Geranins C and D, additional new antiprotozoal A-type proanthocyanidins from Geranium niveum

Two new additional A-type proanthocyanidins have been isolated from Geraniu m niveum. Their structures were determined by spectroscopic, chemical and c hiroptical methods as epi-afzelechin-(4 beta -->8,2 beta -->O -->7)-galloca techin (1) and epi-afzelechin-(4 beta -->8,2 beta -->O -->7)-afzelechin-(4 beta -->8,2 beta -->O -->7)-afzelechin (2). Proanthocyanidins 1 and 2 were given the trivial names of geranins C and D, respectively. Compound 2 showe d moderate antiprotozoal activity against Entamoeba histolytica and Giardia lamblia, whereas 1 exhibited weak activity toward E. histolytica.