FMOC-Cl is a derivatizing agent widely used both in N-protection reactions of α-amino acids as well as in quantification and detection of amino acids and related molecules using HPLC-PDA or fluorescence analysis. In this work we studied the reaction of FMOC-Cl with gabapentin. However, it was observed that the degradation of gabapentin-N-FMOC and FMOC-Cl to FMOC-OH occur simultaneously in presence of the basic reaction medium which is specific for gabapentin derivatization. The degradation reaction is accelerated in temperatures above 45 °C and also by the time of contact of the reactant and product with basic medium. In this study, gabapentin derivatization reactions were shown to be cleaner and more efficient when an FMOC-Cl/gabapentin ratio of 2:1 was used, at 25 °C over a period of 15 minutes.

Fifty-two samples of street cocaine seized in the state of Rio de Janeiro, from May 2016 to April 2017, were evaluated according to their purity, presence of inorganic and sugar diluents and concentration of pharmacologically active adulterants. Cocaine contents, as well as the adulterants caffeine, lidocaine and phenacetin, were evaluated by gas chromatography coupled with mass spectrometry. The samples were screened by Raman spectroscopy for the presence of inorganic diluents and carbohydrates. The main diluents were calcium carbonate and sodium bicarbonate, which were found in 93% and 71% of the cocaine hydrochloride samples, respectively. Caffeine was found in 91% of the cocaine hydrochloride samples, while phenacetin was found in all freebase cocaine samples. Freebase cocaine samples were majorly composed of pharmacological active compounds (adulterants), unlike cocaine hydrochloride samples, which were majorly composed of inorganic compounds (diluents). It could be observed, by Raman Spectroscopy associated to multivariate analysis, similarities on cocaine hydrochloride composition according to certain criminal gangs. The percentage of pharmacological active compounds varied significantly on the analyzed samples, showing that these adulterants are indiscriminately added to street cocaine, what may increase consumers’ health risks.

A new series of dialkylphosphorylhydrazones was synthesized through the condensation of aromatic aldehydes with different phosphorylhydrazines. All synthesized compounds were characterized by IR, ¹H-NMR, 13C-NMR and 31P-NMR spectroscopies. The in vitro investigation of the activity of these compounds against Leishmania amazonensis promastigotes and epimastigotes of T. cruzi, showed an efficient inhibition of proliferation, at non toxic concentrations to mammalian cells. The results have shown some derivatives as potential antiparasitic agents against trypanosomatids.

Um mecanismo alternativo para a indução assimétrica 1,4, na adição estereosseletiva da (R)-pantolactona ao 2-fenilpropilceteno foi investigado teoricamente. Um mecanismo envolvendo uma transferência de hidrogênio intermolecular foi proposto, que considera a participação ativa da dimetiletilamina e seu íon como agentes de transferência de hidrogênio. No primeiro passo, uma molécula de dimetiletilamina neutra interage com o anel de 7 membros do enol intermediário. Uma interação ácido-base específica é estabelecida entre o grupo hidroxila do enol e o átomo de nitrogênio da amina. A amina neutra é básica o suficiente para remover o hidrogênio. Uma outra molécula de amina protonada doa seu hidrogênio à ligação dupla C=C, para fornecer os produtos desejados. A estereoquímica foi definida pelo modo como as moléculas de amina neutra e protonada aproximam-se do enol. O excesso diasteroisomérico encontrado concorda com o dado experimental [para (S, R) e (R, R) é de 99:1].

An alternative mechanism for the 1,4-assymmetric induction in the stereoselective addition of (R)-pantolactone to 2-phenylpropylketene was theoretically investigated. A mechanism involving an intermolecular proton transfer assisted by two amine molecules was proposed, which considered the active participation of the dimethylethylamine and its ion as proton transfer agents. In the first step, a neutral dimethylethylamine interacts with the seven-membered ring of the enol intermediate. A specific acid-base interaction is established between the hydroxyl group of the enol and the nitrogen atom of the dimethylethylamine. The neutral dimethylethylamine is basic enough to remove the proton. Another protonated dimethylethylamine is considered to donate its proton to the C=C double bond to give the desired products. The stereochemical outcome was defined by the way that the neutral and protonated dimethylethylamine approached to the enol. The diastereoisomeric ratio found is in good agreement with experiments [for (S, R) and (R, R) it is 99:1].

O estrigol é um sesquiterpeno natural que possui elevada atividade como estimulante da germinação, principalmente de sementes de espécies invasoras, pertencentes aos gêneros Striga e Orobanche. Soluções contendo 0,01; 0,1; 10 e 1000 mg/L de um novo análogo de estrigol, sintetizado a partir de um alilbenzeno natural, o safrol (isolado do óleo de sassafraz), foram aplicadas em sementes de alface e de Ipomoea grandifolia e Bidens pilosa. Observou-se que houve efeito estimulador na germinação das sementes das ervas invasoras, sem afetar a germinação da alface. Os resultados indicam que essa substância apresenta potencial de uso para estimular a germinação de sementes de ervas invasoras, que poderiam ser eliminadas do solo, antes do plantio de hortaliças como a alface.

Strigol is a natural sesquiterpene and is a strong stimulant of germination, mainly of weed seeds from the genera Striga and Orobanche. Solutions with concentrations from 0.01; 0.1; 10 and 1000 mg/l of a new strigol analogue, synthesized from natural safrole (isolated from sassafraz oil) were applied to seeds of lettuce, Ipomoea grandifolia and Bidens pilosa. A stimulating effect in the germination of weed seeds was observed, whereas no effect on lettuce was observed. The results indicate that the new analogue presents potential application as a germination stimulant of weed seeds, which could be eliminated from the soil, before sowing vegetables such as lettuce.

O alil-benzeno natural safrol, isolado do óleo de Sassafraz (Ocotea pretiosa, Benth) foi utilizado como matéria-prima na síntese de um novo análogo aromático do estrigol que é um potente estimulante de germinação. O novo análogo foi obtido como uma mistura de epímeros em C2' que foram quantificados e separados por cromatografia líquida de alta eficiência.

Safrole, isolated from Sassafraz Oil (Ocotea pretiosa, Benth), has been used as starting material in the synthesis of a new strigol analogue which is active as germination stimulant. The new analogue was obtained as a mixture of epimers at C2' which could be separated by high-performance liquid chromatography.

In a previous work we demonstrated that diarylheptanoids extracted from Centrolobium sclerophyllum are very active against Leishmania amazonensis promastigotes. In order to continue our studies with these class of compounds, we decided to evaluate the activity of several diarylheptanoids derived from curcumin (diferuloyl methane) against the extracellular form (promastigotes) of L. amazonensis. Furthermore, an experiment against the intracellular form of the parasite (amastigotes) was carried out, comparing the most active compound among the curcumin derivatives (the methylcurcumin) with des-O-methylcentrolobine, the most active diarylheptanoid derived from C. sclerophyllum.

The preparation and chemical potentiality of a,a-dichlorocyclobutanones as useful intermediates in the total synthesis of natural products are reviewed. Some aspects related to the recent advances reported in the literature about the mechanism of [2+2] cycloaddition reaction between dichloroketene and olefins are also presented.