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Robert M. DiPardo

Other affiliations: Merck & Co.
Bio: Robert M. DiPardo is an academic researcher from United States Military Academy. The author has contributed to research in topics: Cholecystokinin & Cholecystokinin receptor. The author has an hindex of 21, co-authored 61 publications receiving 3268 citations. Previous affiliations of Robert M. DiPardo include Merck & Co..


Papers
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Journal ArticleDOI
TL;DR: 3-(Acylamino)-5-phenyl-2H-1,4-benzodiazepines, antagonists of the peptide hormone cholecystokinin (CCK), are described, and the method of development of these compounds is discussed in terms of its relevance to the general problem of drug discovery.
Abstract: 3-(Acylamino)-5-phenyl-2H-1,4-benzodiazepines, antagonists of the peptide hormone cholecystokinin (CCK), are described. Developed by reasoned modification of the known anxiolytic benzodiazepines, these compounds provide highly potent, orally effective ligands selective for peripheral (CCK-A) receptors, with binding affinities approaching or equaling that of the natural ligand CCK-8. The distinction between CCK-A receptors on the one hand and CNS (CCK-B), gastrin, and central benzodiazepine receptors on the other is demonstrated by using the structure-activity profiles of the new compounds. Details of the binding of these agents to CCK-A receptors are examined, and the method of development of these compounds is discussed in terms of its relevance to the general problem of drug discovery.

1,311 citations

Journal ArticleDOI
TL;DR: The design and synthesis of nonpeptidal antagonists of the peptide hormone cholecystokinin are described, and several of these compounds have high specificity and nanomolar binding affinity and are active after oral administration.
Abstract: We describe the design and synthesis of nonpeptidal antagonists of the peptide hormone cholecystokinin. Several of these compounds have high specificity and nanomolar binding affinity and are active after oral administration. To our knowledge, the design of such agents has not previously been accomplished for any peptide hormone. The structural similarities between these synthetic compounds and the anxiolytic 1,4-benzodiazepines are noted, and the potential of this structural feature for future design of ligands for other peptide hormone receptors is discussed.

313 citations

Journal ArticleDOI
TL;DR: In this article, 3.3-(Acylamino)-5-phenyl-2H-1,4-benzodiazepines, antagonists of the peptide hormone cholecystokinin (CCK), are described.
Abstract: 3-(Acylamino)-5-phenyl-2H-1,4-benzodiazepines, antagonists of the peptide hormone cholecystokinin (CCK), are described. Developed by reasoned modification of the known anxiolytic benzodiazepines, these compounds provide highly potent, orally effective ligands selective for peripheral (CCK-A) receptors, with binding affinities approaching or equaling that of the natural ligand CCK-8. The distinction between CCK-A receptors on the one hand and CNS (CCK-B), gastrin, and central benzodiazepine receptors on the other is demonstrated by using the structure-activity profiles of the new compounds. Details of the binding of these agents to CCK-A receptors are examined, and the method of development of these compounds is discussed in terms of its relevance to the general problem of drug discovery.

178 citations

Journal ArticleDOI
TL;DR: A series of 3-substituted 5-phenyl-1,4-benzodiazepines, nonpeptidal antagonists of the peptide hormone cholecystokinin, serve to illuminate the distinction between central and peripheral CCK receptors, as well as to provide orally effective CCK antagonists of potential pharmacological or therapeutic utility.
Abstract: A series of 3-substituted 5-phenyl-1,4-benzodiazepines, nonpeptidal antagonists of the peptide hormone cholecystokinin (CCK), have been synthesized. Designed on the basis of facts regarding CCK, its natural-product antagonist asperlicin (3), and the antianxiety agent diazepam (4), these compounds represent a significant departure from existing CCK antagonists. They also constitute perhaps the first examples of simple, nonpeptidal ligands for a peptide receptor to arise by design rather than by screening. These compounds serve to illuminate the distinction between central and peripheral CCK receptors, as well as to provide orally effective CCK antagonists of potential pharmacological or therapeutic utility. One rationale for their receptor affinity has possible applications in the design of nonpeptidal ligands for other receptors, peptidal as well as nonpeptidal.

176 citations


Cited by
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Journal ArticleDOI
TL;DR: Privileged substructures are believed to achieve this through the mimicry of common protein surface elements that are responsible for binding, such as β- and gamma;-turns.
Abstract: Privileged substructures are of potentially great importance in medicinal chemistry. These scaffolds are characterized by their ability to promiscuously bind to a multitude of receptors through a variety of favorable characteristics. This may include presentation of their substituents in a spatially defined manner and perhaps also the ability to directly bind to the receptor itself, as well as exhibiting promising characteristics to aid bioavailability of the overall molecule. It is believed that some privileged substructures achieve this through the mimicry of common protein surface elements that are responsible for binding, such as β- and gamma;-turns. As a result, these structures represent a promising means by which new lead compounds may be identified.

2,620 citations

Journal ArticleDOI
TL;DR: This review traces natural products drug discovery, outlining important drugs from natural sources that revolutionized treatment of serious diseases and effective drug development depends on multidisciplinary collaborations.

2,272 citations

Journal ArticleDOI
TL;DR: Recent technological advances that help to address issues such as the lack of compatibility of traditional natural-product extract libraries with high-throughput screening and unrealized expectations from current lead-generation strategies have led to a renewed interest in natural products in drug discovery.
Abstract: Natural products and their derivatives have historically been invaluable as a source of therapeutic agents. However, in the past decade, research into natural products in the pharmaceutical industry has declined, owing to issues such as the lack of compatibility of traditional natural-product extract libraries with high-throughput screening. However, as discussed in this review, recent technological advances that help to address these issues, coupled with unrealized expectations from current lead-generation strategies, have led to a renewed interest in natural products in drug discovery.

2,254 citations

Journal ArticleDOI
TL;DR: The effects of the strategic incorporation of fluorine in drug molecules and applications in positron emission tomography are provided, as well as new synthetic methodologies that allow more facile access to a wide range of fluorinated compounds.
Abstract: The role of fluorine in drug design and development is expanding rapidly as we learn more about the unique properties associated with this unusual element and how to deploy it with greater sophistication. The judicious introduction of fluorine into a molecule can productively influence conformation, pKa, intrinsic potency, membrane permeability, metabolic pathways, and pharmacokinetic properties. In addition, 18F has been established as a useful positron emitting isotope for use with in vivo imaging technology that potentially has extensive application in drug discovery and development, often limited only by convenient synthetic accessibility to labeled compounds. The wide ranging applications of fluorine in drug design are providing a strong stimulus for the development of new synthetic methodologies that allow more facile access to a wide range of fluorinated compounds. In this review, we provide an update on the effects of the strategic incorporation of fluorine in drug molecules and applications in po...

2,149 citations