A simple and rapid spectrophotometric method for the determination of trans-chalcone in raw-materialand topical formulation / Método espectrofotométrico simples e rápido paradeterminação de trans-chalcona em matéria-primae em formulação tópica

Trans-chalcone (TC) is a flavonoid precursor characterized by a wide spectrum of action, with anti-inflammatory and antioxidant effects. However, no validated methods are available in official compendia for the analysis of this substance. Thus, the aim of this work was to develop and validate a simple, fast, and reproducible spectrophotometric method for the analysis of TC in raw material, and in topical pharmaceutical formulation containing TC. The established conditions were: methanol as extracting solvent, and detection wavelength of 309 nm by UV spectrophotometer. All tests followed the rules of Resolution RDC 166, 2017. The proposed method was selective. Linearity was demonstrated in the concentration range of 1 to 8 µg/mL (r = 0.999). Repeatability and intermediate precision were confirmed by low relative standard deviation values of 1.53% and 2.70% for TC, and of 1.73% and 2.91% for formulation containing TC. Accuracy, evaluated through recovery test, was adequate, with minimum of 98.24% and maximum of 100.23% of recovery. It was observed that the small deliberate modifications done did not interfere with the results, demonstrating the method is robust. The results showed that the method was considered suitable for the intended purpose, inexpensive, easy to apply, selective, linear, precise, accurate, and robust for the determination TC, and pharmaceutical formulation containing TC. Thus, the method developed satisfies the need for an analytical method for the determination of TC, and topical formulation containing TC, being effective, innovative and able to aid in the development of the pharmaceutical field.

Trans-chalcona (TC) é um precursor de flavonoides caracterizado por um amplo espectro de ação, como efeitos anti-inflamatórios e antioxidantes. No entanto, não há método validado disponível em compêndio oficial para análise deste composto. Então, o objetivo deste trabalho foi desenvolver e validar um método espectrofotométrico, simples, rápido e reprodutível para análise de TC em matéria-prima, e em formulação farmacêutica tópica contendo TC. As condições estabelecidas foram: metanol como o solvente de extração, e detecção no comprimento de onda de 309 nm por espectrofotometria no UV. Todos os testes seguiram as normas da RDC 166, 2017. O método proposto foi seletivo. A linearidade foi demonstrada na faixa de concentração de 1 a 8 µg/mL (r = 0.999). A repetibilidade e a precisão intermediária foram confirmadas pelos valores baixos de desvio padrão relativo de 1,53% e 2,70% para a TC, e de 1,73% e 2,91% para a formulação contendo TC. A exatidão, avaliada por meio de testes de recuperação, foi adequada, com mínimo de 98,24% e máximo de 100,04% de recuperação. Observou-se que pequenas modificações no método não interferiram nos resultados, demonstrando que o método é robusto. Os resultados demonstraram que o método foi adequado para a finalidade pretendida, barato, de fácil aplicação, seletivo, linear, preciso, exato e robusto para determinação de TC, e de formulação contendo TC. Então o método desenvolvido satisfaz as necessidades de um método analítico para determinação de TC, e de formulação tópica contendo TC, e é eficaz, inovador e pode contribuir para o desenvolvimento da área farmacêutica.

Evaluación de la toxicidad de chalconas sintéticas con potencial anti-Leishmania en ratones BALB/c / Toxicity assessment of synthetic chalcones with antileishmanial potential in BALB/c mice

RESUMEN Objetivo: Evaluar la toxicidad de tres chalconas sintéticas administradas por vía intraperitoneal en ratones BALB/c. Materiales y métodos: La dosis letal media (DL50) se estimó por el método Up-and-Down de Dixon. La toxicidad subcrónica de las chalconas se evaluó a 20 y 40 mg/kg por 21 días. Se evaluó el efecto tóxico a nivel de comportamiento, fisiológico, bioquímico e histológico. Resultados: La chalcona 43 generó moco en las heces, daño visceral (hígado) y alteración en el coeficiente de órganos (riñón, p = 0,037 y cerebro, p = 0,008) en comparación con el grupo control. Además, en el análisis histológico se observó que esta chalcona produjo edema, inflamación y necrosis en los órganos evaluados, aunque no hubo diferencia significativa con el control. Todos los parámetros bioquímicos no difirieron significativamente entre los grupos de tratamiento a dosis de 40 mg/kg y el control. Conclusiones: La DL50 para las tres chalconas fue superior a 550 mg/kg de peso corporal. Las chalconas 40 y 42 son relativamente no tóxicas. Ambas pueden considerarse seguras para la aplicación vía intraperitoneal en ratones BALB/c y, en consecuencia, son posibles candidatas para ser usadas en el tratamiento contra las leishmaniosis.

