58207-46-8

Upstream product

• 13734-34-4 N-tert-butoxycarbonyl-L-phenylalanine 
• 622-33-3 N-benzyloxyamine 
• 3674-06-4 Boc-Phe-ONSu 
• 2687-43-6 O-benzylhydoxylamine hydrochloride 
• 115364-82-4 (S)-tert-butyl (1-((benzyloxy)amino)-1-oxo-3-phenylpropan-2-yl)-carbamate 
• 76-05-1 trifluoroacetic acid 

Downstream Products

• 115364-55-1 (S)-N-(2-carboxy-1-oxoethyl)phenylalanine N'-hydroxyamide 

Relevant academic research and scientific papers

Synthesis, physicochemical characterization and neuroprotective evaluation of novel 1-hydroxypyrazin-2(1 H)-one iron chelators in an in vitro cell model of Parkinson's disease

Iron dysregulation, dopamine depletion, cellular oxidative stress and α-synuclein protein mis-folding are key neuronal pathological features seen in the progression of Parkinson's disease. Iron chelators endowed with one or more therapeutic modes of action have long been suggested as disease modifying therapies for its treatment. In this study, novel 1-hydroxypyrazin-2(1H)-one iron chelators were synthesized and their physicochemical properties, iron chelation abilities, antioxidant capacities and neuroprotective effects in a cell culture model of Parkinson's disease were evaluated. Physicochemical properties (log β, log D7.4, pL0.5) suggest that these ligands have a poorer ability to penetrate cell membranes and form weaker iron complexes than the closely related 1-hydroxypyridin-2(1H)-ones. Despite this, we show that levels of neuroprotection provided by these ligands against the catecholaminergic neurotoxin 6-hydroxydopamine in vitro were comparable to those seen previously with the 1-hydroxypyridin-2(1H)-ones and the clinically used iron chelator Deferiprone, with two of the ligands restoring cell viability to ≥89% compared to controls. Two of the ligands were endowed with additional phenol moieties in an attempt to derive multifunctional chelators with dual iron chelation/antioxidant activity. However, levels of neuroprotection with these ligands were no greater than ligands lacking this moiety, suggesting the neuroprotective properties of these ligands are due primarily to chelation and passivation of intracellular labile iron, preventing the generation of free radicals and reactive oxygen species that otherwise lead to the neuronal cell death seen in Parkinson's disease.

Solution/solid-phase synthesis of partially modified retro- and retro-inverso-ψ[NHCH(CF3)]-peptidyl hydroxamates and their evaluation as MMP-9 inhibitors

The synthesis of a novel family of partially modified (PM) retro-and retro-inverso-peptidyl hydroxamates, each incorporating a [CH(CF3)CH2CO] unit as a surrogate for the conventional malonyl group, has been accomplished both in solution and in solid phase. The key step is the Michael-type N-addition of free or polymer-bound α-amino hydroxamates to 3-[(E)-enoyl]-1,3-oxazolidin-2-ones, which takes place in high yields, although with low stereocontrol. This method is suitable for the preparation of combinatorial libraries of PM retro-ψNHCH(CF3)]-peptidyl hydroxamates for screening as metalloprotease inhibitors. A number of tri- and tetrapeptidyl hydroxamates were indeed obtained either in diastereomerically pure form by solution-phase synthesis followed by chromatographic purification, or as mixtures of two epimers by solid-phase synthesis and release from the resin. X-ray diffraction of a Tfm-retropeptidyl hydroxamate showed an interesting turn-like conformation with an intramolecularly hydrogen-bonded nine-membered ring, and a nearly planar geometry of the NH group bound to the CH(CF3) group. Three retro-peptidyl hydroxamates were submitted to bioassays, and displayed the capacity to reduce MMP-9 (Gelatinase B) gelatinolytic activity.

Solution/solid-phase synthesis of partially modified retro-ψ[NHCH(CF3)]-peptidyl hydroxamates

The synthesis of a novel family of partially-modified (PM) retropeptidyl hydroxamates incorporating a [CH(CF3)CH2CO] unit as a surrogate of the conventional malonyl group, has been accomplished both in solution and in solid-phase. The key step is the Michael-type N-addition of free or polymer bound α-amino hydroxamates to 3-(E-enoyl)-1,3-oxazolidin-2-ones, which takes place very effectively, although with low stereocontrol. A number of tri- and tetra-peptidyl hydroxamates were obtained either in diastereomerically pure form (by solution-phase synthesis, after chromatographic purification), or as mixtures of two epimers in very good chemical purity (by solid-phase, after release from the resin), demonstrating that this method is suitable for preparing combinatorial libraries of PM retro-ψ[NHCH(CF3)]-peptidyl hydroxamates for screening as metalloprotease inhibitors.

Retro-inverso concept applied to the complete inhibitors of enkephalin-degrading enzymes

Peptide retro-inverso modification was applied to the complete hydroxamate inhibitors of the three zinc metallopeptidases (neutral endopeptidase 24-11 (NEP, EC 3.4.24.11), aminopeptidase N (APN, EC 3.4.11.2), and a dipeptidylaminopeptidase (DAP) involved in the in vitro enkephalin degradation by brain tissues. Compounds corresponding to the general formula RN(OH)CO(CH2)(n)CH(CH2Ph)NHCOCH(R')COOH (n=0, 1) were synthesized. In the first series of inhibitors (n=0), the 'retro-inverso' modification induced a large decrease in inhibitory potency for NEP as compared to that of the parent compounds. In contrast, the presence of a methylene group between the hydroxamate and CHα in the second series (n=1) led to derivatives with inhibitory potencies in the nanomolar range, similar to their analogues with a natural amide bond. On the other hand, the retro-inverso modification led to a slight improvement in the inhibition of DAP and APN, in the first series of inhibitors, while the inverse result occurred in the second series. Thus, compounds containing an α-amino acid moiety in P'1 position behave as weak inhibitors of the three enzymes, with IC50 values in the micromolar range, and compounds bearing a β-amino acid moiety in the same position are more specific than the parent compounds for NEP inhibition.