Methylxanthinei

Methylxanthinei, more commonly referred to as methylxanthines in English, denotes a class of purine alkaloids derived from xanthine. They are naturally occurring stimulants found in several plants and are also produced synthetically for medical and dietary uses. The term “Methylxanthinei” is not standard in English science literature, but may appear in some non-English texts as a plural or Latinized form of methylxanthine derivatives.

Chemistry and occurrence: Methylxanthines are methylated derivatives of xanthine, with one or more methyl groups attached to nitrogen atoms. The best known members are caffeine (1,3,7-trimethylxanthine), theobromine (3,7-dimethylxanthine), and theophylline (1,3-dimethylxanthine). They occur in coffee, tea, cacao, guarana, and related products, with varying concentrations that influence taste and stimulant effects.

Mechanism of action: The primary pharmacological action is antagonism of adenosine receptors, especially A1 and A2A, which promotes wakefulness and alertness. At higher concentrations, methylxanthines inhibit phosphodiesterase, increasing intracellular cAMP and producing additional physiological effects such as bronchodilation and mild cardiac stimulation.

Applications and safety: Theophylline has historically been used as a bronchodilator in asthma and COPD, though it is less favored today due to train of side effects and drug interactions. Caffeine is widely consumed as a stimulant and is also used in some pharmaceutical preparations. Theobromine contributes to the effects of chocolate but is less potent. Excessive intake can cause anxiety, insomnia, tachycardia, or other adverse effects; toxicity risks exist for pets and in certain drug interactions.

See also: Xanthine, Adenosine receptor, Caffeine.