Search

This article presents a multilingual (Portuguese, Spanish, English, and French) game-based application to the Android and the iOS platforms. The game allows undergraduate Chemical Engineering and Chemistry students to individually review organic reactions in an engaging and fun way by answering over 600 multi-choice questions. Undergraduate students tested and evaluated the game, and their opinions revealed that they liked to use the game as a complementary educational tool able to aid them in their studies. Moreover, the usability assessment of the game provided a good SUS score close to 79.

We present a bilingual hybrid board game (English and Portuguese) as an innovative educational method to aid students in understanding concepts related to organic acids and bases. The proposed game promotes interaction between students in an enjoyable activity to review and learn the content, requiring minimal supervision from the professor.

Black mold, a disease caused by the fungus Pilgeriella anacardii Arx & Müller, affects cashews (Anacardium occidentale). Some cashew clones are more resistant to the pathogen; however, little is known about the chemical profile responsible for this trait. The investigation of volatile organic compounds (VOCs) from leaves of dwarf cashew clones resistant (BRS 226 and BRS 265) and susceptible (CCP 76 and BRS 189) to the pathogen was carried out. Leaves were collected during the months of disease incidence and decline (March to July 2019, Brazil), and VOCs were analyzed by gas chromatography-mass spectrometry (GC-MS) combined with chemometric tools. The GC-MS analysis tentatively identified 96 compounds. Partial least squares discriminant analysis (PLS-DA), orthogonal partial least squares discriminant analysis (OPLS‑DA), hierarchical cluster analysis (HCA), and ROC curves analysis were useful in dividing VOCs into distinct resistance and associated chemical susceptibility groups for different clones. The VOCs in the leaves of the resistant clones were identified as alcohols and aldehydes containing six carbons: (E)-hex-2-enal, hex-3-en- 1-ol, (Z)-hex-2-en-1-ol, (E)-hex-2-en-1-ol, and hexan-1-ol. Moreover, α-pinene, pseudolimonene, α-phellandrene, β-myrcene, sylvestrene, β-cis-ocimene, methyl salicylate, myrtenol, α-copaene, γ-muurolene, germacrene D, valencene, and germacrene B were also detected in these samples and may be candidate chemical biomarkers for cashew resistance to P. anacardii.

Aldehydes and acyl hydrazines have been employed in a conjugation reaction that produces an acyl hydrazone bridge. A drawback to this linkage is hydrolysis, which prevents its broader use in a controllable manner. We have developed a new strategy for the cleavage of this group using a ruthenium(II) metal complex as a photogenerator of singlet oxygen. Isoniazid, an anti-tuberculosis prodrug, was chosen as a proof-of-concept compound; in this case it was coupled to an aldehyde-derivative trisbipyridine ruthenium(II) metal complex. Studies carried out using HPLC, MS, EPR, fluorescence and UV-vis showed that light could efficiently disrupt the acyl hydrazone linkage with the production of an isonicotinoyl radical. In addition, biological studies showed that bacterial strains and cancer cells became susceptible upon light irradiation. These results support a novel strategy of photoactivation based on a ruthenium metal complex conjugated to a pro-drug through an acyl hydrazone linkage, opening a broad range of applications.

Made available in DSpace on 2021-06-25T10:11:17Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-12-01 Spondias species are a relevant source of natural-bioactive compounds in Brazilian folk medicine, and its biological potential has not been explored. Thus, this study aimed to determine the metabolomic fingerprint of Spondias mombin and Spondias tuberosa leaves based on the use of reversed-phase liquid chromatography coupled to a high-resolution mass spectrometer (UPLC-HRMS). The analysis by UPLC-HRMS allowed the annotation of 31 metabolites. The multivariate analysis allowed us to identify the biomarkers responsible for the distinction between species. Also, we correlate the biomarkers of S. mombin and S. tuberosa as supposed responsible for the difference in the degree of cytotoxicity between them. The in silico evaluation was performed to give more consistency to the correlation between biomarkers and cytotoxicity, which were compared to commercial drugs. Therefore, this study showed that S. mombin has the potential to become an input for the pharmaceutical industry as a source of raw material that can positively impact the sectors of agricultural production. Departamento de Química Analítica e Físico-Química Universidade Federal do Ceará, Av. Humberto Monte, s/n - Pici Embrapa Agroindústria Tropical. Rua Dra. Sara Mesquita, 2270 - Pici Núcleo de Pesquisa e Desenvolvimento de Medicamentos - NPDM Universidade Federal do Ceará, Rua Coronel Nunes de Mello 1000 Empresa Paraibana de Pesquisa Extensão Rural e Regularização Fundiária - EMPAER - PB Embrapa Semiárido, Rodovia BR-428, Km 152, Zona Rural Universidade Estadual Paulista (Unesp) Instituto de Biociências Letras e Ciências Exatas (IBILCE), Câmpus São José do Rio Preto Departamento de Química Orgânica e Inorgânica Universidade Federal do Ceará, Av. Humberto Monte, s/n - Pici Embrapa Alimentos e Territórios - Maceió Universidade Estadual Paulista (Unesp) Instituto de Biociências Letras e Ciências Exatas (IBILCE), Câmpus São José do Rio Preto

