Studies on the antimicrobial activity and brine shrimp toxicity of Zeyheria tuberculosa (Vell.) Bur. (Bignoniaceae) extracts and their main constituents

<p>Abstract</p> <p>Background</p> <p>Due to the indiscriminate use of antimicrobial drugs, the emergence of human pathogenic microorganisms resistant to major classes of antibiotics has been increased and has caused many clinical problems in the treatment of infectious diseases. Thus, the aim of this study was to evaluate for the first time the <it>in vitro </it>antimicrobial activity and brine shrimp lethality of extracts and isolated compounds from <it>Zeyheria tuberculosa </it>(Vell.) Bur., a species used in Brazilian folk medicine for treatment of cancer and skin diseases.</p> <p>Methods</p> <p>Using the disc diffusion method, bioautography assay and brine shrimp toxicity test (<it>Artemia salina </it>Leach), we studied the antimicrobial activity and lethality of extracts and isolated compounds against three microorganisms strains, including Gram-positive (<it>Staphylococcus aureus</it>) and Gram-negative (<it>Pseudomonas aeruginosa</it>) bacteria and yeasts (<it>Candida albicans</it>).</p> <p>Results</p> <p>In this study, the extracts inhibited <it>S. aureus </it>(8.0 ± 0.0 to 14.0 ± 0.0 mm) and <it>C. albicans </it>(15.3 ± 0.68 to 25.6 ± 0.4 mm) growth. In the brine shrimp test, only two of them showed toxic effects (LC₅₀29.55 to 398.05 μg/mL) and some extracts were non-toxic or showed weak lethality (LC₅₀705.02 to > 1000 μg/mL). From these extracts, four flavones [5,6,7,8-tetramethoxyflavone (1), 5,6,7-trimethoxyflavone (2), 4'-hydroxy-5,6,7,8-tetramethoxyflavone (3), and 4'-hydroxy-5,6,7-trimethoxyflavone (4)] were isolated through bioassay-guided fractionation and identified based on the 1D and 2D NMR spectral data. By bioautography assays, compounds 1 [<it>S. aureus </it>(16.0 ± 0.0 mm) and <it>C. albicans </it>(20.0 ± 0.0 mm)] and 3 [<it>S. aureus </it>(10.3 ± 0.6 mm) and <it>C. albicans </it>(19.7 ± 0.6 mm)] inhibited both microorganisms while 2 inhibited only <it>S. aureus </it>(11.7 ± 0.6 mm). Compound 4 did not restrain the growth of any tested microorganism.</p> <p>Conclusion</p> <p>Our results showed that extracts and isolated flavones from <it>Z. tuberculosa </it>may be particularly useful against two pathogenic microorganisms, <it>S. aureus </it>and <it>C. albicans</it>. These results may justify the popular use this species since some fractions tested had antimicrobial activity and others showed significant toxic effects on brine shrimps. However, in order to evaluate possible clinical application in therapy of infectious diseases, further studies about the safety and toxicity of isolated compounds are needed.</p

New 3‐ethynylaryl coumarin‐based dyes for dssc applications: Synthesis, spectroscopic properties, and theoretical calculations

PTDC/QUI‐QOR/7450/2020 POCI‐01‐0145‐FEDER‐016387 UIDB/50006/2020 UIDP/50006/2020 RECI/BBB‐BQB/0230/2012 RECI/BBB‐BEP/0124/2012 2020.09047.BD PD/BD/135087/2017 PD/BD/145324/2019/ (G.M.) .A set of 3‐ethynylaryl coumarin dyes with mono, bithiophenes and the fused variant, thieno [3,2‐b] thiophene, as well as an alkylated benzotriazole unit were prepared and tested for dye‐sensitized solar cells (DSSCs). For comparison purposes, the variation of the substitution pattern at the coumarin unit was analyzed with the natural product 6,7‐dihydroxycoumarin (Esculetin) as well as 5,7‐dihydroxycomarin in the case of the bithiophene dye. Crucial steps for extension of the conjugated system involved Sonogashira reaction yielding highly fluorescent molecules. Spectroscopic characterization showed that the extension of conjugation via the alkynyl bridge resulted in a strong red‐shift of absorption and emission spectra (in solution) of approximately 73–79 nm and 52–89 nm, respectively, relative to 6,7‐dimethoxy‐4‐methylcoumarin (λabs = 341 nm and λem = 410 nm). Theoretical density functional theory (DFT) calculations show that the Lowest Unoccupied Molecular Orbital (LUMO) is mostly centered in the cyanoacrylic anchor unit, corroborating the high intramolecular charge transfer (ICT) character of the electronic transition. Photovoltaic performance evaluation reveals that the thieno [3,2‐b] thiophene unit present in dye 8 leads to the best sensitizer of the set, with a conversion efficiency (η = 2.00%), best VOC (367 mV) and second best Jsc (9.28 mA∙cm−2), surpassed only by dye 9b (Jsc = 10.19 mA∙cm−2). This high photocurrent value can be attributed to increased donor ability of the 5,7‐dimethoxy unit when compared to the 6,7 equivalent (9b).publishersversionpublishe

