The plant-derived macrocyclic resin glycoside ipomoeassin F (Ipom-F) binds to Sec61α
and significantly disrupts multiple aspects of Sec61-mediated protein biogenesis at the endoplas mic reticulum, ultimately leading to cell death. However, extensive assessment of Ipom-F as a
molecular tool and a therapeutic lead is hampered by its limited production scale, largely caused
by intramolecular assembly of the macrocyclic ring. Here, using in vitro and/or in cellula biological
assays to explore the first series of ring-opened analogues for the ipomoeassins, and indeed all resin
glycosides, we provide clear evidence that macrocyclic integrity is not required for the cytotoxic
inhibition of Sec61-dependent protein translocation by Ipom-F. Furthermore, our modeling suggests
that open-chain analogues of Ipom-F can interact with multiple sites on the Sec61α subunit, most
likely located at a previously identified binding site for mycolactone and/or the so-called lateral gate.
Subsequent in silico-aided design led to the discovery of the stereochemically simplified analogue 3
as a potent, alternative lead compound that could be synthesized much more efficiently than Ipom-F
and will accelerate future ipomoeassin research in chemical biology and drug discovery. Our work
may also inspire further exploration of ring-opened analogues of other resin glycosides