Isolation of two new C-glucofuranosyl isoflavones fromPueraria lobata(Wild.) Ohwi with HPLC–MS guiding analysis

A profiling analysis of the total isoflavone extract of the root of Pueraria lobata (Wild.) Ohwi was performed using HPLC coupled with ESI-ion trap mass spectrometry. A total of seven isoflavones were identified according to their retention times, UV, MS data, and comparing with the literature data. Among them, two proposed new compounds were isolated and their structures were determined to be 8-C-alpha-glucofuranosyl-7,4'-dihydroxyisoflavone and 8-C-beta-glucofuranosyl-7,4'-dihydroxyisoflavone, named as neopuerarin A (7) and neopuerarin B (6), on the basis of chemical and spectral analyses.