2798-73-4Relevant articles and documents
Synthesis of deuterated volatile lipid degradation products to be used as internal standards in isotope dilution assays. 1. Aldehydes
Lin, Jianming,Welti, Dieter H.,Arce Vera, Francia,Fay, Laurent B.,Blank, Imre
, p. 2813 - 2821 (1999)
The isotopically labeled compounds [5,6-2H2]hexanal (d-I), [2,3-2H2]-(E)-2-nonenal (d-II), [3,4-2H2]-(E,E)-2,4-nonadienal (d-III), and [3,4-2H2]-(E,E)-2,4-decadienal (d-IV) were prepared in good yields using new or improved synthesis procedures. Labeling position, chemical purity, and isotopic distribution of the compounds were characterized by various MS and NMR techniques. These molecules are used as internal standards in quantification experiments based on isotope dilution assay. Synthesis of d-I, d-III, and d-IV has not yet been reported in the literature.
Characterization of the key aroma compounds in apricots (Prunus armeniaca) by application of the molecular sensory science concept
Greger, Veronika,Schieberle, Peter
, p. 5221 - 5228 (2008/02/10)
An aroma extract dilution analysis applied on an aroma distillate prepared from fresh apricots revealed (R)-γ-decalactone, (E)-β-damascenone, δ-decalactone, and (R/S)-linalool with the highest flavor dilution (FD) factors among the 26 odor-active compounds identified. On the basis of quantitative measurements performed by application of stable isotope dilution assays, followed by a calculation of odor activity values (OAVs), β-ionone, (Z)-1,5-octadien-3-one, γ-decalactone, (E,Z)-2,6-nonadienal, linalool, and acetaldehyde appeared with OAVs >100, whereas in particular certain lactones, often associated with an apricot aroma note, such as γ-undecalactone, γ-nonalactone, and δ-decalactone, showed very low OAVs (5). An aroma recombinate prepared by mixing the 18 most important odorants in concentrations as they occurred in the fresh fruits showed an overall aroma very similar to that of apricots. Omission experiments indicated that previously unknown constituents of apricots, such as (E,Z)-2,6-nonadienal or (Z)-1,5-octadien-3-one, are key contributors to the apricot aroma.
Selective inhibition of bovine plasma amine oxidase by homopropargylamine, a new inactivator motif
Qiao, Chunhua,Jeon, Heung-Bae,Sayre, Lawrence M.
, p. 8038 - 8045 (2007/10/03)
Propargylic and activated allylic amines are known to inactivate the quinone-dependent plasma amine oxidases, possibly through active-site modification by the α,β-unsaturated aldehyde turnover products. Although homopropargylamine (1-amino-3-butyne, 1) is a nonobvious candidate as a mechanism-based inhibitor, 1 was found to be an unusually potent time- and concentration-dependent irreversible inactivator of bovine plasma amine oxidase (BPAO), exhibiting a 30 min IC50 of 2.9 μM at 30 °C ([BPAO] = 1.2 μM). Preserved cofactor redox activity of the denatured inactivated enzyme indicates that inactivation by 1 involves either a cofactor modification that reverses upon enzyme denaturation or a modification of an active-site residue. Because inactivation by 1 may involve enzyme alkylation by the reactive 2,3-butadienal (3) tautomer of the 3-butynal turnover product of 1, aldehyde 3 was prepared and was found to inactivate BPAO, but only at high concentration. In addition, whereas inhibition by 3 was blunted by the presence of mercaptoethanol, no such protection was observed against 1. The amine whose turnover should lead directly to 3 was prepared (1-amino-2,3-butadiene, 4) and was found to be an even more potent inactivator of BPAO than 1, exhibiting a 5 min IC50 of 1.25 μM. Rat liver mitochondrial monoamine oxidase was also inactivated by 4, as expected, but only very weakly by 1. Potential mechanisms explaining the selective inhibition of BPAO by 1 are discussed.
Reactions of Unsaturated Azides, 8. - Azidobutatriene and Azidobutenynes
Banert, Klaus
, p. 1175 - 1178 (2007/10/02)
When 1-azido-4-chloro-2-butyne (11), obtained from 1,4-dichloro-2-butyne (10), is treated with sodium hydroxide in methanol, 4-ethynyl-1H-1,2,3-triazole (19) is the main product besides the two triazoles 9 and 21.On the way from 11 to 19 and 21 azidobutatriene (14) most probably acts as a short-lived intermediate leading to five-membered heterocyclic compounds as azidoallenes do.In contrast to 14, the azidobutenynes 23 and 27 are relatively stable.They mainly give 2H-azirines (24, 28) on thermolysis and photolysis. - Keywords: Azidobutatriene, ring closure of; Triazole, preparation via azidobutatriene; Azirines
HYDROBORATION OF METHOXYENYNES. A NOVEL SYNTHESIS OF (E)-METHOXYENONES
Zweifel, George,Najafi, M. Ramin,Rajagopalan, Shyamala
, p. 1895 - 1898 (2007/10/02)
Chemo- and regioselective hydroboration of (Z)-methoxyenynes with dialkylboranes furnishes organoboranes which produce on oxidation the synthetically valuable (E)-methoxyenones
METHANOLYSIS OF VICINALLY SUBSTITUTED TETRAHALOGENOBUTENES
Mavrov, M. V.
, p. 626 - 632 (2007/10/02)
The methanolysis of Z,E-1,2,3,4-tetrabromo-1-butene in the presence of strong bases leads predominantly to the formation of the ortho ester 1,1,1-trimethoxy-2,3-butadiene and the ether-acetal 1,1,4-trimethoxy-2-butyne.In the case of E-2,3-dibromo-1,4-dichloro-2-butene it leads predominantly to the ortho ester.During the reaction 10-12 linear unsaturated products containing 1-3 methoxyl groups are formed as side products.
Alkine und Cumulene, XV. Ueber die Photodimerisierung konjugierter Enine
Eisenhuth, Ludwig,Siegel, Herbert,Hopf, Henning
, p. 3772 - 3788 (2007/10/02)
On irradiation in the presence of triplet sensitizers having a triplet energy >250 KJ/mol, vinylacetylene (1a) dimerizes to cis- and trans-1,2-diethynylcyclobutane (cis- and trans-2) as well as minor amounts of 4-ethynyl-1-vinylcyclobutene (3).The effect of substituents on the course of the reaction is investigated: whereas alkyl, vinyl, and phenyl substituents, respectively, in the 4-position of 1a do not influence the photoaddition, 2-substituted enynes yield the corresponding cyclobutanes in poor yields only.Finally, 1-substituted vinylacetylenes (besides the substituents mentioned above the influence of ethynyl, chloro, and methoxy groups has been investigated) do not provide photodimers; they are cis-trans-isomerized instead.The mechanism of the photoaddition is discussed.
