Dihydroeugenol derivatives associated with blue LED light: A different form to face multidrug resistant (MDR) bacteria.

Eugenol has already had its pharmacological properties elucidated in previous studies, including antibacterial and antifungal properties. Based on such information, this study aimed to evaluate the antibacterial and modulatory activity of coumarin compounds prepared from dihydroeugenol and to associate them with blue LED light for the same activity. For this study, five of the substances available: compound 1 (C1), 8-methoxy-2-oxo-6-propyl-2H-chromen-3-carboxylic acid, compound (C2), 3-(hydroxy(4-nitrophenyl)methyl)-8- methoxy-6-propyl-2H-chromen-2-one, compound 7 (C3), 8-hydroxy-3-(4-nitrobenzoyl)-6-propyl-2H-chromen-2-one, compound 8 (C4), 3-(4-aminobenzoyl)-8-methoxy-6-propyl-2H-chromen-2-one and Compound 9 (C5), 8-methoxy-3-(4-nitrobenzoyl)-6-propyl-2H-chromen-2-one 2-one. To determine the MIC, the broth microdilution technique was used. The products were evaluated for their potential to modulate the activity of antibiotics. Afterward, the plates were submitted to blue LED light for 20 min. When exposed to LED, C3 exhibited a decrease in MIC for SA ATCC and C5 for EC ATCC, with an average of 645.08 µg/mL for both cases. C2 and C4 exhibited synergism in a greater number of situations. However, C3 showed promising activity against S. aureus. C1 and C2 already acted better against E. coli, with the difference that C1 acted better against these bacteria when associated with LED. In general, the compounds studied here exhibited good antibacterial activity when associated with LED.

Anti-inflammatory effect, antibiotic potentiating activity against multidrug-resistant strains of Escherichia coli and Staphylococcus aureus, and evaluation of antibiotic resistance mechanisms by the ibuprofen derivative methyl 2-(-4-isobutylphenyl)propanoate.

The prevalence of multidrug-resistant (MDR) bacteria and the limited efficacy of current available antibiotics cause every year approximately 700 000 deaths per year. This study aimed to evaluate the anti-inflammatory effect and antibacterial potential of the ibuprofen derivative Methyl 2-(-4-isobutylphenyl)propanoate (MET-IBU). The molecular structure of MET-IBU was confirmed by Nuclear Magnetic Resonance (NMR) and, Attenuated Total Reflectance Fourier Transform Infrared spectroscopy (ATR-FTIR) spectroscopy. Our in vivo study using adult zebrafish model demonstrated that the ibuprofen derivative MET-IBU also possesses anti-inflammatory effect, and in vitro antibacterial activity assays showed that in the association of ampicillin, norfloxacin, and gentamicin with MET-IBU occurred reduction in the minimum inhibitory concentration (MIC) for MDR bacterial strains of Escherichia coli 06 and Staphylococcus aureus 10, indicating a potentiating in the growth inhibition of these pathogenic bacteria. Regarding the strain of Staphylococcus aureus K2068 (overexpressing mepA gene), a potentiation of ethidium bromide was found in the association with MET-IBU, indicating the action of this compound on the efflux pump mechanism present in this strains. This result corroborates the molecular docking study that indicated a high affinity of the MET-IBU with the MepA efflux pump. It was also noticed an antibiotic potentiating activity in the association MET-IBU with norfloxacin against strains of Staphylococcus aureus 1199B (overexpressing norA gene) when compared to the norfloxacin control. This enhanced antibiotic effect of MET-IBU is associated with a second resistance mechanism, which is due to the modification in the topoisomerase enzyme. These results bring attention to the ibuprofen derivative MET-IBU as possible candidate for the development of new options for the treatment of bacterial infections with protective anti-inflammatory action.

Paradigm shift in xylose isomerase usage: a novel scenario with distinct applications.

