Hollow viscus perforation in blunt abdominal trauma: A 14-year experience from a trauma center.

BACKGROUND: Isolated perforations of hollow viscus (HV) represent less than 1% of injuries in blunt abdominal trauma (BAT). When they do present, they are generally due to high-impact mechanisms in the segments of the intestine that are fixed. The aim of this study is to determine the incidence of major HV injuries in BAT at the "Dr. Domingo Luciani" General Hospital (HDL), and address the literature gap regarding updated HV perforations following BAT, especially in low-income settings. METHODS: A retrospective review was conducted on the medical records of patients admitted to our trauma center with a diagnosis of complicated BAT with HV perforation over 14 years. RESULTS AND DISCUSSION: Seven hundred sixty-one patients were admitted under the diagnosis of BAT. Of them, 36.79% underwent emergency surgical resolution, and 6.04% had HV perforation as an operative finding. Almost half (44.44%) of these cases presented as a single isolated injury, while the remaining were associated with other intra-abdominal organ injuries. The most common lesions were Grade II-III jejunum and Grade I transverse colon, affecting an equal proportion of patients at 13.33%. In recent years, an increased incidence of HV injuries secondary to BAT has been observed. Despite this, in many cases, the diagnosis is delayed, so even in the presence of negative diagnostic studies, the surgical approach based on the trauma mechanism, hemodynamic status, and systematic reevaluation of the polytraumatized patient should prevail.

Thiourea-Based Receptors for Anion Recognition and Signaling.

This work reports on two thiourea-based receptors with pyridine and amine units including 1-naphthyl (MT1N) and 4-nytrophenyl (MT4N) as signaling units. For both compounds, their affinity and signaling ability toward various anions of different geometry and basicity in DMSO were studied using UV-vis, fluorescence, and 1H NMR techniques. Anion recognition studies revealed that both MT1N and MT4N have, in general, high affinities toward basic anions. In this regard, a higher acidity of the MT4N receptor was demonstrated. Furthermore, MT4N has a higher affinity for fluoride (log K1 = 5.98) than for the other anions and can effectively detect it through colorimetric changes that can be monitored by the UV-vis technique. The interaction between receptors and anions mainly involves the hydrogens of the amino and thiourea groups of the former. Complementary single-crystal X-ray diffraction studies and molecular modeling at the DFT level were also performed.

Tetrandrine Derivatives as Promising Antibacterial Agents.

This work reports on the antibacterial activity of two tetrandrine derivatives, with acridine (MAcT) and anthracene (MAnT) units, against Gram-positive and Gram-negative bacteria of clinical importance by the broth microdilution method as well as their antioxidant activity against ABTS•+ and DPPH•+ radicals. Unlike natural tetrandrine, its derivatives inhibited bacterial growth, showing selectivity against Staphylococcus aureus with notable activity of MAnT (MIC = 0.035 µg/mL); this compound also has good activity against the ABTS•+ radical (IC50 = 4.59 µg/mL). Cell membrane integrity studies and reactive oxygen species (ROS) detection by fluorescent stains helped to understand possible mechanisms related to antibacterial activity, while electrophoretic mobility assays showed that the derivatives can bind to bacterial DNA plasmid. The results indicate that MAnT can induce a general state of oxidative stress in S. aureus and Escherichia coli, while MAcT induces an oxidative response in S. aureus. Complementary electrochemical studies were included.

Efficient and Sustainable Bidentate Amines-Functionalized Resins for Removing Ag+, Cu2+, Pb2+, and Fe3+ from Water.

