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Alectrol was originally isolated from root exudates of cowpea (Vigna unguiculata) as a germination stimulant for Striga gesnerioides and Alectra vogelii. The strigolactone was also isolated from red clover (Trifolium pretense) as a stimulant for Orobanche minor and identified most probably as (+)-orobanchyl acetate. However, authentic (+)-orobanchyl acetate induced negligible S. gesnerioides seed germination. In this study, the germination stimulants for seeds of S. gesnerioides produced by cowpea were reinvestigated. Root exudates of cowpea were collected and fractionated. Two germination stimulants were detected. Based on chromatographic behavior on HPLC and physicochemical properties including CD and NMR spectra, structures of the isolated stimulants were determined as ent-2'-epi-orobanchol and ent-2'-epi-orobanchyl acetate. The same strigolactones were identified in root exudates of red clover.