Cinnamic acid and its derivatives show a remarkable variety of biological activities and are often studied in search of the development of new and highly effective drugs. This work aims to synthesize, characterize and evaluate the cytotoxic activity of esters derived from cinnamic acid. Eighteen esters were synthesized through Steglich’s esterification, of which eleven were not reported in the literature. All compounds were fully characterized by Fourier transform infrared epectroscopy (FTIR), nuclear magnetic resonance (1H and 13C NMR) and high-resolution mass spectrometry (HRMS) data. The cytotoxic activity of esters obtained was evaluated using four human tumor cell lines: SNB-19 (astrocytoma), HCT-116 (colon carcinoma, human), PC3 (prostate) and HL60 (promyelocytic leukemia) through the 3-(4,5-dimethyl-2-thiazolyl)- 2,5‑diphenyl-2H‑tetrazolium (MTT) colorimetric assay. These studies showed that the compound 3-methoxybenzyl (E)‑3‑(4‑methoxyphenyl)acrylate (12) is the most potent against HCT-116, PC3 and SBN-19 cells, with the lowest half maximal inhibitory concentration (IC50) value of 16.2 μM in the HCT-116 strain. The derivatives were obtained in good yields (76.6-95%), except for compounds 5-isopropyl-2-methylphenyl (E)-3-(3-hydroxy-4-methoxyphenyl)acrylate (17) (18.6%) and 2-isopropyl-5-methylphenyl (E)-3-(3-hydroxy-4-methoxyphenyl)acrylate (18) (15.5%).

In this work, a nanohybrid material was developed and used for the first time to the kinetic resolution of secondary alcohols as rac-indanol, rac-1-phenylethanol (rac-1), rac-1-(3-bromophenyl)-1-ethanol (rac-2) and rac-1-(3-methylphenyl)-1-ethanol (rac-3). Chiral indanol is used as a precursor intermediate for the synthesis of enantiomeric drugs, such as (+)-Indatraline, Irindalone, Indinavir, (+)-Sertraline and Rasagiline mesylate. Chiral 1-phenylethanol is used as an ophthalmic preservative, a solvatochromic dye and an inhibitor of cholesterol absorption and as a mild floral fragrance. For this purpose, the ultrasound irradiation was used to couple APTES on the superparamagnetic nanoparticles surface. Then, the system was activated with glutaraldehyde and used as a support for immobilization of lipase from Pseudomonas fluorescens. Thermal stability analysis was performed in buffer and hexane, showing an excellent stability in buffer solution at 60 °C, holding 72% of the initial activity, even after 7 h. In hexane (40 °C), the immobilized enzyme retained 100% of activity with 693 min of half-life time at 50 °C. The high thermal stability is mainly related to the covalent bonding between enzymes and support. Immobilized lipase on magnetic support proved to be a robust biocatalyst in the kinetic resolution, leading to (S)-indanol with high selectivity (e.e. > 99%, E > 200) in 1.75 h at 50 °C, being reused five times without significant loss of the activity and selectivity. The kinetic resolution of rac-1, via acetylation reaction, catalyzed by lipase from Pseudomonas fluorescens immobilized on magnetic support, led to (R)-acetate with enantiomeric excess > 99% and to the remaining (S)-alcohol with enantiomeric excess of 94%, conversion of 49% and E > 200, after 48 h of reaction at 40 °C. Under the same reactions conditions, rac-2 and rac-3 were slightly less reactive, since the corresponding (R)-acetates were obtained with conversion values of 44%, but with high enantioselectivity (enantiomeric excesses > 99% and E values > 200). These results correspond to an important step in heterogeneous catalysis due to the ability to obtain important precursors for the synthesis of enantiomerically pure chiral drugs and other bioactive substances.

Cyclic lipopeptides (CLPs) are non-ribosomal biosurfactants produced by Bacillus species that exhibit outstanding interfacial activity. The synthesis of CLPs is under genetic and environmental influence, and representatives from different families are generally co-produced, generating isoforms that differ in chemical structure and biological activities. This study to evaluate the effect of low and high NaCl concentrations on the composition and surface activity of CLPs produced by Bacillus strains TIM27, TIM49, TIM68, and ICA13 towards microbial enhanced oil recovery (MEOR). The strains were evaluated in mineral medium containing NaCl 2.7, 66, or 100 g L-1 and growth, surface tension and emulsification activity were monitored. Based on the analysis of 16S rDNA, gyrB and rpoB sequences TIM27 and TIM49 were assigned to Bacillus subtilis, TIM68 to Bacillus vallismortis, and ICA13 to Bacillus amyloliquefaciens. All strains tolerated up to 100-g L-1 NaCl, but only TIM49 and TIM68 were able to reduce surface tension at this concentration. TIM49 also showed emulsification activity at concentrations up to 66-g L-1 NaCl. ESI-MS analysis showed that the strains produced a mixture of CLPs, which presented distinct CLP profiles at low and high NaCl concentrations. High NaCl concentration favored the synthesis of surfactins and/or fengycins that correlated with the surface activities of TIM49 and TIM68, whereas low concentration favored the synthesis of iturins. Taken together, these findings suggest that the determination of CLP signatures under the expected condition of oil reservoirs can be useful in the guidance for choosing well-suited strains to MEOR.

