Barbara Dörner

The synthesis of peptidomimetic combinatorial libraries through successive amide alkylations

A soluble peptidomimetic combinatorial library of 57,500 compounds was prepared. This library has a dipeptide scaffold with each amide hydrogen replaced with five different alkyl groups (methyl, ethyl, allyl, benzyl, or naphthylmethyl). Solid-phase methodology in combination with N-alkylation were used to synthesize the library, which incorporated 50 different L-, D-, and unnatural amino acids. Repetitive amide alkylations were carried out on the solid support following each amino acid coupling step. Individual model compounds were synthesized in order to optimize the alkylation conditions, to study potential amino acid side chain modifications, to determine the extent of racemization, and to provide analytical controls during the library synthesis.

GENERATION AND USE OF NONSUPPORT-BOUND PEPTIDE AND PEPTIDOMIMETIC COMBINATORIAL LIBRARIES

Publisher Summary The practical use of nonsupport-bound combinatorial libraries represents an important breakthrough in all the areas of basic research and drug discovery. The use of a wide variety of chemical transformations permits a range of peptidomimetic libraries to be generated that greatly expands the chemical diversity available. The results described in this chapter demonstrate that an existing peptide positional scanning- synthetic combinatorial libraries (PS-SCL) can be chemically transformed to generate a peptidomimetic SCL, from which highly active individual compounds can be identified. The synthesis and deconvolution methods developed for peptide libraries are easily applied to other types of chemical pharmacophores. The soluble nature of the nonsupport-bound combinatorial libraries is a distinct advantage over the other methods in that membrane-bound and whole cell assays can also be used. In addition, the deconvolution methods used allow the chemical structure of peptidic, peptidomimetic, and organic compounds to be determined based solely on the structural similarities of compounds, within each active pool or sublibrary.

Libraries from libraries: Generation and comparison of screening profiles

SummaryA positional scanning tetrapeptide library was chemically modified through alkylation and/or reduction of the amide bonds, thus generating three new combinatorial libraries with physico-chemical properties very different from the parent peptide library (‘libraries from libraries’). Specific results were obtained with each of these libraries upon screening in κ-opioid receptor binding and microdilution antimicrobial assays, illustrating the potential of the ‘libraries from libraries’ concept for the efficient generation of a variety of chemically diverse combinatorial libraries.