数据之源，洞见之始

Oxipurinol is a xanthine oxidase inhibitor. Oxipurinol is potentially used for treatment of congestive heart failure. PMID: 15139781.

Xanthine, also known as 2,6-dioxopurine, belongs to the class of organic compounds known as xanthines. These are purine derivatives with a ketone group conjugated at carbons 2 and 6 of the purine moiety. Xanthine is also classified as an oxopurine. An oxopurine in which the purine ring is substituted by oxo groups at positions 2 and 6 and N-9 is protonated. Xanthine exists in all living species, ranging from bacteria to plants to humans. In plants, several stimulants can be derived from xanthine, including caffeine, theophylline, and theobromine. Derivatives of xanthine (known collectively as xanthines) are a group of alkaloids commonly used for their effects as mild stimulants and as bronchodilators, notably in the treatment of asthma or influenza symptoms. Within humans, xanthine participates in a number of enzymatic reactions. In particular, xanthine can be biosynthesized from guanine; which is mediated by the enzyme guanine deaminase. In addition, xanthine and ribose 1-phosphate can be biosynthesized from xanthosine through the action of the enzyme purine nucleoside phosphorylase. In humans and other primates, xanthine can be converted to uric acid by the action of the xanthine oxidase enzyme. People with rare genetic disorders, specifically xanthinuria and Lesch–Nyhan syndrome, lack sufficient xanthine oxidase and cannot convert xanthine to uric acid. Individuals with xanthinuria have unusually high concentrations of xanthine in their blood and urine, which can lead to health problems such as renal failure and xanthine kidney stones. Individuals with Lesch-Nyhan syndrome have a deficiency of the enzyme hypoxanthine-guanine phosphoribosyltransferase (HGPRT). The HGPRT deficiency causes a build-up of uric acid in all body fluids. This results in both high levels of uric acid in the blood and urine, associated with severe gout and kidney problems. Neurological signs include poor muscle control and moderate intellectual disability.

6,8-Dihydroxypurine is an endogenous nucleoside found in human fluids. Purine bases are present in higher amounts in tumor-bearing patients compared to healthy controls. DNA hypermethylation is a common finding in malignant cells and has been explored as a therapeutic target for hypomethylating agents. When chemical bonds to DNA, the DNA becomes damaged and proper and complete replication cannot occur to make the normal intended cell. A DNA adduct is an abnormal piece of DNA covalently-bonded to a cancer-causing chemical. This has shown to be the start of a cancerous cell, or carcinogenesis. DNA adducts in scientific experiments are used as bio-markers and as such are themselves measured to reflect quantitatively, for comparison, the amount of cancer in the subject. (PMID: 3506820, 17044778, 17264127, 16799933).

A purine nucleobase found in humans and other organisms." []

An oxopurine that is 3,9-dihydro-6H-purine which is substituted by an oxo group at position 6 and in which the hydrogen attached to the nitrogen at position 3 is replaced by a hydroxy group. It is a major component of Schreckstoff, an alarm pheromone found in fish." []