Several species of Croton have been described with biological activities, mainly due to diterpenes, alkaloids and/or other secondary metabolites. These activities account for the traditional use of Croton species to treat certain diseases in South America, Asia and Western Africa. The crude methanol extracts obtained from leaves and steam bark of Croton dichrous Müll. Arg., C. erythroxyloides Baill., C. myrianthus Müll. Arg. and C. splendidus Mart. ex Colla were tested for antiproliferative activity against ten human cancer cell lines. Chemical analyses of all extracts were carried out by GC/MS and HPLC/MS/MS. The leaf extract obtained from C. erythroxyloides showed potent activity against PC-3 (prostate) and OVCAR-3 (ovary) cell lines. Lupeol is suggested to be involved in such activity. Tiliroside, an acyl-glycosilated flavonoid ubiquitous in all tested extracts, seems to play an important role in the observed moderate activity of most extracts against the leukemia K562 cell lineage.

Six samples of Brazilian propolis from Minas Gerais and Paraná states were analyzed to identify the constituents (GC/MS and HPLC/MS) and to determine their contents (HPLC and external standardization). All samples contained characteristic constituents of green propolis, but the samples from Minas Gerais had higher contents of prenylated phenylpropanoids and caffeoylquinic acids. Kaempferide and two other flavonoids were among the major constituents of the samples from Minas Gerais. Luteolin 5-O-methyl ether was detected only in samples from Paraná. Baccharis dracunculifolia was a source of resins for all samples analyzed, but the samples from Paraná had more complex plant origin.

Amostras de ceras do ninho e da própolis de Apis mellifera foram analisadas. Observou-se a predominância de ésteres, seguidos de hidrocarbonetos. Os constituintes foram identificados por cromatografia a gás/espectrometria de massas. Amplas variações foram observadas nos padrões de hidrocarbonetos e dos ácidos e álcoois de ésteres. As cadeias carbônicas dos hidrocarbonetos abrangem a faixa C23 - C35, com o predomínio de C27 e C31. O principal ácido carboxílico foi C16:0, seguido de C18:0 e C18:1. Os principais álcoois constituintes de ésteres foram homólogos saturados normais, na faixa C24 - C32, C30 sendo o mais abundante, seguido de C24. Não foram observadas diferenças que permitam distinção, o que sugere uma origem comum para ambas as fontes de cera.

Samples of propolis and comb waxes of Apis mellifera were analyzed. Monoesters predominated, followed by hydrocarbons. The constituents were identified by gas chromatography/mass spectrometry. Wide variations in the patterns of hydrocarbons, acids and alcohols of the esters were found. Hydrocarbon chains cover the range C23 - C35, C27 and C31 alkanes predominating. The main carboxylic acid was C16:0, followed by C18:0 and C18:1. The alcohols were predominantly saturated n-homologues, ranging from C24 to C32, C30 being the most abundant, followed by C24. No differences were found to allow a distinction, suggesting a common origin for both wax sources.