid-liquid extraction with low-temperature partitioning (SLE/LTP) and analysis by gas chromatography coupled to mass spectrometry (GC-MS) was optimized and validated for the determination of pesticide residues (pirimiphos-methyl, flutriafol, cyproconazole, and bifenthrin) in dehydrated green tea leaves. After low-temperature partitioning (LTP), the extract in acetonitrile was subjected to a clean-up step using primary secondary amine (PSA) and octadecylsilane (C18) as sorbents for chlorophyll removal. The optimized SLE/LTP-GC-MS method was validated, and it proved to be effective and selective for extracting pesticides from green tea samples, presenting limit of detection (LOD) and limit of quantification (LOQ) of 0.015 and 0.050 mg kg-1, respectively. Recovery ranged between 81-111%, coefficients of variation were less than 16% and coefficients of determination (R2) were greater than 0.990. The optimized and validated method was applied to green tea and 13 other tea varieties sampled in South and Southeast regions of Brazil. The pesticides under study were detected in some of those samples at values higher than the maximum residue limits (MRLs) allowed by the European Union. solidliquid solid liquid lowtemperature low temperature SLE/LTP SLELTP SLE LTP (SLE/LTP GCMS GC MS (GC-MS pirimiphosmethyl, pirimiphosmethyl pirimiphos methyl, methyl (pirimiphos-methyl flutriafol cyproconazole bifenthrin leaves LTP, , (LTP) cleanup clean up PSA (PSA C18 C (C18 removal SLE/LTPGCMS SLELTPGCMS LOD (LOD LOQ (LOQ 0015 0 015 0.01 0050 050 0.05 kg1, kg1 kg 1, 1 kg-1 respectively 81111%, 81111 81 111%, 111 81-111% 16 R2 R (R2 0990 990 0.990 Brazil MRLs (MRLs Union (LTP C1 (C1 LTPGCMS 001 01 0.0 005 05 kg- 81111% 8111 8 111% 11 81-111 (R 099 99 0.99 (C 00 0. 811 81-11 09 9 0.9 81-1 81-

In this study, we aimed to investigate the anticancer activity of the extract, fractions, and isolated compounds of the flowers of Fridericia platyphylla, and to characterize the bioactive compounds. The chemical diversity of the extracts and fractions was investigated using liquid chromatography coupled with high resolution mass spectrometry (LC-HRMS). We were able to annotate 26 compounds from the classes of flavones, flavonols, flavanones, isoflavones, and cinnamic acid and its derivatives. The dichloromethane fraction showed greater cytotoxicity at a concentration of 100 µg mL−1. In addition, the inhibitory concentrations of the dichloromethane fraction were 22.14 and 30.9 µg mL−1 for MCF-7 and MDA-MB-231 cell lines, respectively, and were capable of inhibiting tumor cell migration. Brachydins A and C were isolated from the dichloromethane fraction and showed the greatest cytotoxicity. The results obtained from this study show the potential biological effect of F. platyphylla flowers as a possible antitumor pharmacological agent. extract LCHRMS. LCHRMS LC HRMS . (LC-HRMS) 2 flavones flavonols flavanones isoflavones derivatives 10 mL1 mL 1 addition 2214 22 14 22.1 309 30 9 30. mL− MCF7 MCF 7 MCF- MDAMB231 MDAMB MDA MB 231 MDA-MB-23 lines respectively migration F agent (LC-HRMS 221 22. 3 MDAMB23 23 MDA-MB-2 MDAMB2 MDA-MB- MDA-MB

A green supramolecular vortex-assisted microextraction employing a mixture of 1-decanol and tetrahydrofuran (THF) was developed for the simultaneous extraction of pesticides from different classes (insecticides, fungicides, and herbicides) from water and flour samples, followed by their determination in high-performance liquid chromatography with diode array detector (HPLC-DAD). The most favorable results were achieved at pH 6.0 in the presence of 4% (m/v) NaCl, utilizing a low volume of 1-decanol and THF (75 and 400 µL, respectively), a short vortex-assisted extraction time (120 s), and centrifugation time (120 s). These conditions yielded high preconcentration factors ranging from 50.1 to 90.3 and low limits of quantification (LOQs) ranging from 1.3 to 27.3 µg L-1. The intraday (n = 10) and interday (n =1 0) precision, assessed as the percentage of relative standard deviation (RSD), varied from 4.4 to 12.4%. The optimized method was successfully applied to determine the pesticides in water and flour samples, with recoveries ranging from 81 to 111%. vortexassisted vortex assisted 1decanol decanol 1 (THF insecticides, insecticides (insecticides fungicides herbicides samples highperformance performance HPLCDAD. HPLCDAD HPLC DAD . (HPLC-DAD) 60 6 0 6. 4 m/v mv m v (m/v NaCl 75 (7 40 µL respectively, respectively , respectively) 120 (12 s, s s) s. 501 50 50. 903 90 3 90. LOQs (LOQs 13 1. 273 27 27. L1. L1 L L-1 n 10 precision RSD, RSD (RSD) 44 4. 124 12 12.4% 8 111 111% (HPLC-DAD 7 ( (1 5 9 2 L- (RSD 12.4 11 12.

