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
A61K31/535
having six-membered rings with at least one nitrogen and one oxygen as the ring hetero atoms, e.g. 1,2-oxazines
A61K31/535
having six-membered rings with at least one nitrogen and one oxygen as the ring hetero atoms, e.g. 1,2-oxazines