Lapachol was chemically modified to obtain its thiosemicarbazone and semicarbazone derivatives. These compounds were tested for antimicrobial activity against several bacteria and fungi by the broth microdilution method. The thiosemicarbazone and semicarbazone derivatives of lapachol exhibited antimicrobial activity against the bacteria Enterococcus faecalis and Staphylococcus aureus with minimal inhibitory concentrations (MICs) of 0.05 and 0.10 µmol/mL, respectively. The thiosemicarbazone and semicarbazone derivatives were also active against the pathogenic yeast Cryptococcus gattii (MICs of 0.10 and 0.20 µmol/mL, respectively). In addition, the lapachol thiosemicarbazone derivative was active against 11 clinical isolates of Paracoccidioides brasiliensis, with MICs ranging from 0.01-0.10 µmol/mL. The lapachol-derived thiosemicarbazone was not cytotoxic to normal cells at the concentrations that were active against fungi and bacteria. We synthesised, for the first time, thiosemicarbazone and semicarbazone derivatives of lapachol. The MICs for the lapachol-derived thiosemicarbazone against S. aureus, E. faecalis, C. gattii and several isolates of P. brasiliensis indicated that this compound has the potential to be developed into novel drugs to treat infections caused these microbes.

Organic extracts from leaves and stems of Stillingia oppositifolia Baill. ex Müll. Arg., Euphorbiaceae, were screened for antifungal and cytotoxic properties. The extracts presented Minimum Inhibitory Concentration values around 250 µg.mL-1 against Candida krusei and Candida tropicalis, and around 63 µg.mL-1 for Paracoccidioides brasiliensis. They were tested on three human cell lines (UACC-62, MCF-7, and TK-10), disclosing GI50 values, (concentration able to inhibit 50% of the cell growth) ranging from 50 to 100 µg.mL-1. Organic extract from stems furnished hexanic, dichloromethanic and aqueous phases after partition. Chromatographic fractionation of the hexanic soluble phase of the stems yielded aleuritolic acid 3-acetate, β-sitosterol, 3-epi-β-amyrin, β-amyrone and palmitic acid. These compounds showed antifungal and cytotoxic activities in the same range as the organic crude extract and low toxic effect against mononuclear cells obtained from human peripheral blood. This is the first report on chemical and biological potential of S. oppositifolia.

Xantoma eruptivo e granuloma anular são doenças dermatológicas com quadros clínicos distintos que, algumas vezes, apresentam semelhanças histopatológicas que podem conduzir a diagnóstico errôneo. Relata-se o caso de paciente do sexo masculino com 34 anos, portador de dislipidemia, com lesões clinicamente características de xantoma eruptivo cujo exame histopatológico foi sugestivo de granuloma anular. No entanto, a revisão da lâmina mostrou tratar-se de xantoma eruptivo. A remissão completa e rápida das lesões após o tratamento da dislipidemia confirmou o diagnóstico de xantoma eruptivo e motivou a pesquisa sobre as semelhanças e diferenças histopatológicas entre essas doenças.

Eruptive xanthoma with unexpected granuloma annulare-like microscopic appearance - Case report Abstract: Eruptive xanthoma and granuloma annulare are dermatological diseases with different clinical findings that, sometimes, exhibit histopathological similarities with potential for misinterpretation. We report a case of an eruption of yellow-orange papules with erythematous borders in a 34-year-old male with high levels of serum triglycerides and cholesterol. The skin biopsy specimen has diagnosed granuloma annulare. Review of the histologic material revealed eruptive xanthoma. Remission of the eruption after treatment of dyslipidemia confirmed the diagnosis of the eruptive xanthoma and motivated research about the histological similarities and differences between these diseases.