Northwestern Chemists Solve 30-Year Rye Pollen Mystery — SkimNews
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- Karl A. Scheidt and Northwestern chemists confirmed the structures of secalosides A and B, molecules discovered ~30 years ago in rye pollen whose tumor-slowing effects in animal studies could never be followed up because no one could resolve their 3D shape.
- The team used total synthesis to construct both competing structural models, which were identical except as mirror images at one critical region — a difference Scheidt compared to needing a left-handed glove for a right hand.
- Both candidate structures contained an extremely rare, highly strained 10-membered ring at their core; the researchers built it by first assembling a larger flexible ring and then triggering a one-step chemical contraction.
- After synthesizing both versions, the team compared them against natural rye pollen extracts and found only one matched perfectly, ending decades of structural debate.
- The result was published as "Synthesis and Structural Confirmation of Secalosides A and B" in the Journal of the American Chemical Society (2025, Vol. 148, Issue 1), with funding from the National Institute of General Medical Science, the NSF, and Northwestern's Chemistry of Life Processes Institute.
- Now that the structures are known, Scheidt's group plans to identify which molecular region drives immune-system interactions and is actively seeking immunology collaborators for possible clinical translation.
- Rye pollen extract is already sold commercially as a dietary supplement marketed for prostate health, though it has never been developed as a pharmaceutical — the unresolved molecular structure had been a major barrier to that path.
Why it matters: Drug development requires a known molecular structure to design derivatives with predictable biological activity. Until now, scientists couldn't reliably distinguish which of two mirror-image forms of secalosides A and B actually occurs in nature, making the supplement-on-shelves cancer angle essentially untestable. With the structure settled, the field can finally isolate which fragment drives immune effects and engineer optimized versions.
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