Transferrin (
Transferrin, TRF, TF) has drawn increasing attention in
cancer therapy due to its potential applications in
drug delivery. TF receptor, highly expressed in
tumor cells, recognizes and transports Fe(3+)-TF into cells to release
iron into cytoplasm. Thus, discovering TF-binding compounds has become an active research area and is of great importance for target
therapy. In this study, an on-line analysis method was established for screening TF-binding compounds from the flowers of Bauhinia blakeana Dunn using a high-performance liquid chromatography-diode-array detector-multi-stage mass spectrometry-
transferrin-fluorescence detector (HPLC-DAD-MS(n)-TF-FLD) method. As a result, 33 of 80 identified or tentatively characterized compounds in the sample were TF-binding active. Twenty-five
flavonol glycosides and eight phenolic
acids were identified as TF-binders. Twelve of these active compounds together with six standard compounds were used to study the dose-response effects and structure-activity relationships of
flavonoids and phenolic
acids. The method was validated by
vitexin with a good linearity in the range of concentrations used in the study. The limit of detection for
vitexin was 0.1596 nmol. Our study indicated that the established method is simple, rapid and sensitive for screening TF-binding active compounds in the extract of Bauhinia blakeana Dunn, and therefore is important for discovering potential anti-
cancer ingredients from complex samples for TF related
drug delivery.