1: Li Z, Lu X, Feng LJ, Gu Y, Li X, Wu Y, Luo HB. Molecular dynamics-based discovery of novel phosphodiesterase-9A inhibitors with non-pyrazolopyrimidinone scaffolds. Mol Biosyst. 2015 Jan;11(1):115-25. doi: 10.1039/c4mb00389f. Epub 2014 Oct 20. PubMed PMID: 25328054.
2: Nagy D, Tingley FD 3rd, Stoiljkovic M, Hajós M. Application of neurophysiological biomarkers for Huntington's disease: evaluating a phosphodiesterase 9A inhibitor. Exp Neurol. 2015 Jan;263:122-31. doi: 10.1016/j.expneurol.2014.10.001. Epub 2014 Oct 12. PubMed PMID: 25315303.
3: Heckman PR, Wouters C, Prickaerts J. Phosphodiesterase inhibitors as a target for cognition enhancement in aging and Alzheimer's disease: a translational overview. Curr Pharm Des. 2015;21(3):317-31. Review. PubMed PMID: 25159073.
4: Schwam EM, Nicholas T, Chew R, Billing CB, Davidson W, Ambrose D, Altstiel LD. A multicenter, double-blind, placebo-controlled trial of the PDE9A inhibitor, PF-04447943, in Alzheimer's disease. Curr Alzheimer Res. 2014;11(5):413-21. PubMed PMID: 24801218.
5: Singh N, Patra S. Phosphodiesterase 9: insights from protein structure and role in therapeutics. Life Sci. 2014 Jun 13;106(1-2):1-11. doi: 10.1016/j.lfs.2014.04.007. Epub 2014 Apr 16. Review. PubMed PMID: 24746902.
6: Zhihui Q. Modulating nitric oxide signaling in the CNS for Alzheimer's disease therapy. Future Med Chem. 2013 Aug;5(12):1451-68. doi: 10.4155/fmc.13.111. Review. PubMed PMID: 23919554.
7: Claffey MM, Helal CJ, Verhoest PR, Kang Z, Fors KS, Jung S, Zhong J, Bundesmann MW, Hou X, Lui S, Kleiman RJ, Vanase-Frawley M, Schmidt AW, Menniti F, Schmidt CJ, Hoffman WE, Hajos M, McDowell L, O'Connor RE, Macdougall-Murphy M, Fonseca KR, Becker SL, Nelson FR, Liras S. Application of structure-based drug design and parallel chemistry to identify selective, brain penetrant, in vivo active phosphodiesterase 9A inhibitors. J Med Chem. 2012 Nov 8;55(21):9055-68. doi: 10.1021/jm3009635. Epub 2012 Oct 12. PubMed PMID: 23025719.
8: Verhoest PR, Fonseca KR, Hou X, Proulx-Lafrance C, Corman M, Helal CJ, Claffey MM, Tuttle JB, Coffman KJ, Liu S, Nelson F, Kleiman RJ, Menniti FS, Schmidt CJ, Vanase-Frawley M, Liras S. Design and discovery of 6-[(3S,4S)-4-methyl-1-(pyrimidin-2-ylmethyl)pyrrolidin-3-yl]-1-(tetrahydro-2H-pyr an-4-yl)-1,5-dihydro-4H-pyrazolo[3,4-d]pyrimidin-4-one (PF-04447943), a selective brain penetrant PDE9A inhibitor for the treatment of cognitive disorders. J Med Chem. 2012 Nov 8;55(21):9045-54. doi: 10.1021/jm3007799. Epub 2012 Jul 25. PubMed PMID: 22780914.
9: Vardigan JD, Converso A, Hutson PH, Uslaner JM. The selective phosphodiesterase 9 (PDE9) inhibitor PF-04447943 attenuates a scopolamine-induced deficit in a novel rodent attention task. J Neurogenet. 2011 Dec;25(4):120-6. doi: 10.3109/01677063.2011.630494. Epub 2011 Nov 9. PubMed PMID: 22070409.
10: Hutson PH, Finger EN, Magliaro BC, Smith SM, Converso A, Sanderson PE, Mullins D, Hyde LA, Eschle BK, Turnbull Z, Sloan H, Guzzi M, Zhang X, Wang A, Rindgen D, Mazzola R, Vivian JA, Eddins D, Uslaner JM, Bednar R, Gambone C, Le-Mair W, Marino MJ, Sachs N, Xu G, Parmentier-Batteur S. The selective phosphodiesterase 9 (PDE9) inhibitor PF-04447943 (6-[(3S,4S)-4-methyl-1-(pyrimidin-2-ylmethyl)pyrrolidin-3-yl]-1-(tetrahydro-2H-py ran-4-yl)-1,5-dihydro-4H-pyrazolo[3,4-d]pyrimidin-4-one) enhances synaptic plasticity and cognitive function in rodents. Neuropharmacology. 2011 Sep;61(4):665-76. doi: 10.1016/j.neuropharm.2011.05.009. Epub 2011 May 19. PubMed PMID: 21619887.