Isomerases are enzymes that induce physical changes in a molecule without affecting the original molecular formula. Among this class of enzymes, xylose isomerases (XIs) are the most studied to date, partly due to their extensive application in industrial processes to produce high-fructose corn sirups. In recent years, the need for sustainable initiatives has triggered efforts to improve the biobased economy through the use of renewable raw materials. In this context, D-xylose usage is crucial as it is the second-most abundant sugar in nature. The application of XIs in biotransforming xylose, enabling downstream metabolism in several microorganisms, is a smart strategy for ensuring a low-carbon footprint and producing several value-added biochemicals with broad industrial applications such as in the food, cosmetics, pharmaceutical, and polymer industries. Considering recent advancements that have expanded the range of applications of XIs, this review provides a comprehensive and concise overview of XIs, from their primary sources to the biochemical and structural features that influence their mechanisms of action. This comprehensive review may help address the challenges involved in XI applications in different industries and facilitate the exploitation of xylose bioprocesses.

Electrostatic interaction optimization improves catalytic rates and thermotolerance on xylanases.

Understanding the aspects that contribute to improving proteins' biochemical properties is of high relevance for protein engineering. Properties such as the catalytic rate, thermal stability, and thermal resistance are crucial for applying enzymes in the industry. Different interactions can influence those biochemical properties of an enzyme. Among them, the surface charge-charge interactions have been a target of particular attention. In this study, we employ the Tanford-Kirkwood solvent accessibility model using the Monte Carlo algorithm (TKSA-MC) to predict possible interactions that could improve stability and catalytic rate of a WT xylanase (XynAWT) and its M6 xylanase (XynAM6) mutant. The modeling prediction indicates that mutating from a lysine in position 99 to a glutamic acid (K99E) favors the native state stabilization in both xylanases. Our lab results showed that mutated xylanases had their thermotolerance and catalytic rate increased, which conferred higher processivity of delignified sugarcane bagasse. The TKSA-MC approach employed here is presented as an efficient computational-based design strategy that can be applied to improve the thermal resistance of enzymes with industrial and biotechnological applications.

Phytochemical characterization of the Ziziphus joazeiro Mart. metabolites by UPLC-QTOF and antifungal activity evaluation.

The aim of this study was to evaluate the antifungal and modulatory potential of the Ziziphus joazeiro bark and leaf extracts, both in isolation and in association with fluconazole, against resistant species from the Candida genus. Antifungal assays were used to determine the half maximal inhibitory concentration (IC50) of the extract in isolation and in combination with fluconazole using the broth microdilution method and spectrophotometric readings, followed by verification of the minimum fungicidal concentration by solid medium subculture. According to the cell viability curve, both extracts inhibited fungal growth in a concentration dependent manner, in addition to showing inhibitory concentrations similar to fluconazole. However, the extracts behaved in a fungistatic manner with minimum inhibitory concentration > 8.19 mg/mL and IC50 values ranging from 0.450 mg/mL to 9 mg/mL. The minimum inhibitory concentration for both extracts decreased when in combination with fluconazole, with the AEL standing out against Candida albicans URM 4387, displaying an IC50 equal to that of fluconazole (0.002 mg/mL). Nevertheless, fluconazole antagonism was observed against the tested strains. Overall, the evaluation of both extracts against Candida spp. presented inhibitory concentration values greater than fluconazole. Moreover, despite these being chemically complex crude extracts, they did demonstrate antifungal effects and properties that concur with their ethno-biological aspect.

Effects of Far-Infrared Emitting Ceramic Materials on Recovery During 2-Week Preseason of Elite Futsal Players.

