adrenolytic and hypoglycaemic, tetr:hydro alstonine prepn. - by extn. of Apocynaceous plants and borohydride redn.

摘要

Tetrahydroalstonine (I) is prepd. from plants of the Apocynaceous family by (a) extracting the plants (aq) alcohol, (b) concentrating the extract, (c) reducing the conc. extract, nd) filtering off the pptd. raubasine to give crude (I) in the organic phase, (e) converting the crude (I) to the citrate, and (f) taking up the citrate in 95 degrees ethanol to give pure (I). (I) has antihyperglycaemic and cerebral vasodilating activity. Much better yields of (I) are obtd. than are possible with previous methods.