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: 2.5 Å
  • R-Value Free: 0.245 
  • R-Value Work: 0.194 

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

  • 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 avail ...

    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: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Phosphatidylinositol 4,5-bisphosphate 3-kinase catalytic subunit alpha isoform
A
1074Homo sapiensMutation(s): 2 
Gene Names: PIK3CA
EC: 2.7.1.153
Find proteins for P42336 (Homo sapiens)
Go to Gene View: PIK3CA
Go to UniProtKB:  P42336
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Phosphatidylinositol 3-kinase regulatory subunit alpha
B
323Homo sapiensMutation(s): 1 
Gene Names: PIK3R1 (GRB1)
Find proteins for P27986 (Homo sapiens)
Go to Gene View: PIK3R1
Go to UniProtKB:  P27986
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
GOL
Query on GOL

Download SDF File 
Download CCD File 
A
GLYCEROL
GLYCERIN; PROPANE-1,2,3-TRIOL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
 Ligand Interaction
5XV
Query on 5XV

Download SDF File 
Download 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
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
5XVIC50: 3 nM BINDINGMOAD
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.5 Å
  • R-Value Free: 0.245 
  • R-Value Work: 0.194 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 105.200α = 90.00
b = 105.320β = 90.00
c = 134.390γ = 90.00
Software Package:
Software NamePurpose
SCALAdata scaling
BUSTERrefinement
MOSFLMdata reduction
PHASERphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

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