Abstract: 6,8-Disubstituted purines which can be used in drug and cosmetic compositions and/or applications are provided. These 6,8-disubstituted purines have a wide range of biological activities, including for example anti-inflammatory, anti-senescent, as well as well as other activities which are especially useful in pharmaceutical and cosmetic applications. The 6,8-disubstituted purine compounds and compositions containing such 6,8-disubstituted purines provide growth-regulatory, differentiating, antisenescent and antiaging properties with improved selectivities and efficiencies and lower toxicities than analogues known heretofore.

Abstract: Various substituted nitrogen heterocyclic derivatives and their pharmaceutically acceptable salt derivatives are provided for use as medicaments, and particularly, as antimitotic, anti-viral, anti-cancer, anti-degenerative, immunosuppressive, and anti-microbial drugs or, vaccines. These heterocyclic derivatives can be used as an active agent in a pharmaceutical, as well as a diagnostic utility. To this end, several families of heterocyclic derivatives are provided including pyrrolopyrimidines, pyrazolopyrimidines, purines, and imidazopyridines. In particular, certain tri-substituted and tetra-substituted purines and pyrazolopyrimidines and their deaza analogues are provided for inhibiting cyclin-dependent kinase (“cdk”) proteins, viruses, and immunostimulation.