5FI4

Discovery of imidazo[1,2-a]-pyridine inhibitors of pan-PI3 kinases that are efficacious in a mouse xenograft model


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.50 Å
  • R-Value Free: 0.245 
  • R-Value Work: 0.194 
  • R-Value Observed: 0.196 

wwPDB Validation   3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

Discovery of imidazo[1,2-a]-pyridine inhibitors of pan-PI3 kinases that are efficacious in a mouse xenograft model.

Han, W.Menezes, D.L.Xu, Y.Knapp, M.S.Elling, R.Burger, M.T.Ni, Z.J.Smith, A.Lan, J.Williams, T.E.Verhagen, J.Huh, K.Merritt, H.Chan, J.Kaufman, S.Voliva, C.F.Pecchi, S.

(2016) Bioorg Med Chem Lett 26: 742-746

  • DOI: 10.1016/j.bmcl.2016.01.003
  • Primary Citation of Related Structures:  
    5FI4

  • PubMed Abstract: 
  • Alterations in PI3K/AKT signaling are known to be implicated with tumorigenesis. The PI3 kinases family of lipid kinases has been an attractive therapeutic target for cancer treatment. Imidazopyridine compound 1, a potent, selective, and orally available ...

    Alterations in PI3K/AKT signaling are known to be implicated with tumorigenesis. The PI3 kinases family of lipid kinases has been an attractive therapeutic target for cancer treatment. Imidazopyridine compound 1, a potent, selective, and orally available pan-PI3K inhibitor, identified by scaffold morphing of a benzothiazole hit, was further optimized in order to achieve efficacy in a PTEN-deleted A2780 ovarian cancer mouse xenograft model. With a hypothesis that a planar conformation between the core and the 6-heteroaryl ring will allow for the accommodation of larger 5'-substituents in a hydrophobic area under P-loop, SAR efforts focused on 5'-alkoxy heteroaryl rings at the 6-position of imidazopyridine and imidazopyridazine cores that have the same dihedral angle of zero degrees. 6'-Alkoxy 5'-aminopyrazines in the imidazopyridine series were identified as the most potent compounds in the A2780 cell line. Compound 14 with 1,1,1-trifluoroisopropoxy group at 6'-position demonstrated excellent potency and selectivity, good oral exposure in rats and in vivo efficacy in A2780 tumor-bearing mouse. Also, we disclose the X-ray co-crystal structure of one enantiomer of compound 14 in PI3Kα, confirming that the trifluoromethyl group fits nicely in the hydrophobic hot spot under P-loop.


    Organizational Affiliation

    Global Discovery Chemistry, Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, CA 94608, United States.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Phosphatidylinositol 4,5-bisphosphate 3-kinase catalytic subunit alpha isoform A1074Homo sapiensMutation(s): 2 
Gene Names: PIK3CA
EC: 2.7.1.153 (PDB Primary Data), 2.7.11.1 (PDB Primary Data)
Find proteins for P42336 (Homo sapiens)
Explore P42336 
Go to UniProtKB:  P42336
NIH Common Fund Data Resources
PHAROS:  P42336
Protein Feature View
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  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
Phosphatidylinositol 3-kinase regulatory subunit alpha B323Homo sapiensMutation(s): 1 
Gene Names: PIK3R1GRB1
Find proteins for P27986 (Homo sapiens)
Explore P27986 
Go to UniProtKB:  P27986
NIH Common Fund Data Resources
PHAROS:  P27986
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
5XV
Query on 5XV

Download Ideal Coordinates CCD File 
A
~{N}-[6-[5-azanyl-6-[(2~{S})-1,1,1-tris(fluoranyl)propan-2-yl]oxy-pyrazin-2-yl]imidazo[1,2-a]pyridin-2-yl]ethanamide
C16 H15 F3 N6 O2
ADLJEZREHNJMCU-QMMMGPOBSA-N
 Ligand Interaction
GOL
Query on GOL

Download Ideal Coordinates CCD File 
A
GLYCEROL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
 Ligand Interaction
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
5XVIC50:  3   nM  BindingDB
5XVEC50:  40   nM  BindingDB
5XVIC50:  3   nM  Binding MOAD
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.50 Å
  • R-Value Free: 0.245 
  • R-Value Work: 0.194 
  • R-Value Observed: 0.196 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 105.2α = 90
b = 105.32β = 90
c = 134.39γ = 90
Software Package:
Software NamePurpose
BUSTERrefinement
MOSFLMdata reduction
SCALAdata scaling
PHASERphasing

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2016-02-03
    Type: Initial release
  • Version 1.1: 2016-07-20
    Changes: Data collection