We describe the microwave-assisted synthesis of thirteen functionalized peptoids and evaluate their in vitro antileishmanial activity against forms of Leishmania (Leishmania) amazonensis promastigotes. Synthesis via the Ugi four-component reaction (Ugi 4CR) reaction furnished the compounds of interest in 55-80% yield; reactions were conducted in a microwave reactor and lasted only 10 min. We then screened the antileishmanial activity of the synthesized compounds in vitro. To determine the IC50 (inhibitory concentration necessary to inhibit the growth of 50% of parasites) values, we selected the compounds that inhibited L. (L.) amazonensis growth by more than 50%. The seven selected compounds displayed IC50 values ranging from 2.6 to 72 µM after incubation for 48 h. Three peptoids gave IC50 values between 2.6 and 7.9 µM and can be considered as bioreactive molecules (hit criteria).

In this work we present a complete proton (1H) and carbon 13 (13C) nuclear magnetic resonance (NMR) spectral analysis of two synthetic dihydrofuran neolignans (±)-trans-dehydrodicoumarate dimethyl ester and (±)-trans-dehydrodiferulate dimethyl ester. Unequivocal assignments were achieved by 1H NMR, proton decoupled 13C (13C{1H}) NMR spectra, gradient-selected correlation spectroscopy (gCOSY), J-resolved, gradient-selected heteronuclear multiple quantum coherence (gHMQC), gradient-selected heteronuclear multiple bond coherence (gHMBC) and nuclear Overhauser effect spectroscopy (NOESY) experiments. All hydrogen coupling constants were measured, clarifying all the hydrogen signals multiplicities. Computational methods were also used to simulate the 1H and 13C chemical shifts and showed good agreement with the trans configuration of the substituents at C7 and C8.

Descrevemos a síntese assistida por micro-ondas de dez derivados de 3-metoxicarbonil-γ-butirolactona e a avaliação in vitro da atividade leishmanicida desses compostos contra formas promastigotas de Leishmania amazonensis. A síntese forneceu a maioria dos compostos com 80-95% de rendimento e as reações duraram cerca de 10-20 min. A maior parte dos compostos apresentaram valores de IC50 superiores a 400 uM. Os compostos 5 (trans-3-(p-metoxi)benzil-4-metil-3-metoxicarbonil-γ-butirolactona) e 10 (trans-3-(p-metoxi)benzil-4-benzil-3-metoxicarbonil-γ-butirolactona) foram as exceções, pois exibiram valores de IC50 de 170,4 e 179,6 µM, respectivamente, o que sugere que a atividade leishmanicida das 3-metoxicarbonil-γ-butirolactonas pode estar relacionada com a natureza e o tamanho do substituinte na posição C-4.

We describe the microwave-assisted synthesis of ten 3-methoxycarbonyl-γ-butyrolactone derivatives and evaluate their in vitro antileishmanial activity against promastigote forms of Leishmania amazonensis. The synthesis furnished most of the compounds in 80-95% yield and reactions lasted about 10-20 min. Most of the compounds displayed IC50 values higher than 400 µM. Compounds 5 (trans-3-(p-methoxy)benzyl-4-methyl-3-methoxycarbonyl-γ-butyrolactone) and 10 (trans-3-(p-methoxy)benzyl-4-benzyl-3-methoxycarbonyl-γ-butyrolactone) were the exceptions: they displayed IC50 values of 170.4 and 179.6 µM, respectively, suggesting that the leishmanicidal activity of 3-methoxycarbonyl-γ-butyrolactones may be related to the nature and size of the substituent at position C-4.

Uma síntese total da (3S, 5R, 3'S, 5'R)-capsorubina (1) enriquecida enantiomericamente, através da condensação aldólica da (1R, 4S)-1-(4-hidróxi-1,2,2-trimetil-ciclopentil)etanona (2a) e do crocetindial (3) é descrita. Uma síntese alternativa do composto 2a opticamente ativo (ee 89%), com apenas oito etapas, também foi desenvolvida.

The total synthesis of enantiomerically enriched (3S, 5R, 3'S, 5'R)-capsorubin (1) by aldol condensation of (1R, 4S)-1-(4-hydroxy-1,2,2-trimethyl-cyclopentyl) ethanone (2a) and crocetindial (3) is described. An alternative, short eight-step synthesis of the optically active compound 2a (ee 89%) is also reported.

It has been carried out an investigation of ethanol electro-oxidation on Ti/IrO2 electrodes. The experimental results show a high selectivity towards acetaldehyde formation thus, offering potential advantages in cost and availability of raw material. It has been observed that the electrode is partially blocked by a film formed after the oxidation of the starting material which can be removed by pulse technique between RDO and RDH onset. The mechanism and the selectivity of the product formed is presented.