A methodology that controls the reaction regioselectivity of a substrate with two reactive functions using a whole cell biocatalyst in a biphasic water/[(bmim)PF 6 ] medium is described. While the aqueous baker's yeast reduction of ethyl ( E/Z )−2-acetyl-3-phenylpropenoate 1a produces ethyl 2-benzyl-3-hydroxybutanoate 3a due to tandem reactions of C˭C and C˭O bond reduction, the bioreduction performed by the same microorganism in a biphasic water/[(bmim)PF 6 ] medium gives ethyl 2-benzyl-3-oxobutanoate 2a by reducing only the C˭C bond. This result is due to substrate and intermediate partitioning between water and hydrophobic IL, thereby decreasing the concentration of the substrate and intermediate species in water as well as the difference in K M values of ene-reductase and ketoreductase operating in the baker's yeast cells. The same methodology was applied to the bioreduction of the analogs of 1a to obtain the corresponding products, where only the C˭C bond was reduced.

A straightforward chemoenzymatic synthesis of (S)-Pindolol has been developed. The key step involved the enzymatic kinetic resolution of rac-2-acetoxy-1-(1H-indol-4-yloxy)-3-chloropropane with lipase from Pseudomonas fluorescens via hydrolytic process to obtain enantiomerically enriched halohydrin (2S)-1-(1H-indol-4-yloxy)-3-chloro-2-propanol (96% ee) and (2R)-2-acetoxy-1-(1H-indol-4-yloxy)-3-chloropropane (97% ee). The latter was subjected to a hydrolysis reaction catalyzed by Candida rugosa leading to (2R)-1-(1H-indol-4-yloxy)-3-chloro-2-propanol (97% ee), followed by a reaction with isopropylamine, producing (S)-Pindolol (97% ee) in quantitative yield.

( Z )-3-XCH 2 -4-(C 6 H 5 )-3-buten-2-one enones (X = SCN, N 3 , SO 2 Me, OC 6 H 5 ) were synthesized and submitted to biotransformations using whole Saccharomyces cerevisiae cells. The enone (X = SCN) produced ( R )-4-(phenyl)-3-methylbutan-2-one ( R )- 6 with 93% ee and enones (X = N 3 , SO 2 Me, OC 6 H 5 ) yielded a mixture of ( R )- 6 and the corresponding C C bond reduction products. Biotransformation with enone (X = N 3 ) mediated by Saccharomyces cerevisiae resulted in two products via two different routes: (i) the ketone ( R )-4-azido-3-benzylbutan-2-one in 28% yield and with >99% ee by C C bond reduction; (ii) ketone ( R )- 6 in 51% yield and with 95% ee via cascade reactions beginning with azido group displacement by the formal hydride from flavin mononucleotide in an S N 2′ type reaction followed by reduction of the newly formed C C bond.

Pulsed light, as a postharvest technology, is an alternative to traditional fungicides, and can be used on a wide variety of fruit and vegetables for sanitization or pathogen control. In addition to these applications, other effects also are detected in vegetal cells, including changes in metabolism and secondary metabolite production, which directly affect disease control response mechanisms. This study aimed to evaluate pulsed ultraviolet light in controlling postharvest rot, caused by Fusarium pallidoroseum in 'Spanish' melon, in natura, and its implications in disease control as a function of metabolomic variation to fungicidal or fungistatic effects. The dose of pulsed light (PL) that inhibited F. pallidoroseum growth in melons (Cucumis melo var. Spanish) was 9 KJ m-2. Ultra-performance liquid chromatography (UPLC) coupled to a quadrupole-time-of-flight (QTOF) mass analyzer identified 12 compounds based on tandem mass spectrometry (MS/MS) fragmentation patterns. Chemometric analysis by Principal Components Analysis (PCA) and Orthogonal Partial Least Squared Discriminant Analysis (OPLS-DA) and corresponding S-Plot were used to evaluate the changes in fruit metabolism. PL technology provided protection against postharvest disease in melons, directly inhibiting the growth of F. pallidoroseum through the upregulation of specific fruit biomarkers such as pipecolic acid (11), saponarin (7), and orientin (3), which acted as major markers for the defense system against pathogens. PL can thus be proposed as a postharvest technology to prevent chemical fungicides and may be applied to reduce the decay of melon quality during its export and storage.

Myracrodruon urundeuva (aroeira-do-sertão) is a species threatened with extinction due to anthropogenic exploitation. Phytochemical analysis of bark, branch and leaf extracts revealed the presence of several compounds such as flavonoids, phenols, tannins, quercetin derivatives and anacardic acids. Dereplication methodology was performed to tentatively identify 50 compounds analyzed by ultra-performance liquid chromatography coupled with an electrospray ionization quadrupole time-of-flight mass spectrometry operating in MSE mode (UPLC-QTOF-MSE). The extracts exhibited anti-tumor effect in cancer cells HCT-116 (colorectal), SF-295 (glioblastoma), HL-60 (leukemia), and RAJI (leukemia). Also, these results correlate with the principal component analysis (PCA) data that identified three distinct groups indicating, efficiently, metabolic differences between organs of M. urundeuva. Through discriminatory analysis of the orthogonal partial least squares (OPLS-DA), the variable of importance in the projection (VIP) and S-Plot, we were able to determine 30 potential biomarkers. The fingerprint of hydroethanolic extracts was correlated with the cytotoxicity assay and demonstrated a significant difference in the composition of plant extract. Made available in DSpace on 2020-01-24T18:17:42Z (GMT). No. of bitstreams: 1 MetabolomicsBasedDiscoveryofBiomarkerswith2019.pdf: 3991156 bytes, checksum: 1d6d7fbdb69123f422ac2fdeac45d5cb (MD5) Previous issue date: 2019 On-line