Nunes, RFH, Cidral-Filho, FJ, Flores, LJF, Nakamura, FY, Rodriguez, HFM, Bobinski, F, De Sousa, A, Petronilho, F, Danielski, LG, Martins, MM, Martins, DF, and Guglielmo, LGA. Effects of far-infrared emitting ceramic materials on recovery during 2-week preseason of elite futsal players. J Strength Cond Res 34(1): 235-248, 2020-We investigated the effects of far-infrared emitting ceramic materials (cFIR) during overnight sleep on neuromuscular, biochemical and perceptual markers in futsal players. Twenty athletes performed a 2-week preseason training program and during sleep wore bioceramic (BIO; n = 10) or placebo pants (PL; n = 10). Performance (countermovement jump [CMJ]; squat jump [SJ]; sprints 5, 10, and 15-m) and biochemical markers (tumor necrosis factor alpha-TNF-α, interleukin 10-IL-10, thiobarbituric acid-reactive species [TBARS], carbonyl, superoxide dismutase [SOD], catalase [CAT]) were obtained at baseline and after the 1st and 2nd week of training. Delayed-onset muscle soreness (DOMS) and training strain were monitored throughout. Changes in ΔCMJ and ΔSJ were possibly (60/36/4 [week-1]) and likely (76/22/2 [week-2]) higher in BIO. Both groups were faster in 5-m sprint in week 2 compared with baseline (p = 0.015), furthermore, BIO was likely faster in 10-m sprint (3/25/72 [week 1]). Significant group × time interaction in %ΔTNF-α were observed (p = 0.024 [week-1]; p = 0.021 [week-2]) with values possibly (53/44/3 [week 1]) and likely (80/19/1 [week 2]) higher in BIO. The %ΔIL-10 decreased across weeks compared with baseline (p = 0.019 [week-1]; p = 0.026 [week-2]), showing values likely higher in BIO (81/16/3 [week-1]; 80/17/3 [week-2]). Significant weekly increases in %ΔTBARS (p = 0.001 [week-1]; p = 0.011 [week-2]) and %ΔCarbonyl (p = 0.002 [week-1]; p < 0.001 [week-2]) were observed compared with baseline, showing likely (91/5/4 [week-1]) and possibly (68/30/2 [week-2]) higher changes in BIO. Significant weekly decreases in %ΔSOD were observed compared with baseline (p = 0.046 [week 1]; p = 0.011 [week-2]), and between week 2 and week 1 (p = 0.021), in addition to significant decreases in %ΔCAT compared with baseline (p = 0.070 [week 1]; p = 0.012 [week 2]). Training strain (p = 0.021; very -likely [0/2/98]; week 1) and DOMS was lower in BIO (likely; 7 sessions) with differences over time (p = 0.001). The results suggest that the daily use of cFIR clothing could facilitate recovery, especially on perceptual markers during the early phases of an intensive training period.

New roles of fluoxetine in pharmacology: Antibacterial effect and modulation of antibiotic activity.

The antimicrobial activity of psychotropic drugs, especially those of the class of mainly phenothiazines has been previously reported. Other drugs, including verapamil and trifluoperazine demonstrated to be effective against multidrug-resistant strains. Selective serotonin reuptake inhibitors (SSRIs) are antidepressant drugs that have presented significant activity against resistant bacterial resistance, but the antibacterial effect as well the antibiotic modulating properties of fluoxetine remain to be elucidated. Therefore, the present study aimed to evaluate in vitro, the antibacterial effect and the antibiotic modulating activity of fluoxetine against standard and multiresistant bacterial strains. The microorganisms used were Pseudomonas aeruginosa, Staphylococcus aureus and Escherichia coli. For the antibacterial tests, 10 mg fluoxetine hydrochloride were and diluted in 1 mL of dimethyl sulfoxide (DMSO) and then diluted in sterile distilled water to a concentration of 1024 µg/mL. To determine the Minimum Inhibitory Concentrations (MICs), the drugs were diluted to concentrations ranging from 512 to 0.5 µg/mL in 96-well microdilution plates. The evaluation of the modulatory activity of fluoxetine was performed by combining this drug with the following antibiotics: Erythromycin, Gentamicin, Imipenem, Norfloxacin and Tetracycline at subinhibitory concentrations (MIC/8). Our results demonstrated that the MIC fluoxetine were 256 and 102 µg/mL against standard and resistant strains of S. aureus, respectively. The MIC of fluoxetine against both standard and resistant strains of P. aeruginosa was 161 µg/mL and against E. coli, the MIC of fluoxetine was 102 µg/mL for both standard and resistant strains, demonstrating that this drug present significant antibacterial activity. The association of fluoxetine with gentamicin and erythromycin P. aeruginosa and E. coli presented synergistic effects, demonstrating that this drug can selectively modulate the activity of antibiotics of clinical use. In conclusion, fluoxetine presented significant antibacterial effect and potential antibiotic modulating activity against multiresistant bacteria. Therefore, additional studies are needed to characterize the antimicrobial properties of this drug, as well as the clinical implications of its use in the treatment of infections by resistant microorganisms.

In vitro tooth reattachment techniques: A systematic review.

