61262-97-3Relevant articles and documents
Divergent synthesis of four isomers of 6,7-dihydroxy-3,7-dimethyloct-2-enoic acid, esters and evaluation for the antifungal activity
Wang, Weiwei,Zhang, Xiaoteng,Zhao, Yu,Liu, Xinlei,Zhang, Zhenhua,Wang, Mingan
supporting information, (2018/03/12)
The four isomers of 6,7-dihydroxy-3,7-dimethyloct-2-enoic acid 2 were synthesized via the selective direct Sharpless asymmetry dihydroxylation of geraniol as the key step in 35.0%-48.0% overall yields with 91.9%-97.7% ee values for esters 4 and 31.3%-36.4% overall yields with 90.3-97.5% ee values for acids 2 using cis- and trans-geraniol as raw materials. Their structures were characterized by 1H, 13C NMR and HR-ESI-MS data. The in vivo bioassay results showed that the chiral acid (Z, S)-2 was a good lead compound with 80%-100% inhibitory rates against P. cubensis, E. graminis, P. sorghi and C. gloeosporioides at the concentration of 400μg/mL.
Reconstitution of biosynthetic machinery for indole-diterpene paxilline in Aspergillus oryzae
Tagami, Koichi,Liu, Chengwei,Minami, Atsushi,Noike, Motoyoshi,Isaka, Tetsuya,Fueki, Shuhei,Shichijo, Yoshihiro,Toshima, Hiroaki,Gomi, Katsuya,Dairi, Tohru,Oikawa, Hideaki
, p. 1260 - 1263 (2013/03/29)
Indole-diterpenes represented by paxilline share a common pentacyclic core skeleton derived from indole and geranylgeranyl diphosphate. To shed light on the detailed biosynthetic mechanism of the paspaline-type hexacyclic skeleton, we examined the reconstitution of paxilline biosynthetic machinery in Aspergillus oryzae NSAR1. Stepwise introduction of the six pax genes enabled us to isolate all biosynthetic intermediates and to synthesize paxilline. In vitro and in vivo studies on the key enzymes, prenyltransferase PaxC and cyclase PaxB, allowed us to elucidate actual substrates of these enzymes. Using the isolated and the synthesized epoxide substrates, the highly intriguing stepwide epoxidation/cyclization mechanism for the construction of core structure has been confirmed. In addition, we also demonstrated "tandem transformation" to simultaneously introduce two genes using a single vector (paxG/paxB, pAdeA; paxP/paxQ, pUNA). This may provide further option for the reconstitution strategy to synthesize more complex fungal metabolites.
Total Syntheses of (+)-Thyrsiferol, (+)-Thyrsiferyl 23-Acetate, and (+)-Venustatriol
Hashimoto, Masaru,Kan, Toshiyuki,Nozaki, Koji,Yanagiya, Mitsutoshi,Shirahama, Harushia,Matsumoto, Takeshi
, p. 5088 - 5107 (2007/10/02)
The first total syntheses of (+)-thyrsiferol (1), (+)-thyrsiferyl 23-acetate (3), and (+)-venustatriol (5) have been accomplished in a stereoselective manner.An effective synthetic scheme to construct the BC ring system, which adopts a chair/twist-boat conformation, was first developed by means of a model study.This method involves stereoselective formation of the strained C ring by intramolecular attack of the C7-hydroxyl group at the C3-postion of the 2,3-epoxy alcohol, employing titanium tetraisopropoxide as an acidic activator.Based on the information accumulated in the model study and retrosynthetic considerations, the total syntheses of 1,3, and 5 were performed in the sequence of (1) construction of the BC ring system equipped with a C1-C6 carbon unit, (2) elongation of the C17-C24 carbon chain, (3) formation of a D ring through the stereoselective epoxidation of the 4-en-1-ol system and successive cyclization, and (4) construction of the A ring by bromonium ion induced cyclization of the 4-en-1-ol system.
