The pollen of rye (Secale cereale) was shown to contain a biologically highly active family of glycosides called the secalosides. Secalosides A and B (1), both of molecular formula C46H51-NO24, were found to be epimeric esters of (2-oxo-3-indolyl)acetic acid (4). They are made up, in addition to this heterocyclic aglycon I (4), of three hexose building blocks and a carbocyclic aglycon II, which...