<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>Isolation and structure elucidation of ten new scarce dihydrobenzophenanthridine alkaloids, ambidalmines A1 (Ia), B1 (Ib), their enantiomers ambidalmines A2 and B2, resp., ambidalmines C, D (IIa), E (IIb), and three stereoisomeric dimers, ambidimerines F1, F2 (III), and F3 are described.</p> </abstract>