The dried powder of Oroxylum indicum bark (9.2 kg) was extracted four times with methanol. The methanol extract was resolved in water and extracted with n-hexane, dichloromethane, ethyl acetate to give the partition extracts. This study only focuses on the dichloromethane extract. The dichloromethane extract (100 g) was fractionated by column chromatography to yield 12 fractions. Further separation and purification of these fractions led to the isolation of one compound. The structure of this compound has been elucidated by modern spectral data of: ¹H-NMR, ¹³C-NMR, DEPT and compared with some previous reports. The isolated compound is: ORI.P3 (Baicalein).

  This study also mentions the process of using ultra sound basin to extract flavonoid from the bark of Oroxylum indicum (L.) Vent. and UV-Vis spectroscopy to quantify the total flavonoids.