1619-26-7Relevant academic research and scientific papers
Comparative analysis of three Australian finger lime (Citrus australasica) cultivars: Identification of unique citrus chemotypes and new volatile molecules
Delort, Estelle,Jaquier, Alain,Decorzant, Erik,Chapuis, Christian,Casilli, Alessandro,Frérot, Eric
, p. 111 - 124 (2015/02/19)
The volatile constituents of the peel of three cultivars of Australian finger lime (Citrus australasica) were investigated: Alstonville, Judy's Everbearing and Durham's Emerald. Both qualitative and quantitative GC-MS analyses were performed on their peel solvent extract. The results showed that the unique phenotypes of finger lime are also correlated to unique molecular compositions. Each cultivar revealed a different chemotype: limonene/sabinene for cv. Alstonville, limonene/citronellal/isomenthone for cv. Judy's Everbearing, and limonene/citronellal/ citronellol for cv. Durham's Emerald. To the best of our knowledge, these chemotypes have never been reported in any other citrus species. Furthermore, the amounts of some volatile constituents (γ-terpinene, α-pinene, β-pinene, citral), which are generally the major constituents besides limonene in lime species, were surprisingly low in the three cultivars. Comparative GC-MS analysis also showed that some volatile molecules tended to be specific to one cultivar and could therefore be considered as markers. Moreover six molecules were reported for the first time in a citrus extract and confirmed by synthesis. Heart-cutting enantioselective two-dimensional GC-MS was performed to determine the enantiomeric distribution of the major chiral constituents. The combined data on three finger lime cultivars gives evidence of their divergence from other citrus species.
Ruthenium(II)-Catalyzed Reactions of 1,4-Epiperoxides
Suzuki, Masaaki,Ohtake, Hiroaki,Kameya, Yoshimi,Hamanaka, Nobuyuki,Noyori, Ryoji
, p. 5292 - 5302 (2007/10/02)
The behavior of 1,4-epiperoxides in the presence of transition-metal complexes is highly dependent on the structures of the substrates and the nature of the metal catalysts.Reaction of saturated epiperoxides such as 1,3-epiperoxycyclopentane, 1,4-epiperoxycyclohexane, or dihydroascaridole catalyzed by RuCl2(PPh3)3 in dichloromethane gives a mixture of products arising from fragmentation, rearrangement, reduction, disproportionation, etc.Prostaglandin H2 methyl ester undergoes clean and stereospecific fragmentation to afford methyl(5Z,8E,10E,12S)-12-hydroxy-5,8,10-heptadecatrienoate and malonaldehyde.Bicyclic 2,3-didehydro 1,4-epiperoxides give the syn-1,2:3,4-diepoxides by the same catalyst.The monocyclic analogues are transformed to a mixture of diepoxides and furan products.The stereochemical outcome of the epoxide formation reflects unique differences in the ground-state geometry of the starting epiperoxide substrates.FeCl2(PPh3)2 serves as a useful catalyst for the skeletal change of sterically hindered bicyclic 2,3-didehydro 1,4-epiperoxides to the syn-diepoxides.In addition, the Fe complex best effects the conversion of 1,4-unsubstituted 2,3-didehydro epiperoxides to furans.The Ru-catalyzed reactions are interpreted in terms of the intermediacy of inner-sphere radicals formed by atom transfer of the Ru(II) species to peroxy substrates, in contrast to the Fe-catalyzed reactions proceeding via free, outer-sphere radicals generated by an electron-transfer mechanism.
