Two new C-glucofuranosyl isoflavones in puerarin injection

Two pairs of diastereoisomeric isoflavone glucosides from the roots of Pueraria lobata

Phytochemical investigation of the roots of Pueraria lobata led to the isolation of two pairs of new isoflavone glucosides, 3'-hydroxyneopuerarin A/B (1-2) and 3'-methoxyneopuerarin A/B (3-4). A pair of known compounds (5-6), which possess a very similar structure, were obtained together. Their structures were elucidated on the basis of spectroscopic data interpretation. Compounds 3-6 dose-dependently blocked the production of TNF-α and IL-6 in LPS-stimulated RAW264.7 cells, which indicated the potential anti-inflammatory effect of these compounds.

Isolation of two new C-glucofuranosyl isoflavones from Pueraria 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.