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Abstract

A new strategy is presented here which integrates combinatorial library technology with the antitumor in vitro screening system at the National Cancer Institute in the search for novel antitumor agents. Mixture-based synthetic combinatorial libraries (SCLs) representing hundreds of thousands to millions of individual compounds were screened against the cell-based assay, which evaluates compounds for their ability to inhibit the growth of 60 different human tumor cell lines. Five different SCLs, composed of peptides, peptidomimetics, polyamines or small molecules were first tested against three cell lines to identify the most active SCLs. Two SCLs, namely the N-perbenzylated pentamine and the N-acylated permethylated triamine, were deconvoluted to yield individual compounds having significant activities against the 60 tumor cell lines. Active compounds were tested in mice to determine the maximum tolerated dose, followed by in vivo testing in a hollow fiber assay. Using this strategy, three different compounds identified directly from SCLs are currently being evaluated in human tumor xenografts. This study demonstrates for the first time the use of in vitro cell-based assays to identify antitumor lead compounds from mixture-based combinatorial libraries.

Positional Scanning Peptide Libraries for Kinase Substrate Specificity Determinations: Straightforward and Reproducible Synthesis Using Pentafluorophenyl Esters

“…The so-called positional scanning synthetic combinatorial library (PS-SCL) is a collection of compounds all of which share the same core structure and that are organized in a manner that uses well-defined mixtures to exponentially reduce the number of samples that need to be tested. This type of library was pioneered by Houghten et al and has given researchers the possibility to efficiently search upward of a trillion compounds in a matter of weeks. ,− PS-SCLs have found applications in areas such as cancer drug development, vaccine development, and endoprotease studies. − Recently, a groundbreaking and time saving approach to establishing the optimal motifs for phosphorylation by protein kinases was presented by Hutti et al They adapted the concept of PS-SCLs to kinase assays using 32 P radiolabeled ATP and radiometry for detection and quantification. Determination of which protein kinases are responsible for phosphorylating which protein substrates in the cell is critical for mapping signal transduction cascades that regulate cell growth, division, differentiation, and death.…”

“…1,[3][4][5] PS-SCLs have found applications in areas such as cancer drug development, vaccine development, and endoprotease studies. [6][7][8][9][10][11][12][13] Recently, a groundbreaking and time saving approach to establishing the optimal motifs for phosphorylation by protein kinases was presented by Hutti et al 14 They adapted the concept of PS-SCLs to kinase assays using 32 P radiolabeled ATP and radiometry for detection and quantification. Determination of which protein kinases are responsible for phosphorylating which protein substrates in the cell is critical for mapping signal transduction cascades that regulate cell growth, division, differentiation, and death.…”

Combinatorial Oligocarbamate Collections: Synthesis by the Premix Method and Quality Control by HPLC‐MS

“…The premix protocol allows the synthesis of collections in a positional scan format. Positional scanning collections were first described for peptides in 1992 [22] and later for non-peptide molecules such as carbamates [23], polyamines [24,25], cyclic ureas and thioureas [15,26], and bicyclic guanidines [14,15]. Further examples are reviewed in books on combinatorial chemistry [6 ± 8].…”

Synthesis of Platinum(II) Chiral Tetraamine Coordination Complexes

“…In both instances, support-bound peptides were used as starting materials 8 to generate diversities of compounds having completely different physical−chemical properties relative to the starting peptides. These have been successfully used in the identification of highly active individual, biologically active polyamines . The ability of polyamines to serve as multidentate ligands in the formation of metal coordination complexes, along with various reported medicinal applications of amine−metal coordination compounds, prompted us to extend our “libraries from libraries” approach used for the preparation of polyamines to include the synthesis of metal−polyamine complexes.…”