ABSTRACT Objective: To evaluate the toxicity of three synthetic chalcones administered intraperitoneally to BALB/c mice. Materials and methods: The median lethal dose (LD50) was estimated by Dixon's Up-and-Down method. Subchronic toxicity of chalcones was evaluated at 20 and 40 mg/kg for 21 days. Behavioral, physiological, biochemical, and histological toxic effects were evaluated. Results: Chalcone 43 produced mucus in feces, visceral damage (liver) and alterations in organ coefficient (kidney, p = 0.037 and brain, p = 0.008) when compared to the control group. In addition, histological analysis showed that this chalcone produced edema, inflammation and necrosis in the evaluated organs, although there was no significant difference with the control. None of the biochemical parameters differed significantly between the treatment groups at 40 mg/kg dose and the control. Conclusions: The LD50 for all three chalcones was greater than 550 mg/kg of body weight. Chalcones 40 and 42 were found to be relatively non-toxic. Both can be considered safe for intraperitoneal application in BALB/c mice and, consequently, are potential candidates for use in the treatment of leishmaniasis.

Evaluation of direct pulp capping with a synthetic chalcone: a preliminary histological study / Evaluación del recubrimiento pulpar directo con una chalcona sintética: estudio histológico preliminar

The aim of this study is to evaluate the action of the synthetic chalcone 1-phenyl-3-(4-chlorophenyl)-2-propen-1-one to induce pulp healing in rats. Material and Methods: Sixty lower first molars of male Wistar rats were divided into 3 groups (n=20): control (no treatment); calcium hydroxide and chalcone. After relative isolation, the cavities were prepared using a sterile low-speed » round dental bur. After controlling the hemorrhaging, all the pulp exposures were capped with the capping material, by groups. The cavities were sealed with glass ionomer cement and the repair process was assessed at 21 days of procedure. The data were statistically analyzed using the Fisher exact test (p<0.05). Results: Moderate inflammation was observed in all the experimental groups and significant (p<0.05) reparative dentin (tertiary) formation in the calcium hydroxide and chalcone groups. The chalcone group showed dentinal tubules and a low number of cellular inclusions (p<0.05). Conclusion: The chalcone used in this study indicates potential as an inducer of reparative dentine (tertiary) in a rat model...

El objetivo de este estudio es evaluar la acción de la chalcona sintética 1-fenil-3- (4-clorofenil) -2-propen-1-ona para inducir la reparación de la pulpa dentaria en ratas. Materiales y métodos: Sesenta primeros molares inferiores de ratas Wistar machos se dividieron en 3 grupos (n = 20): control (sin tratamiento); hidróxido de calcio y chalcona. Después del aislamiento relativo, las cavidades se prepararon usando una fresa dental redonda de » estéril a baja velocidad. Después de controlar la hemorragia, todas las exposiciones pulpares se taparon con el material de recubrimiento de acuerdo con los grupos del experimiento. Las cavidades fueron selladas con cemento de ionómero de vidrio y el proceso de reparación se evaluó a los 21 días del procedimiento. Los datos fueron analizados estadísticamente mediante la prueba exacta de Fisher (p<0,05). Resultados: Se observó inflamación moderada en todos los grupos experimentales y significativa (p <0,05) formación de dentina reparadora (terciaria) en los grupos de hidróxido de cálcio y chalcona. El grupo de chalcona mostró túbulos dentinarios y un bajo número de inclusiones celulares (p <0,05). Conclusión: La chalcona utilizada en este estudio indica potencial como un inductor de la dentina reparadora (terciaria) en ratas...

