25 anos de quimiometria no Brasil

Chemometric activities in Brazil are described according to three phases: before the existence of microcomputers in the 1970s, through the initial stages of microcomputer use in the 1980s and during the years of extensive microcomputer applications of the ´90s and into this century. Pioneering activities in both the university and industry are emphasized. Active research areas in chemometrics are cited including experimental design, pattern recognition and classification, curve resolution for complex systems and multivariate calibration. New trends in chemometrics, especially higher order methods for treating data, are emphasized.

Derivados citotóxicos de vitanolidos isolados das folhas de Acnistus arborescens

In view of anticancer activity of 7 β-acetoxywithanolide D (2) and 7β-16α-diacetoxywithonide D (3), isolated from the leaves of Acnistus arborescens (Solanaceae), five withanolide derivatives were obtained and their structures were determined by NMR, MS and IV data analysis. The in vitro anticancer activity of these derivatives was evaluated in a panel of cancer cell lines: human breast (BC-1), human lung (Lu1), human colon (Col2) and human oral epidermoid carcinoma (KB). Compounds 2a (acetylation of 2), 3b (oxidation of 3) and 2c (hydrogenation of 2) exhibited the highest anticancer activity against human lung cancer cells, with ED50 values of 0.19, 0.25 and 0.63 μg/mL, respectively.