ABSTRACT The dichloromethane extract of Plectranthus ornatus Codd., a tradicional medicinal plant, showed antibiotic activity with minimum inhibitory concentration (MIC) values of 0.4 mg.mL-1 and 100 percent of biofilm inhibition against Staphylococcus aureus strains isolated from animals with mastitis infections. Based on these antibacterial activities, in addition to ethnopharmacological reports from healing men and farmers in Brazil, an herbal soap was produced from this active extract and was tested both in vitro and in vivo. In vivo assays conducted on these herbal soaps led to results similar to those previously conducted with the active extract. These results indicated the great potential of this plant for use as an excipient by preparing herbal antibacterial soaps as an alternative veterinary medicine aimed at controlling bovine mastitis infections on small Brazilian farms.

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.

Extratos de acetato de etila obtidos dos fungos fitopatogênicos Diplodia maydis e Sclerotium rolfsii mostraram atividade bactericida contra bactérias multi droga resistentes isoladas de pacientes de Hospital Brasileiro.

Ethyl acetate extracts of the phytopathogenic fungi Diplodia maydis and Sclerotium rolfsii presented antibacterial activity against multidrug resistant bacteria isolated from patients in the University Hospital (HUOP-Unioeste, Brazil).

Nesse trabalho descrevemos uma abordagem sintética para a preparação de um esqueleto carbônico que tem dois centros quaternários vizinhos, um dos quais apresenta uma unidade espiro gama-butirolactona. Esse arranjo molecular é encontrado em nor-sesquiterpenos isolados de corais marinhos. A estratégia sintética utilizada se baseou no uso de uma reação de adição 1,4 do dimetilcuprato de lítio sobre a 2-metilcicloexenona, seguida da interceptação do enolato intermediário com brometo de alila, para obter a trans-2-alil-2,3-dimetilcicloexanona com moderada diastereosseletividade. Essa última já tem incorporada em sua estrutura um dos centros quaternários do esqueleto. O segundo centro quaternário, que porta a unidade espiro gama-butirolactona, foi preparado através de uma reação de adição de um reagente organolítio, seguido da separação dos isômeros e de etapas de oxidação. Essa estratégia permitiu obter o esqueleto carbônico dos sesquiterpenos e ao mesmo tempo relatar a síntese total de um derivado nor-sesquiterpênico não natural, em 6 etapas com um rendimento global de 16%, a partir da 2-metilcicloexenona.

We disclose herein a synthetic approach for the preparation of an unusual carbon skeleton, which was found in nor-sesquiterpenes isolated from marine corals. The main structural feature of this skeleton is the presence of two contiguous quaternary centers, one of them bears a spiro gamma-butyrolactone moiety. One of the quaternary centers was prepared with moderate stereoselectivity by the conjugate addition of lithium dimethylcuprate to 2-methylcyclohexenone, followed by the trapping of the intermediate enolate with allyl bromide to furnish trans-2-allyl-2,3-dimethylcyclohexan-2-one, as a major diastereoisomer. The preparation of the quaternary centers bearing the spiro gamma-butyrolactone moiety was secured by the addition of a suitably functionalized organolithium reagent on trans-2-allyl-2,3-dimetylcyclohexan-2-one, followed by separation of the isomers and two oxidation steps. This strategy has permitted us to report the racemic total synthesis of a non-natural nor-sesquiterpene derivative, in 6 steps and 16% overall yield, from 2-methylcyclohexenone.