RESUMO Os biossurfactantes apresentam inúmeras aplicações ambientais e são produzidos por diversos microrganismos. Os provenientes da levedura Saccharomyces cerevisiae são pouco estudados para fins ambientais, sendo atóxicos. Objetivou-se o estudo da produção de biossurfactantes intra e extracelular por essa levedura, desenvolvida em meio de cultivo contendo 0,5% de extrato de levedura e 1% de peptona, além de concentrações variadas de sacarose e indutores oleosos - glicerol e óleos de soja e diesel. Os experimentos foram realizados durante 96 horas, e a produção de biossurfactantes foi avaliada diariamente, por meio da redução da tensão superficial e de estabilização de emulsões. O biossurfactante extracelular foi extraído da biomassa obtida, com posterior precipitação e caracterização química por intermédio de espectrometria de massa. As maiores produtividades de emulsificantes extracelulares foram obtidas com glicerol (0,20 UE.h-1) e óleo de soja (0,21 UE.h-1), em 48 horas de cultivo. Em ensaios posteriores, realizados com aumento da concentração de indutor, foi verificado um aumento das produtividades extracelulares para 0,45 UE.h-1 para o glicerol e 0,30 UE.h-1 para o óleo de soja. A maior redução da tensão superficial foi de 9,89%, em 72 horas, para o indutor óleo diesel. A diminuição dessa tensão, aliada ao aumento das atividades emulsificantes, é um importante indicativo da utilização do substrato hidrofóbico pelo microrganismo. O estudo comprova aumento na produção de biossurfactantes extracelulares quando realizada otimização de cultivo. Para a produção dos intracelulares, a necessidade de processo de rompimento celular aumenta os custos do bioprocesso.

Inflammation is a physiological process triggered in response to tissue damage, and involves events related to cell recruitment, cytokines release and reactive oxygen species (ROS) production. Failing to control the process duration lead to chronification and may be associated with the development of various pathologies, including autoimmune diseases and cancer. Considering the pharmacological potential of metal-based compounds, two new ruthenium complexes were synthesized: cis-[Ru(NO2)(bpy)2(5NIM)]PF6 (1) and cis-[RuCl(bpy)2(MTZ)]PF6 (2), where bpy = 2,2′-bipyridine, 5NIM = 5-nitroimidazole and MTZ = metronidazole. Both products were characterized by spectroscopic techniques, followed by Density Functional Theory (DFT) calculations in order to support experimental findings. Afterwards, their in vitro cytotoxic, antioxidant and anti-inflammatory activities were investigated. Compounds 1 and 2 presented expressive in vitro antioxidant activity, reducing lipid peroxidation and decreasing intracellular ROS levels with comparable effectiveness to the standard steroidal drug dexamethasone or α-tocopherol. These complexes showed no noticeable cytotoxicity on the tested cancer cell lines. Bactericidal assay against metronidazole-resistant Helicobacter pylori, a microorganism able to disrupt oxidative balance, unraveled compound 1 moderate activity over that strain. Besides this, it was able to inhibit interleukin-6 (IL-6) and tumor necrosis factor-α (TNF- α) production as well as interleukin-1β (IL-1β) and cyclooxygenase-2 (COX-2) expression in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages. This latter activity is remarkable, which has not been reported for other ruthenium-based complexes. Altogether, these results suggest cis-[Ru(NO2)(bpy)2(5NIM)]PF6 complex has potential pharmacological application as an anti-inflammatory agent that deserve further biological investigation.

Metal-based compounds have emerged as a novel strategy to improve our arsenal of medicines. Among these compounds, carbon monoxide donor agents have been developed mainly as metal complexes. These compounds have shown exciting biological activities, among them strong anti-inflammatory, antibiotic, and anticancer activity, although some of those properties might be associated with the metal moiety as well. Aiming to prepare a new ruthenium complex containing CO, we prepared a cis-[RuCl(CO)(dppb)(dppz)]PF6 complex (dppb = 1,4-bis(diphenylphosphino)butane and dppz = dipyrido[3,2-a:2′,3′-c]phenazine), which was fully characterized along with DFT studies. This compound exhibited great thermal stability in phosphate buffer solution, but showed fast and efficient release of CO upon light irradiation, including blue LED. Surprisingly, DNA binding was quite weak, despite the dppz ligand moiety, suggesting that steric effects prevented intercalation binding. Nonetheless, this compound exhibited promising antibiotic activity against S. aureus, S. epidermidis and C. albicans in a low micromolar range. However, there was no further improvement upon light irradiation suggesting that there is no role of CO. Additionally, cytotoxicity assay using cancer cells showed quite low IC50 (92 nM, HCT-116) along with moderate to low toxicity assayed in lymphocytes and Artemia. Altogether, these results supported that this compound has great potential as a biological agent, whereas neither CO release nor DNA binding seemed to have a direct role in its activity.

In this study, we investigated the ability of matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) to characterize the lipid contents of canine spermatozoa. For that, samples of pure semen were analysed. Indeed, quite comprehensive lipid coverage was observed, and the most abundant phospholipid ions detected were from four phosphatidylcholines, that is those of m/z 760.6; 782.6; 808.6; and 830.6 and one of m/z 725.6 from a sphingomyelin. In conclusion, MALDI-MS was found to offer an easy, fast, accurate, and sensitive analytical method for lipid profiling in canine spermatozoa and could be used as a tool to select sires by assessing the relationship between sperm lipid profiles and variables such as age and breeding history as well as to study the effects of cryopreservation on lipid contents.