We evaluate the effectiveness of chelating resins (CR) derived from Merrifield resin (MR) and 1,2-phenylenediamine (PDA), 2,2'-dipyridylamine (DPA), and 2-(aminomethyl)pyridine (AMP) as adsorbent dosimeters for Ag+, Cu2+, Fe3+, and Pb2+ cations from water under competitive and noncompetitive conditions. MR-PDA, MR-DPA, and MR-AMP were obtained in a 95-97% yield and characterized by IR, fluorescence, and SEM. The ability of CRs as adsorbents was determined by batch and flow procedures. MR-PDA showed a batch adsorption capacity order of Fe3+ (29.8 mg/g) > Ag+ (2.7 mg/g) > Pb2+ (2.6 mg/g) at pH 3.4. The flow adsorption showed affinity towards the Ag+ cation at pH 7 (18.4 mg/g) and a reusability of 10 cycles. In MR-DPA, the batch adsorption capacity order was Ag+ (9.1 mg/g) > Pb2+ (8.2 mg/g) > Cu2+ (3.5 mg/g) at pH 5. The flow adsorption showed affinity to the Cu2+ cation at pH 5 (2.2 mg/g) and a reuse of five cycles. In MR-AMP, the batch adsorption capacity was Ag+ (17.1 mg/g) at pH 3.4. The flow adsorption showed affinity to the Fe3+ cation at pH 2 (4.3 mg/g) and a reuse of three cycles. The three synthesized and reusable CRs have potential as adsorbents for Ag+, Cu2+, Fe3+, and Pb2+ cations and showed versatility in metal removal for water treatment.

Design, synthesis, in silico, and in vitro evaluation of benzylbenzimidazolone derivatives as potential drugs on α-glucosidase and glucokinase as pharmacological targets.

Benzimidazolones have shown biological activities, including antihyperglycemic and hypoglycemic, by inhibiting or activating of α-glu and GK. The aim of this study is the rational design of compounds using in silico assays to delimitate the selection of structures to synthesize and the in vitro evaluation of benzimidazolone derivatives in blood glucose control. A docking of 23 benzimidazolone derivatives was performed; selecting the compounds with better in silico profiles to synthesize by microwave-irradiation/conventional heat and evaluate in enzymatic in vitro evaluation. Compounds 2k, 2m, 2r, and 2s presented the best in silico profiles, showing good affinity energy (-10.9 to -8.6 kcal mol-1) and binding with catalytic-amino acids. They were synthesized at 70 °C and 24 h using DMF as the solvent and potassium carbonate (yield: 22-38%). The results with α-glu showed moderate inhibition of 2k (14 ± 1.23-29 ± 0.45), 2m (12 ± 2.21-36 ± 0.30), 2r (7 ± 2.21-13 ± 1.34), and 2s (11 ± 0.74-35 ± 2.95) at evaluated concentrations (0.1 to 100 µg mL-1). The GK activation assay showed an enzymatic activity increase; compound 2k increased 1.31 and 2.83 more than normal activity, 2m (2.13-fold), 2s (2.86 and 3.74-fold) at 100 and 200 µg mL-1 respectively. The present study showed that the 2s derivative presents moderate potential as an α-glu inhibitor and a good activator potential of GK, suggesting that this compound is a good candidate for blood glucose control through antihyperglycemic and hypoglycemic mechanisms.

La simulación como herramienta de enseñanza y aprendizaje quirúrgico / Surgical simulation as a teaching and learning tool

La simulación es la técnica de replicar un proceso o situación. El objetivo de la simulación quirúrgica es transferir de manera efectiva las habilidades adquiridas en el laboratorio al quirófano, reduciendo las curvas de aprendizaje y los costos operativos. Objetivos : Describir la utilización, ventajas, desventajas, y estado actual de la práctica basada en simulación como método de enseñanza y aprendizaje para la capacitación de residentes y cirujanos en los programas de formación quirúrgica, según lo reportado en la literatura científica actual. Métodos : Se realizó una búsqueda en la literatura utilizando palabras claves. Se sintetizaron los hallazgos de cada estudio en una revisión narrativa. Resultados : La simulación quirúrgica es una herramienta educativa que confiere ventajas únicas. Permite el desarrollo de programas de formación flexibles e individualizados, enfatiza el aprendizaje basado en problemas, basado en competencias y basado en destrezas, y acelera el proceso de aprendizaje al ofrecer entornos seguros para practicar procedimientos quirúrgicos complejos. Además, respalda la retroalimentación y el análisis posterior, fomenta la formación multidisciplinaria y facilita la investigación y la innovación, mejorando en última instancia la calidad de la atención médica. Conclusiones : Las ventajas prácticas de los programas de formación estructurados han convertido a la educación basada en la simulación en un método de enseñanza factible, confiable y altamente atractivo. La simulación no solo contribuye al desarrollo profesional de los residentes, sino que también mejora la seguridad del paciente y la calidad general de los servicios de salud(AU)