Ação de chalconas contra a formação de biofilme de Candida albicans / Action of chalcones against biofilm formation of Candida albicans

Candida albicans é uma levedura oportunista que apresenta um conjunto de fatores de virulência que conferem uma maior patogenicidade a estes micro- organismos. Neste trabalho foram estudadas a expressão de determinados fatores de virulência de C. albicans isoladas de cavidade bucal, com ênfase na formação de biofilme, e a atividade antifúngica e o impacto de concentrações subinibitórias de derivados de chalconas na formação de biofilme por estes micro-organismos. Os compostos foram avaliados quanto à toxicidade pelo ensaio de letalidade de Artemia salina e determinação da dose letal a 50% (DL 50 ) ao micro-crustáceo. Nas chalconas sintetizadas, manteve-se o grupameno hidroxil no anel B e foram feitas modificações no anel A que resultaram em diferenças na toxicidade dos compostos variando de 714,3 a 1798,1?g/mL. As leveduras expressaram de forma variável os fatores de virulência com predomínio de alta produção de fosfolipases, aspartil proteinases e com formação do tubo germinativo em até duas horas. A formação de biofilmes foi categorizada em dois grupos distintos nos quais 16 (48%) leveduras foram consideradas como formadoras fracas e 17 (52%) como formadoras fortes. A susceptibilidade as chalconas foi > 1000?g/mL exceto para (E)-1-fenil-3-(4-hidroxifenil) prop-2-em-1-ona que apresentou uma concentração inibitória mínima de 62,5?g/mL para os isolados e de 250?g/mL para a cepa de C. albicans ATCC 10231. Entretanto, concentrações subinibitórias das chalconas apresentaram uma significativa atividade inibitória da formação de biofilme por C. albicans, com graus de inibição variando de 75 a 90%, o que indica a potencial utilização destes compostos na inibição deste importante fator de virulência.(AU)

Candida albicans is an opportunistic yeast that has a number of virulence factors that increase pathogenicity of these micro-organisms. In this study the expression of certain virulence factors were studied of C. albicans isolated from the oral cavity with emphasis on biofilm formation and antifungal activity and the impact of subinibitory concentrations of derivatives of chalconas in biofilm formation by these micro-organisms. The compounds were evaluated for toxicity testing of brine shrimp lethality and determination of 50% lethal dose (LD50) to the micro-crustacean. In synthesized chalconas, remained grouping the hydroxyl in ring B and ring modifications were made on the resulting differences in toxicity of the compounds ranging from 714.3 to 1798.1 ?g/mL. Yeasts shown variable expressed virulence factors with prevalence of high production of phospholipases, aspartyl proteases and formation of germ tube within two hours. The biofilm formation was categorized into two distinct groups in which 16 (48%) yeasts were considered as poor and 17 trainers (52%) as forming strong. Susceptibility was chalcones ? 1000 ?g/mL except for (E)-1-phenyl-3-(4-hydroxyphenyl) prop-2-en-1-one, which showed a minimum inhibitory concentration of 62.5?g/mL for the clinical isolates and 250?g/mL for the strain of C. albicans ATCC 10231. However, subinibitory concentrations of chalcones showed significant inhibitory activity of biofilm formation by C. albicans with degrees of inhibition ranging from 75 to 90%, indicating the potential use of these compounds in the inhibition of this important virulence factor.(AU)

Presencia del elemento genético transportable dTdic1 en Dianthus caryophyllus con flores variegadas y no variegadas / Presence of the transposable genetic element dTdic1 in Dianthus caryophyllus with variegated and no variegated flowers

