In this study, we assessed the cytotoxic effect of 1,3-diphenyl-2-allyl-1,3-propanedione (DPAP) on B16F10 and Tm5 melanoma cells and investigated its interaction with DNA (deoxyribonucleic acid) using optical tweezers. The compound showed to be effective against B16F10 cells with selectivity index (SI) of 7.92 and interaction to the outer surface of the double helix, probably at the minor groove of DNA. This likely induced a bending deformation of the polymer chain, decreasing persistence length, and indicated that each DPAP molecule occupies a single base pair upon binding to the double helix.

This study describes the stereoselective synthesis of two new γ-lactones in 6 and 3 steps and 19 and 32% yield, respectively, directed toward the total synthesis of the natural product (−)-cleistenolide. The starting material was an enantiomerically pure diacetonide diol, derived from d-mannitol with the required stereocenters for (−)-cleistenolide synthesis. γ-Lactone syntheses were based on highly selective protection and deprotection of hydroxyls from d-mannitol. The formation of γ-lactone rings was the culmination of this approach, made possible by a Horner-Wadsworth-Emmons Z-olefination between diacetal aldehyde and ethyl 2-(bis(o-tolyloxy)phosphoryl)acetate to produce an unsaturated ester. The Z-isomer ester was highly favored in relation to the E-isomer (Z/E ratio of 94:6), allowing the formation of the γ-lactone ring under acid catalysis. This strategy precluded the use of chiral auxiliaries or catalysts for the control of stereocenters in the novel γ-lactones.

The stereoselective total synthesis of (+)-epi-cytoxazone was performed satisfactorily in 8 steps, in 17% overall yield, via a novel route from 2,3-O-(3-pentylidene)-(R)-glyceraldehyde. The bulky group alkene-ketal allowed intramolecular control of the target molecule's asymmetric centers in the dihydroxylation step by promoting the approach of OsO4 to the face opposite to that of the ketal group.

A novel one-pot sequence (in 2 or 3 steps) was developed for the synthesis of the tetrahydroquinoline alkaloids (±)-galipinine, (±)-cuspareine, (±)-galipeine and (±)-angustureine, and the derivative (±)-11-methoxy-5,6,6a,7,8,13-hexahydro-13a-aza-benzo[5,6]cyclohepta [1,2-a]naphthalene-12-ol from their respective Wittig adducts in moderate and high yields. The solvolytic N-methylation reaction was shown to be catalyzed by Pt0, generated in situ by reduction of PtO2. The evaluation of biofilm inhibition and antibacterial activity of the compounds against Staphylococcus aureus strains isolated from cows with mastitis revealed that the alkaloid derivative is a promising candidate for an antibiotic drug.

Uma nova síntese dos enantiômeros (-)-(R)- e (+)-(S)-angustureina, assim como do racemato (±)-angustureina, a partir de um β-amino éster racêmico controlado por resolução cinética enzimática, é descrita. Esta estratégia permitiu, incorporar tanto o esqueleto básico como controlar o único estereocentro no carbono 2 de ambos enantiômeros. A sequência em cinco etapas a partir dos β-amino éster e o carboxilato de sódio quirais para a síntese de ambos os alcalóides foi feita com um rendimento global de 80 e 44%, respectivamente, e excelentes excessos enantiomericos (95 e 96%, respectivamente) e sem nenhuma proteção de grupos funcionais em todas as etapas.

The present study describes a new synthesis of (-)-(R)-and (+)-(S)-angustureine enantiomers, as well as of racemate (±)-angustureine, from a racemic β-amino ester controlled by kinetic enzymatic resolution. This strategy allowed to incorporate the basic skeleton, as well as to control the single stereocenter at carbon 2 in both enantiomers. The sequence of five steps starting from the chiral β-amino ester and sodium carboxylate for the synthesis of both alkaloids achieved overall yields of 80 and 44%, respectively, and produced excellent enantiomeric excesses (95 and 96%, respectively) with no protection of functional groups in any of the steps.

Staphylococcus aureus é o principal agente causador de mastite bovina. A atividade de diversos extratos de dez plantas medicinais tradicionalmente usadas no Brasil como anti-sépticas foi investigada contra quinze cepas de Staphylococcus aureus isoladas de animais com manifestação de mastite pelo método de difusão em ágar e ensaio de microdiluição. A interferência dos extratos na célula bacteriana em forma de colônias aderidas também foi avaliada. Os valores de MIC variaram de 0.5 mg/mL a 1.0 mg/mL e a concentração inibitória de biofilme (BIC) variou de 0.25 mg/mL a 0.8 mg/mL. Os resultados revelaram o potencial dos extratos de Senna macranthera, Artemisia absinthium, Cymbopogon nardus e Baccharis dracunculifolia como agentes antibacterianos contra cepas de S. aureus isolados de mastite bovina e suportam o possível uso destas plantas no manejo clínico da doença.

Staphylococcus aureus is the main causative agent of bovine mastitis. The activity of several extracts from ten medicinal plants traditionally used in Brazil as antiseptic was investigated against fifteen strains of Staphylococcus aureus isolated from animals with mastitis manifestation by the disc diffusion method and broth microdilution assay. The interference of the extracts on cell in the form of adherent colonies was also evaluated. MIC values ranged from 0.5 mg/mL to 1.0 mg/mL and biofilm inhibitory concentration (BIC) were between 0.25 mg/mL and 0.8 mg/mL. Results revealed the potential of extracts of Senna macranthera, Artemisia absinthium, Cymbopogon nardus and Baccharis dracunculifolia as antibacterial agents against S. aureus strains isolated from bovine mastitis and support the possible use of these phytotherapic agents in the clinical management of the disease.