43060-37-3Relevant articles and documents
Improved selectivity of an engineered multi-product terpene synthase
Lauchli, Ryan,Pitzer, Julia,Kitto, Rebekah Z.,Kalbarczyk, Karolina Z.,Rabe, Kersten S.
, p. 4013 - 4020 (2014)
Mutation of the sesquiterpene synthase Cop2 was conducted with a high-throughput screen for the cyclization activity using a non-natural substrate. A mutant of Cop2 was identified that contained three amino acid substitutions. This mutant, 17H2, converted the natural substrate FPP into germacrene D-4-ol with 77% selectivity. This selectivity is in contrast to that of the parent enzyme in which germacrene D-4-ol is produced as 29% and α-cadinol is produced as 46% of the product mixture. The mutations were shown to each contribute to this selectivity, and a homology model suggested that the mutations lie near to the active site though would be unlikely to be targeted for mutation by rational methods. Kinetic comparisons show that 17H2 maintains a kcat/KM of 0.62 mM-1 s -1, which is nearly identical to that of the parent Cop2, which had a kcat/KM of 0.58 mM-1 s-1. This journal is the Partner Organisations 2014.
Stereochemistry of 1,6-germacradien-5-ol, a constituent of the needles of Scots pine (Pinus sylvestris) and of the defence secretion from larvae of the pine sawfly Neodiprion sertifer
Nordin,Hedenstrom,Hogberg
, p. 124 - 132 (2007/10/03)
(-)-1,6-Germacradien-5-ol [(E,E)-1,5-dimethyl-8-isopropylcyclodeca-1,6-dien-5-ol, 1] has been isolated from the defence secretion from larvae of the pine sawfly Neodiprion sertifer and from needles of Scots pine (Pinus sylvestris). It was characterized by means of spectroscopic methods and by its optical rotation. Acid-promoted transannular cyclisation isomerised 1 to the known (-)-α-cadinol (4), whereby the configuration at position 8 was established as S. The configuration at the second stereocentre, position 5, carrying the alcohol group is discussed on the basis of molecular mechanics calculations (MM2), NMR shift values, coupling constants and NOESY experiments. 1-endo-Bourbonanol (7a) and (-)-5-methoxy-1,6-germacradiene (8) were prepared from 1 and investigated by NMR spectroscopy. The evidence collected indicated that the stereoisomer isolated was (5S,8S)-1,6-germacradien-5-ol.
STEREOSELEKTIVE TOTALSYNTHESE VON (+/-)-TORREYOL
Franke, L.R. Rodriguez-Avial,Wolf, H.,Wray, V.
, p. 3491 - 3498 (2007/10/02)
Enones of formulae Ia-d undergo cyclization to give stereoselectively the enol esters IIa-d, respectively.IIa-d are suitable synthones for some sesquiterpene syntheses.-In this paper the synthesis of torreyol (1) is described by an all step strereocontrolled reaction sequence: cyclization educt 10 (Ic) was prepared by alkylation of 8 with 5 and enol ether cleavage of 9.The reaction sequence 11a (IIc)14a 1518 (ester hydrolysis, formation of the tert. alcohol, degradation of the isopropenyl group) followed by oxidation resulted in the formation of ketone 19 whose relative configuration was determined by the 2D J-resolved 400 MHz (1)H NMR spectrum.After methylation at C-8 (2223) the tosylhydrazone 25 underwent Bamford-Stevens reaction to yield (+/-)-1.