Nanocomposites of GO/γ-Fe2O3 were used for magnetic dispersive solid-phase microextraction (m-d-μ-SPE) of six pesticides from river water samples, followed by the determination using high performance liquid chromatography-diode array detection. The synthesis of the nanocomposites is described and characterized using Fourier transform-infrared spectroscopy, X-ray diffraction, and scanning electron microscopy. A central composite design was used to optimize the extraction time, sample solution pH, and adsorbent amount. The solvent type and volume for desorption and the effect of the ionic strength for adsorption were also investigated. The optimum adsorption conditions were achieved at 84 min of extraction time, pH 5.4, 115 mg of absorbent, and 1% (m/v) of NaCl, while the desorption solvent selected was 1.0 mL of methanol-acetic acid (9:1, v/v). The limits of detection ranged from 0.1 to 0.9 μg L-1, and a good precision was achieved with relative standard deviation (RSD) lower than 7.6% (n = 10). The accuracy of the method was accessed by recovery tests ranging from 82 to 117% (n = 3, RSD < 8%). GO/γFe2O3 GOγFe2O3 GOγFeO GO/γ Fe2O3 GO γ Fe O GO/γ-Fe2O solidphase solid phase mdμSPE m d μ SPE (m-d-μ-SPE samples chromatographydiode chromatography diode transforminfrared transform infrared spectroscopy Xray X ray diffraction microscopy time amount investigated 8 54 5 4 5.4 11 absorbent 1 m/v mv v (m/v NaCl 10 0 1. methanolacetic methanol acetic 91, 91 9 1, (9:1 v/v. vv v/v . v/v) 01 0. 09 L1, L1 L L-1 (RSD 76 7 6 7.6 n 10. 10) 117 3 8%. 8% 8%) γFe2O3 γFe GO/γFe2O GOγFe GOγFe2O GOγ FeO Fe2O 5. (9: L- 7. γFeO γFe2O (9 (

Lantana caatingensis Moldenke (Verbenaceae) is an endemic plant from northeastern Brazil. However, its chemical composition is almost unknown. This study aimed to characterize the chemical compounds found in L. caatingensis and investigate the antileishmanial potential of its hydroalcoholic extract and polar fractions. Compounds present in the hydroalcoholic extract obtained from L. caatingensis leaves and its polar fractions (ethyl acetate and methanolic) were analyzed by liquid chromatography with a photodiode-array detector coupled to electrospray ionization quadrupole time-of-flight mass spectrometry. An antileishmanial assay was performed in a 96-well plate against Leishmania major promastigotes using resazurin on a plate spectrophotometer and the results were expressed as percentage of growth inhibition. Nine compounds were determined in the investigated extract and fractions, classified as flavonoids, flavonoid C-glycosides and phenylethanoid glycosides. The antileishmanial activity revealed that the hydroalcoholic extract and the ethyl acetate fraction were active against L. major promastigotes with inhibitory concentration of 71.78 and 26.86 µg mL-1, respectively, while the methanolic fraction was inactive (478.40 µg mL-1). This is the first report on the chemical composition and antileishmanial activity of L. caatingensis extracts. These results contribute to further knowledge of species belonging to the Lantana genus. Verbenaceae (Verbenaceae Brazil However unknown L photodiodearray photodiode array timeofflight time flight spectrometry 96well well 96 inhibition flavonoids Cglycosides C glycosides 7178 71 78 71.7 2686 26 86 26.8 mL1, mL1 mL 1, 1 mL-1 respectively 478.40 47840 478 40 (478.4 mL1. . mL-1) extracts genus 9 717 7 71. 268 2 8 26. mL- 478.4 4784 47 4 (478. 478. (478 (47 (4 (

