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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 .
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]
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.
One example of an organism that uses alkaloids for protection is the Utetheisa ornatrix, more commonly known as the ornate moth. Pyrrolizidine alkaloids render these larvae and adult moths unpalatable to many of their natural enemies like coccinelid beetles, green lacewings, insectivorous hemiptera and insectivorous bats. [ 203 ]
What they look like: Chiggers, a type of small mite, typically leave clusters of bites that are often very itchy. In many cases, chigger bites appear as small, red and itchy bumps. Sometimes, they ...
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.