BACKGROUND/AIMS: Fragment reattachment is a procedure that offers advantages, such as preservation of tooth structure and maintenance of color, shape, and translucency of the original tooth. The aim of this study was to analyze the reattachment techniques used to restore anterior teeth fractured by trauma. MATERIALS AND METHODS: The PubMed, LILACS, Web of Science, Cochrane, and Scopus databases were searched in October 2016, and the search was updated in February 2017. A search of the gray literature was performed in Google Scholar and OpenGrey. Reference lists of eligible studies were evaluated to identify additional studies. Two authors assessed studies for inclusion and extracted the data. In vitro studies that evaluated permanent human teeth fractured by trauma were included. RESULTS: Twenty-one studies remained after screening. The bond strength between the fragment and the crown was evaluated in 119 experimental groups. Ten different techniques were evaluated as follows: no preparation, chamfer, bevel, anchors, overcontour, internal groove, no preparation associated with chamfer after reattachment, fragment dentin removal associated with chamfer after reattachment, bevel associated with overcontour, and groove associated with shoulder. Five different materials were used to reattach the fragment: bonding system, luting composite resin, flowable composite, microhybrid composite, and nanocomposite. CONCLUSION: Fragment reattachment using a technique with no preparation and an adhesive system associated with an intermediate composite with good mechanical properties can restore part of the resistance of the fractured tooth.

Increased biomass saccharification by supplementation of a commercial enzyme cocktail with endo-arabinanase from Bacillus licheniformis.

OBJECTIVES: The use of endo-arabinanase from Bacillus licheniformis (ABNase) for sugarcane saccharification has been evaluated by enzyme immobilization and commercial cocktail supplement with the immobilized heterologous protein. RESULTS: Biochemical characterization of the purified ABNase showed that the catalytic activity was strongly inhibited by 5 mM Cu(2+), Zn(2+) or Fe(3+). The optimum pH and temperature for activity were 5.5-6.5 and 35-40 °C, respectively. The enzyme stability increased 128-fold when immobilized with glyoxyl agarose, and the hydrolysis of pretreated sugar cane biomass increased by 15 % when a commercial enzyme cocktail was supplemented with immobilized ABNase. CONCLUSION: Pectin hydrolysis by recombinant ABNase plays a role in the effective application of enzymatic cocktails for biomass saccharification.

Experimental vibration dataset collected of a beam reinforced with masses under different health conditions.

Vibration signals extracted from structures across diverse health conditions have become indispensable for monitoring structural integrity. These datasets represent a resource for real-time condition monitoring, enabling the precise detection and diagnosis of system anomalies. This paper aims to enrich the scientific community's database on structural dynamics and experimental methodologies pertinent to system modelling. Leveraging experimental measurements obtained from mass-reinforced beams, these datasets validate numerical models, refine identification techniques, quantify uncertainties, and continuously foster machine learning algorithms' evolution to monitor structural integrity. Furthermore, the beam dataset is data-driven and can be used to develop and test innovative structural health monitoring strategies, specifically identifying damages and anomalies within intricate structural frameworks. Supplemental datasets like Mass-position and damage index introduce parametric uncertainty into experimental and damage identification metrics. Thereby offering valuable insights to elevate the efficacy of monitoring and control techniques. These comprehensive tests also encapsulate paramedic uncertainty, providing robust support for applications in uncertainty quantification, stochastic modelling, and supervised and unsupervised machine learning methodologies.

Active E. coli heteromeric acetyl-CoA carboxylase forms polymorphic helical tubular filaments.

The Escherichia coli heteromeric acetyl-CoA carboxylase (ACC) has four subunits assumed to form an elusive catalytic complex and are involved in allosteric and transcriptional regulation. The E. coli ACC represents almost all ACCs from pathogenic bacteria making it a key antibiotic development target to fight growing antibiotic resistance. Furthermore, it is a model for cyanobacterial and plant plastid ACCs as biofuel engineering targets. Here we report the catalytic E. coli ACC complex surprisingly forms tubes rather than dispersed particles. The cryo-EM structure reveals key protein-protein interactions underpinning efficient catalysis and how transcriptional regulatory roles are masked during catalysis. Discovering the protein-protein interaction interfaces that facilitate catalysis, allosteric and transcriptional regulation provides new routes to engineering catalytic activity and new targets for drug discovery.

Activity of Fatty Acid Biosynthesis Initiating Ketosynthase FabH with Acetyl/Malonyl-oxa/aza(dethia)CoAs.

