Distribution of hydroxyanthracene derivatives in Cassia alata and the factors affecting the quality of the raw material

Analyses have been carried out on the content of hydroxyanthracene derivatives of the leaves, flowers and pods of Cassia alata, which had been collected at different harvesting times and different leaf-positions. It was found that when the leaves had been harvested in March, June or September, the hydroxyanthracene derivatives were accumulated more in the leaf-positions 1-3 (1.82, 1.25, 1.63 %w/w, respectively) and 4-6 (1.39, 1.58, 1.09 %w/w, respectively). In December (the flowering and fruiting season), hydroxyanthracene derivatives were accumulated more in the flowers (2.21%w/w) and the pods (1.82 %w/w), respectively. The method and temperature of drying markedly affected the hydroxyanthracene derivative content. Drying of the leaves in a hot air oven at 50oC gave a higher hydroxyanthracene derivative content (1.43 %w/w) than drying in a hot air oven at 80oC (0.44 %w/w) or drying in the sun (0.95 %w/w). Study on the stability of hydroxyanthracene derivatives in C. alata leaf powder, which was kept in tight container at room temperature, found that the hydroxyanthracene derivative content did not decrease within 9 months.