El objetivo de este trabajo era la búsqueda del EGT (Elemento Genético Transponible) dTdic1 que ha sido asociado con la variegación del color de las flores de clavel y su relación con dos genes que codifican para enzimas involucradas en la biosíntesis de antocianinas, Chalcona isomerasa (CHI) y Dihidroflavonol reductasa (DFR). Su presencia y expresión se evaluó en siete genotipos con flores variegadas (líneas híbridas) y en cuatro genotipos de flores no variegadas (una línea híbrida y tres cultivares comerciales). Un alto número (indefinido) de copias del elemento dTdic1 se detectó en todas las líneas variegadas y no variegadas. En consecuencia, la sola presencia de este EGT no pudo asociarse directamente con la variegación de los pigmentos florales de flores de clavel. Adicionalmente, dTdic1 se encontró interrumpiendo el gen CHI en cuatro genotipos variegados y uno no variegado. No se observó evidencia de inserción de dTdic1 en el gen DFR en ninguno de los genotipos.

The objective of this work was to search for the EGT (Transposable Genetic Element) dTdic1 that has been associated with color variegation of carnation flowers and its relationship with two genes that code for enzymes involved in the synthesis of anthocyanins, Chalcona isomerase (CHI) and Dihidroflavonol reductase (DFR). Its presence and expression was evaluated in seven genotypes of variegated flowers and four no variegated flower genotypes (one hybrid line and three commercial cultivars). A high number of copies (undefined) of copies of the dTdic1 element was detected in variegaated and no variegated lines. Therefore, the main presence of this EGT was not associated directly with variegation of floral pigments. Additionally, dTdic1 was found interrupting the CHI gene in four variegated and one no variegated phenotypes. No evidence was observed of insertion of dTdic1 in the DFR gene in any of the genotypes.

Actividad del (2E)-3-(2, 3-dimetoxifenil)-1-(4-metilfenil) prop-2-en-1-ona en presencia del poli(ácido maleico-co-2-vinil-pirrolidona) sobre un aislamiento clínico de Staphylococcus aureus / Activity of (2E)-3-(2, 3-dimetoxifenil)-1-(4-metilfenil) prop-2-en-1-ona in the presence of poli(maleic acid-co-2-vinyl-pyrrolidone)

Introducción: debido a la problemática actual de fármaco-resistencia hacia los antibióticos b-lactámicos, se ha hecho necesario, en busca de una solución, trabajar con nuevas moléculas con potencial farmacológico, así como utilizar novedosos sistemas poliméricos como matrices o excipientes farmacéuticos. Objetivo: evaluar la actividad antibiótica de la ampicilina, combinada con un compuesto sintético de tipo chalcona, denominado (2E)-3-(2,3-dimetoxifenil)-1-(4-metilfenil)prop-2-en- 1-ona, sobre un aislamiento clínico de Staphylococcus aureus resistente a penicilinas, en presencia de una matriz polimérica hidrosoluble denominada poli(ácido maleico-co-2-vinilpirrolidona). Materiales y métodos: el compuesto sintético y la matriz polimérica se obtuvieron por métodos descritos en la literatura. Se usó un aislamiento clínico de Staphylococcus aureus resistente a penicilinas y se hicieron ensayos de actividad antibiótica por la técnica de macrodilución en caldo, de la cual se obtuvieron las concentraciones inhibidoras mínimas de los compuestos evaluados. Resultados: la mezcla ampicilina-chalcona muestra un efecto antibiótico menor que el de su referente ampicilina-sulbactam. No obstante, cuando se utiliza la matriz polimérica en combinación con la ampicilina-chalcona se aprecia un incremento significativo de la actividad antibiótica, evidenciado en que la concentración inhibidora mínima es la mitad de la del referente comercial.

Introduction: Due to the current problem of resistance to b-lactam antibiotics, it has become necessary, in search of a solution, to work with new molecules with pharmacological potential, and to use novel polymeric systems as matrices or pharmaceutical excipients. Objective: To evaluate the antibiotic activity of ampicillin combined with a synthetic chalcone-type compound, the (2E)-3-(2,3-dimethoxyphenyl)-1-(4- methylphenyl) prop-2-en-1-one, on a clinical isolate of penicillin-resistant Staphylococcus aureus in the presence of a water soluble polymer matrix known as poly(maleic acid-co-2-vinyl-pyrrolidone). Materials and methods: The synthetic compound and the polymeric matrix were obtained by previously described methods. Tests for antibiotic activity against the strain of penicillin-resistant Staphylococcus aureus were done by the broth dilution technique which provided the minimal inhibitory concentrations of the compounds tested. Results: The chalcone-ampicillin mix shows lesser antibiotic effect than the ampicillin-sulbactam used as referent. However, when such mix is combined with the polymer matrix, antibiotic activity significantly increases as evidenced by decrease in the minimal inhibitory concentration with respect to the ampicillin-sulbactam referent.

