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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]
Caffeine is a central nervous system (CNS) stimulant of the methylxanthine class and is the most commonly consumed psychoactive substance globally. [9] [10] It is mainly used for its eugeroic (wakefulness promoting), ergogenic (physical performance-enhancing), or nootropic (cognitive-enhancing) properties.
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.
Alfred Blaschko, a private practice dermatologist from Berlin, first described and drew the patterns of the lines of Blaschko in 1901. He obtained his data by studying over 140 patients with various nevoid and acquired skin diseases and transposed the visible patterns the diseases followed onto dolls and statues, then compiled the patterns onto a composite schematic of the human body.
The characteristic signals, distinguishing theophylline from related methylxanthines, are approximately 3.23δ and 3.41δ, corresponding to the unique methylation possessed by theophylline. The remaining proton signal, at 8.01δ, corresponds to the proton on the imidazole ring, not transferred between the nitrogen.
Methylxanthines activate histone deacetylases, promoting the deacetylation of histone and subsequent DNA folding. This inhibits the synthesis of pro-inflammatory factors that induce asthma attacks and exacerbations, achieving anti-inflammatory effects. [19] For asthma maintenance therapy, methylxanthines are taken orally. [2]