1330596-44-5Relevant academic research and scientific papers
Optimization of an imidazopyridazine series of inhibitors of plasmodium falciparum calcium-dependent protein kinase 1 (Pf CDPK1)
Chapman, Timothy M.,Osborne, Simon A.,Wallace, Claire,Birchall, Kristian,Bouloc, Nathalie,Jones, Hayley M.,Ansell, Keith H.,Taylor, Debra L.,Clough, Barbara,Green, Judith L.,Holder, Anthony A.
, p. 3570 - 3587 (2014/05/20)
A structure-guided design approach using a homology model of Plasmodium falciparum calcium-dependent protein kinase 1 (PfCDPK1) was used to improve the potency of a series of imidazopyridazine inhibitors as potential antimalarial agents. This resulted in high affinity compounds with PfCDPK1 enzyme IC 50 values less than 10 nM and in vitro P. falciparum antiparasite EC50 values down to 12 nM, although these compounds did not have suitable ADME properties to show in vivo efficacy in a mouse model. Structural modifications designed to address the ADME issues, in particular permeability, were initially accompanied by losses in antiparasite potency, but further optimization allowed a good balance in the compound profile to be achieved. Upon testing in vivo in a murine model of efficacy against malaria, high levels of compound exposure relative to their in vitro activities were achieved, and the modest efficacy that resulted raises questions about the level of effect that is achievable through the targeting of PfCDPK1.
IMIDAZO [1, 2 - B] PYRIDAZINE DERIVATIVES AS CDPK1 INHIBITORS
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, (2012/10/08)
A first aspect of the invention relates to a compound of formula (I), or a pharmaceutically acceptable salt or ester thereof, (Formula (I)) wherein: R1 is -(CH2)nNR3R4, -OR5 or -(CH2)n-heterocycloalkyl, wherein said heterocycloalkyl group is optionally substituted by one or more R7 groups; R2 is selected from aryl, heteroaryl, fused aryl-heterocycloalkyl and fused hetero aryl-heterocycloalkyl each of which is substituted by at least one R8 group; R3 is H or alkyl; R4 is: (i) cycloalkyl optionally substituted by one or more -NR11R12 or NHCOR11 groups; or (ii) -(CH2)n-heterocycloalkyl, wherein said heterocycloalkyl is a 4, 5 or 6-membered nitrogen-containing group optionally containing one or more CO groups, wherein said heterocycloalkyl is optionally substituted by one or more one or more (CH2)nR7 groups; or (iii) alkyl substituted by one or more -NR11R12groups; or R3 and R4 are linked together with the nitrogen to which they are attached to form a 4, 5, 6 or 7-membered monocyclic heterocycloalkyl group or a bicyclic heterocyclic group, each of which optionally contains one or two further groups selected from CO, O, N and S, and which is optionally further substituted by one or more R7 groups; R5 is selected from alkyl, -(CH2)n-heteroaryl and - (CH2)n-heterocycloalkyl, wherein said heteroaryl and heterocycloalkyl groups are each optionally substituted by one or more R7 groups; each R8 is independently selected from - NR16R17, -OR17 and -(CH2)nR17 where each R16 is H and each R17 is independently - (CHR10)n-heteroaryl, wherein said heteroaryl group is in turn optionally substituted by one or more R7 groups; each R10, R11 and R12 is independently H or alkyl; or in the case of an - NR11R12 group, R11 and R12 may be linked together with the nitrogen to which they are attached to form a 4, 5, 6 or 7-membered monocyclic or bicyclic heterocycloalkyl group optionally containing one or two further groups selected from CO, O, N and S, and which is optionally further substituted by one or more R7 groups; each m is independently an integer from 1 to 6; and each n is independently an integer from 0 to 6. Further aspects relate to the use of said compounds in the treatment of various therapeutic disorders, and more particularly as inhibitors of PfCDPK1.
