Purvalanol B (NG 95) is a CDK inhibitor that inhibits Cdk2/cyclin A, Cdk2/cyclin E, Cdk5/p35, and Cdk2/cyclin B (IC50s = 6, 9, 6, and 6 nM, respectively)

CDK5-p35:6 nM , CDK2-CyclinE:9 nM , CDK2-CyclinA:6 nM , CDK2-CyclinB:6 nM

Purvalanol B application decreases the ability of late-stage P.falciparum trophozoites to form multinucleated schizonts and up-regulates proteasome subunits and proteins that contribute to redox homeostasis, which may indicate an increase in oxidative stress as a result of inhibitor application[1].

A SYBR Green I parasite growth assay was used to measure the IC50 of Purvalanol B with P. falciparum (strain W2). Purvalanol B or DMSO control were applied to synchronized parasites 36 hours post invasion and parasites were incubated for 12 hours. Giemsa-stained blood smears were used to determine the effect of Purvalanol B on parasite growth, global quantitative proteomic analysis was used to examine differences in protein expression between Purvalanol B-treated and control parasites and results were confirmed by qPCR[1].