In this work, we have studied the effect of Crotalus basiliscus snake venom on the redox reaction of myoglobin (Mb), and by means of electrochemical techniques, we have shown that this reaction is undoubtedly affected following the interaction with the venom. Surface plasmon resonance, electrophoresis, UV–Vis, and circular dichroism showed that the interaction involves the attachment of some constituent of the venom to the protein, although not affecting its first and secondary structures. Mass spectra support this suggestion by showing the appearance of signals assigned to the Mb dimer and to a new species resulting from the interaction between Mb and the venom proteins. In addition, the mass spectra suggest the aromatic amino acids of myoglobin, mainly tryptophan and phenylalanine, are more exposed to the solvent medium upon the exposure to the venom solution. The results altogether indicate that the harmful effects of the venom of Crotalus basiliscus snake are likely connected to the blocking of the redox site of Mb.

Cyclic lipopeptides (CLPs) are non-ribosomal biosurfactants produced by Bacillus species that exhibit outstanding interfacial activity. The synthesis of CLPs is under genetic and environmental influence, and representatives from different families are generally co-produced, generating isoforms that differ in chemical structure and biological activities. This study to evaluate the effect of low and high NaCl concentrations on the composition and surface activity of CLPs produced by Bacillus strains TIM27, TIM49, TIM68, and ICA13 towards microbial enhanced oil recovery (MEOR). The strains were evaluated in mineral medium containing NaCl 2.7, 66, or 100 g L

Nitric oxide has been involved in many key biological processes such as vasodilation, platelet aggregation, apoptosis, memory function, and this has drawn attention to the development of exogenous NO donors. Metallonitrosyl complexes are an important class of these compounds. Here, two new ruthenium nitrosyl complexes containing a thiocarbonyl ligand, with the formula cis-[Ru(phen)2(L)(NO)](PF6)3 (phen = phenantroline, L = thiourea or thiobenzamide), were synthesized and characterized by electronic spectroscopy, FTIR, NMR, mass spectrometry and voltammetric techniques. Theoretical calculations using Density Functional Theory (DFT) and Time-dependent Density Functional Theory (TD-DFT) were also used and further supported the characterizations of these complexes. An efficient release of nitric oxide by blue light was validated using a NO/HNO probe: 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide, known as cPTIO. Interestingly, the complex containing thiourea cleaved DNA even in the dark, while both complexes showed great DNA photocleavage activity in blue light. This process might work mainly through NO and hydroxyl radical production. Additionally, these complexes showed promising vasodilator activity, whose mechanism of action was investigated using N-Nitro- l -arginine methyl ester hydrochloride (L-NAME) and 1H-[1,2,4]Oxadiazolo[4,3-a]quinoxalin-1-one (ODQ) and compared to sodium nitroprusside. Both compounds were indeed NO-mediated heme-dependent activators of soluble guanylate cyclase. Additionally, they did not show any significant cytotoxicity against cancer cell lines U87 and GBM02. Altogether, these results supported both complexes having potential pharmacological applications that deserve further studies.

Made available in DSpace on 2018-12-11T17:16:35Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-03-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) The membrane of spermatozoa, which contributes to cellular cryoresistance, contains numerous lipids with a composition that directly affects membrane fluidity and the fertilization process. In light of variations in the degree of sensitivity in equine seminal freezing, this study aimed to correlate equine semen lipids with post-thawing characteristics of spermatozoa. We used ejaculates from 34 stallions, which were evaluated (total motility ≥ 60%), frozen and thawed and reevaluated for motility of spermatozoa, membrane integrity and lipid peroxidation. Lipid extraction of the fresh semen samples was performed by liquid-liquid extraction, and fingerprinting lipid analysis was conducted by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). Based on the characteristics of spermatozoa after thawing, the animals could be separated into two groups: resistant (Good Freezers, n = 5) and sensitive (Bad Freezers, n = 6) to freezing, and their MALDI-MS data were then compared. The Good Freezers group showed a higher abundance of phosphatidylcholines (m/z 796.6, 846.6, 810.6, 854.6 and 732.6). The ions of m/z 812.6, 832.6, 836.6 and 838.6 belonging to the phosphatidylcholine lipid class were also positively correlated with motility of spermatozoa, whereas that of m/z 794.6 was negatively correlated with lipid peroxidation in thawed semen. The Bad Freezer group, displayed higher abundance of one phosphatidylcholines (m/z 806.6), as well as a sphingomyelins (m/z 703.5), which were negatively correlated (univariate analysis) with kinetics of spermatozoa after thawing (m/z 703.5) and with membrane integrity (m/z 792.6). The ion of m/z 717.5, assigned to phosphatidic acid, was negatively correlated with lipid peroxidation. In general therefore, the phosphatidylcholines are associated with higher quality of spermatozoa after thawing, especially in functional capacity, and that lipid semen composition was found to influence the resistance of spermatozoa to cryopreservation and may interfere with motility, membrane integrity and lipid peroxidation in stallions. Department of Animal Reproduction and Veterinary Radiology Faculty of Veterinary Medicine FMVZ São Paulo State University (UNESP) ThoMSon Mass Spectrometry Laboratory Institute of Chemistry University of Campinas (UNICAMP) Institute of Chemistry Federal University of Uberlândia (UFU) Department of Animal Reproduction and Veterinary Radiology Faculty of Veterinary Medicine FMVZ São Paulo State University (UNESP) FAPESP: 13/12.838-9

