What Is Adenine? Purine Base, Formula and Role in DNA and RNA
Adenine is a purine nucleobase, not an amino acid, protein, nucleoside or nucleotide. Public chemical records identify it as CAS 73-24-5, molecular formula C5H5N5 and molecular weight about 135.13 g/mol. Adenine is represented by the letter A in DNA and RNA. When adenine is attached to ribose it forms the distinct nucleoside adenosine; adding phosphate group(s) produces adenosine nucleotides such as AMP, ADP and ATP.
Adenine identity at a glance
| Preferred name | Adenine |
|---|---|
| CAS Registry Number | 73-24-5 |
| Chemical class | Purine nucleobase; member of the 6-aminopurines |
| IUPAC name | 9H-purin-6-amine |
| Fórmula molecular | C5H5N5 |
| Peso molecular | 135.13 g/mol (NIST: 135.1267) |
| PubChem CID | 190 |
| ChEBI ID | CHEBI:16708 |
| EC number | 200-796-1 |
| InChIKey | GFFGJBXGBJISGV-UHFFFAOYSA-N |
| ChEBI SMILES | Nc1ncnc2ncnc12 |
Identity references: NIST Chemistry WebBook, PubChem CID 190 y EMBL-EBI ChEBI CHEBI:16708. These sources establish public identity and classification fields; they do not establish a current Longchang specification, purity, grade, lot result, inventory or suitability.
Is adenine a purine?
Yes. ChEBI classifies adenine as both a purine nucleobase and a member of the 6-aminopurines. Its fused purine ring contains a six-membered ring joined to a five-membered ring, with an amino group at carbon 6. This classification is why “adenine is a purine” is correct while “adenine is an amino acid” is not.
What is the role of adenine in DNA and RNA?
The U.S. National Human Genome Research Institute lists adenine among the four bases used in DNA and among the four bases used in RNA. In double-stranded DNA, adenine pairs with thymine. In RNA, uracil replaces thymine in the base set. This biological context refers to adenine as the base component of nucleotides within nucleic-acid polymers—not to a claim that free Adenine CAS 73-24-5 is a medicine, energy supplement or finished biological product.
Genome references: NHGRI DNA glossary, NHGRI RNA glossary y NHGRI nucleotide glossary.
Adenine, adenosine and ATP are not the same substance
| Term | What it is | Key distinction |
|---|---|---|
| Adenine | Purine nucleobase; CAS 73-24-5 | The base alone; formula C5H5N5 |
| Adenosine | Purine ribonucleoside | Adenine attached to ribose; ChEBI records CAS 58-61-7 |
| AMP | Adenosine monophosphate | Adenosine with one phosphate group |
| ADP | Adenosine diphosphate | Adenosine nucleotide with two phosphate groups |
| ATP | Adenosine triphosphate | Adenosine nucleotide with three phosphate groups |
| Adenine derivative or analog | A related but chemically modified substance | Its properties, hazards and biological activity cannot be assigned to adenine itself |
ChEBI defines adenosine as adenine attached to a ribofuranose moiety. That relationship does not make the two names interchangeable in a specification, analytical record or RFQ.
Why does the adenine formula contain no oxygen?
Free adenine has the formula C5H5N5, so it contains carbon, hydrogen and nitrogen but no oxygen. Adenosine and adenine nucleotides contain oxygen because the ribose and phosphate components add oxygen atoms. A formula search must therefore be matched to the exact chemical entity rather than to the wider “adenine-containing molecule” family.
What does “Vitamin B4” mean?
NIST lists “Vitamin B4” among historical or alternative names associated with Adenine CAS 73-24-5. A legacy synonym is not, by itself, a current nutrition classification, health claim, permitted supplement claim or evidence that a supplied lot is suitable for food use. Use “Adenine” and CAS 73-24-5 as the controlled procurement identity.
Claims removed from the earlier page
| Earlier statement | Why it is not retained | Evidence required before reuse |
|---|---|---|
| Adenine supports energy levels or provides health benefits | Confuses free adenine with ATP biology and implies a human benefit | Exact product form, route, dose, intended market and competent medical/regulatory substantiation |
| Adenine treats metabolic conditions or acts as an antiviral | Confuses adenine with distinct drugs, analogs or derivatives | Exact active substance, primary clinical evidence, approved labeling and jurisdiction-specific review |
| Generally recognized as safe for research and pharmaceutical applications | Research handling and regulated-product suitability are different questions; no applicable determination was cited | Current SDS, intended use, exposure context and applicable regulatory basis |
| Cell-culture, supplement or pharmaceutical grade is available | No current controlled grade specification or release evidence was shown | Current specification, methods, applicable lot COA and intended-use qualification |
| High purity, reliable supply, competitive pricing or bulk availability | No dated specification, inventory or quotation supported the promise | Current documents and a destination-specific quotation |
Choose the next Adenine page by intent
- Use this page for the head question “what is adenine,” its purine classification, formula and DNA/RNA context.
- Utilice Is Adenine an amino acid? Adenine vs adenosine and nucleotides for terminology and comparison questions.
- Use the product page for current document, sample and quotation requests.
Request current Adenine information
Open the Adenine CAS 73-24-5 product page to request the current specification, analytical methods, applicable lot COA, SDS status, sample availability, packaging and commercial information.
Correo electrónico info@longchangchemical.com with the intended technical context, required tests and limits, quantity, packaging, destination and document requirements.
Frequently asked questions
Is adenine an amino acid?
No. Adenine is a purine nucleobase. Amino acids are a different class of compounds used as protein building blocks.
What is the molecular formula of adenine?
C5H5N5. NIST reports molecular weight 135.1267, commonly rounded to 135.13 g/mol.
Is adenine the same as adenosine?
No. Adenosine is the nucleoside formed when adenine is attached to ribose.
Is an adenine analog the same as adenine?
No. An analog or derivative is a distinct chemical entity. Do not transfer a derivative’s efficacy, hazard, authorization or application claim to Adenine CAS 73-24-5.
Spanish 
English 
Danish 
German 
Hungarian 
French 
Russian 
Turkish