Simulation is the act of replicating a process or situation. The objective of surgical simulation is to effectively transfer the skills acquired in the laboratory to the operating room, reducing the learning curves and operational costs. Objectives: To describe the use, advantages, disadvantages, and current state of simulation-based practice as a method of teaching and learning for the training of residents and surgeons in surgical training programs, as reported in the current scientific literature. Methods: A literature search was conducted using keywords. The findings of each study were synthesized in a narrative review. Results: Surgical simulation is an educational tool that offers unique advantages. It allows for the development of flexible and individualized training programs, emphasizes problem-based, competency-based, and skill-based learning, and accelerates the learning process by providing safe environments to practice complex surgical procedures. Furthermore, it supports feedback and post-analysis, encourages multidisciplinary training, and facilitates research and innovation, ultimately enhancing the quality of healthcare. Conclusions: The practical benefits of structured training programs have made simulation-based education a feasible, reliable, and highly attractive teaching method. Simulation not only contributes to the professional development of residents but also improves patient safety and the overall quality of healthcare services(AU)

Situación actual de la enseñanza quirúrgica por simulación en Venezuela / Current status of surgical training with simulation in Venezuela

La simulación constituye un instrumento beneficioso para la adquisición de destrezas quirúrgicas. Su disponibilidad en países en vías de desarrollo representa un obstáculo importante en la educación quirúrgica contemporánea.Objetivo : Identificar centros de capacitación quirúrgica en Venezuela que utilicen la simulación para el entrenamiento de habilidades técnicas y conocer la opinión de los miembros de la Sociedad Venezolana de Cirugía (SVC) acerca de su uso para desarrollar habilidades en cirugía abierta.Métodos : Estudio transversal y descriptivo. Se enviaron encuestas por correo electrónico a todos los miembros activos de la SVC. Se utilizó estadística descriptiva para el análisis y presentación de los datos.Resultados : De 1115 encuestas enviadas, 111 fueron completadas; 67,6 % de los participantes no tienen conocimientos sobre la existencia de centros de entrenamiento basados en simulación quirúrgica; el 99,1 % están de acuerdo con implementar la simulación como método de capacitación complementario y consideran importante el entrenamiento de habilidades en cirugía abierta; 94,6 % manifestó que el entrenamiento debe estructurarse y ejecutarse en módulos que inicien con tareas básicas para luego avanzar hacia procedimientos más complejos; 75 % de los procedimientos avanzados que deben practicarse con mayor frecuencia corresponden al sistema gastrointestinal, destacando las anastomosis intestinales (74,7 %).Conclusión : la gran mayoría de los cirujanos en las Instituciones de salud de Venezuela no tienen acceso a la simulación como herramienta educativa, a pesar de estar de acuerdo con que su implementación es altamente potenciadora para el desarrollo de habilidades técnicas(AU)

