Alkylating agents are generally highly reactive with DNA but demonstrate limited DNA sequence selectivity. In contrast, synthetic pyrrole-imidazole polyamides recognize specific DNA sequences with high affinity but are unable to permanently damage DNA. An eight-ring hairpin polyamide conjugated to the alkylating moiety cyclopropylpyrroloindole, related to the natural product CC-1065, affords a ...

A hairpin pyrrole-imidazole polyamide (1) targeted to the androgen receptor consensus half-site was found to exert antitumor effects against prostate cancer xenografts. A previous animal study showed that 1, which has a chiral amine at the α-position of the γ-aminobutyric acid turn (γ-turn), did not exhibit toxicity at doses less than 10 mg/kg. In the same study, a polyamide with an acetamide a...

Sequence-specific pyrrole-imidazole polyamides can be designed to interfere with transcription factor binding and to regulate gene expression, both in vitro and in living cells. Polyamides bound adjacent to the recognition sites for TBP, Ets-1, and LEF-1 in the human immunodeficiency virus, type 1 (HIV-1), long terminal repeat inhibited transcription in cell-free assays and viral replication in...

To investigate the binding of 5'-CpG-3' sequences by small molecules, two pyrrole (Py)-imidazole (Im) hairpin polyamides, PyImPyIm-gamma-PyImPyIm-beta-Dp (1) and PyIm-beta-Im-gamma-PyIm-beta-Im-beta-Dp (2), which recognize the sequence 5'-CGCG-3', were synthesized. The binding affinities of the 5'-CGCG-3' sequence to the Py-Im hairpin polyamides were measured by surface plasmon resonance (SPR) ...

With the purpose of gaining insights into the mechanisms of ion uptake and permeation in desalination membranes, MD investigation of a model polyamide membrane was carried out. A relatively large membrane (45K atoms) was assembled, which closely matched real desalination membrane in terms of chemistry and water permeability. Simulations demonstrate that the mechanism of ion uptake distinctly di...

The advancement of DNA-based bionanotechnology requires efficient strategies to functionalize DNA nanostructures in a specific manner with other biomolecules, most importantly peptides and proteins. Common DNA-functionalization methods rely on laborious and covalent conjugation between DNA and proteins or peptides. Pyrrole-imidazole (Py-Im) polyamides, based on natural minor groove DNA-binding ...

In this research, modification on the ultrafiltration (UF) membrane by synthesis of a thin layer of polyamide selective layer was designed for high performances of forward osmosis (FO) water treatment. Two monomers, m-Phenylenediamine (MPD) and Trimesoyl chloride (TMC) with different concentrations of MPD (2.0% w/v and 1.0% w/v) were reacted with TMC (0.15% w/v) for interfacial polymerization (...

Small amounts of cyclic monomers and oligomers are present in polyamide (PA)-based kitchen utensils. In this study, we isolated eight PA-based cyclic monomers and oligomers from kitchen utensils made from PA6 (a polymer of ε-caprolactam) and PA66 (a polymer of 1,6-diaminohexane and adipic acid). Their structures were identified using high-resolution mass spectrometry and 1H- and 13C-nuclear mag...

The application of fibers to reinforce cementitious materials is a well-known subject. At first, asbestos fibers are used in industrial process to produce fiber reinforced cement sheets. Thereafter, various types of synthetic fibers are produced and used as asbestos substitutes. The aim of the present work is to evaluate the effect of synthetic fibers on the flexural behavior of cementitious co...