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Methylxanthines are chemical compounds which are derivatives of xanthine with one or more methyl groups, including: One methyl group: 1-Methylxanthine;
7-Methylxanthine (7-MX), also known as heteroxanthine, is an active metabolite of caffeine (1,3,7-trimethylxanthine) and theobromine (3,7-dimethylxanthine). [ 1 ] [ 2 ] It is a non-selective antagonist of the adenosine receptors .
Xanthine (/ ˈ z æ n θ iː n / or / ˈ z æ n θ aɪ n /, from Ancient Greek ξανθός xanthós ' yellow ' for its yellowish-white appearance; archaically xanthic acid; systematic name 3,7-dihydropurine-2,6-dione) is a purine base found in most human body tissues and fluids, as well as in other organisms. [2]
Paraxanthine is the primary metabolite of caffeine in humans and other animals, such as mice. [3] Shortly after ingestion, roughly 84% of caffeine is metabolized into paraxanthine by hepatic cytochrome P450 , which removes a methyl group from the N3 position of caffeine.
Its pharmacology is similar to other methylxanthine drugs (e.g., theobromine and caffeine). [1] Trace amounts of theophylline are naturally present in tea, coffee, chocolate, yerba maté, guarana, and kola nut. [1] [3] The name 'theophylline' derives from "Thea"—the former genus name for tea + Legacy Greek φύλλον (phúllon, "leaf") + -ine.
IBMX (3-isobutyl-1-methylxanthine), like other methylxanthine derivatives, is both a: competitive non-selective phosphodiesterase inhibitor [1] which raises intracellular cAMP, activates PKA, inhibits TNFα [2] [3] and leukotriene [4] synthesis, and reduces inflammation and innate immunity, [4] and; nonselective adenosine receptor antagonist. [5]
8-Phenyltheophylline (8-phenyl-1,3-dimethylxanthine, 8-PT) is a drug derived from the xanthine family which acts as a potent and selective antagonist for the adenosine receptors A 1 and A 2A, but unlike other xanthine derivatives has virtually no activity as a phosphodiesterase inhibitor.
Adenosine's effects are concentration-dependent. Adenosine’s receptors are competitively antagonized by methylxanthines such as aminophylline. [3] [17] [18] Aminophylline competitively antagonizes the cardiac actions of adenosine at the cell surface receptors. [17] Thus, it increases heart rate and contractility.