Benzoxazines are a modern class of monomers which have aroused great interest in the scientific and industrial scenarios due to their remarkable properties. Nevertheless, few is known about the influence of position 2 of the oxazine ring upon its polymerization. Here, we report for the first time, the introduction of natural-occurring aldehydes (valeraldehyde and benzaldehyde) in the oxazine ring of bio-based benzoxazines. The chemical structures of the monomers were confirmed by different spectroscopic techniques and their thermal stabilities were evaluated by thermogravimetric analysis (TGA). The influence of the chemical nature of the substituents on the polymerization behavior was investigated by differential scanning calorimetry (DSC), applying Kissinger, Flynn-Wall-Ozawa and Crane methods to determine the Arrhenius parameters of the studied systems. Results presented that 2-substituted benzoxazines have lower activation energy values and polymerization temperatures compared to the corresponding unsubstituted benzoxazine, reinforcing the potential of this class of compounds in developing tailor-made polymers due to its structural versatility.

Enones (Z)-3-methyl-(Z)-3-chloromethyl- and (Z)-3-bromomethyl-4-R-3-buten-2-one (R = n-pentyl, phenyl, 2′- and 4′-chlorophenyl, 3′- and 4′-nitrophenyl, 4′-methoxyphenyl) were synthesized and subjected to reduction by the microorganisms Saccharomyces cerevisiae andGeotrichum candidum. Whereas the bioreduction of 3-methy-4-R-3-buten-2-ones afforded the corresponding (S)-4-R-3-methybutan-2-ones, the bioreduction of 3-chloromethyl- and 3-bromomethyl-4-R-3-buten-2-ones afforded the corresponding (R)-4-R-3-methybutan-2-ones.

The fatty acid composition of the sperm membrane is an important factor involved in the overall sperm quality, including motility. However, in the canine species, the exact composition of the plasma membrane is still unknown. Therefore, the purpose of this study was to evaluate the plasma membrane lipid composition of motile sperm cells and to compare it with asthenospermic samples, as an attempt to determine possible involvements of membrane lipids in dog sperm cell motility. The sperm-rich fraction of ten mature dogs was collected, and samples were subjected to density gradient centrifugation by Percoll® , in order to separate motile and asthenospermic samples. Processed semen samples were evaluated for sperm motility, plasma and acrosome membrane integrity, mitochondrial activity and susceptibility to oxidative stress. Lipid plasma membrane composition was identified by mass spectrometry (MALDI-MS). The motile sperm samples presented the following phospholipids in a high frequency in the plasma membrane: phosphatidylcholine 38:4 (composed of stearic and arachidonic fatty acids), phosphatidylcholine 36:1 (stearic and oleic fatty acids), phosphatidylethanolamine 34:4 (myristic and arachidonic fatty acids), glycerophosphatidic acid 36:4 (palmitic and arachidonic fatty acids), phosphatidylcholine 40:4 plasmanyl and phosphatidylcholine 40:5 plasmenyl. Furthermore, no lipid markers were found in the asthenospermic samples. Results also indicate that differences on plasma membrane composition between motile and asthenospermic samples are crucial factors for determining sperm motility, sperm functionality and susceptibility to oxidative stress. In conclusion, plasma membrane lipid composition varies considerable between motile and asthenospermic samples. Therefore, lipid markers of sperm motility can be considered, such as phosphatidylcholine, phosphatidylethanolamine, phosphatidylcholine plasmanyl, phosphatidylcholine plasmenyl and phosphatidic acid.

Reductions of ( Z )-C 6 H 5 CH CXC( O)CH 3 (X = Cl, Br) mediated by Saccharomyces cerevisiae , Candida albicans , Rhodotorula glutinis , Geotrichum candidum and Micrococcus luteus gave the corresponding halohydrins through consecutive reduction reactions of C C and C O bonds. In general, the reactions performed in the biphasic system water/[(bmim)PF 6 ] gave better diastereoselectivity and enantioselectivity than in pure water.

Reductions of (Z)-C6H5CH CXC( O)CH3 (X = Cl, Br) mediated by Pichia stipitis gave 4-phenylbutan-2-one through dehalogenation of intermediaries 3-halo-4-phenylbutan-2-one by an electron transfer mechanism. The addition of 1,3-dinitrobenzene avoids the dehalogenation and thus the corresponding (2S,3S)-halohydrins were obtained in excellent enantiomeric excesses by a hydride transfer mechanism. Irganox® 1010 and 1076 were also used to inhibit the electron transfer mechanism. The obtained halohydrins are important chiral building blocks to obtain optically active epoxides and aminoalcohols.

The enantioselective oxidation of (1R,2S)-1-phenyl-1,2-propanediol [(1R,2S)-1], mediated by baker’s yeast, gave (−)-(S)-1-phenyl-2-hydroxy-1-propanone [(S)-2] in 64 % isolated yield and 93 % ee. Kinetic experiments of the bio-oxidation of (±)-anti-1 revealed that the enantiomer (1R,2S)-1 was more reactive than (1S,2R)-1. Therefore, this result allowed us to devise a kinetic resolution experiment to obtain (1S,2R)-1 in >99 % ee from (±)-anti-1. The preparation of (1S,2R)-1 is interesting, as it is the antipode of the product obtained by the reduction of 1-phenyl-1,2-propanedione using baker’s yeast. Other microorganisms, such as Micrococcus luteus, Candida albicans, and Geotrichum candidum, were also used for kinetic resolution experiments of (±)-anti-1. The best result was obtained using Geotrichum candidum, which gave (1S,2R)-1 in 32 % yield and 99 % ee.