Comparative profiles of Achyrocline alata (Kunth) DC. and A. satureioides (Lam.) DC., Asteraceae, applying HPLC-DAD-MS / Perfil comparativo entre Achyrocline alata (Kunth) DC. e A. satureioides (Lam.) DC., Asteraceae, utilizando HPLC-DAD-MS

A comparative analysis between the hydromethanolic extracts of Achyrocline alata (Kunth) DC. and A. satureioides (Lam.) DC., Asteraceae, was performed by the use of HPLC-DAD-MS. Both plants were used without distinction and under the same indications in folk medicine in Mato Grosso do Sul, Brasil. While Achyrocline alata ("jatei-ka-ha") is used in folk medicine of the Brazilian state of Mato Grosso do Sul, A. satureioides is predominantly used in other states. Samples of both plants collected in different periods, 1996 and 2002, showed a very similar chemical profile. The results indicate that A alata could be used in phytotherapeutic preparations as substitue for A. satureioides, since they have similar chemical compositions of the polar extract.

Análises comparativas entre os extratos hidrometanólico de Achyrocline alata (Kunth) DC. e A. satureioides (Lam.) DC., Asteraceae,foram desenvolvidas utilizando HPLC-DAD-MS. Ambas as plantas são utilizadas indistintamente para as mesmas indicações na medicina popular de Mato Grosso do Sul, Brasil, enquanto a A. alata ("jatei-ka-há) é predominante neste estado, a A. satureioides ("marcela") é predominante nos demais estados da Federação. Amostras das duas espécies coletadas em épocas diferentes, 1996 e 2002, apresentaram o mesmo perfil cromatográfico. O presente resultado pode justificar que A. alata possa ser utilizada como sucedânea de A. satureioides, pois apresentam similar composição de metabólitos secundários polares.

NUEVAS CHALCONAS DE Beilschmiedia tovarensis / NEW CHALCONES FROM Beilschmiedia tovarensis

Del extracto etanólico de madera de Beilschmiedia tovarensis fueron aisladas e identificadas dos nuevas chalconas: 2’, 6’-dihidroxi-4’-isopenteniloxi-3,4(3’’’ ’, 3’’ ’’-dimetilpirano) chalcona y 4,2’, 6’- trihidroxi-3’, 4’ metilenodioxi-3-isopentenilchalcona. El aislamiento y la purificación fueron realizados por técnicas cromatográficas. La elucidación estructural de estos compuestos se determinó mediante técnicas espectroscópicas (IR, RMN-¹H, 13C y EM). Además, fue probada la actividad biológica in vitro del extracto etanólico de madera, dando resultados significativos para actividad antimicrobiana en cepas Gram(+): Staphylococcus aureus y Enterococcus faecalis. Las pruebas de actividades antimalárica y antituberculosa dieron resultados negativos.

Two new chalcones: 2’, 6’-dihydroxy-4-isopenteniloxy-3,4(3’’ ’,3’’ ’-dimethylpyrano) chalcone and 4,2’, 6’- trihydroxy-3’,4’-metilenodioxo-3-isopentenilchalcone were isolated from the wood ethanolic extract of Beilschmiedia tovarensis. Isolation was performed by chromatographic techniques. The elucidation of the structure of the compounds was accomplished by spectroscopic techniques (IR, NMR-¹H, 13C and MS). Also, the crude wood extract was tested in vitro for biological activity, having significant results for antimicrobial activity in Gram (+) stumps: Sataphylococcus aureus and Enterococcus faecalis. Test of antimalarial and antituberculosis activities gave negative results.