| 摘要 |
<p>A method for separating and purifying individual benzophenanthridine alkaloids from alkaloid extracts by using the pH differences in formation of their respective alkanolamine or base forms and iminium ions. The insoluble base form of the alkaloid is collected as a precipitate and dissolved in an organic solvent and converted to the insoluble iminium ion form with a mineral or organic acid.</p> |
