Unnatural natural triterpenes produced by altering isoleucine into alanine at position 261 in hopene synthase and the importance of having the appropriate bulk size at this position for directing the stereochemical destiny during the polycyclization cascadeElectronic supplementary information (ESI) available: EIMS and NMR assignments. See http://www.rsc.org/suppdata/cc/b0/b000711k/

Abstract

Incubation of squalene with the site-directed mutant of Ile261Ala of squalene-hopene cyclase from Alicyclobacillus acidocaldarius afforded multiple triterpenes consisting of tri-, tetra- and penta-cyclic skeletons, together with a final product of hopene, among which the previously unknown 6/6/6/6-fused tetracyclic skeletal compounds, denoted prohopene A and B, are included.