15438-93-4Relevant academic research and scientific papers
Mechanism-Based Post-Translational Modification and Inactivation in Terpene Synthases
Kersten, Roland D.,Diedrich, Jolene K.,Yates, John R.,Noel, Joseph P.
, p. 2501 - 2511 (2015/12/01)
Terpenes are ubiquitous natural chemicals with diverse biological functions spanning all three domains of life. In specialized metabolism, the active sites of terpene synthases (TPSs) evolve in shape and reactivity to direct the biosynthesis of a myriad of chemotypes for organismal fitness. As most terpene biosynthesis mechanistically involves highly reactive carbocationic intermediates, the protein surfaces catalyzing these cascade reactions possess reactive regions possibly prone to premature carbocation capture and potentially enzyme inactivation. Here, we show using proteomic and X-ray crystallographic analyses that cationic intermediates undergo capture by conserved active site residues leading to inhibitory self-alkylation. Moreover, the level of cation-mediated inactivation increases with mutation of the active site, upon changes in the size and structure of isoprenoid diphosphate substrates, and alongside increases in reaction temperatures. TPSs that individually synthesize multiple products are less prone to self-alkylation then TPSs possessing relatively high product specificity. In total, the results presented suggest that mechanism-based alkylation represents an overlooked mechanistic pressure during the evolution of cation-derived terpene biosynthesis.
Synthesis of the racemate of (Z)-exo-alpha-bergamotenal, a pheromone component of the white-spotted spined bug, Eysarcoris parvus Uhler.
Alizadeh, Babak Heidary,Kuwahara, Shigefumi,Leal, Walter Soares,Men, Hong-Chao
, p. 1415 - 1418 (2007/10/03)
The racemate of (Z)-exo-alpha-bergamotenal, a sex pheromone component of the white-spotted spined bug, was synthesized from racemic exo-alpha-bergamotene by a five-step sequence involving regioselective epoxidation and (Z)-selective Wittig olefination reactions. The 1H- and 13C-NMR spectra of the synthetic sample were identical with those of the natural material.
Identification of &α-Santalenoic and endo-&β-Bergamotenoic Acids as Moth Oviposition Stimulants from Wild Tomato Leaves
Coates, Robert M.,Denissen, Jon F.,Juvik, John A.,Babka, Barbara A.
, p. 2186 - 2192 (2007/10/02)
The presence of oviposition-stimulating phytochemicals in hexane extracts of whole leaves of wild tomato (Lycopersicon hirsutum) accession LA 1777 was indicated by oviposition preference assays with gravid female Heliothis zea (Boddie) moths.Three sesquiterpenes isolated from these extracts were identified as (+)-(E)-α-santalen-12-oic acid (1a), (+)-(E)-endo-β-bergamoten-12-oic acid (2a), and (-)-(E)-endo-α-bergamoten-12-oic acid (3a).Structure assignments based primarily on 1H and 13C NMR spectral interpretations were confirmed by conversion to the parent sesquiterpene hydrocarbons and subsequent comparisons with authentic endo-β-bergamotene and/or literature data.The identity of 1a was verified by comparison of its methyl ester (1b) with a sample synthesized from (+)-α-santalol (9).Quantitative assays demonstrated that the two major sesquiterpene acids, 1a and 2a, are the principal oviposition stimulants in the tomato leaf extracts and that the activity of 2a is about twice that of 1a.
Synthesis of Terpenes Containing the Bicycloheptane Ring System by the Intramolecular Cycloaddition Reaction of Vinylketenes with Alkenes. Preparation of Chrysanthenone, β-Pinene, β-cis-Bergamotene, β-trans-Bergamotene, β-Copaene, and β-Ylangene and Lemnalol
Kulkarni, Yashwant S.,Niwa, Maho,Ron, Eyal,Snider, Barry B.
, p. 1568 - 1576 (2007/10/02)
Treatment of geranoyl chloride (20) with triethylamine in toluene at reflux gave the vinylketene 21 which underwent a cycloaddition to give 7,7-dimethyl-2-methylenebicycloheptan-6-one (24) in 43percent yield.Isomerization over Pd gave chrysanthenone (6) in quantitative yield.Wolf-Kischner reduction gave β-pinene (5) in 70percent yield.A similar sequence of reactions starting from (Z,E)- and (E,E)-farnesoyl chloride gave ketones 51 and 57, which were converted to β-cis-bergamotene (8) and β-trans-bergamotene (9), respectively. β-Copaene (10) and β-ylangene (11) were prepared from 57 by a three-step sequence.Treatment of the imidazole 59 with tri-n-butyltin hydride in toluene at reflux gave a 46percent yield of a 1:1 mixture of 10 and 11.Selenium dioxide oxidation of 11 gave the antitumor agent lemnalol.The mechanisms of the regiospecific ketene generation and the cycloaddition reaction have been explored, and the reactivity of the novel bicycloheptanones has been examined.
Intramolecular Cycloadditions of Ketenes. 2. Synthesis of Crysanthenone, β-Pinene, β-cis-Bergamotene, and β-trans-Bergamotene
Kulkarni, Yashwant S.,Snider, Barry B.
, p. 2809 - 2810 (2007/10/02)
Vinylketenes prepared from geranoyl and farnesoyl chloride by treatment with triethylamine react to give bicycloheptanones which can be converted to β-pinene and the β-bergamotenes by Wolff-Kishner reduction.
SIMPLE SYNTHESIS OF (+)-β-TRANS-BERGAMOTENE
Corey, E. J.,Desai, Manoj C.
, p. 3535 - 3538 (2007/10/02)
(+)-β-trans-Bergamotene (4) has been synthesized in five steps from geranylacetone using intramolecular ketene-olefin cycloadditon as a key step.
SIMPLE SYNTHESES OF (+/-)-β-COPAENE, (+/-)-β-YLANGENE AND LEMNALOL.
Snider, Barry B.,Kulkarni, Yashwant S.
, p. 5675 - 5676 (2007/10/02)
The ketone 1a, which we have prepared from geranylacetone in 38percent yield by a four step sequence, has been converted to β-copaene and β-ylangene by a three step secquence.Oxidation of β-ylangene with SeO2 gives lemnalol in 76percent yield.
