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Abstract Ubiquinone mimics known as quinone outside inhibitors (QoIs) are one of the most prominent fungicides used to protect crops in the agricultural industry. Due to chemotype similarities with known QoIs, peniciaculin A, a triaryl natural product, was proposed to exhibit similar broad spectrum antifungal activity against phytopathogens. Instability of the tertiary alcohol and phenol motif, however, prompted exploration of the antifungal properties of simplified analogues to probe possible overlap in mechanism of action between the natural product and QoIs. Peniciaculin A inspired analogues mimicking known QoI scaffolds displayed broad spectrum antifungal activity while those containing scaffolds dissimilar to QoIs possessed negligible bioactivity. These activity profiles suggest peniciaculin A is likely acting as a QoI. 

Abstract Synthetic investigations of natural products has been instrumental in the development of novel antibacterial small molecules. 1‐hydroxyboivinianin A, a lactone containing phenolic bisabolane isolated from marine sediment, has reported antibacterial activity against the aquatic pathogenVibrio harveyi. The total synthesis of 1‐hydroxyboivinianin A and its enantiomer was completed in a six‐step sequence in 42 % overall yield. The synthesis leveraged a key diastereoselective nucleophilic addition with chiral imidazolidinone to establish the benzylic tertiary alcohol and intramolecular Horner‐Wadsworth Emmons to furnish the lactone. Both enantiomers were found to have negligible antibacterial activity against a panel of gram‐positive and negative bacteria and minimal antifungal activity against phytopathogens. Investigations of a possiblein vitrolactone hydrolysis to produce an inactive linear acid led to the discovery of a spontaneous cyclization, suggesting the lactone is resistant to hydrolysis and the lactone is not degrading to produce an inactive species.