stereoselective total synthesis of (+)-pentalenene was achieved through the tandem cycloaddition reaction of the allenyl diazo substrate prepared from (+)-citronellal. The initial intramolecular [2+3] cycloaddition reaction between the diazo functionality and the allenyl group produced the trimethylenemethane (TMM) intermediate after immediate loss of nitrogen molecule from the cycloaddition intermediate.
The substrate flexibility of eight purified sesquiterpene cyclases was evaluated using six new heteroatom‐modified farnesyl pyrophosphates, and the formation of six new heteroatom‐modified macrocyclic and tricyclic sesquiterpenoids is described. GC‐O analysis revealed that tricyclic tetrahydrofuran exhibits an ethereal, peppery, and camphor‐like olfactoric scent.
Pentalenene Synthase. Analysis of Active Site Residues by Site-Directed Mutagenesis
作者:Myriam Seemann、Guangzhi Zhai、Jan-Willem de Kraker、Chiana M. Paschall、David W. Christianson、David E. Cane
DOI:10.1021/ja026058q
日期:2002.7.1
and k(cat)/K(m). By contrast, single H309 mutants gave rise to both (+)-germacrene A (7) and protoilludene (8) in addition to pentalenene (2). Mutation to glutamate of each of the three aspartate residues in the Mg(2+)-binding aspartate-rich domain, (80)DDLFD, resulted in reduction in the k(cat)/K(m) for farnesyl diphosphate and formation of varying proportions of pentalenene and (+)-germacrene A (7)
Theoretical Studies on Farnesyl Cation Cyclization: Pathways to Pentalenene
作者:Pradeep Gutta、Dean J. Tantillo
DOI:10.1021/ja058031n
日期:2006.5.1
In this article, we describe studies, using quantum chemical computations, on possible polycyclization pathways of the farnesyl cation leading to the complex sesquiterpene pentalenene. Two distinct pathways to pentalenene with similar activation barriers are described, each differing from previous mechanistic proposals, and each involving unusual and unexpected intermediates. Direct deprotonation of
A Gene Cluster for Biosynthesis of the Sesquiterpenoid Antibiotic Pentalenolactone in <i>Streptomyces avermitilis</i>
作者:Charles N. Tetzlaff、Zheng You、David E. Cane、Satoshi Takamatsu、Satoshi Omura、Haruo Ikeda
DOI:10.1021/bi060419n
日期:2006.5.1
biochemical function of the individual biosyntheticgenes came from expression of the ptlA gene (SAV2998) in Escherichia coli. Assay of the resultant protein established that PtlA is a pentalenene synthase, catalyzing the cyclization of farnesyl diphosphate to pentalenene, the parent hydrocarbon of the pentalenolactone family of metabolites. The most upstream gene in the cluster, gap1 (SAV2990), was shown to