RESUMO
This study delves into the early development of Vieja fenestrata (Cichlidae), with a specific focus on the description of external morphological and morphometric changes, and growth patterns from hatching to the loss of larval characters under controlled laboratory conditions at a temperature of 28°C. Asynchronous hatching was observed between 58 and 60 h postfertilization, with the posterior body emerging first. Over 14 days, significant morphological, physiological, and behavioral changes were observed, revealing a complex developmental trajectory. The initial developmental phases were characterized by rapid vascularization, fin differentiation, and heightened activity, and the subsequent days witnessed the flexion of the notochord, emergence of swim bladder functionality, and transition to exogenous feeding. Maturation progressed with the absorption of the yolk sac, regression of cement glands, and fin ray development, culminating in metamorphosis by 14 days post-hatching. Throughout this period, evolving pigmentation patterns and structural adaptations highlight the species' adaptive strategies. During the larval period of V. fenestrata, substantial changes in morphological proportions were observed. Before the inflection, tail length, trunk length, and body depth had negative allometric growth, and head length, eye diameter, and snout length had positive allometric growth. After the inflection, body depth and snout length showed positive allometric growth; head length and trunk length exhibited isometric growth, whereas tail length and eye diameter demonstrated negative allometric growth. These findings contribute insights into the intricate developmental dynamics of V. fenestrata. Moreover, further research may explore these developmental dynamics' ecological and evolutionary implications.
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We report a new family of hexa-peri-hexabenzocoronene (HBC)-based helical nanographenes incorporating π-extended carbo[5]helicenes bearing an octagonal carbocycle. This family represents a new kind of highly distorted saddle-helix hybrid nanographenes. For the first time, the eight-membered ring becomes a constituent of both a carbo[5]helicene and a HBC and thus, the negative curvature is responsible for twisting both units. This novel chiral motif, namely, oct-[5]helicene results in the largest torsion angle recorded so far for a carbo[5]helicene (θ=79.5°), as it has been suggested by DFT-calculations and confirmed by X-ray crystallography. Consequently, the barriers of isomerization become exceptionally high for a [5]helicene unsubstituted in the fjord region since neither racemization nor decomposition were observed at 200 °C for 1 or 3 during 5â h. Therefore, racemic resolutions allowed subsequent chiroptical studies showing the ECD and CPL responses of this novel family of chiral nanographenes.
RESUMO
An analytical method for the analysis of relevant secoiridoid-based components in olive oil, oleacein and oleuropein aglycone, is described using for the first time deuterated surrogates. 0.2 g of sample was necessary to perform the analysis using liquid-liquid extraction and ultrasound-assisted extraction with a mixture of methanol/water (4:1, v/v). To avoid the formation of by-products, normal-phase ultra high performance liquid chromatography was chosen for the chromatographic separation. The selected mobile phase was a gradient mixture of tetrahydrofurane and hexane, and an ACE Excel 3 CN-ES column as stationary phase. The detection and quantification was performed with a SYNAPT G2-Si mass spectrometer. The calibration curves for oleacein and oleuropein aglycone were linear and quadratic, respectively. The validation was done at three levels of concentration. Relative errors from 0.1 to 10.5% and relative standard deviations lower than 9% were obtained. The method was applied to study different samples of olive oil.
Assuntos
Acetatos/análise , Aldeídos/análise , Azeite de Oliva/química , Fenóis/análise , Piranos/análise , Cromatografia Líquida de Alta Pressão , Monoterpenos Ciclopentânicos , Espectrometria de Massas , Estrutura MolecularRESUMO
The in vitro antiproliferative activities of some taiwaniaquinoids and related compounds with functionalized A, B, or C rings against human breast (MCF-7), colon (T-84), and lung (A-549) tumor cell lines were assayed. The most potent compounds, 16, 27, and 36, were more effective than the naturally occurring taiwaniaquinones A (4) and F (5) in all three cell lines. The structure-activity relationship study of these new taiwaniaquinoids highlighted the correlation between the bromo substituent and the antiproliferative activity, especially in MCF-7 cells. These findings indicate that some of the taiwaniaquinoids might be useful as cytostatic agents against breast, colon, and lung cancer cell lines.
Assuntos
Antineoplásicos/farmacologia , Terpenos/farmacologia , Antineoplásicos/química , Proliferação de Células/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Humanos , Células MCF-7 , Estrutura Molecular , Estereoisomerismo , Taiwan , Terpenos/químicaRESUMO
The first synthesis of spirolactone (+)-vitedoin B (14 steps, 8.0% global yield) and spiro enol ether (+)-negundoin A (19 steps, 3.7% global yield), via a nor-labdane acetoxy ester, has been achieved starting from commercial (+)-abietic acid.
