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Synthesis of new beta-amidodehydroaminobutyric acid derivatives and of new tyro...

Several beta-amidodehydroaminobutyric acid derivatives were prepared from N,C-diprotected beta-bromodehydroaminobutyric acids and amides by a copper catalyzed C-N coupling reaction. The best reaction conditions include the use of a catalytic amount of CuI, N,N’-dimethylethylenediamine as ligand and K2CO3 as base in toluene at 110 ºC. The stereochemistry of the products was determined using NOE difference experi...

Synthesis of fluorescent alanines by a rhodium catalysed conjugate addition of ...

Several arylalanine derivatives containing fluorescent groups were prepared in good yields using a rhodium catalysed conjugate addition of arylboronic acids to N,N-diprotected and N-monoprotected dehydroalanines. The best conditions for these reactions require the use of an excess of aryl boronic acid (4 equiv.), [Rh(COD)2]BF4 as catalyst and CsF as base in dioxane:H2O (10:1) at 110 ºC. These conditions were al...

Thermodynamic stability and relaxation studies of small, triaza-macrocylic Mn(I...

Due to its favorable relaxometric properties, Mn2+ is an appealing metal ion for magnetic resonance imaging (MRI) contrast agents. This paper reports the synthesis and characterization of three new triazadicarboxylate-type ligands and their Mn2+ chelates (NODAHep, 1,4,7-triazacyclononane-1,4-diacetate-7-heptanil; NODABA, 1,4,7-triazacyclononane-1,4-diacetate-7-benzoic acid; and NODAHA (1,4,7-triazacyclononane-1...

Amide conjugates of the DO3A-N-(alfa-amino)propionate ligand : leads for stable...

A novel synthetic methodology for preparing amide conjugates of the DO3A-N-(alfa-amino)propionate chelator is described, using the synthesis of the DO3A-N-(alfa-benzoylamido)propionate chelator as an illustrative example. The model Gd(DO3A-N-(alfa-benzoylamido)propionate) chelate displays accelerated water exchange, stability in a wide pH range and inertness towards transmetallation by Zn2+. The Gd(DO3A-N-(al...

Synthesis of 2,6-bis-(oxazolyl)pyridine ligands for luminescent Ln(III) complexes

Submitted to the European Journal of Organic Chemistry ; New bis-(oxazolyl)pyridine ligands for Ln(III) ions were prepared using a expeditious methodology from threonine and dipicolinic acid chloride. The synthetic strategy includes a dehydration step to give a bis-dehydroaminobutyric acid derivative followed by bromination and cyclization with DBU. Photophysical studies of Eu(III) and Tb(III) complexes of th...

Fluorescence studies of 2-quinolinones and coumarins including peptide derivati...

Photophysical properties of 2-quinolinones and coumarins, including peptide derivatives, were determined. Fluorescence emission and anisotropy measurements of compounds incorporated in lipid vesicles were performed. Our studies indicate that these compounds may be used as fluorescent probes for peptides and lipid membranes.

Gold nanoparticles functionalised with stable, fast water exchanging Gd3+ chela...

Gold nanoparticles functionalized with Gd3+ chelates displaying fast water exchange, superb pH stability and inertness towards transmetalation with Zn2+ have been prepared and characterized as a new high relaxivity (29 mM-1s-1, 30 MHz, 25 ºC) Contrast Agent potentially safe for in vivo MRI applications. The Lipari-Szabo treatment for internal rotation was used to evaluate the effect of linker flexibility on the...

Synthesis, in vitro and in vivo characterization of new chelator DO3AAHA and it...

Mn(II) chelates with potential interest for MRI

Phenanthrenyl-indole as a fluorescent probe for peptides and lipid membranes

Prova tipográfica ; A 3-(phenanthren-9-yl)-1H-indole-2-carboxylic acid (2) obtained from the cleavage of the methyl ester of the methyl 3-(phenanthren-9-yl)-1H-indole-2-carboxylate (1) was inserted into a peptide containing the RGD sequence. The GGRGDG peptide sequence was prepared by solid phase synthesis and coupled to compound (2), using diisopropylcarbodiimide (DIC) and 1-hydroxybenzotriazole (HOBt) in DMF...