A61K31/395
having nitrogen as a ring hetero atom, e.g. guanethidine or rifamycins
A61K31/395
having nitrogen as a ring hetero atom, e.g. guanethidine or rifamycins
A61K31/435
having six-membered rings with one nitrogen as the only ring hetero atom
A61K31/435
having six-membered rings with one nitrogen as the only ring hetero atom