Fatty acid and polyketide biosynthetic enzymes exploit the reactivity of acyl- and malonyl-thioesters for catalysis. A prime example is FabH, which initiates fatty acid biosynthesis in many bacteria and plants. FabH performs an acyltransferase reaction with acetyl-CoA to generate an acetyl-S-FabH acyl-enzyme intermediate and subsequent decarboxylative Claisen-condensation with a malonyl-thioester carried by an acyl carrier protein (ACP). We envision that crystal structures of FabH with substrate analogues can provide insight into the conformational changes and enzyme/substrate interactions underpinning the distinct reactions. Here, we synthesize acetyl/malonyl-CoA analogues with esters or amides in place of the thioester and characterize their stability and behavior as Escherichia coli FabH substrates or inhibitors to inform structural studies. We also characterize the analogues with mutant FabH C112Q that mimics the acyl-enzyme intermediate allowing dissection of the decarboxylation reaction. The acetyl- and malonyl-oxa(dethia)CoA analogues undergo extremely slow hydrolysis in the presence of FabH or the C112Q mutant. Decarboxylation of malonyl-oxa(dethia)CoA by FabH or C112Q mutant was not detected. The amide analogues were completely stable to enzyme activity. In enzyme assays with acetyl-CoA and malonyl-CoA (rather than malonyl-ACP) as substrates, acetyl-oxa(dethia)CoA is surprisingly slightly activating, while acetyl-aza(dethia)CoA is a moderate inhibitor. The malonyl-oxa/aza(dethia)CoAs are inhibitors with Ki's near the Km of malonyl-CoA. For comparison, we determine the FabH catalyzed decomposition rates for acetyl/malonyl-CoA, revealing some fundamental catalytic traits of FabH, including hysteresis for malonyl-CoA decarboxylation. The stability and inhibitory properties of the substrate analogues make them promising for structure-function studies to reveal fatty acid and polyketide enzyme/substrate interactions.

Photobiological effect of eugenol-derived 3-benzoylcoumarin associated with led lights against MDR microorganisms.

The problem of antibiotic resistance by bacteria threatens human health. Therefore, studies in this area seek alternatives to circumvent it. The study with coumarins and eugenol has already proven that these classes of compounds act against bacteria. In this same aspect, exposure to LED also shows a bactericidal effect. Seeking a possible enhancement of this effect, the present work studied coumarins derived from eugenol in association with LED to investigate the bactericidal effect. Four compounds were tested. For this, minimum inhibitory concentrations (MICs) and modulation with three antibiotics against Escherichia coli and Staphylococcus aureus bacteria were determined. To test the behavior of the activity against exposure to LED, the plates were exposed for 20 min to blue light, 415 nm and then incubated at 37°C for 24 h. For control, duplicates were made, and one of them did not undergo this exposure. C1 exhibited better activity against S. aureus, as synergism prevailed under the conditions tested. C3 and C4 were promising against E. coli as they showed synergism in association with the three antibiotics both with and without LED exposure. Thus, the compounds showed bactericidal activity, and LED was shown to enhance synergism.

Non-Coding RNA in Penile Cancer.

Penile cancer (PC) still presents a health threat for developing countries, in particular Brazil. Despite this, little progress has been made on the study of markers, including molecular ones, that can aid in the correct management of the patient, especially concerning lymphadenectomy. As in other neoplasms, non-coding RNAs (ncRNAs) have been investigated for penile cancer, with emphasis on microRNAs, piRNAs (PIWI-interacting small RNAs), and long non-coding RNAs (LncRNAs). In this context, this review aims to assemble the available knowledge on non-coding RNA linked in PC, contributing to our understanding of the penile carcinogenesis process and addressing their clinical relevance. ncRNAs are part of the novel generation of biomarkers, with high potential for diagnosis and prognosis, orientating the type of treatment. Furthermore, its versatility regarding the use of paraffin samples makes it possible to carry out retrospective studies.

Silver Trimolybdate (Ag2Mo3O10.2H2O) Nanorods: Synthesis, Characterization, and Photo-Induced Antibacterial Activity under Visible-Light Irradiation.

