Assertion: alkaloid's activity | /r/HasProperty | biological
Facets:
Source sentences:
text: Based upon the understanding of the biological activity of benzophenanthridine alkaloids as conveyed by the art, it is expected that these alkaloids would have no biological activity at an approximately neutral pH or above.
text: The biological activity, however, is believed to be associated with the iminium structure, which is the predominant structure at the lower pH. Consequently, it is surprising to find according to the present invention that the benzophenanthridine alkaloids have increased biological activity at such higher pH's and very little activity at lower pH's which cause the iminium structure to be predominant.
text: To have biological activity, the benzophenanthridine alkaloid is maintained as the free amine either by control of the pH of the carrier, permanent synthetic alteration of the alkaloid structure into the free amine or formation of a chemically equilibrated free amine.