Fruits of Schinus terebinthifolia Raddi were investigated. A fast and efficient method for the simultaneous determination of 11 polyphenolic substances by high performance liquid chromatography-diode array detector (HPLC-DAD) was applied. Limits of quantification ranged between 0.78 and 3.14 mg L-1. High concentrations of kaempferol were found. An exploratory evaluation was performed using principal component analysis (PCA) for fruit origin differentiation. Total phenolic content (TPC) ranged from 274 to 517 mg GAE 100 g-1; total flavonoid content (TFC) ranged from 101 to 283 mg QE 100 g-1. In vitro analyses showed that antioxidant capacity with 2,2-diphenyl-1-picrylhydrazyl (DPPH) ranged from 1.7 to 7 µM DPPH 100 g-1. The bacteriostatic and bactericidal effect were also evaluated against: Bacillus subtilis, B. cereus, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Salmonella choleraesuis, Candida albicans and C. glabrata, using broth microdilution assay. It can be inferred that S. terebinthifolia Raddi fruit has the potential to act as an ally in the search for new alternatives in the action against pathogens, and it can be used as a potential natural antioxidant and antimicrobial agent. Metals (Cu, Fe, Mg, Mn and Zn) were also determined by flame atomic absorption spectrometry (FAAS), with emphasis on high concentrations of Mg, Zn and Fe. investigated 1 chromatographydiode chromatography diode HPLCDAD HPLC DAD (HPLC-DAD applied 078 0 78 0.7 314 3 14 3.1 L1. L1 L 1. L-1 found PCA (PCA differentiation TPC (TPC 27 51 10 g1 g g-1 TFC (TFC 28 g1. 2,2diphenyl1picrylhydrazyl 22diphenyl1picrylhydrazyl diphenylpicrylhydrazyl 2,2 diphenyl picrylhydrazyl 2 (DPPH 17 subtilis B cereus aureus coli aeruginosa choleraesuis C glabrata assay S pathogens agent Cu, Cu (Cu Fe Mg FAAS, FAAS , (FAAS) 07 0. 31 3. L- 5 g- 2diphenyl1picrylhydrazyl 22 2, (FAAS

Palicourea tomentosa (Aubl.) Borhidi (Rubiaceae, Palicoureeae), earlier classified as Psychotria poeppigiana Müll. Arg., is used in folk medicine for a variety of diseases. Biological studies on the plant describes their vasorelaxant, antiplasmodial, antitumoural and anticholinesterase activities. To expand the knowledge on the chemical and biological potential of this species, in this work, phytochemical and dereplication studies, as well as antimicrobial and anticholinesterase evaluation of Palicourea tomentosa were carried out. Phytochemical investigation deals with the isolation of lutein (1), a mixture of dehydrovomifoliol (2) and megastigma-4,7-dien-3-one (3), loliolide (4), 5,13-epoxy-9-hydroxy-megastigma-7-en,3-one (5), vomifoliol (6), asperuloside (7), 3-O-p-coumaroylquinic acid (8), and a mixture of the pyrrolizidinoindoline alkaloids hodgkinsine (9), chimonanthine (10) and psychotriasine (11). The ultra-high performance liquid chromatography coupled to high-resolution mass spectrometry (UHPLC HRMS/MS) based on molecular networking dereplication of dichloromethane fraction led to putative identification of other two megastigmanes, one terpene lactone and three carotenoids, besides seven triterpenes and four indole alkaloids. The dichloromethane, ethyl acetate and hydromethanol fractions of P. tomentosa were able to inhibit Candida albicans with minimum inhibitory concentrations (MICs) of 125, 250 and 125 µg mL-1, respectively. The methanol crude extract, dichloromethane and alkaloid fractions inhibited selectively the butyrilcholinesterase (BuChE) at percentages of 63.09, 60.39 and 56.22%, respectively. Aubl. Aubl (Aubl. Rubiaceae, Rubiaceae (Rubiaceae Palicoureeae, Palicoureeae , Palicoureeae) Müll Arg Arg. diseases vasorelaxant antiplasmodial activities species work out 1, 1 (1) 2 (2 megastigma4,7dien3one megastigma47dien3one megastigmadienone megastigma 4,7 dien 3 4 7 3, (3) 4, (4) 5,13epoxy9hydroxymegastigma7en,3one 513epoxy9hydroxymegastigma7en3one epoxyhydroxymegastigmaenone 5,13 epoxy 9 hydroxy en,3 5 13 en 5, (5) 6, 6 (6) 7, (7) 3Opcoumaroylquinic Opcoumaroylquinic O p coumaroylquinic 8, 8 (8) 9, (9) 10 (10 11. 11 . (11) ultrahigh ultra high highresolution resolution UHPLC HRMS/MS HRMSMS HRMS MS megastigmanes carotenoids P MICs (MICs 25 12 mL1, mL1 mL mL-1 respectively extract BuChE (BuChE 6309 63 09 63.09 6039 60 39 60.3 5622 56 22 56.22% (Aubl (1 ( megastigma4 7dien3one 47 (3 (4 13epoxy9hydroxymegastigma7en 3one hydroxymegastigma 513 5,1 en3 en, (5 (6 (7 (8 (9 (11 mL- 630 0 63.0 603 60. 562 56.22 dienone epoxyhydroxymegastigmaen 51 63. 56.2 56.

