N-phthaloylglycine-derived strigol analogues. Influence of the D-ring on seed germination activity of the parasitic weeds Striga hermonthica and Orobanche crenata

Several strigol analogues with modifications in the D-ring were synthesized and assayed for germination stimulatory activity of seeds of Striga hermonthica and Orobanche crenata. All of these D-ring analogues are derived from N-phthaloylglycine as the common ABC-fragment. It was concluded that the correct structure of the 2(5H)-furanone D-ring is essential to retain full biological activity. Keywords: Striga; Orobanche; germination; strigol analogue