Identification of a Component that Induces Flowering of Lemna among the Reaction Products of α-Ketol Linolenic Acid (FIF) and Norepinephrine

Identification of reaction products of 9-hydroxy-10-oxo-12(Z),15(Z)-octadecadienoic acid (KODA) and norepinephrine that strongly induce flowering in Lemna

“…Catecholamine structure is also important for flowerinducing activity in Lemna (Yamaguchi et al 2001). Catecholamines are widespread in the plant kingdom, as well as in mammals (Smith 1977).…”

“…However, we can not rule out the possibility that compounds other than FN1, FN7 or FN10 are the active agents in L. paucicostata in vivo. Other active adducts may be generated by the reactions of other catecholamines, such as dopamine and epinephrine (Yamaguchi et al 2001). Structure-activity analyses of many adducts reveal the essential structural requirements for flowering-inducing activity in L. paucicostata in nature, and thereby provide clues as to the mechanism involved and the development of a flower-regulating agent.…”

“…Fractions were collected at 5-minute intervals and assayed for flower-inducing activity; every fraction showed distinct activity (Yamaguchi et al 2001). We planned to isolate the components in peaks FN6, FN7, and FN10, in addition to FN1, because they seemed to show the highest activities.…”

“…Thus, the structure of FN7-1 was presumed to be as shown in Figure 2. In order to identify the epimers of FN7, 9R-and 9S-KODA, isolated on a Chiralcel OD-R column (Daicel Chemical Industries, Ltd, Tokyo) (Yamaguchi et al 2001), were separately reacted with NE. Reverse-phase HPLC (30% CH 3 CN, 0.1% TFA) comparison of the products with the epimers of FN7 indicated that FN7-1 is the 9R-epimer and FN7-2 is the 9S-epimer.…”

“…However, other active components were also generated in smaller amounts in the incubation mixture of KODA and NE (Yamaguchi et al 2001). Here we report the structures of two new components of the mixture.…”