SEASONAL VARIATION IN PRODUCTION OF THE HEAD AND ACCUMULATION OF GLYCOSIDES IN THE HEAD OF MATRICARIA CHAMOMILLA

In order to know the appropriate harvest time in the cultivation of the medicinal plant, M. chamomilla L., we investigated seasonal variation in the yield of the head (capitula) and the content of two phenylpropanoid glycosides; (1) cis- and (2) trans-2--D-glucophyranosyloxy-4-methoxy cinnamic acid and one flavonoid glycoside; (3) cosmosiin (apigenin-7-o--D-glucophyranoside) in the heads harvested during the flowering time from May to July in 1993.

The maximum head size was observed at the beginning of May, and then the size which was harvested later season decreased as the size and number of ligulate flowers decreased. But those of tubular flowers did not decrease significantly.

The content of glycoside (1) was the highest among the three glycosides during the flowering time. (1) and (2) were concentrated at about 2.0% and 0.5% in the heads harvested from the end of May to the middle of June respectively. Then the content of (1) decreased rapidly but (2) decreased gradually. These two kinds of glycosides were more in the ligulate flowers than tubular flowers, but the dry weight ratio of the ligulate flowers to the tubular flowers in a head was 1/6–1/10. Therefore, the decreases of (1) and (2) did not seem to be attributable to the decrease of the ligulate flowers. The content of (3) became higher in an early time.

The results indicate that harvesting the heads from the beginning to the middle of June is appropriate for the preparation of the crude drug.