title: Strigone, isolation and identification as a natural strigolactone from Houttuynia cordata.
abstract: (+)-Strigone was described earlier in a paper on isolation of strigol and then recently examined for hyphal branching activity in arbuscular mycorrhizal fungi as a strigolactone. Herein, it was isolated from root exudates of Houttuynia cordata, and its structure was confirmed by direct comparison with synthetic standards in LC-MS/MS, GC-MS, and (1)H and (13)C NMR analyses. The stereochemistry of strigone was determined by comparing the CD spectra and RR(t) in chiral LC-MS/MS with those of synthetic (+)-strigone and (-)-strigone. Four stereoisomers of strigone exhibited clearly different levels of stimulation activity on the seeds of three root parasitic plants, Orobanche minor, Phelipanche ramosa, and Striga hermonthica. (+)-Strigone was a highly potent germination stimulant on S. hermonthica and also on P. ramosa, but less active than ent-2'-epi-strigone on O. minor. In addition to strigone, H. cordata was found to produce strigol, sorgomol, and 5-deoxystrigol, indicating that this plant produces mainly strigol-type strigolactones derived from 5-deoxystrigol.
authors.affiliation: Weed Science Center, Utsunomiya University, 350 Mine-machi, Utsunomiya, Japan.
authors.forename: Takaya
authors.initials: T
authors.lastname: Kisugi
authors.forename: Xiaonan
authors.initials: X
authors.lastname: Xie
authors.forename: Hyun Il
authors.initials: HI
authors.lastname: Kim
authors.forename: Kaori
authors.initials: K
authors.lastname: Yoneyama
authors.forename: Aika
authors.initials: A
authors.lastname: Sado
authors.forename: Kohki
authors.initials: K
authors.lastname: Akiyama
authors.forename: Hideo
authors.initials: H
authors.lastname: Hayashi
authors.forename: Kenichi
authors.initials: K
authors.lastname: Uchida
authors.forename: Takao
authors.initials: T
authors.lastname: Yokota
authors.forename: Takahito
authors.initials: T
authors.lastname: Nomura
authors.forename: Koichi
authors.initials: K
authors.lastname: Yoneyama
mesh_terms: D052859:Houttuynia / Q000737:chemistry*; D007783:Lactones; D015394:Molecular Structure; D031672:Orobanche / Q000737:chemistry; D032134:Saururaceae / Q000737:chemistry; D034362:Striga / Q000737:chemistry
chemical_list: D007783:Lactones