The present study reports the synthesis, characterization, and antibacterial properties of silver trimolybdate (Ag2Mo3O10.2H2O) nanorods. The synthesis was performed using a conventional hydrothermal method. The sample was characterised by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, UV-Vis-NIR diffuse reflectance, thermogravimetric analysis (TGA), and differential scanning calorimeter (DSC). The direct antibacterial activity was evaluated using the microdilution method to determine the minimum inhibitory concentration (MIC). To assess the ability of Ag2Mo3O10.2H2O nanorods to modulate antibacterial resistance, the MIC of aminoglycosides was established in the presence of a subinhibitory concentration of this substance alone and associated with LED light exposure. The characterization of the sample indicated that the synthesis of silver trimolybdate generated nanometric crystals with rod-like morphology, without secondary phases. The treatment with Ag2Mo3O10.2H2O nanorods alone or combined with visible LED lights exhibited clinically relevant antibacterial activity against both Gram-negative and Gram-positive bacteria. This nanostructure presented a variable antibiotic-modulating action, which was not improved by visible LED light exposure. Nevertheless, LED lights showed promising antibiotic-enhancing activities in the absence of Ag2Mo3O10.2H2O nanorods. In conclusion, silver trimolybdate dihydrate nanorods have antibacterial properties that can be photocatalysed by visible-light exposure. While showing the potential use to combat antibacterial resistance, the simultaneous combination of silver trimolybdate, visible LED lights, and antibacterial drugs should be carefully analysed to avoid antagonist effects that could impair the effectiveness of antibiotic therapy.

The prediction of impacted versus spontaneously erupted mandibular third molars.

BACKGROUND: To evaluate the predictive capacity of orthodontists and oral maxillofacial surgeons (OMFSs) in anticipating the process of impaction or eruption of lower third molars (L3Ms) through the examination of serial panoramic radiographs. METHODS: Sixty-eight lower third molars (L3Ms) were analyzed in 34 orthodontically treated patients without extraction. Twenty-seven OMFSs and 27 orthodontists were randomized in order to analyze the radiographs. Initially, the evaluators issued the prognosis for the L3Ms in XR1, a posterior for the XR1 + XR2. Concordance of the diagnosis was examined using Kappa statistics, and the differences between the groups of evaluators were examined using the chi-square test at p<0.05. RESULTS: When examining XR1 in cases where the teeth erupted spontaneously, the prognostic accuracy rate for OMFSs and orthodontists was similar, 63 and 65.7%, respectively (p=0.19). When evaluating XR1 + XR2, the accuracy among orthodontists (60%) was similar to that reported for XR1 (p=0.19), while OMFSs presented a reduction in the accuracy (55.3%, p<0.0001). When the L3Ms remained impacted, accuracy in XR1 was lower than in spontaneously erupting L3Ms, although similar between OMFSs (50.1%) and orthodontists (49.1%). Furthermore, for impacted L3Ms, when examining XR1 + XR2, the OMFSs presented a significant higher accuracy (71.8%, p <0.0001). CONCLUSIONS: Orthodontists and OMFSs seem unable to predict spontaneous eruption or impaction of the lower third molars from single or longitudinal x-rays. When adding a second longitudinal x-ray, orthodontists and more significantly OMFSs tend to indicate more extractions.

Identification of a cold-adapted and metal-stimulated ß-1,4-glucanase with potential use in the extraction of bioactive compounds from plants.

Cold-adapted endo-ß-1,4-glucanases hold great potential for industrial processes requiring high activity at mild temperatures such as in food processing and extraction of bioactive compounds from plants. Here, we identified and explored the specificity, mode of action, kinetic behavior, molecular structure and biotechnological application of a novel endo-ß-1,4-glucanase (XacCel8) from the phytopathogen Xanthomonas citri subsp. citri. This enzyme belongs to an uncharacterized phylogenetic branch of the glycoside hydrolase family 8 (GH8) and specifically cleaves internal ß-1,4-linkages of cellulose and mixed-linkage ß-glucans releasing short cello-oligosaccharides ranging from cellobiose to cellohexaose. XacCel8 acts in near-neutral pHs and in a broad temperature range (10-50 °C), which are distinguishing features from conventional thermophilic ß-1,4-glucanases. Interestingly, XacCel8 was greatly stimulated by cobalt ions, which conferred higher conformational stability and boosted the enzyme turnover number. The potential application of XacCel8 was demonstrated in the caffeine extraction from guarana seeds, which improved the yield by 2.5 g/kg compared to the traditional hydroethanolic method (HEM), indicating to be an effective additive in this industrial process. Therefore, XacCel8 is a metal-stimulated and cold-adapted endo-ß-1,4-glucanase that could be applied in a diverse range of biotechnological processes under mild conditions such as caffeine extraction from guarana seeds.

