146118-22-1Relevant articles and documents
Mechanistic implications of the enantioselective addition of alkylzinc reagents to aldehydes catalyzed by nickel complexes with α-amino amide ligands
Escorihuela, Jorge,Burguete, M. Isabel,Ujaque, Gregori,Lledós, Agustí,Luis, Santiago V.
supporting information, p. 11125 - 11136 (2016/12/07)
The enantioselective alkylation of aldehydes catalysed by nickel(ii)-complexes derived from α-amino amides was studied by means of density functional theory (DFT) and ONIOM (B3LYP:UFF) calculations. A mechanism was proposed in order to investigate the origin of enantioselectivity. The chirality-determining step for the alkylation was the formation of the intermediate complexes with the involvement of a 5/4/4-fused tricyclic transition state. The predominant products predicted theoretically were of (S)-configuration, in good agreement with experimental observations. The scope of the reaction was examined and high yields and enantioselectivities were observed for the enantioselective addition of Et2Zn and Me2Zn to aromatic and aliphatic aldehydes.
Synthesis and evaluation of pseudopeptidic fluorescence pH probes for acidic cellular organelles: In vivo monitoring of bacterial phagocytosis by multiparametric flow cytometry
Burguete, M. Isabel,Galindo, Francisco,Izquierdo, M. Angeles,O'Connor, Jose-Enrique,Herrera, Guadalupe,Luis, Santiago V.,Vigara, Laura
scheme or table, p. 5967 - 5979 (2011/02/26)
A new family of fluorescent anthracenic pH probes has been synthesized, chemically characterized, and their photophysical properties have been investigated by steady-state and time-resolved fluorescence spectroscopy. The ability of these compounds to monitor pH has been investigated in solution and it was found that molecules 1-12 can act as fluorescent sensors for pH in a range between 4.6 and 6.5. This range corresponds to the pH of acidic organelles in the cell (pH 4.5-6.0) for which a limited number of probes are described. The acid-base behavior of each sensor varies slightly depending on the nature of substituents close to the amines present in the molecules. Thus, the pK a of this family of compounds can be finely tuned by the appropriate selection of the synthetic building blocks at the design stage. To test the potential diagnostic applications of this family of probes, macrocyclic pseudopeptide 2 was used to monitor the phagocytosis of a culture of GFP-labelled bacteria by human monocytic cells U937 using flow cytometry as the analytical tool. It was found that the occurrence of bacterial killing was concomitant with the production of reactive oxygen species and a drop in pH, the latter monitored indirectly by macrocyclic sensor 2, which suggests its potential use for diagnostic purposes. A new family of anthracenic macrocycles has been synthesized that can act as fluorescent probes for pH in the range 4.6-6.5. The pKa values of these compounds can be finely tuned. In flow cytometry experiments, it was found that bacterial killing by human monocytes (U937) occurred with a simultaneous drop in pH, which was monitored by one of the macrocyclic sensors.
In the search for new anticancer drugs. XXIV: Synthesis and anticancer activity of amino acids and dipeptides containing the 2-chloroethyl- and [N'- (2-chloroethyl)-N'-nitroso]-aminocarbonyl groups
Sosnovsky,Prakash,Rao
, p. 1 - 10 (2007/10/02)
A series of L,L-(42, 44, 46, and 60) and D,D-(43, 45, 47, and 61) dipeptide derivatives composed of phenylglycine, phenylalanine, homophenylalanine, and valine and containing a 2-chloroethylamino group at the C-terminus and an N'-(2-chloroethyl)-N'-nitrosoaminocarbonyl group at the N-terminus of the dipeptides were prepared. The dipeptide derivatives (42- 47, 60, and 61) were first evaluated in vivo for their anticancer activities against the murine lymphocytic leukemia P388. Compounds 42, 44, 46, and 60 possessed activities ranging from 46 to 111 percent increase in life span (%ILS), whereas 43 was marginal (%ILS = 31) and 45, 47, and 61 were inactive. In general, the L,L-series exhibited low to good activity (%ILS = 46-111), whereas the corresponding D,D-series, except for 43 (%ILS = 31), was devoid of activity. The analogously structured monoamino acid derivatives of L- alanine (74), L-phenylalanine (75), and L-aspartic acid (76) exhibited higher activity against P388 than the dipeptide derivatives (i.e., 481, 297, and 481 %ILS, respectively). The more active representatives of dipeptides (i.e., 42, 44, and 60) and the amino acids derivatives 74-76 were then tested in vivo against the murine lymphoid leukemia L1210. Compounds 42, 44, and 60 exhibited either low or marginal activity (i.e., the %ILS values were 46, 31, and 26, respectively). Compounds 74, 75, and 76 possessed low to moderate activity, as evidenced by the %ILS values of 56, 48, and 64, respectively. The %ILS parameters obtained against the P388 and L1210 tumor lines were correlated with the corresponding lipophilicities, and there is a trend towards higher activity with concomitant decrease in hydrophobicity.
