Characterization of aromatase binding agents from the dichloromethane extract of Corydalis yanhusuo using ultrafiltration and liquid chromatography tandem mass spectrometry

Abstract

Aromatase represents an important target for the treatment of hormone-dependent breast cancer. In the present study, nine alkaloids from the dichloromethane extract of Corydalis yanhusuo were identified by liquid chromatography tandem mass spectrometry (LC-MS/MS) and tested for their aromatase binding activities using an ultrafiltration LC-MS method by investigating the differences of peak areas of compounds before and after incubations with aromatase. It was demonstrated that the quaternary protoberberine alkaloids and the tertiary protoberberine alkaloids exhibited potent aromatase binding activities. The quaternary ammonium group and the methyl group at C-13 position of tertiary protoberberine alkaloids might be necessary for the activity. The findings should provide guidance for the discovery of potential aromatase inhibitors from natural products.

Figure 1

The HPLC-DAD chromatogram (a) and the total ion current (TIC) chromatogram (b) of the dichloromethane extract of C. yanhusuo.

Figure 2

Chemical structures of isolated compounds from the dichloromethane extract of C. yanhusuo.

Figure 3

Ultrafiltration LC-MS screening for the aromatase binding activity of naringenin. (A) Schematic of the ultrafiltration LC-MS screening method. (B) HPLC chromatograms before (blue) and after (red) incubation of naringenin with aromatase.

Figure 4

HPLC chromatograms before (black) and after (red) incubation of the dichloromethane extract of C. yanhusuo with aromatase.

Figure 5

HPLC chromatograms before (black) and after (red) incubation of the mixed reference compounds with aromatase.

Figure 6

The possible structure-binding activity relationships of the alkaloids from the dichloromethane extract of C. yanhusuo.