Resumen El perrito de la pradera (Cynomys mexicanus) es un roedor endémico de los pastizales del Norte de México, considerada una especie clave para el mantenimiento de su ecosistema. La principal problemática a la que enfrenta es el aumento de la frontera agrícola, por lo que se encuentra en constante exposición a productos químicos utilizados en zonas de cultivo cercanas, como los plaguicidas. El objetivo de este estudio fue detectar y cuantificar residuos de plaguicidas en muestras de suelo de colonias de C. mexicanus de los estados de Zacatecas y San Luis Potosí. Se analizaron un total de 5 muestras de suelo y se analizaron por medio de la técnica de Cromatografía Líquida de Alta Eficiencia (HPLC). Se detectaron ocho plaguicidas presentes en el 100% de las muestras analizadas, de los cuales el glifosato y el metamidofos tuvieron concentraciones mayores, de hasta 5.5 mg/g y 4.8 mg/g respectivamente. Los resultados muestran que en el suelo se encuentran altas concentraciones de los plaguicidas mencionados comparadas con las detectadas en otros estudios y mayores a la DL5O establecida para ambos. Por lo que el suelo es una fuente de exposición importante y medio para la entrada hacia el organismo de C. mexicanus.

Abstract The Mexican prairie dog (Cynomys mexicanus) is an endemic rodent of the grasslands of northern Mexico, considered a keystone species for the maintenance of its ecosystem. The main problem it faces is the increase in the agricultural frontier, which means that it is constantly exposed to chemical products used in nearby farming areas, such as pesticides. The objective of this study was to detect and quantify pesticide residues in soil samples of C. mexicanus colonies from the states of Zacatecas and San Luis Potosí. High Performance Liquid Chromatography (HPLC) analyzed five soil samples. Eight pesticides were detected in 100 % of the samples analyzed, of which glyphosate and methamidophos had higher concentrations, up to 5.5 mg/g and 4.8 mg/g respectively. The results show that high concentrations of the mentioned pesticides are found in the soil compared to those detected in other studies and higher than the DL5O established for both. Therefore, soil is an important source of exposure and means of entry into the organism of C. mexicanus.

Summary: Excessive use of chlorpyrifos affects the quality of agricultural soils causing negative effects on the safety of harvested food. The behavior of chlorpyrifos residues depends on soil properties, especially organic matter. Our aim in this research was to determine the effect of the application of vermicompost on the residual and dissipation of chlorpyrifos in an entisol soil of semi-arid climate with variations in its edaphic fertility. Four treatments were studied. T1: 7.5% vermicompost (V) and 92.5% soil (S); T2: 5% V and 95% S; T3: 2.5% V and 97.5% S; T4: 0% V and 100% S. The treatments were subjected to a seven-day incubation period. Subsequently, a dose of chlorpyrifos of 1.5 mg kg-1 as active ingredient was applied once for each treatment. A completely randomized design was used with three replicates for each treatment, forming 12 experimental units. The analytical determination of chlorpyrifos was carried out by high performance liquid chromatography (HPLC). The evaluations were carried out 1.7, 14, 28, 42, 70 and 98 days after the application of chlorpyrifos. The results showed that the incorporation of vermicompost to the soil at increasing levels promoted a decrease in the residual concentration of chlorpyrifos and facilitated its gradual dissipation. The chlorpyrifos dissipation curves correspond to a first order logarithmic equation where the effects of the treatments caused greater dissipation of chlorpyrifos as the evaluation period elapsed. At 98 days of evaluation, T1 registered lower residuality (0.786 m kg-1), higher daily dissipation rate (0.008) and lower half-life of chlorpyrifos (86.64 days). At the end of the research period, edaphic levels of P, K, EC and CEC increased while OM, N and pH decreased after vermicompost application.