Simulation represents a beneficial tool for acquiring surgical skills. Its availability in developing countries poses a significant obstacle in contemporary surgical education.Objective : To identify surgical training centers in Venezuela that use simulation for technical skills training, and to understand the opinion of members of the Venezuelan Society of Surgery (SVC) regarding its use for developing open surgical skills.Methods : A cross-sectional, descriptive study. Surveys were sent via email to all active SVC members. Descriptive statistics were used for data analysis and presentation.Results : Of the 1,115 surveys sent, 111 were completed. 67.6% of the participants were unaware of the existence of simulation-based surgical training centers. 99.1% agreed with implementing simulation as a complementary training method and considered training in open surgery skills important. 94.6% stated that training should be structured and conducted in modules starting with basic tasks and progressing to more complex procedures; 75% of the advanced procedures that should be practiced more frequently were related to the gastrointestinal system, with intestinal anastomoses (74.7%) being particularly highlighted.Conclusion : The majority of surgeons in Venezuelan healthcare institutions do not have access to simulation as an educational tool, despite agreeing that its implementation is highly beneficial for the development of technical skills(AU)

SLCO1B1 and SLC10A1 polymorphism and plasma rifampin concentrations in patients with co-morbidity tuberculosis-diabetes mellitus in Baja California, Mexico.

Rifampicin is one of the most important drugs for the treatment of tuberculosis (TB). Polymorphisms in SLCO1B1 and SLC10A1 genes are associated with impaired transporter function of drug compounds such as rifampicin. The relationship between genetic variation, clinical comorbidities, and rifampicin exposures in TB patients has not been completely elucidated. The aim of this study was to investigate the prevalence of SLCO1A1 and SLCO1B1 polymorphisms in TB and TB-DM patients and to determine their relationship with rifampicin pharmacokinetics on patients from México. Blood samples were collected in two hospitals in Baja California, Mexico from February through December 2017. Sampling included 19 patients with TB, 11 with T2DM and 17 healthy individuals. Polymorphisms genotype rs2306283, rs11045818, rs11045819, rs4149056, rs4149057, rs72559746,rs2291075 and rs4603354 of SLCO1B1 and rs4646285 and rs138880008 of SLC10A1 were analyzed by Sanger's sequencing. None of the SLCO1B1 and SLC10A1 variants were significantly associated with rifampicin Cmax. TB and T2DM patients with suboptimal Cmax rifampicin levels showed wild alleles in rs11045819 and rs2291075 in SLCO1B1 SLC10A1 and SLC10A1. This is the first study to analyze SLC10A1 and SLCO1B1 polymorphisms in TB and TB-T2DM patients and healthy individuals in Mexico. Further research to confirm and extend these findings is necessary.

Experimental and theoretical study of novel aminobenzamide-aminonaphthalimide fluorescent dyads with a FRET mechanism.

In this work, both experimental and theoretical methods were used to study the photophysical and metal ion binding properties of a series of new aminobenzamide-aminonaphthalimide (2ABZ-ANAPIM) fluorescent dyads. The 2-aminobenzamide (2ABZ) and 6-aminonaphthalimide (ANAPIM) fluorophores were linked through alkyl chains (C2 to C6) to obtain four fluorescent dyads. These dyads present a highly efficient (0.61 to 0.98) Förster Resonant Energy Transfer (FRET) from the 2ABZ to the ANAPIM due to the 2ABZ emission and ANAPIM excitation band overlap and the configurational stacking of both aromatic systems which allows the energy transfer. These dyads interact with Cu2+ and Hg2+ metal ions in solution inhibiting the FRET mechanism by the cooperative coordination of both 2ABZ and ANAPIM moieties. Both experimental and theoretical results are consistent and describe clearly the photophysical and coordination properties of these new dyads.

Cooperative Recognition of Ni2+ Triggered by Fluoride Ions in Naturally Occurring α-Hydroxyquinone Derivatives.

Perezone is a naturally occurring hydroxyquinone that has been deeply studied from different chemical aspects, such as therapeutics, electrochemistry, physical-chemical properties, or synthetic approaches that turn it an attractive template for new semisynthetic derivatives with a wide range of purposes. Herein, we describe a facile synthetic pathway to obtain new perezone derivatives by the addition of a pyrrole moiety that can be used for ion recognition. Compounds 2-4 showed the capability to interact with several anions and M2+ cations as separate events that result in colorimetric changes. Moreover, the compounds can behave as heteroditopic receptors. Besides, a previous interaction between fluoride ions and perezone derivatives triggered a successful recognition of M2+ ions, remarking Ni2+ as the most interesting phenomenon. These results project the compounds as potential colorimetric receptors for nickel ions in complex solutions.

