Structure of Guanine (CAS NO.73-40-5):

Empirical Formula: C₅H₅N₅O
Molecular Weight: 151.1261 
EINECS: 200-799-8
Index of Refraction: 2.047
Density: 2.19 g/cm³
Flash Point: 311.4 °C
Melting point: >300 °C(lit.)
Storage tempreture: 2-8 °C
Water solubility: Practically insoluble
Solubility: 1 M NaOH: 0.1 M at 20 °C, clear, colorless
Appearance: white to light yellow crystal powder
Enthalpy of Vaporization: 88.21 kJ/mol
Boiling Point: 591.4 °C at 760 mmHg
Vapour Pressure: 5.86E-14 mmHg at 25 °C 
IUPAC Name: 2-Amino-3,7-dihydropurin-6-one
Canonical SMILES: C1=NC2=C(N1)C(=O)N=C(N2)N
InChI: InChI=1S/C5H5N5O/c6-5-9-3-2(4(11)10-5)7-1-8-3/h1H,(H4,6,7,8,9,10,11)
InChIKey: UYTPUPDQBNUYGX-UHFFFAOYSA-N
Product Category of Guanine (CAS NO.73-40-5): Pharmaceutical Intermediates;Purine;Acyclovir;Biochemistry;Nucleobases and their analogs;Nucleosides, Nucleotides & Related Reagents;Nucleic acids

 Guanine (CAS NO.73-40-5) can be hydrolyzed with strong acid to glycine, ammonia, carbon dioxide, and carbon monoxide. It is first deaminated to xanthine. Guanine oxidizes more readily than adenine, the other purine-derivative base in DNA. Its high melting point of 350°C reflects the intermolecular hydrogen bonding between the oxo and amino groups in the molecules in the crystal. Because of this intermolecular bonding, guanine is relatively insoluble in water, but it is soluble in dilute acids and bases.

Two experiments conducted by Levy et al. showed that heating 10 mol·L−1 NH₄CN at 80 °C for 24 hours gave a yield of 0.0007%, while using 0.1 mol·L−1 NH4CN frozen at -20 °C for 25 years gave a 0.0035% yield.
5NH₃ + CH₄ + 2C₂H₆ + H₂O → C₅H₈N₅O (guanine) + (²⁵/₂)H₂
5CO + (¹/₂)H₂ + 5NH₃ → C₅H₈N₅O (guanine) + 4H₂O

Hazard Codes: Xi
Risk Statements: 36/37/38 
R36/37/38:Irritating to eyes, respiratory system and skin.
Safety Statements: 26-36-37/39 
S26: In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. 
S36:Wear suitable protective clothing. 
S37/39:Wear suitable gloves and eye/face protection.

Guanine, is present in both DNA and RNA along with Adenine and cytosine, , whereas THYMINE is usually seen only in DNA, and URACIL only in RNA. Guanine has two tautomeric forms, the major keto form (see figures) and rare enol form. It binds to cytosine through three HYDROGEN bonds. In cytosine, the amino group acts as the HYDROGEN donor and the C-2 carbonyl and the N-3 amine as the HYDROGEN-bond acceptors. Guanine has a group at C-6 that acts as the HYDROGEN acceptor, while the group at N-1 and the amino group at C-2 act as the HYDROGEN donors.

 Guanine , its cas register number is 73-40-5. It also can be called 2-Amino-1,7-dihydro-6H-purin-6-one ; 2-Amino-6-hydroxypurine ; and 2-Aminohypoxanthine . It is one of the four main nucleobases found in the nucleic acids DNA and RNA, the others being adenine, cytosine, and thymine. It is hazardous, so the first aid measures and others should be known. Such as: When on the skin: first, should flush skin with plenty of water immediately for at least 15 minutes while removing contaminated clothing. Secondly, get medical aid. Or in the eyes: Flush eyes with plenty of water for at least 15 minutes, occasionally lifting the upper and lower eyelids. Then get medical aid soon. While, it's inhaled: Remove from exposure and move to fresh air immediately. Give artificial respiration while not breathing. When breathing is difficult, give oxygen. And as soon as to get medical aid. Then you have the ingesting of the product: Wash mouth out with water, and get medical aid immediately.
 Guanine (CAS NO.73-40-5) is present in both DNA and RNA, whereas thymine is usually seen only in DNA, and uracil only in RNA. The first isolation of guanine was reported in 1844 from the excreta of sea birds, known as guano, which was used as a source of fertilizer.