Classification Term: 2947

Diadenosine diphosphate

C20H26N10O13P2 (676.1156006000001)

Diadenosine diphosphate is a member of the diadenosine polyphosphates. Diadenosine diphosphate is typically synthesized from ADP-ribosyl cyclases. Diadenosine polyphosphates are members of a group of dinucleoside polyphosphates that are ubiquitous, naturally occurring molecules. They form a recently identified class of compounds derived from ATP and consist of two adenosine molecules bridged by up to six phosphate groups. These compounds are stored in high concentrations in platelet dense granules and are released when platelets become activated. Some of the compounds promote platelet aggregation, while others are inhibitory. Possible roles as neurotransmitters, extracellular signalling molecules or alarmones secreted by cells in response to physiologically stressful stimuli have been postulated. Recent studies suggest a role for these compounds in atrial and synaptic neurotransmission. Studies using isolated mesenteric arteries indicate an important role of phosphate chain length in determining whether diadenosine polyphosphates produce vasodilatation or vasoconstriction, but in the coronary circulation, diadenosine polyphosphates generally produce vasodilatation via mechanisms thought to involve release of NO or prostacyclin (PGI2). They produce cardiac electrophysiological effects by altering ventricular refractoriness at submicromolar concentrations and reduce heart rate. Mechanisms involving KATP channels have been proposed in addition to the involvement of P1- and P2-purinergic receptors and the specific diadenosine polyphosphate receptor identified on isolated cardiac myocytes. Clinical evidence suggests a role for diadenosine polyphosphates in hypertensive patients and those with the Chediak-Higashi syndrome. (PMID: 10434992) [HMDB] Diadenosine diphosphate is a member of the diadenosine polyphosphates. Diadenosine diphosphate is typically synthesized from ADP-ribosyl cyclases. Diadenosine polyphosphates are members of a group of dinucleoside polyphosphates that are ubiquitous, naturally occurring molecules. They form a recently identified class of compounds derived from ATP and consist of two adenosine molecules bridged by up to six phosphate groups. These compounds are stored in high concentrations in platelet dense granules and are released when platelets become activated. Some of the compounds promote platelet aggregation, while others are inhibitory. Possible roles as neurotransmitters, extracellular signalling molecules or alarmones secreted by cells in response to physiologically stressful stimuli have been postulated. Recent studies suggest a role for these compounds in atrial and synaptic neurotransmission. Studies using isolated mesenteric arteries indicate an important role of phosphate chain length in determining whether diadenosine polyphosphates produce vasodilatation or vasoconstriction, but in the coronary circulation, diadenosine polyphosphates generally produce vasodilatation via mechanisms thought to involve release of NO or prostacyclin (PGI2). They produce cardiac electrophysiological effects by altering ventricular refractoriness at submicromolar concentrations and reduce heart rate. Mechanisms involving KATP channels have been proposed in addition to the involvement of P1- and P2-purinergic receptors and the specific diadenosine polyphosphate receptor identified on isolated cardiac myocytes. Clinical evidence suggests a role for diadenosine polyphosphates in hypertensive patients and those with the Chediak-Higashi syndrome. (PMID: 10434992).

Guanosine diphosphate adenosine

C20H26N10O14P2 (692.1105156000001)

Guanosine diphosphate adenosine is a dinucleoside polyphosphate. Dinucleoside polyphosphates are an interesting group of signalling molecules that control numerous physiological functions. Diadenosine compounds, with a backbone of anything from two to seven phosphates, are known to occur naturally. Some of them have been isolated from cerebral nerve terminals and, acting via nucleoside (P1), nucleotide (P2), or dinucleotide receptors, can affect central nervous system function. Many of them have been isolated from human blood platelet secretory granules and are potentially involved in haemostatic mechanisms and peripheral control of vascular tone. Many visceral organs respond to the application of adenine dinucleotides and, although they act on receptors in the periphery that can be mainly defined as either P1 or P2, evidence is now accumulating for discrete dinucleotide receptors. In the periphery, adenine dinucleotides can be potent agonists, with diverse functions, causing contraction or relaxation of smooth muscle. Many P2X receptor proteins and P2Y receptors have been cloned and adenine dinucleotides have a variable pharmacological profile at these receptors and may be useful tools for characterising subtypes of P2X and P2Y receptors. Many extracellular roles of diadenosine polyphosphates are emerging as yet increasingly important, natural ligands for a plethora of structurally diverse mononucleotide and dinucleotide receptors. (PMID: 12772275, 7767329) [HMDB] Guanosine diphosphate adenosine is a dinucleoside polyphosphate. Dinucleoside polyphosphates are an interesting group of signalling molecules that control numerous physiological functions. Diadenosine compounds, with a backbone of anything from two to seven phosphates, are known to occur naturally. Some of them have been isolated from cerebral nerve terminals and, acting via nucleoside (P1), nucleotide (P2), or dinucleotide receptors, can affect central nervous system function. Many of them have been isolated from human blood platelet secretory granules and are potentially involved in haemostatic mechanisms and peripheral control of vascular tone. Many visceral organs respond to the application of adenine dinucleotides and, although they act on receptors in the periphery that can be mainly defined as either P1 or P2, evidence is now accumulating for discrete dinucleotide receptors. In the periphery, adenine dinucleotides can be potent agonists, with diverse functions, causing contraction or relaxation of smooth muscle. Many P2X receptor proteins and P2Y receptors have been cloned and adenine dinucleotides have a variable pharmacological profile at these receptors and may be useful tools for characterising subtypes of P2X and P2Y receptors. Many extracellular roles of diadenosine polyphosphates are emerging as yet increasingly important, natural ligands for a plethora of structurally diverse mononucleotide and dinucleotide receptors. (PMID: 12772275, 7767329).

Cytidylyl-(3',5')-guanosine

C19H25N8O12P (588.1329499999999)

Cytidylyl-(5'-3')-5'-inosinic acid homopolymer

C19H25N7O15P2 (653.088384)

Uricase

C18H26N5O14P (567.1213826)

Uricase is also known as oxidase, urate or urate oxidase. Uricase can be found in soy bean, which makes uricase a potential biomarker for the consumption of this food product. The enzyme urate oxidase (UO), or uricase or factor-independent urate hydroxylase, absent in humans, catalyzes the oxidation of uric acid to 5-hydroxyisourate: Uric acid + O2 + H2O ‚Üí 5-hydroxyisourate + H2O2 5-hydroxyisourate + H2O ‚Üí allantoin + CO2 . Uricase is also known as oxidase, urate or urate oxidase. Uricase can be found in soy bean, which makes uricase a potential biomarker for the consumption of this food product. The enzyme urate oxidase (UO), or uricase or factor-independent urate hydroxylase, absent in humans, catalyzes the oxidation of uric acid to 5-hydroxyisourate: Uric acid + O2 + H2O → 5-hydroxyisourate + H2O2 5-hydroxyisourate + H2O → allantoin + CO2 .