492462-02-9Relevant articles and documents
3-Aminopyrrolidine-4-carboxylic acid as versatile handle for internal labeling of pyrrolidinyl PNA
Reenabthue, Nisanath,Boonlua, Chalothorn,Vilaivan, Chotima,Vilaivan, Tirayut,Suparpprom, Chaturong
, p. 6465 - 6469 (2011/12/02)
Conformationally restricted pyrrolidinyl PNAs with an a/b-dipeptide backbone consisting of a nucleobase- modified proline and a cyclic five-membered amino acid spacer such as (1S,2S)-2-aminocyclopentanecarboxylic acid (ACPC) (acpcPNA) can form very stable hybrids with DNA with high Watson-Crick base pairing specificity. This work aims to explore the effect of incorporating 3-aminopyrrolidine-4-carboxylic acid (APC), whi h is isosteric to the ACPC spacer, into the acpcPNA. It is expected that the modification should not negatively affect the DNA binding properties, and that the additional nitrogen atom in the APC should provide a handle for internal modification. Orthogonally-protected (N3-Fmoc/N1-Boc and N3-Fmoc/N1-Tfa) APC monomers have been successfully synthesized and incorporated into the acpcPNA by Fmoc-solid-phase peptide synthesis. Tm, UV and CD spectroscopy confirmed that the (3R,4S)-APC could substitute the (1S,2S)-ACPC spacer in the acpcPNA with only slightly decreasing the stability of the hybrids formed between the modified acpc/apcPNA and DNA. In contrast, the (3S,4R) enantiomer of APC caused substantial destabilization of the hybrids. Furthermore, a successful on-solid-support internal labeling of the acpc/apcPNA via amide bond formation between pyrene-1-carboxylic acid or 4-(pyrene-1-yl) butyric acid and the pyrrolidine nitrogen atom of the APC spacer has been demonstrated. Fluorescence properties of the pyrene-labeled acpc/apcPNAs are sensitive to their hybridization states and can readily distinguish between complementary and single-mismatched DNA targets.
Novel α- and β-amino acid inhibitors of influenza virus neuraminidase
Kati,Montgomery,Maring,Stoll,Giranda,Chen,Laver,Kohlbrenner,Norbeck
, p. 2563 - 2570 (2007/10/03)
In an effort to discover novel, noncarbohydrate inhibitors of influenza virus neuraminidase we hypothesized that compounds which contain positively charged amino groups in an appropriate position to interact with the Asp 152 or Tyr 406 side chains might be bound tightly by the enzyme. Testing of 300 α- and β-amino acids led to the discovery of two novel neuraminidase inhibitors, a phenylglycine and a pyrrolidine, which exhibited Ki values in the 50 μM range versus influenza virus A/N2/Tokyo/3/67 neuraminidase but which exhibited weaker activity against influenza virus B/Memphis/3/89 neuraminidase. Limited optimization of the pyrrolidine series resulted in a compound which was about 24-fold more potent than 2-deoxy-2,3-dehydro-N-acetylneuraminic acid in an anti-influenza cell culture assay using A/N2/Victoria/3/75 virus. X-ray structural studies of A/N9 neuraminidase-inhibitor complexes revealed that both classes of inhibitors induced the Glu 278 side chain to undergo a small conformational change, but these compounds did not show time-dependent inhibition. Crystallography also established that the α-amino group of the phenylglycine formed hydrogen bonds to the Asp 152 carboxylate as expected. Likewise, the β-amino group of the pyrrolidine forms an interaction with the Tyr 406 hydroxyl group and represents the first compound known to make an interaction with this absolutely conserved residue. Phenylglycine and pyrrolidine analogs in which the α- or β-amino groups were replaced with hydroxyl groups were 365- and 2,600-fold weaker inhibitors, respectively. These results underscore the importance of the amino group interactions with the Asp 152 and Tyr 406 side chains and have implications for anti-influenza drug design.
