Аденозин

Химические свойства

Adenosine is an important nucleoside composed of adenine and ribose. White, crystalline, odorless powder, mild, saline, or bitter taste, quite soluble in hot water, practically insoluble in alcohol. Formed by isolation following hydrolysis of yeast nucleic acid.

Использование

adenosine is an amino acid. Studies indicate anti-wrinkle and skinsmoothing capacities. Although little is written about its direct skin benefit, adenosine plays an important role in biochemical processes. As adenosine triphosphate (ATP) and adenosine diphosphate (ADP), it is involved in energy transfer, and as cyclic adenosine monophosphate (cAMP) in signal transduction.

Определение

ChEBI: Adenosine is a ribonucleoside composed of a molecule of adenine attached to a ribofuranose moiety via a beta-N(9)-glycosidic bond. It has a role as an anti-arrhythmia drug, a vasodilator agent, an analgesic, a human metabolite and a fundamental metabolite. It is a purines D-ribonucleoside and a member of adenosines. It is functionally related to an adenine.

Биологические функции

Adenosine regulates multiple physiological and pathophysiological processes, by acting both through G-protein coupled adenosine receptors and intracellularly. It modulates neuronal plasticity, astrocytic activity , learning and memory, food intake, motor function, sleep/wake cycle, pain, immunosupression, proliferation, and aging. Adenosine is involved in ischemia and stroke, epilepsy, and neurodegenerative pathologies such as Parkinson's disease (PD), Alzheimer's disease (AD), amyotrophic lateral sclerosis (ALS), and Huntington's disease (HD). Extracellular adenosine, interacting with P1 receptors (A1R, A2AR, A2BR, and A3R) regulates metabolism through different signaling pathways[1].

Общее описание

Adenosine is a purine nucleoside and a building block of RNA and many other biomolecules such as adenosine triphosphate and nicotinamide adenine dinucleotide. In the extracellular space, ecto-5′-nucleotidase (CD73) dephosphorylates adenosine triphosphate (ATP) to produce adenosine. Adenosine has four receptors namely A1R, A2AR A2BR and A3R. Adenosine plays a key role in the osteogenic differentiation. A1R induces osteoclast differentiation and A2AR induces osteoblast differentiation.

Биологическая активность

Neurotransmitter that acts as the preferred endogenous agonist at all adenosine receptor subtypes.

Клиническое использование

Adenosine (Adenocard) is an endogenous nucleoside that is a product of the metabolism of adenosine triphosphate. It is used for the rapid termination of supraventricular arrhythmias following rapid bolus dosing.
Adenosine is approved for the acute management and termination of supraventricular tachyarrhythmias, including A-V nodal reentrant tachycardia and A-V reciprocating tachycardia. Adenosine may be helpful in the diagnosis of atrial flutter.

Побочные эффекты

Adverse reactions to the administration of adenosine are fairly common; however, the short half-life of the drug limits the duration of such events.The most common adverse effects are flushing, chest pain, and dyspnea. Adenosine may induce profound bronchospasm in patients with known reactive airway disease. The mechanism for bronchospasm is unclear, and the effect may last for up to 30 minutes despite the short half-life of the drug.

взаимодействия лекарств

Metabolism of adenosine is slowed by dipyridamole, indicating that in patients stabilized on dipyridamole the therapeutically effective dose of adenosine may have to be increased. Methylxanthines antagonize the effects of adenosine via blockade of the adenosine receptors.

Методы очистки

Crystallise adenosine from distilled water and dry it at 110o. It has been purified via the picrate, where ethanolic picric acid is added to adenosine and the picrate is filtered off and recrystallised from EtOH. It has m 180-185o(dec). Adenosine is recovered by dissolving 0.4g of the picrate in 80mL of hot H2O, treated with a small quantity of Dowex 1 anion exchange resin in the chloride form, and the resin is filtered off. The filtrate is treated with more resin and filtered again. One equivalent of aqueous NaOH is added to the colourless filtrate which is evaporated to 4mL and cooled to give 0.176g of adenosine m 236o. [Davoll et al. J Chem Soc 967 1948, Davoll & Lowy J Am Chem Soc 73 1650 1951, Beilstein 26 III/IV 3598.]

Меры предосторожности

Patients with second- or third-degree A-V block should not receive adenosine. As indicated previously, the use of adenosine in asthmatic patients may exacerbate the asthmatic symptoms.