3-Methyladenine (3-MA) is a PI3K inhibitor that selectively inhibits class IB PI3Kγ (IC50 = 60 μM) and class III VPS34 (IC50 = 25 μM). 3-Methyladenine inhibits autophagy.

Paraxanthine (1,7-dimethylxanthine) is a metabolite of caffeine (sc-202514) which functions as an adenosine receptor ligand and a PARP-1 inhibitor in pulmonary epithelial cells. Studies suggest that Paraxanthine is structurally similar to caffeine and possibly mediates the physiological effects of caffeine. Also Paraxanthine acts as a competitive phosphodiesterase inhibitor, which increases intracellular cAMP, activates PKA, inhibits TNF-α and leukotriene synthesis. In addition, Paraxanthine acts as a Na+ K+ ATPase enzymatic effector.

6-Benzylaminopurine (6-BAP), benzyl adenine or BAP is a first-generation synthetic cytokinin that elicits plant growth and development responses, setting blossoms and stimulating fruit richness by stimulating cell division. It is an inhibitor of respiratory kinase in plants, and increases post-harvest life of green vegetables.

Xanthine (Isoxanthine) is a product on the pathway of purine degradation. Xanthine is subsequently converted to uric acid by the action of the Xanthine oxidase enzyme. Xanthine is found in most body tissues and fluids in various organisms. Biologically Xanthine is produced from guanine by cypin (guanine deaminase). Furthermore, Xanthines act as antagonists for adenosine receptors, with selectivity depending on whether there are substitution of alkyl groups.

Purine (7H-Imidazo(4,5-d)pyrimidine) is a heterocyclic aromatic organic compound, consisting of a pyrimidine ring fused to an imidazole ring. Two of the bases in nucleic acids, adenine and guanine, are purines. Purines from food (or from tissue turnover) are metabolised by several enzymes, including xanthine oxidase, into uric acid. High levels of uric acid can predispose to gout when the acid crystalises in joints; this phenomenon only happens in humans and some animal species (e.g. dogs) that lack an intrinsic uricase enzyme that can further degrade uric acid.