Resumen: El uso excesivo de clorpirifos afecta la calidad de los suelos agrícolas provocando efectos negativos en la inocuidad de los alimentos cosechados. El comportamiento de los residuos de clorpirifos depende de las propiedades edáficas especialmente la materia orgánica. El objetivo de la investigación fue determinar el efecto de la aplicación de vermicompost en la residualidad y disipación de clorpirifos en un suelo entisol de clima semiárido con variaciones en su fertilidad edáfica. Se estudiaron cuatro tratamientos. T1: 7.5% vermicompost (V) y 92.5% suelo (S); T2: 5% V y 95% S; T3: 2.5% V y 97.5% S; T4: 0% V y 100% S. Los tratamientos fueron sometidos a un periodo de incubación de siete días. Posteriormente, se aplicó una dosis de clorpirifos de 1.5 mg kg-1 como ingrediente activo en una sola oportunidad por cada tratamiento. Se utilizó un diseño completamente al azar con tres repeticiones por cada tratamiento conformando 12 unidades experimentales. La determinación analítica de clorpirifos se efectuó por cromatografía líquida de alta resolución (HPLC). Las evaluaciones se realizaron a 1,7, 14, 28, 42, 70 y 98 días de la aplicación de clorpirifos. Los resultados demostraron que la incorporación de vermicompost al suelo en niveles crecientes promovió la disminución de la concentración residual de clorpirifos y facilitó su disipación de manera gradual. Las curvas de disipación de clorpirifos corresponden a una ecuación logarítmica de primer orden donde los efectos de los tratamientos ocasionaron mayor disipación de clorpirifos conforme transcurrió el periodo de evaluación. A 98 días de evaluación el T1 registró menor residualidad (0.786 m kg-1), mayor tasa de disipación diaria (0.008) y menor vida media de clorpirifos (86.64 días). Al final del periodo de investigación, los niveles edáficos de P, K, CE y CIC se incrementaron mientras que la MO, N y pH descendieron luego de la aplicación de vermicompost.

Abstract Introduction: The use of antimicrobials is a permanent challenge as it is constantly confronted with the ability of bacteria to develop resistance mechanisms. Objective: The objective of this research was to evaluate the antimicrobial effect of polyphenolic extracts present in Ananas comosus crown. Materials and Methods: 3.5 kg of Ananas comosus pineapple crown leaves were collected and taken to a tray dryer to reduce humidity, then, they were milled until a fine flour was obtained, for the extraction process of the oleaginous extract a Soxhlet equipment was used, using 70% ethanol as solvent, The identification of phenolic compounds was carried out by ultra-high resolution liquid chromatography with an Orbitrap mass detector. The microbiological analysis was evaluated by the standardized method of diffusion with discs using Mueller-Hinton agar, for which the Staphylococcus aureus strain (ATCC 25923) was used, using oxacillin as a positive control and DMSO as a negative control. Results: from the drying obtained, the humidity was reduced by 50%, with which the dry matter obtained was ground and used to carry out the extraction process of the oleaginous extract, obtaining 63 ml of which 27 phenolic compounds were identified. As for the microbiological analysis carried out, inhibition halos varying between 4.5 mm and 6.0 mm were observed. Conclusion: Finally, it was concluded that the polyphenols present in the extract of Ananas comosus showed antibacterial activity on Staphylococcus aureus, with a greater inhibition effect observed when a higher concentration of the extract was applied.

Resumen Introducción: La utilización de antimicrobianos es un desafío permanente ya que se enfrenta en todo momento a la capacidad de las bacterias para desarrollar mecanismos de resistencia. Objetivo: el objetivo de esta investigación fue evaluar el efecto antimicrobiano de los extractos polifenolicos presentes en la corona Ananas comosus. Materiales y Métodos: se recolectaron 3,5 kg de hojas de coronas de piña Ananas comosus para ello se llevaron a un secador de charolas, para reducir humedad, posteriormente, se realizó la molienda hasta obtener una harina fina, para el proceso de extracción del extracto oleaginoso se utilizó un equipo Soxhlet utilizando etanol al 70 % como solvente, la identificación de compuestos fenólicos se realizó por cromatografía líquida de ultra-alta resolución con detector de masas Orbitrap,el análisis microbiológico se evaluó mediante el método estandarizado de difusión con discos utilizando agar Mueller-Hinton, para lo cual se utilizó la cepa Staphylococcus aureus (ATCC 25923), utilizando como control positivo oxacilina y como control negativo (DMSO). Resultados: del secado obtenido se disminuyó la humedad en 50 %, con el cual la materia seca obtenida fue molida y utilizada para realizar el proceso de extracción del extracto oleaginoso obteniendo 63ml del cual se identificaron de 27 compuestos fenólicos. En cuanto al análisis microbiológico realizado, se observaron halos de inhibición variables entre 4,5 mm y 6,0 mm. Conclusión: finalmente se concluyó que los polifenoles presentes en el extracto de Ananas comosus presentaron actividad antibacteriana en Staphylococcus aureus observándose mayor efecto de inhibición al aplicar de mayor concentración del extracto.