[7] Thapsigargin treatment and the resulting ER calcium depletion inhibits autophagy independent of the UPR.

The ring closing is important, because it will proceed via 1,10 - epoxidation in order to retain the 4,5 - double bond needed in thapsigargin.

It is not known whether the secondary modifications to the guaianolide occur before, or after the formation of thapsigargin, but will need to be considered when elucidating the true biosynthesis.

[10] Since inhibition of SERCA is a mechanism of action that has been used to target solid tumors, thapsigargin has attracted research interest.

[17] Preclinical studies demonstrated that other effects of thapsigargin include suppression of nicotinic acetylcholine receptors activity in neurons of the guinea-pig ileum submucous plexus[18] and rat superior cervical ganglion.

S.; Bajaj, S. O "Promising anticancer drug thapsigargin: A perspective toward the total synthesis" Synthetic communication 2018, 48(1), 1-13/>