SummaryThe nests of social insects provide suitable microenvironments for many microorganisms as they offer stable environmental conditions and a rich source of food [1–4]. Microorganisms in turn may provide several benefits to their hosts, such as nutrients and protection against pathogens [1, 4–6]. Several examples of symbiosis between social insects and microorganisms have been found in ants and termites. These symbioses have driven the evolution of complex behaviors and nest structures associated with the culturing of the symbiotic microorganisms [5, 7, 8]. However, while much is known about these relationships in many species of ants and termites, symbiotic relationships between microorganisms and social bees have been poorly explored [3, 4, 9, 10]. Here, we report the first case of an obligatory relationship between the Brazilian stingless bee Scaptotrigona depilis and a fungus of the genus Monascus (Ascomycotina). Fungal mycelia growing on the provisioned food inside the brood cell are eaten by the larva. Larvae reared in vitro on sterilized larval food supplemented with fungal mycelia had a much higher survival rate (76%) compared to larvae reared under identical conditions but without fungal mycelia (8% survival). The fungus was found to originate from the material from which the brood cells are made. Since the bees recycle and transport this material between nests, fungus would be transferred to newly built cells and also to newly founded nests. This is the first report of a fungus cultivation mutualism in a social bee.

The enantioselective reduction of α-methylene nitrile derivatives catalysed by ene-reductases affords the corresponding (R)-2-arylpropanenitriles with high conversion values. The reaction is investigated either in aqueous medium (with an organic cosolvent or by loading the substrate onto hydrophobic resins) or in a biphasic ionic liquid–water system. The use of ionic liquids, herein with isolated ene-reductases, is found to improve the work-up and the substrate recovery method. The synthetic manipulation of the final chiral nitrile derivatives indicates how this biocatalysed method can be exploited for the preparation of a wide range of chiral compounds.

The OYE1-3-mediated reductions of some ?,?-difunctionalised alkenes, showing on the double bond a nitrile and ester group, are submitted to a careful stereochemical analysis, in order to identify which of the two electron-withdrawing groups (EWGs) is responsible for the activation of the CC double bond towards reduction and for establishing hydrogen bond interactions within the binding pocket of the enzymes. The results show that for most of these substrates the activating EWG is the CN moiety linked to the prostereogenic olefinic carbon atom. The final stereochemical outcome can be explained through the empirical model which has been recently developed for difunctionalised alkenes activated by carbonyl/carboxyl containing EWGs. In a single case the activation is due to the COOR group linked to the less substituted olefinic carbon atom: an alternative empirical model is established for this kind of substrates, taking into consideration the OYE-catalysed reductions of ?,??-disubstituted-?-monofunctionalised alkenes. © 2014 Elsevier B.V.

Benzoquinones are usually present in arthropod defence exudates. Here, we describe the chemical profiles of 12 harvestman species belonging to the neotropical family Gonyleptidae. Nine of the studied species produced benzoquinones, while three produced alkyl phenols. Two benzoquinones and one phenol exhibited biological activity against bacteria and fungi. We also studied the biosynthesis of 2-ethyl-1,4-benzoquinone by feeding Magnispina neptunus individuals with 13C-labelled precursors; the benzoquinones were biosynthesised through a polyketide pathway using acetate and propionate building blocks.

The Knoevenagel condensation is an important C=C bond formation in organic synthesis. Among possible solvents, refluxing benzene or toluene are common choices, 1 and removal of water from the reaction medium is typically done by means of a Dean-Stark trap. To avoid the use of hazardous organic solvents and relatively high temperatures, we were interested in the use of ionic liquids as potential solvents for this condensation. In the course of our studies towards the synthesis of chiral halogenated β-hydroxyesters, we were particularly interested in the reaction between ethyl 4-chloroacetoacetate and different aromatic aldehydes to produce the corresponding 2chloroacetyl-3-arylpropenoates.

The synthesis of optically active compounds is a highly challenging task for organic chemists, especially if targeted final products possess remarkable applications for the fine chemical industrial sector. 1 It has been extensively demonstrated along recent years that Biocatalysis offers ecological, economic, scalable and straightforward methods for the production of fine chemical with high enantiomeric excess. For all of that, we have focused our attention in the production of chiral fragrances. 1

Commercial cattle breeders produce their own herd offspring for the dairy and beef market using artificial insemination. The procedure involves sanitary risks associated with the collection and commercialization of the germplasm, and the in vitro production and transfer of the bovine embryos must be monitored by strict health surveillance. To avoid the spreading of infectious diseases, one must rely on using controlled and monitored germplasm, media, and reagents that are guaranteed free of pathogens. In this article, we investigated the use of a new mass spectrometric approach for fast and accurate identification of bacteria and fungi in bovine semen and in culture media employed in the embryo in vitro production process. The microorganisms isolated from samples obtained in a commercial bovine embryo IVP setting were identified in a few minutes by their conserved peptide/protein profile, obtained applying matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS), matched against a commercial database. The successful microorganisms MS identification has been confirmed by DNA amplification and sequencing. Therefore, the MS technique seems to offer a powerful tool for rapid and accurate microorganism identification in semen and culture media samples.

