What Are Xanthines?

Xanthines are a group of commonly used as mild stimulants and bronchodilators, especially for the treatment of asthma symptoms. Xanthine derivatives include caffeine, theophylline, theobromine (mainly found in chocolate), and mateine. The main compound, xanthine, is a product of the purine degradation pathway and is converted to uric acid by the action of xanthine oxidase.

Chinese name: xanthine

English name: Xanthine

Alias name: 3,7-dihydro-1H-

CAS number: 69-89-6

MDL number: MFCD00078453

EINECS number: 200-718-6

RTECS number: ZD7700000

BRN number: 8733

PubChem number: 24902122 ^[1]

1. Properties: white scaly or flaky crystals.

2. Density (g / mL, 25/4 ): Uncertain

3. Relative vapor density (g / mL, air = 1): uncertain

4. Melting point ( ^o C): 300

5. Boiling point ( ^o C, normal pressure): uncertain

6. Boiling point ( ^o C, 5.2kPa): Uncertain

7. Refractive index: uncertain

8.

Acute toxicity: Oral LD in mice:> 3333 mg / kg; mouse abdominal cavity

1,

1. Reference value for calculation of hydrophobic parameters (XlogP): -0.7

2,

This product should be stored in a cool, dry and sealed place.

4-amino-5-formyl

For biochemical research and organic synthesis, it is a medicine

Xanthine alkaloid structure is a bicyclic compound composed of imidazole and pyrimidine. The molecular structure contains four nitrogen atoms. Typical drugs are the central stimulant caffeine and the smooth muscle relaxant theophylline. ^[2]

Xanthine pharmacological effects

Central nervous system

The range of caffeine to stimulate the central nervous system is related to the dose. Small doses can excite the cerebral cortex, showing mental excitement and active thinking, which can reduce fatigue and eliminate drowsiness; large doses cause mental tension, hand and foot tremor, insomnia and headache. It also excites the medullary cerebrovascular motor center and vagus nerve center, which increases blood pressure and slows heart rate.

2. Cardiovascular system

Caffeine directly relaxes vascular smooth muscle, dilates blood vessels, and reduces peripheral resistance. It has the opposite effect on the cerebral blood vessels, and directly acts on the muscularis of the cerebral arterioles, causing its blood vessels to constrict, increasing cerebral vascular resistance and reducing cerebral blood flow. Diastolic small bronchus and alveolar smooth muscle can also cause pulmonary arteriolar relaxation and increased pulmonary blood flow.

3. Other

It has a diastolic effect on the smooth muscles such as the bronchus and biliary tract, increases the glomerular filtration rate, reduces the reabsorption of Na ⁺ by the renal tubules and has a diuretic effect. ^[2]

Xanthine application

It can be used to prevent drowsiness, breathing and circulation caused by poisoning of severe infectious diseases and central inhibitors (such as analgesics, sedative hypnotics and antihistamines). Compatible with ergot preparations for headaches. Combined with bromide for neurosis.

Xanthine adverse reactions

Adverse reactions are rare. Higher doses can cause agitation, restlessness, insomnia, palpitations, headaches, nausea, and vomiting; excessive doses can cause convulsions. A few patients developed tolerance after use. ^[2]

Xanthine precautions

Convulsions are prone to occur when infants have high fever, and it is not appropriate to use caffeine-containing antipyretic compounds. Because it can increase gastric acid secretion, patients with peptic ulcer should not use it for a long time. This medicine can cause birth defects, delayed bone development, and should be used with caution in pregnant women. ^[2]

The content of Baidu Encyclopedia is edited by netizens. If you find your entry is inaccurate or incomplete, you are welcome to use my entry editing service (free of charge) to participate in the correction. Go Now >>