Determination of indirubin and indigo in Baphicacanthus cusia (Nees) Bremek by HPLC

Objective To establish a method for content determination of indirubin and indigo in Baphicacanthus cusia (Nees) Bremek. Method HPLC was used with C18 column, methanol-water (75:25) as mobile phase and detecting wavelength 289 nm. Results The range linear curve was 3.875 approximately 23.25 microg/ml (indirubin), 3.05 approximately 18.3 microg/ml (indigo). The average recovery was 96.9%, RSD =3.5%, n =5 (indirubin); 96.9% RSD = 2.8%, n = 5 (indigo). Conclusion The method is proper for the quality control of Baphicacanthus cusia (Nees) Bremek.