In this work we report the use of lanthanide nitrates [Ln(NO3)3] acting as catalyst in direct one-pot synthesis of 3-benzoyl- and 3-acetyl-1,2,4-oxadiazoles derivatives from ketones, nitriles and nitric acid. This is the first example of one-pot synthesis of benzoyl- and acetyl 1,2,4-oxadiazoles derivatives preparation using acetophenones derivates with electron-donator groups. Neste trabalho relatamos o uso de nitratos de lantanídeos [Ln(NO3)3] atuando como catalisador na síntese de uma única etapa de derivados de 3-benzoíla- e 3-acetila-1,2,4-oxadiazóis a partir de cetonas, nitrilas e ácido nítrico. Este é o primeiro exemplo da síntese em única etapa de preparação de derivados benzoíla e acetila-1,2,4-oxadiazóis, usando acetofenonas com grupos doadores de elétrons.

Knoevenagel condensations of aromatic aldehydes with ethyl 4-chloro-3-oxobutanoate catalyzed by morpholine/acetic acid were carried out in ionic liquids to give ethyl 2-chloroacetyl-3-arylpropenoates in 44-84% yield after 0.5 to 2 h at room temperature (25-28 ºC). These conditions represent a greener protocol for the Knoevenagel condensation than those using refluxing benzene or toluene as solvent. Aromatic aldehydes having aryl groups 4-chlorophenyl, 4-methoxyphenyl, 2-thiofuranyl, 2-furanyl, phenyl and 3,4-methylenedioxyphenyl gave (E)/(Z) diastereomeric ratios of products from 56/44 to 85/15. The two isomers of each compound were separately isolated and characterized. The structure of the (E)-isomer of ethyl 2-chloroacetyl-3-(3',4' methylenedioxyphenyl)propenoate was determined by X-ray crystallography and an unequivocal methodology of (E)/(Z)-structural analysis by 13C NMR (nuclear magnetic resonance) is presented. Condensações de Knoevenagel de aldeídos aromáticos com 4-cloro-3-oxobutanoato de etila catalisadas por morfolina/ácido acético foram conduzidas em líquidos iônicos para fornecerem 2-cloroacetil-3-arilpropenoatos de etila em 44 a 84% de rendimentos após 0,5 a 2 h à temperatura ambiente (25-28 ºC). Estas condições representam um protocolo mais verde para a condensação de Knoevenagel do que aquelas realizadas com refluxo de benzeno e tolueno, utilizados como solventes. Aldeídos aromáticos contendo grupos arila, 4-clorofenila, 4-metoxifenila, 2-tiofuranila, 2-furanila, fenila e 3,4-metilenodioxifenila apresentaram razões diastereoméricas (E)/(Z) de 56/44 a 85/15. A estrutura do isômero-(E) do 2-cloroacetil-3-(3',4'-metilenodioxifenil)propenoato de etila foi determinada por difração de raio X, e uma metodologia inequívoca da análise estrutural-(E)/(Z) por RMN de 13C (ressonância magnética nuclear) é apresentada.

Frozen bovine semen used in the IVF process can be a potential source of microorganisms that can prevent or disturb embryo development and cause issues with the sanitary certification for bovine embryo commercialization and export. Therefore, the aim of this work is to introduce a novel tool for the fast identification of the pathogens on the frozen semen based on the mass spectra of their ribosomal proteins analysed by matrix-assisted desorption/ionization-mass spectrometry (MALDI-MS). Thirty bovine semen samples, which were aliquots of commercial sealed straws used daily in the commercial IVF routine at In vitro Brasil Ltd. (Mogi Mirim, SP, Brazil), were used for this work. Fifty microlitres of semen were incubated in 10 mL of brain heart infusion broth (BHI) for 24 h at 37°C. If turbidity was observed, the bacterial cultures were submitted to bacterial extraction and mass spectrometric analysis according to Barreiro et al. (2010). The mass spectra were obtained using an AUTOFLEX MALDI TOF/TOF and were analysed with the database library MALDI Biotyper 3.0 software (Bruker Daltonik, Germany) at default settings. For each sample, the result was given by means of a log score with a maximum value of 3.0. In this study, only scores higher than 2.0 were considered, which provide confident species identification. The bacteria identified were Citrobacter freundii (2 samples), Stenotrophomonas maltophilia (4 samples), Enterobacter cloacae (6 samples) complex, Candida parapsilosis (2 samples), and Enterococcus mundtii (2 samples). Note that all the identified bacteria consistently match with the most common contaminants reported in literature for bovine frozen semen (Bielanskia et al. 2003). The capability of the technique to identify the bacteria without the ribosomal extraction (i.e. of bacteria pellets diluted in water and acetonitrile) was successful for the pellet of S. maltophilia, C. freundii, and E. cloacae complex with scores higher than 2.3, indicating a very high probability of the identification of the bacterial genus and the species. This can be explained by considering the capability of the mass spectrometric matrix to lyse the membrane of the bacteria and directly extract and then ionize the ribosomal proteins. In order to exclude the presence of a mixing of bacteria in the pellet, the colonies were properly isolated. The results matched with the ones obtained before the isolation. In order to confirm the MALDI-MS identification, the isolated bacteria from the bovine semen were also submitted to sequencing of region 16SrRNA. In conclusion, MALDI-MS technique was successfully applied for the identification of pathogens in the bovine semen. Experiments to evaluate the presence of microorganisms in media used for in vitro maturation, IVF, and in vitro culture of the bovine oocytes and embryos using this strategy are underway. This robust and fast approach is able to detect early contamination and allows prevention of economic losses and sanitary excellence in the bovine IVF process.