A fluorescent PET probe based on polyethyleneimine-Ag nanoclusters as a reversible, stable and selective broad-range pH sensor.

In this work, nanoclusters (NCs) of Cu and Ag capped with hyperbranched polyethyleneimine (PEI) were prepared using chemical reduction by a one-step hydrothermal method. The PEI coated-NCs were characterized by high-resolution transmission electron microscopy, ζ potential, thermogravimetric analysis, dynamic light scattering, Fourier-transform infrared, UV-visible, and fluorescence spectroscopy. The PEI-NCs exhibited strong absorption and fluorescence, high stability, and excellent water dispersibility. The resulting PEI-NCs showed a reversible and linear response of fluorescence intensity with pH over a wide range (3-11); however, PEI-AgNCs showed a better reversibility and sensitivity than PEI-CuNCs. Unlike several types of pH sensors based on modified NCs, which are based on a nanoparticle aggregation/disaggregation mechanism, the response of our sensor is based on a photoinduced electron transfer process, which gives it a high reversibility. This method was successfully applied in pH measurements in tap water and green tea samples, with excellent results, indicating its practical utility for these applications. A visual device was obtained by immobilizing PEI-AgNCs into agarose hydrogels at different pH values. The results show that the proposed sensor can be used as a pH visual detector. Besides, the light emission of the nanosensor was corroborated by fluorescence microscopy, confirming that the nanosensor based on PEI-AgNCs has great potential to be used in cellular imaging.

Synthesis of covalent bonding MWCNT-oligoethylene linezolid conjugates and their antibacterial activity against bacterial strains.

Nowadays, infectious diseases caused by drug-resistant bacteria have become especially important. Linezolid is an antibacterial drug active against clinically important Gram positive strains; however, resistance showed by these bacteria has been reported. Nanotechnology has improved a broad area of science, such as medicine, developing new drug delivery and transport systems. In this work, several covalently bounded conjugated nanomaterials were synthesized from multiwalled carbon nanotubes (MWCNTs), a different length oligoethylene chain (S n ), and two linezolid precursors (4 and 7), and they were evaluated in antibacterial assays. Interestingly, due to the intrinsic antibacterial activity of the amino-oligoethylene linezolid analogues, these conjugated nanomaterials showed significant antibacterial activity against various tested bacterial strains in a radial diffusion assay and microdilution method, including Gram negative strains as Escherichia coli (11 mm, 6.25 µg mL-1) and Salmonella typhi (14 mm, ≤0.78 µg mL-1), which are not inhibited by linezolid. The results show a significant effect of the oligoethylene chain length over the antibacterial activity. Molecular docking of amino-oligoethylene linezolid analogs shows a more favorable interaction of the S 2-7 analog in the PTC of E. coli.

Novel Linezolid analogues with antiparasitic activity against Hymenolepis nana.

The stereoselective synthesis and anti- Hymenolepis nana activity of six Linezolid-type compounds, obtained by chemical modification of l-Alanine, are reported in this work. The synthetic strategy was to prepare diasteromeric N,N-dibenzylamino oxazolidinones 1 and 2, and coupling with 4-(4-bromophenyl)morpholine (3) to obtain N,N-dibenzylamino Linezolid analogues 4 and 5. A hydrogenolysis reaction over 4 and 5 resulted in amino-free Linezolid analogues 6 and 7, which were acetylated to reach diasteromeric Linezolid analogues 8 and 9. The six Linezolid analogues 4-9 show in vitro antiparasitic activity against Hymenolepis nana cestode, but not against several bacterial strains. Interestingly, compounds 6, 7 and 9 exhibit high potency, having shorter paralysis and death times after exposure (6-10 and 18-21 min, respectively), shorter than those found with antihelmintic compound Praziquantel (20 and 30 min) at 20 mg/mL. In addition, a cytocompatibility assay of 6-9 with human cells (ARPE-19 cells) demonstrate a non-cytotoxic effect at 0.4 mM. These results show the pharmacological potential of the newly reported Linezolid-type analogues as antiparasitic agents against Hymenolepis nana.