Catechol versus carboxyl linkage impact on DSSC performance of synthetic pyranoflavylium salts

co-financed by the ERDF under the PT2020 Partnership Agreement (POCI-01-0145-FEDER - 007265). FCT/MCTES is acicnowledged for Project PTDC/QEQ-QFI/1971/2014, grants PD/BD/135087/2017 (ALP), SFRH/BD/136556/2018 (VG) and a research FCT contract (LC).Anthocyanins are the main polyphenolic dyes found in young red wines, which are transformed into more stable structures such as pyranoanthocyanins, during wine ageing and maturation. While anthocyanins practically lose their red color between pH 1 and 5, as a result of the formation of colorless hemiketals, pyranoanthocyanins practically do not change their color intensity. For that they constitute a photosensitizer family with great potential for bio-inspired dye-sensitized solar cells (DSSCs). In this work, a series of pyranoanthocyanin derivatives were designed, synthesized and applied for the first time as dye sensitizers in DSSCs. A relation was established between dye structure and cell efficiency. Specifically, the influence of different linker units, carboxyl and catechol, was studied in terms of their influence in the various parameters related to DSSC efficiency. The presence of the catechol unit was shown to be essential for efficient electron injection of the dye into the TiO2 semiconductor, since carboxylic units showed a deleterious effect in electron injection due to their electron withdrawing character. An overall efficiency of 1.15% was obtained for the best performing compound, 10-catecholpyrano-3′,4’,5,7-tetrahydroxyflavylium, with no further optimization.authorsversionpublishe

Análise da pulsatilidade da testosterona em mulheres com ciclos menstruais ovulatórios

OBJECTIVE: To evaluate the pattern of the pulsatile secretion of testosterone in normal menstrual cycle. METHODS: Eight healthy women with ovulatory menstrual cycles were enrolled. Blood samples were collected at ten-minute intervals for six hours, starting between 7 and 8 am, after a ten-hour fasting, in three phases: mid-follicular (Day 7), late follicular (Day 12) and mid-luteal phase (Day 21). Samples were assayed for testosterone, LH and the baseline also for SHBG. RESULTS: Testosterone pulse frequency, mean amplitude pulse, percentage of increment in pulse amplitude, mean duration of pulses and pulse interval were similar in the three phases. LH pulsatility was statistically different among the three phases (p < 0.001) representing normal ovulatory cycles. CONCLUSIONS: These data increase the knowledge about the testosterone secretion profile in the human menstrual cycle and can be used as a contribution to clinical investigation in both hyperandrogenism and androgen insufficiency syndrome.OBJETIVO: Avaliar o padrão pulsátil da secreção da testosterona em mulheres normais. MÉTODOS: Oito mulheres saudáveis com ciclos ovulatórios foram selecionadas. Amostras sanguíneas foram coletadas a cada dez minutos durante seis horas, começando entre 7 e 8 h da manhã, após dez horas de jejum, nas três fases do ciclo menstrual: folicular média (Dia 7), folicular tardia (Dia 12) e lútea (Dia 21). Foram mensurados: testosterona, LH e, no basal, também SHBG. RESULTADOS: A frequência dos pulsos de testosterona, média da amplitude do pulso, porcentagem do incremento da amplitude, duração e intervalos dos pulsos foram similares nas três fases (p > 0,05). A pulsatilidade do LH foi estatisticamente diferente entre as três fases (p < 0,001), caracterizando padrão característico do ciclo ovulatório normal. CONCLUSÕES: Esses dados aumentam o conhecimento sobre o padrão de secreção da testosterona no ciclo menstrual humano e representam uma contribuição para a investigação clínica, tanto no hiperandrogenismo como na síndrome de insuficiência androgênica