Assuntos
Abietanos/química , Diterpenos/química , Diterpenos/síntese química , Espironolactona/análogos & derivados , Espironolactona/síntese química , Ciclização , Estrutura Molecular , Espironolactona/química , EstereoisomerismoRESUMO
A very efficient method for synthesizing spirolactones is reported. Treatment of δ,ε-unsaturated carboxylic acids with iodine and triphenylphosphine under mild conditions leads to the corresponding spiro γ-lactones in high yield and with complete stereoselectivity. Utilizing this, the first synthesis of the terpene spirolactones (-)-isoambreinolide, (+)-vitexifolin D and (+)-vitedoin B has been achieved.
Assuntos
Diterpenos/síntese química , Lactonas/síntese química , Compostos de Espiro/síntese química , Diterpenos/química , Lactonas/química , Conformação Molecular , Compostos de Espiro/química , EstereoisomerismoRESUMO
Treatment of o-allyl phenols with catalytic NIS-PPh3 affords the corresponding spirodihydrobenzofuran derivatives in high yield with high regio- and total stereoselectivity under mild conditions. These results were utilized to achieve the first total synthesis of the protein kinase C inhibitor corallidictyal D starting from α-ionone.
Assuntos
Indicadores e Reagentes/química , Fenóis/química , Fosfinas/química , Sesquiterpenos/síntese química , Compostos de Espiro/síntese química , Succinimidas/química , Conformação Molecular , Sesquiterpenos/química , Compostos de Espiro/químicaRESUMO
A new strategy for synthesizing taiwaniaquinoids, a group of terpenoids with an unusual rearranged 5(6â7) or 6-nor-5(6â7)abeo-abietane skeleton, which exhibit promising biological activities, is reported. The procedure, based on the cleavage of the C7-C8 double bond of abietane diterpenes, is the only one yet reported for synthesizing C(20) taiwaniaquinoids bearing a carbon function on the cyclopentane B ring; it is also applicable to the synthesis of the wide variety of existing taiwaniaquinoids. Utilizing this, (-)-taiwaniaquinone A, F, G, and H, (-)-taiwaniaquinol B, and (-)-dichroanone have been synthesized from (+)-abietic acid. The versatility of this strategy allows us to propose the abietane C7-C8 cleavage as a possible biosynthetic pathway to this type of rearranged diterpenes; this proposal seems to be supported by phytochemical evidence.
Assuntos
Abietanos/química , Diterpenos/química , Diterpenos/síntese química , Terpenos/química , Terpenos/síntese química , Estrutura Molecular , EstereoisomerismoRESUMO
Although certain microbial lipids are toxins, the structural features important for cytotoxicity remain unknown. Increased functional understanding is essential for developing therapeutics against toxic microbial lipids. Group B Streptococci (GBS) are bacteria associated with preterm births, stillbirths, and severe infections in neonates and adults. GBS produce a pigmented, cytotoxic lipid, known as granadaene. Despite its importance to all manifestations of GBS disease, studies towards understanding granadaene's toxic activity are hindered by its instability and insolubility in purified form. Here, we report the synthesis and screening of lipid derivatives inspired by granadaene, which reveal features central to toxin function, namely the polyene chain length. Furthermore, we show that vaccination with a non-toxic synthetic analog confers the production of antibodies that inhibit granadaene-mediated hemolysis ex vivo and diminish GBS infection in vivo. This work provides unique structural and functional insight into granadaene and a strategy to mitigate GBS infection, which will be relevant to other toxic lipids encoded by human pathogens.
Assuntos
Hemólise , Lipídeos/química , Polienos/química , Nascimento Prematuro/microbiologia , Infecções Estreptocócicas/metabolismo , Adulto , Animais , Linfócitos B , Toxinas Bacterianas/química , Vacinas Bacterianas , Linfócitos T CD4-Positivos , Modelos Animais de Doenças , Feminino , Humanos , Recém-Nascido , Lipídeos/imunologia , Lipídeos/toxicidade , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Polienos/imunologia , Gravidez , Infecções Estreptocócicas/imunologia , Infecções Estreptocócicas/microbiologia , Infecções Estreptocócicas/prevenção & controle , Streptococcus agalactiae , VacinaçãoRESUMO
In recent years, a large number of biological properties and an important role in the organoleptic characteristics of olive oil have been attributed to phenolic secoiridoids, such as oleacein, oleocanthal, oleuropein aglycone and ligstroside aglycone. Consequently, quantifying them is of great interest for the olive oil sector. Currently, there is no consensus in which analytical method must be use to accurately determine these compounds in olive oil, mainly owing to the lack of reference standards for calibration. In this work, analytical standards of phenolic secoiridoids have been used to develop a quantitative and rapid analytical method by UHPLC-MS/MS, in which sample extraction is not carried out. Simple dilutions of the sample with dry tetrahydrofuran and dry acetonitrile were performed before analysing them. It is worth noting that under these conditions the generation of artefacts such as acetals and hemiacetals of the aldehydic forms is highly reduced. The detection and quantification was performed with a Xevo TQS tandem quadrupole mass spectrometer. The method was validated at four concentration levels and finally applied to six samples of extra virgin olive oil.