Synthesis and molecular docking studies of imines as α-glucosidase and α-amylase inhibitors.

Imine functionality is found in many compounds with important biological activity. Thus, the development of novel synthetic approaches for imines is important. In this work, it is propose an easy, eco-friendly and straightforward synthesis pathway of aryl imines under microwave irradiation catalyzed by Alumina-sulfuric acid. In addition, the in vitro enzymatic inhibition, antioxidant activity and molecular docking studies were performed. The aryl imines were isolated with yields in the range of 37-94%. All aryl imines synthesized were evaluated for in vitro inhibitory potential against α-glucosidase and α-amylase enzymes and the results exhibited that the most of the compounds displayed inhibitory activity against both enzymes. The (E)-1-(4-nitrophenyl)-N-(pyridin-2-yl)methanimine (3d) was 1.15-fold more active than acarbose against α-amylase whilst the (E)-1-phenyl-N-(pyridin-2-yl)methanimine (3c) displayed similar activity that acarbose against α-glucosidase. The molecular docking studies in α-glucosidase and α-amylase reveal that aryl imines mainly establish an H-bond with the R2-subtituent and hydrophobic interactions with the R1-subtituent. The docking analysis reveals these synthetic aryl imines 3d-i interact in same active site than acarbose drug in both enzymes.

Design, synthesis and evaluation of the antibacterial activity of new Linezolid dipeptide-type analogues.

Worldwide studies towards development of new drugs with a lower rate in emergence of bacterial resistance have been conducted. The molecular docking analysis gives a possibility to predict the activity of new compounds before to perform their synthesis. In this work, the molecular docking analysis of 64 Linezolid dipeptide-type analogues was performed to predict their activity. The most negative scores correspond to six Fmoc-protected analogues (9as, 9bs, 9bu, 10as, 10ax and 10ay) where Fmoc group interacts in PTC for Linezolid. Twenty-six different Fmoc-protected Linezolid dipeptide-type analogues 9(as-bz) and 10(as-bz) were synthesized and tested in antimicrobial experiments. Compounds 9as, 9ay, 9ax, 10as, 10ay and 9bu show significant activity against group A Streptococcus clinical isolated. Analogue 10ay also display high activity against ATCC 25923 Staphylococcus aureus strain and MRSA-3, MRSA-4 and MRSA-5 clinical isolates, with MIC values lower than Linezolid. The highest activity against multidrug-resistant clinical isolates of Mycobacterium tuberculosis was exhibited by 9bu. Finally, a cytotoxicity assay with ARPE-19 human cells revealed a non-cytotoxic effect of 9bu and 10ay at 50 and 25 µM, respectively.

Synthesis and anion recognition studies of new oligomethylene bis(nitrophenylureylbenzamide) receptors.

A new series of oligomethylene bis(nitrophenylureylbenzamide) receptors were synthesized varying the relative position of the urea and amide groups (ortho4 and meta8) and the length of the oligomethylene chain (C2 to C8). An anion recognition study was performed with TBAX salts (X = AcO-, BzO-, F-, H2PO4 -, and HP2O7 3-) by UV-vis and 1H NMR. The flexibility of these receptors allows a cooperative effect of both ureylbenzamide units in the receptors. Noteworthy, the ortho position favored the 1 : 1 stoichiometry in the complexes with the carboxylates. The formation of 2 : 1 receptor-anion complexes with both types of receptors 4 and 8 and with hydrogen pyrophosphate and high log K values obtained were very significant in this work. The NMR studies evidenced the formation of supramolecular complexes, even in a competitive solvent, such as DMSO.

