Abstract
Fibroblast activation protein (FAP) belongs to the prolyl peptidase family. FAP inhibition is expected to become a new antitumor target. Most known FAP inhibitors often resemble the dipeptide cleavage products, with a boroproline at the P1 site; however, these inhibitors also inhibit DPP-IV, DPP-II, DPP8, and DPP9. Potent and selective FAP inhibitor is needed in evaluating that FAP as a therapeutic target. Therefore, it is important to develop selective FAP inhibitors for the use of target validation. To achieve this, optimization of the nonselective DPP-IV inhibitor 8 led to the discovery of a new class of substituted 4-carboxymethylpyroglutamic acid diamides as FAP inhibitors. SAR studies resulted in a number of FAP inhibitors having IC(50) of <100 nM with excellent selectivity over DPP-IV, DPP-II, DPP8, and DPP9 (IC(50) > 100 μM). Compounds 18a, 18b, and 19 are the only known potent and selective FAP inhibitors, which prompts us to further study the physiological role of FAP.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Amides / chemical synthesis*
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Amides / pharmacokinetics
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Amides / pharmacology
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Animals
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Dipeptidases / antagonists & inhibitors
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Dipeptidyl-Peptidase IV Inhibitors
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Dipeptidyl-Peptidases and Tripeptidyl-Peptidases / antagonists & inhibitors
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Endopeptidases
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Gelatinases / antagonists & inhibitors*
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Humans
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Membrane Proteins / antagonists & inhibitors*
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Mice
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Mice, Inbred BALB C
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Pyrrolidonecarboxylic Acid / analogs & derivatives*
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Pyrrolidonecarboxylic Acid / chemical synthesis*
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Pyrrolidonecarboxylic Acid / pharmacokinetics
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Pyrrolidonecarboxylic Acid / pharmacology
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Serine Endopeptidases
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Stereoisomerism
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Structure-Activity Relationship
Substances
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Amides
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Dipeptidyl-Peptidase IV Inhibitors
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Membrane Proteins
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Endopeptidases
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Dipeptidases
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DPP9 protein, human
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Dipeptidyl-Peptidases and Tripeptidyl-Peptidases
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dipeptidyl peptidase II
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DPP8 protein, human
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Serine Endopeptidases
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fibroblast activation protein alpha
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Gelatinases
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Pyrrolidonecarboxylic Acid