Importance of the methyl group at C10 of squalene for hopene biosynthesis and novel carbocyclic skeletons with 6/5 + 5/5 + (6) ring system(s).
[reaction: see text] Incubation of (6E,10E,14E,18E)-2,6,10,19,23-pentamethyl-tetracosa-2,6,10,14,18,22-hexaene with Alicyclobacillus acidocaldarius hopene cyclase afforded four products having two types of carbocyclic skeletons, i.e., two hopane products and two products having an unprecedented carbocyclic skeleton of 6/5 + 5/5 +6 pentacyclic and 6/5 + 5/5 tetracyclic ring systems. The former two hopane skeletons were formed from the bioconversion of C15-desmethylsqualene and the latter two skeletons from that of C10-desmethylsqualene.
Hoshino
Tsutomu
T
Department of Applied Biological Chemistry, Faculty of Agriculture, and Graduate School of Science and Technology, Niigata University, Ikarashi, Niigata 950-2181. hoshitsu@agr.niigata-u.ac.jp
Ohashi
Shumi
S
D001407:Bacillus / Q000201:enzymology; D003500:Cyclization; D006840:Hydrocarbons, Alicyclic / Q000737:chemistry / Q000378:metabolism; D019751:Intramolecular Transferases / Q000378:metabolism*; D011108:Polymers / Q000737:chemistry; D013185:Squalene / Q000737:chemistry / Q000378:metabolism*; D014315:Triterpenes / Q000378:metabolism*
D006840:Hydrocarbons, Alicyclic; D011108:Polymers; D014315:Triterpenes; C028765:diploptene; D013185:Squalene; D019751:Intramolecular Transferases; C066630:squalene-hopene cyclase