Synthesis of new quinazolin-2,4-diones as anti-Leishmania mexicana agents.

The quinazolin-2,4-dione moiety is found in many compounds with important biological activities making it a target for its synthesis. In this work, a one-pot three-step synthesis of new quinazolin-2,4-diones from phthalic anhydrides and their activity against Leishmania mexicana are described. The new quinazolin-2,4-diones were isolated with yields in the range of 32-70 %. All compounds displayed lower cytotoxicity in RAW 264.7 macrophage over miltefosine. Compound 6,7-dichloro-3-phenylquinazoline-2,4(1H,3H)-dione (6e) displayed an attractive profile which includes anti-Leishmania mexicana activity ([Formula: see text] [Formula: see text]M), much lower cytotoxic activity ([Formula: see text] [Formula: see text]M) and a high selective index ([Formula: see text]) proving to be superior to miltefosine.

Synthesis and antioxidant evaluation of enantiomerically pure bis-(1,2,3-triazolylmethyl)amino esters from modified α-amino acids.

The efforts for synthesis of enantiomerically pure bis-(1,2,3-triazolylmethyl)amino esters 6 are reported in good yields from an in situ generated α-azidomethyl ketone. Optimum experimental conditions were established for preparation of α-halomethyl ketones 10 and α-N,N-dipropargylamino esters 11, all derived from α-amino acids. The starting materials reacted under conventional click chemistry conditions, revealing a specific reactivity of bromomethyl ketones over chloromethyl ketones. The antioxidant activity of compounds 6 was assayed by DPPH method. The compound 6c with an IC50 of 75.57 ± 1.74 µg mL(-1) was the most active. Technically, this methodology allows the preparation of a combinatorial library of analogues with different structural characteristics depending on the nature of the modified α-amino acids employed in the synthesis.

Antibacterial activity of new oxazolidin-2-one analogues in methicillin-resistant Staphylococcus aureus strains.

Staphylococcus aureus is one of the most common causes of nosocomial infections. The purpose of this study was the synthesis and in vitro evaluation of antimicrobial activity of 10 new 3-oxazolidin-2-one analogues on 12 methicillin resistant S. aureus (MRSA) clinical isolates. S. aureus confirmation was achieved via catalase and coagulase test. Molecular characterization of MRSA was performed by amplification of the mecA gene. Antimicrobial susceptibility was evaluated via the Kirby-Bauer disc diffusion susceptibility test protocol, using commonly applied antibiotics and the oxazolidinone analogues. Only (R)-5-((S)-1-dibenzylaminoethyl)-1,3-oxazolidin-2-one (7a) exhibited antibacterial activity at 6.6 µg. These results, allow us to infer that molecules such as 7a can be potentially used to treat infections caused by MRSA strains.

A novel and highly regioselective synthesis of new carbamoylcarboxylic acids from dianhydrides.

A regioselective synthesis has been developed for the preparation of a series of N,N'-disubstituted 4,4'-carbonylbis(carbamoylbenzoic) acids and N,N'-disubstituted bis(carbamoyl) terephthalic acids by treatment of 3,3',4,4'-benzophenonetetracarboxylic dianhydride (1) and 1,2,4,5-benzenetetracarboxylic dianhydride (2) with arylalkyl primary amines (A-N). The carbamoylcarboxylic acid derivatives were synthesized with good yield and high purity. The specific reaction conditions were established to obtain carbamoyl and carboxylic acid functionalities over the thermodynamically most favored imide group. Products derived from both anhydrides 1 and 2 were isolated as pure regioisomeric compounds under innovative experimental conditions. The chemo- and regioselectivity of products derived from dianhydrides were determined by NMR spectroscopy and confirmed by density functional theory (DFT). All products were characterized by NMR, FTIR, and MS.