(+)-Strigol, a witchweed seed germination stimulant, from Menispermum dauricum root culture

Production of (+)-5-deoxystrigol by Lotus japonicus root culture

“…Hydroxylation at C-4 and C-5 of (+)-5-deoxystrigol (1) converts the possible intermediate to orobanchol (4) and (+)-strigol (2), respectively, and demethylation at C-9 affords sorgolactone (5). However, no activity was detected in hexane extracts obtained from culture filtrate of high (+)-strigol-producing M. dauricum roots (Yasuda et al, 2003), although the deoxy-derivative appears to be more stable than strigol under our experimental conditions. Further work is necessary to elucidate the biosynthetic pathway of strigolactones.…”

“…Formation of the active compounds accelerated as roots entered late-log phase, typical to the formation of secondary metabolites (Sugimoto et al, 2007). Finding the activity in the hexane extracts suggested that the roots produce and secrete less polar stimulant(s) than (+)-strigol (2), which was not extracted by an apolar solvent (Yasuda et al, 2003). In the light of a previous finding that production of strigolactones by red clover roots was stimulated under low phosphate conditions (Yoneyama et al, 2001), L. japonicus roots were cultured in media with different concentrations of phosphate for 20 days and germination-inducing activity in each of the culture filtrates was evaluated ( Fig.…”

“…However, while only one major fraction with germination-inducing activity was obtained from EtOAc extracts of M. dauricum root culture filtrate (Yasuda et al, 2003), more than seven fractions with the activity were found in EtOAc extracts of L. japonicus root culture filtrate after separation by analytical HPLC. Their purification is currently under way.…”

“…We have previously reported production of (+)-strigol (2) by Menispermum dauricum root culture (Yasuda et al, 2003). Isolation of the strigolactone from the aseptic root culture provided the first unambiguous demonstration that strigolactones are genuine products of the plant roots.…”

Reporter Gene-Facilitated Detection of Compounds in Arabidopsis Leaf Extracts that Activate the Karrikin Signaling Pathway

“…To our surprise, the active compound(s) appeared to be water-soluble and inefficiently extracted into ethyl acetate. This is in marked contrast to KAR 1 and SLs, which are usually extracted into organic solvents such as ether or ethyl acetate (Yasuda et al, 2003; Flematti et al, 2004). …”