- High Affinity Agonists of the Neuropeptide y (NPY) Y4 Receptor Derived from the C-Terminal Pentapeptide of Human Pancreatic Polypeptide (hPP): Synthesis, Stereochemical Discrimination, and Radiolabeling
-
The diastereomeric mixture of d/l-2,7-diaminooctanedioyl-bis(YRLRY-NH2) (BVD-74D, 2) was described in the literature as a high affinity Y4 receptor agonist. Here we report on the synthesis and pharmacological characterization of the pure diastereomers (2R,7R)- and (2S,7S)-2 and a series of homo- and heterodimeric analogues in which octanedioic acid was used as an achiral linker. To investigate the role of the Arg residues, one or two arginines were replaced by Ala. Moreover, Nω-(6-aminohexylaminocarbonyl)Arg was introduced as an arginine replacement (17). (2R,7R)-2 was superior to (2S,7S)-2 in binding and functional cellular assays and equipotent with 17. [3H]Propionylation of one amino group in the linker of (2R,7R)-2 or at the primary amino group in 17 resulted in high affinity Y4R radioligands ([3H]-(2R,7R)-10, [3H]18) with subnanomolar Kd values.
- Kuhn, Kilian K.,Ertl, Thomas,Dukorn, Stefanie,Keller, Max,Bernhardt, Günther,Reiser, Oliver,Buschauer, Armin
-
supporting information
p. 6045 - 6058
(2016/07/26)
-
- Synthesis and antibacterial studies of binaphthyl-based tripeptoids. Part 1
-
An efficient synthesis of 29 new binaphthyl-based neutral, and mono- and di-cationic, peptoids is described. Some of these compounds had antibacterial activities with MIC values of 1.9-3.9 μg/mL against Staphylococcus aureus. One peptoid had a MIC value of 6 μg/mL against a methicillin-resistant strain of S. aureus (MRSA) and a MIC value of 2 μg/mL against vancomycin-resistant strains of enterococci (VRE).
- Bremner, John B.,Keller, Paul A.,Pyne, Stephen G.,Boyle, Timothy P.,Brkic, Zinka,David, Dorothy M.,Robertson, Mark,Somphol, Kittiya,Baylis, Dean,Coates, Jonathan A.,Deadman, John,Jeevarajah, Darshini,Rhodes, David I.
-
supporting information; experimental part
p. 2611 - 2620
(2010/06/16)
-
- Stereoselective synthesis of meso-2,6-diaminopimelic acid and its selectively protected derivatives
-
Four synthetic routes to selectively protected derivatives and isomers of meso-diaminopimelic acid (DAP) (1a), a key constituent of bacterial peptidoglycan, were investigated. N-(tert-butyloxycarbonyl)-D-allylglycine (2) and N-(benzyloxycarbonyl)-L-allylglycine (4) were esterified to ethylene glycol and cyclized via olefin metathesis to a protected derivative 7 of 2,7- diaminosuberic acid. Analogous linking of propane-1,3-diol with 2 and potential precursors of N-(benzyloxycarbonyl)-L-vinylglycine moieties, such as N-(benzyloxycarbonyl)-L-glutamate or N-(benzyloxycarbonyl)-L-methionine sulfoxide, gave 12 or 15, both of which produced the α,β-unsaturated ester 14 upon attempted generation of the vinylglycine precursor for olefin metathesis to DAP derivatives. An alternative route, based on SnCl4- catalyzed ene reaction of methyl N-(benzyloxycarbonyl)-L-allylglycinate (18) with glyoxylate esters of phenylcyclohexanol isomers as chiral auxiliaries, gave ca. 85:15 ratios of diastereomeric alcohols (19 or 20). These could be transformed to DAP derivatives in a series of steps employing azide displacement of corresponding mesylates to introduce the second nitrogen. A third method, involving reduction of pure dimethyl (6S)-2-keto-6-[N- (benzyloxycarbonyl)amino]pimelate (32) to the corresponding alcohol 33 with (S)-binaphthol-ruthenium catalyst as the key step, gives a 79:21 isomeric ratio. The fourth route employs the bis(oxazoline)-copper complex 41 as a chiral catalyst for the ene reaction of methyl (S)-4- (phenylthio)allylglycinate (39) and methyl glyoxylate to afford 42 and 94:6 isometric ratio. Nickel boride removal of sulfur and the double bond in the presence of the Cbz group gives the desired alcohol, dimethyl (2S,6S)-6-[N- (benzyloxycarbonyl)amino]-2-hydroxyheptane-1,7-dioate (33). The required selectively protected second nitrogen is introduced using Mitsunobu inversion with N-tert-butyl [[2-(trimethylsilyl)-ethyl]sulfonyl]carbomate (34) as a key step.
- Gao, Yong,Lane-Bell, Patricia,Vederas, John C.
-
p. 2133 - 2143
(2007/10/03)
-
- Highly practical methodology for the synthesis of D- and L-α-amino acids, N-protected α-amino acids, and N-methyl-α-amino acids
-
Full details are provided for an exceedingly practical method to synthesize D- and L-α-amino acids, N-protected α-amino acids, and N-methyl-α-amino acids, employing as a key step the asymmetric alkylation of pseudoephedrine glycinamide (1) or pseudoephedrine sarcosinamide (2). Practical procedures for the synthesis of 1 and 2 from pseudoephedrine and glycine methyl ester or sarcosine methyl ester, respectively, are presented. Optimum protocols for the enolization and subsequent alkylation of 1 and 2 are described. Alkylation reactions of 1 and 2 are found to be quite efficient with a wide range of alkyl halide substrates, and the products are formed with high diastereoselectivity. The products of these alkylation reactions are hydrolyzed efficiently and with little to no racemization simply by heating in water or water-dioxane mixtures. This protocol provides an exceedingly practical method for the preparation of salt-free α-amino acids of high enantiomeric purity. Alternatively, the alkylation products may be hydrolyzed in high yield and with little to no racemization by heating with aqueous sodium hydroxide. The alkaline hydrolyzate can then be treated with an acylating reagent to provide directly highly enantiomerically enriched N-protected derivatives such as N-Boc and N-Fmoc. Key features necessary for the successful execution of these experimental procedures are identified.
- Myers, Andrew G.,Gleason, James L.,Yoon, Taeyoung,Kung, Daniel W.
-
p. 656 - 673
(2007/10/03)
-