1.3- Dipropyl-8- xanthine

Figure 3. Van t Hoff plots showing the effect of temperature on the equilibrium association constants, K, of both xanthines ( theophylline 1,3-dipropylxanthine x 1,3-dibutylxanthine) and xanthine-7-ribosides ( theophylline-7-riboside O 1,3-dipropyl-xanthine-7-riboside a 1,3-dibutylxanthine-7-riboside). All plots were essentially linear (r > 0.95). Reproduced with permission of principal author and publisher of ref. [34].

ATP, ADP, and adenosine are among the purines that are present in some synapses and activate a variety of receptors. Adenosine receptors are blocked specifically by methylated xanthines such as caffeine (Fig. 25-18) and theophylline.808 80813 A drug almost 105 times as potent as theophylline is l,3-dipropyl-8-(2-amino-4-chlorophenyl)xanthine.809 Adenosine receptors, which are present in large numbers in the hippocampus,149 form functional complexes with metabotropic glutamate receptors.678 Adenosine... 

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