Leishmanicidal activity of fractions rich in aporphine alkaloids from Amazonian Unonopsis species

In vitro evaluation of alkaloidal fractions of twigs, barks and leaves from two Unonopsis species, Unonopsis guatterioides R.E. Fr. and Unonopsis duckei R.E. Fr., Annonaceae, against promastigote forms of Leishmania amazonensis revealed these species as sources of substances with promising leishmanicidal potential. All alkaloidal fractions from twigs, barks and leaves of U. guatterioides were classified as highly active, with IC50 1.07, 1.90, and 2.79 mg/mL, respectively. Only the alkaloidal fraction from the twigs of U. duckei was classified as inactive.2261368137

The optical/X-ray connection: ICM iron content and galaxy optical luminosity in 20 galaxy clusters

X-ray observations of galaxy clusters have shown that the intra-cluster gas has iron abundances of about one third of the solar value. These observations also show that part (if not all) of the intra-cluster gas metals were produced within the member galaxies. We present a systematic analysis of 20 galaxy clusters to explore the connection between the iron mass and the total luminosity of early-type and late-type galaxies, and of the brightest cluster galaxies (BCGs). From our results, the intra-cluster medium (ICM) iron mass seems to correlate better with the luminosity of the BCGs than with that of the red and blue galaxy populations. As the BCGs cannot produce alone the observed amount of iron, we suggest that ram-pressure plus tidal stripping act together to enhance, at the same time, the BCG luminosities and the iron mass in the ICM. Through the analysis of the iron yield, we have also estimated that SN Ia are responsible for more than 50% of the total iron in the ICM. This result corroborates the fact that ram-pressure contributes to the gas removal from galaxies to the inta-cluster medium, being very efficient for clusters in the temperature range 2 < kT (keV)< 10Comment: Accepted for publication in MNRAS (11 pg, 9 figures and 3 tables

Functional evaluation of sublingual microcirculation indicates successful weaning from VA-ECMO in cardiogenic shock

Background: Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) is increasingly adopted for the treatment of cardiogenic shock (CS). However, a marker of successful weaning remains largely unknown. Our hypothesis was that successful weaning is associated with sustained microcirculatory function during ECMO flow reduction. Therefore, we sought to test the usefulness of microcirculatory imaging in the same sublingual spot, using incident dark field (IDF) imaging in assessing successful weaning from VA-ECMO and compare IDF imaging with echocardiographic parameters. Methods: Weaning was performed by decreasing the VA-ECMO flow to 50% (F50) from the baseline

Dye-sensitized solar cells based on dimethylamino-π-bridge-pyranoanthocyanin dyes

UID/QUI/50006/2019 PTDC/QEQ-QFI/1971/2014 PD/BD/135087/2017 SFRH/BD/136556/2018 SFRH/BD/143309/2019 IF/00225/2015 DL57/2016 Program Contract (HC). UID/CTM/50025/2019 PTDC/CTM-ENE/5125/2014 CNPq 444061/2018-5 Universal grant 408181/2016-3The pyranoanthocyanins present in red wine display great potential as photosensitizers in bio-inspired Dye-Sensitized Solar Cells (DSSCs). Following a biomimetic approach, a series of amino-π-bridge-pyranoanthocyanin derivatives were employed as dye sensitizers in DSSCs. The dimethylamine group was selected to take advantage of its electron-donor character and the possibility of ‘dual-mode anchoring’ ([sbnd]OH vs. dimethylamino) to titanium dioxide. The increase in π-conjugation via insertion of C[dbnd]C bonds affected molecule flexibility, electron-donor ability and the pH-dependent equilibria of the pyranoanthocyanin derivatives. The current vs. potential properties of photoanodes using these dyes pointed to essential features of the relationship between power conversion efficiency and dye structure. These included the influences of the dimethylamine group, of π-conjugation and of substitution in ring B on the adsorption of the dyes to TiO2 and on the overall performance of the DSSCs prepared from them with and without added acid. An overall efficiency of 2.55% was obtained for the best performing compound, 4-(dimethylamino)-cinnamyl-pyranocyanidin-3-O-glucoside (JO3), which consolidates the importance of this family of compounds as potential dye-sensitizers for DSSC applications.authorsversionpublishe