Determinação de ácido rosmarínico em Cordia verbenacea por cromatografia líquida: aplicabilidade em estudo sazonal / Determination of rosmarinic acid in Cordia verbenacea by liquid chromatography: applicability in seasonal study

RESUMO Neste estudo, uma técnica de cromatografia líquida de alta resolução em fase reversa (CLAE-FR) para a determinação de ácido rosmarínico em Cordia verbenacea foi desenvolvida e validada. A análise de regressão foi avaliada, com observação de uma boa linearidade (r = 0,9997). Os valores obtidos para a precisão e exatidão estão de acordo com as diretrizes do ICH e com a legislação brasileira. Os valores de repetibilidade e precisão intermediária foram 2,79% e 4,76%, respectivamente. Os limites de detecção e de quantificação de ácido rosmarínico foram de 1,92 µg/mL e 5,81 µg/mL, respectivamente. Os resultados mostraram que o método desenvolvido é uma técnica por CLAE-FR de confiança para a determinação de ácido rosmarínico em tintura de C. verbenacea. Além disso, essa metodologia foi aplicada em estudo sazonal, que revela uma correlação positiva relativamente forte entre o período de chuvas e o teor de ácido rosmarínico.

ABSTRACT In this study, a reverse phase-high performance liquid chromatography (RP-HPLC) technique for determination of rosmarinic acid in the Cordia verbenacea was developed and validated. A regression analysis was performed, with the observation of good linearity (r =0.999949). The values obtained for precision and accuracy determination are in agreement with ICH guidelines and the Brazilian legislation. The values of repeatability and intermediate precision were 2.79% and 4.76%, respectively. The detection and the quantitation limits of the rosmarinic acid were 1.92 µg/mL and 5.81 µg/mL, respectively. The results demonstrated that the developed method is a reliable RP-HPLC technique for the determination of rosmarinic acid in C. verbenacea tincture. In addition, this methodology was applied at a seasonal study indicating relatively strong positive correlation between the rain period and the rosmarinic acid content.

Mating system analysis in a natural population of Acacia nilotica subspecies leiocarpa.

The mating-system was investigated in a natural population of the tetraploid taxon Acacia nilotica ssp. leiocarpa using open-pollinated seeds from 15 families. Six-day-old germinated seeds were used for starch-gel electrophoresis. Three enzyme systems (ADH, EST-1, and 6PGD) were scored. Isozyme banding patterns and segregation of isozyme variants within families suggest that the species is an autotetraploid displaying tetrasomic inheritance. Estimates of single-locus (ts=0.358) and multilocus (tm=0.384) population outcrossing rates were homogeneous, and indicate substantial selfing in the population. Heterogeneity of outcrossing estimates among loci and families were marked, suggesting departure from the assumptions of the mixed-mating model. Implications of the result for the utilization of germplasm in tree-improvement programmes are noted.