Asian Journal
Of Traditional Medicines

Abstract: 1β-hydroxyacovenosigenin (HAG) is the main sterides structure of cardiac glycosides in the family of Asclepiadaceae and Scrophulariaceae. The objective of this study is to perform a practical method to prepare HAG from roots of Streptocaulon juventas (S. juventas) to arrange raw material to synthesize an active compound of TXA9. However, it’s quite hard to get HAG from roots of S. juventas easily. To obtain the HAG efficiently, two orthogonal experiments were designed to optimize the parameters of extraction and hydrolysis condition of S. juventas. A four-factor, three-level orthogonal extracting test was projected to confirm the extraction condition of S. juventas to obtain the total cardiac glycosides (CG). The optimal parameters were determined as extraction time of 3 h, extraction number of 2 times and ethanol (EtOH, 75%) to raw material of 10-fold, respectively. The content of CG was tested with the colorimetric method. To get more HAG, the other three-factor, three-level orthogonal hydrolysis of CG experiment was studied. With the HPLC to test the peak area of HAG, the CG was hydrolyzed with hydrochloric acid (HCl, 0.1 mol/L) at 70 ºC for 1.5 h and extracted with dichloromethane for three times after each reaction. The hydrolysis reaction numbers were intended to be four times. With the optimised extracting and hydrolysis method, a solution rich of HAG and other cardiac aglycones (CA) was obtained. The solution was concentrated and purified with silica gel and ODS. 4.45 g of purified HAG was acquired from 160 kg of roots of S. juventas after recrystallising with dichloromethane/ethyl acetate for several times. The technology has been validated; it shows good results in terms of easy operation, repeatability and high scientificity. It could be used to prepare large amount of HAG in the further research.

Key words: HAG, TXA9, extract, hydrolysis, isolation, orthogonal experiment