The preparation of genistein and LC‐MS/MS on‐line analysis

Genistein, a promising agent for cancer chemoprevention or treatment, can be obtained from soybean seeds, via a complex isolation procedure. The objective of this study was to investigate whether natural and high purity genistein could be acquired from Sophora japonica L. via a simple approach. High‐performance liquid chromatography electrospray ionization combined with tandem mass spectrometry (LC‐ESI‐MS/MS) was used to monitor the whole process of genistein preparation. The results showed there were at least 13 types of flavonoid in the crude extracts from sophora fruits with sophoricoside being the predominant component. The products obtained from our preparation were unambiguously identified as genistein based on molecular ion [M+H]⁺, UV spectra, retention time, IR spectra, ¹HNMR, ¹⁴CNMR spectra, and tandem mass spectrometric analysis. It demonstrated that 99.6% (w/w) genistein could be obtained via our preparation protocol. Drug Dev. Res. 61: 6–12, 2004. © 2004 Wiley‐Liss, Inc.