Crystal structure of a novel xylose isomerase from Streptomyces sp. F-1 revealed the presence of unique features that differ from conventional classes.

BACKGROUND: Enzymatic isomerization is a promising strategy to solve the problem of xylose fermentation and, consequently, to leverage the production of advanced biofuels and biochemicals. In a previous work, our research group discovered a new strain of Streptomyces with great biotechnological potential due to its ability to produce a broad arsenal of enzymes related to lignocellulose degradation. METHODS: We applied a multidisciplinary approach involving enzyme kinetics, biophysical methods, small angle X-ray scattering and X-ray crystallography to investigate two novel xylose isomerases, XylA1F1 and XylA2F1, from this strain. RESULTS: We showed that while XylA1F1 prefers to act at lower temperatures and relatively lower pH, XylA2F1 is extremely stable at higher temperatures and presents a higher turnover number. Structural analysis revealed that XylA1F1 exhibits unique properties in the active site not observed in classical XylAs from classes I and II nor in its ortholog XylA2F1. It encompasses the natural substitutions, M86A and T93K, that create an extra room for substrate accommodation and narrow the active-site entrance, respectively. Such modifications may contribute to the functional differentiation of these enzymes. CONCLUSIONS: We have characterized two novel xylose isomerases that display distinct functional behavior and harbor unprecedented amino-acid substitutions in the catalytic interface. GENERAL SIGNIFICANCE: Our findings contribute to a better understanding of the functional and structural aspects of xylose isomerases, which might be instrumental for the valorization of the hemicellulosic fraction of vegetal biomass.

Comparative Analysis of the Effectiveness of the Topical Administration of Benzocaine and EMLA® on Oral Pain and Tactile Sensitivity.

OBJECTIVES: To compare the effectiveness of the topical administration of benzocaine and EMLA on oral pain and tactile sensitivity. MATERIALS AND METHODS: A randomized, double-blind, split-mouth clinical trial was carried out with 20 volunteers. The sensorial and quantitative tests were applied before the contact with topical anesthetic and after the application. RESULTS: In the superficial tactile perception test, when we compared each group singly, there were statistically significant values in the decrease of superficial tactile perception when compared to the moment prior to the application of anesthetic agents. For the sensitivity to mechanical pain, no statistical significant difference was observed at evaluated times. In the needle penetration test, in an intergroup analysis, we found a decrease in the pain sensitivity to needle penetration at 5 min (p=0.053) and at 10 min (p=0.019) after the contact of the anesthetic drug with the oral mucosa. CONCLUSION: The application of topical anesthetic drugs reduces the discomfort associated with this procedure, mainly until the first 10 minutes. Only the needle penetration sensitivity test showed sufficient sensitivity to reveal a difference in the anesthetic effect between EMLA and benzocaine. This trial is registered with RBR-2N2GSW.

Analysis by UPLC-MS-QTOF and antifungal activity of guava (Psidium guajava L.).

Psidium guajava L. is a plant widely used for food and in folk medicine all over the world. Studies have shown that guava leaves have antifungal properties. In this study, Flavonoid and Tannic fractions were tested to investigate their chemical composition and antifungal potential in vitro.21 compounds in the two fractions, presenting a higher content of phenolic compounds. The antifungal assays were performed against Candida albicans, Candida tropicalis and Candida krusei by microdilution to determine the IC50 and the cell viability curve. Minimal Fungicidal Concentration(MFC) and the inhibitory effects of the association of the fractions with Fluconazole, as well as the assays used to verify any morphological changes were performed in microculture chambers based on the concentrations from the microdilution. The IC50 of the isolated fractions and the fractions associated with each other were calculated, varying from 69.29 to 3444.62 µg/mL and the fractions associated with fluconazole varied from 925.56 to 1.57 µg/mL, it was clear that the association of the natural product with the antifungal presented a synergism. The fractions affected pleomorphism capacity and have a potential antifungal activity as they caused fungal inhibition in isolated use, potentiated the action of Fluconazole, reducing its concentration and impeding morphological transition, one of the virulence factors of the genus.