Guanine is aOrganic compound, chemical formula is CfiveHfiveNfiveO，It is a white to pale yellow crystalline powder with strong absorption to ultraviolet rays, and is a component of guanosine and guanylic acid.Guanine exists widely in animal and plant kingdom.It is one of the basic components of nucleic acids (DNA and RNA).Guanine is a purine derivative, which consists of fused pyrimidine imidazole ring system with conjugated double bonds.[3-4]It is an important base of nucleic acid, one of the four main bases in DNA and RNA, and also a component of various guanylic acids.Its N9 and ribose or deoxyribose C1 are linked by a β - glycoside bond to form guanosine or deoxyguanosine.[4]Guanine is also a natural white pigment, non-toxic.It can be used in general cosmetics, mainly as a pearlescent for lipstick, nail polish and eye cosmetics.[5]
Solubility: soluble in ammonia water, potassium hydroxide aqueous solution, dilute acids, slightly soluble in alcohol and ether, almost insoluble in water[3]
molecular structure
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G (Guanine)
Guanine is a purine organic compound, which is composed ofPyrimidine ringIt is fused with an imidazole ring and is a kind of purine. It is composed of carbon and nitrogen atoms and has a characteristic double ring structurecytosine With threehydrogen bondto be connected.It plays an important role in the organism. Guanine not only has a variety of isomers, but also has the smallest adiabatic ionization potential of four DNA bases. It exists in sea bird feces in free or combined state, and is one of five different nuclear basesDeoxyribonucleic acidandRibonucleic acidMedium.
The modification and expansion of base will cause canceration or other lesions;The accumulation of oxidized bases is easy to lead to aging and guanine is the most easily oxidized base. Therefore, DNA oxidation usually occurs on the guanine base. The C8 position of guanine (G) is the most easily oxidized position, which is easy to form open-loop Fapy-G (guanine) and 8-oxo-G (guanine).One kind of G damage is Fapy-G formed after ring opening. It is generally believed that it can prevent DNA synthesis and has cytotoxicityProkaryotic cellandEukaryotic cellCan be repaired.[1]
Molecular structure data
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1. Molar refractive index: 35.46
2. Molar volume (cmthree/mol）：68.8
3. Isotonic specific volume (90.2K): 229.6
4. Surface tension (dyne/cm): 124.0
5. Polarization (10-24cmthree）：14.06[3]
Calculate chemical data
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1. Reference value for drainage parameter calculation (XlogP): None
2. Number of hydrogen bond donors: 3
3. Number of hydrogen bond receptors: 2
4. Number of rotatable chemical bonds: 0
5. Number of tautomers: 26
6. Topological molecular polar surface area: 96.2
7. Number of heavy atoms: 11
8. Surface charge: 0
9. Complexity: 225
10. Number of isotope atoms: 0
11. Determine the number of atomic structure centers: 0
12. Number of uncertain atomic structure centers: 0
13. Determine the number of chemical bond structure centers: 0
14. Number of uncertain chemical bond structure centers: 0
15. Number of covalent bond units: 1[3]
Physiological and biochemical
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Guanine nucleotide hydrochloride monohydrate loses water at 100 ℃ and hydrogen chloride at 200 ℃ to guanine.It is one of purine type bases in nucleic acid.It exists in DNA and RNA and can be obtained by hydrolysis of bird dung or fish scales, or by using 2,6,8-trichloropurine and NaOH aqueous solution, NHthree, HI reaction.In organisms, hypoxanthine nucleotides are generally synthesized first, then oxidized to xanthine glycosidic acid, and then aminated to guanine nucleotides, while the synthesis of guanine nucleotides from guanine and its nucleosides is only a remedial synthetic way of nucleotide metabolism.adoptGuanylic acidCyclaseCatalytic production of 3 ', 5' - cyclic guanylic acid.In vivo, its content is very low, but it has important physiological functions, and has antagonistic effects with cAMP on metabolic regulation.Like cAMP, cGMP also plays the role of signal transmission as intracellular messenger in cells.Guanine inDNA double helix structureMiddle andcytosine pair.[1]
toxicology data
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acute toxicity
Oral LC of mice:>3333mg/kg
Mice peritoneal LC:>1 mg/kg;[5]
Tumorigenesis
Rats were injected subcutaneously with TDLo: 1300 mg/kg/26W-I[5]
Mutagenicity
Human lymphocyte sex chromosome non separation loss and test system: 10 mg/L
Cytogenetic analysis of mouse peritoneal cavity: 15 mg/kg;[5]
Preparation method
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Method 1: 5-amino-4-imidazolamide was esterified with phenylmethyl isothiocyanate to form an ester, and then reacted with iodomethane and ammonia in turn to obtain the ester.[3]
Method 2: Put the prepared N into a four necked flask in proportionfive-Formyl-2,4,5-triamino-6-hydroxypyrimidine, 88% formic acid, heated to 110 ℃, refluxed for 10 hours, and then evaporated under normal pressureformic acidTo be viscous, cool to 50 ℃, add 200mL of water, dry, wash, dry, and dry to obtain crude guanine.[2]
Coordination principle
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1. Because onimidazoleThere is N element on the ring and benzene ring, and there is N element on the amino group of benzene ringLone pair electronThe coordination reaction may occur when metal ions are added to the solution.
2. In acid solution, there is competition between hydrogen ion and metal ion (metal ion may be protonated), that is, the concentration of hydrogen ion is too high.
3. The coordination ability of N element on benzene ring, imidazole ring and amino group is different. The stronger the coordination ability is, the easier it will occur with metal ionsCoordination reaction。[2]
Numbering system
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CAS No.:73-40-5
MDL No.:MFCD00071533
EINECS No.:200-799-8
RTECS No.:MF8260000
BRN No.:nine thousand six hundred and eighty
PubChem No.:twenty-four million eight hundred and ninety-five thousand two hundred and seventy-four[5]
purpose
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1. Biochemical research
2. Used as an intermediate of antiviral drug acyclovir
3. Intermediate of thioguanine and ring opening guanine[4]