Assuntos
Análise de Alimentos , Iridoides/análise , Azeite de Oliva/análise , Espectrometria de Massas em Tandem , Cromatografia Líquida de Alta PressãoRESUMO
Turning on the fluorescence of [3]cumulenes: we report the luminescence at room temperature upon aggregation of [3]cumulenes functionalized with propeller-like heptagon-containing polyphenylenes. These endgroups turn on the emission of a [3]cumulene by steric protection and restriction of their intramolecular rotations in the aggregates.
RESUMO
Immunization is an invaluable tool in preventing the morbidity and mortality associated with many infectious diseases. The CDC currently recommends that children obtain immunizations against 11 diseases. We examined immunization rates in Louisiana children aged 19-35 months from 1995-2003 and compared these rates with the rates in neighboring states and the national coverage rate. Coverage rates were affected by the number of vaccinations in a series and the year of life at which the vaccines are received. We also found discrepancies in coverage rates of immunizations that should be given simultaneously. While Louisiana coverage rates have improved after a dip in 2001, we suggest steps to help physicians further improve coverage rates.
Assuntos
Serviços de Saúde da Criança/estatística & dados numéricos , Programas de Imunização/estatística & dados numéricos , Vacinação/estatística & dados numéricos , Vacinas/administração & dosagem , Centers for Disease Control and Prevention, U.S. , Pré-Escolar , Feminino , Pesquisas sobre Atenção à Saúde , Humanos , Louisiana , Masculino , Avaliação de Programas e Projetos de Saúde , Estados UnidosRESUMO
In order to decrease the burden of disease from varicella and increase varicella vaccination rates nationally, all states were advised by the Advisory Committee on Immunization Practices of the Centers for Disease Control and Prevention in May 1999 to institute vaccination requirements or documented evidence of natural infection for all children entering elementary school and daycare facilities. Beginning September 1, 2003, Louisiana law requires varicella vaccination or a history of varicella disease prior to entry to school and daycare. In light of these new state requirements, this article discusses the epidemiology of varicella and addresses a number of concerns about the varicella vaccine. The four main issues addressed via a literature review are (1) the perception of varicella as a benign childhood disease, (2) concerns about vaccine efficacy and safety, (3) concerns about waning immunity, and (4) concerns about shifting burden of disease. The article also reviews varicella vaccination recommendations and encourages vaccination of all children in accordance with new state requirements.
Assuntos
Vacina contra Varicela/administração & dosagem , Varicela/prevenção & controle , Creches/legislação & jurisprudência , Instituições Acadêmicas/legislação & jurisprudência , Varicela/epidemiologia , Vacina contra Varicela/efeitos adversos , Criança , Pré-Escolar , Contraindicações , Humanos , Esquemas de Imunização , Louisiana/epidemiologia , Administração em Saúde Pública , Segurança , Critérios de Admissão EscolarRESUMO
An efficient and stereoselective spiroannulation of unsaturated enols is reported. Unsaturated ß-dicarbonyl compounds undergo cyclization by reaction with catalytic I2-PPh3, affording the corresponding spiro enol ether derivatives, with complete regio- and stereoselectivity, under mild conditions. Utilizing this new methodology, the first total synthesis of the anti-inflammatory diterpene negundoin A and a naturally occurring trypanocidal aldehyde is reported.
Assuntos
Diterpenos/síntese química , Iodo/química , Cetonas/química , Compostos Organofosforados/química , Compostos de Espiro/síntese química , Catálise , Ciclização , Diterpenos/química , Estrutura Molecular , Compostos de Espiro/químicaRESUMO
The first synthesis of cytotoxic (-)-taiwaniaquinone A and (-)-taiwaniaquinone F has been achieved through the intramolecular aldol condensation of a ketoaldehyde and the oxidative cleavage of an isopropylidene ketal.