Paraxanthine CAS 611-59-6 vs Theobromine CAS 83-67-0 — High-Purity Xanthine Research Powder Comparison: Caffeine's Primary Metabolite (1,7-Dimethylxanthine) vs the Cocoa Alkaloid (3,7-Dimethylxanthine)
Head-to-head comparison of two high-purity methylxanthine research powders: Paraxanthine (CAS 611-59-6, 1,7-dimethylxanthine, caffeine's principal metabolite) and Theobromine (CAS 83-67-0, 3,7-dimethylxanthine, the primary cocoa alkaloid). Both ≥98% (HPLC), in stock with full COA, HPLC, NMR, MS & MSDS documentation.
Paraxanthine (CAS 611-59-6) vs Theobromine (CAS 83-67-0) — Two Methylxanthines, One Methyl Group Apart
Caffeine is the most consumed psychoactive compound on earth — but what happens after you drink the coffee is where the real chemistry begins. In the liver, CYP1A2 converts caffeine (1,3,7-trimethylxanthine) into three demethylated metabolites: ~80% becomes Paraxanthine (1,7-dimethylxanthine), ~10% becomes Theobromine (3,7-dimethylxanthine), and ~5% becomes theophylline. Meanwhile, theobromine is also the dominant natural alkaloid of Theobroma cacao (cocoa), responsible for much of dark chocolate's mildly stimulating, vasodilating character.
For researchers designing "clean energy", pre-workout, nootropic, or cardiometabolic studies, this pairing has become one of the most searched comparative topics in the methylxanthine space. NutraBiotech supplies both compounds side by side so your lab can run controlled head-to-head or stacked-dosing protocols from a single, documentation-complete source.
🟢 Paraxanthine (1,7-Dimethylxanthine)
Caffeine's primary active metabolite — the compound your body actually runs on after that espresso. Shorter half-life, reported to preserve alertness with reduced anxiogenic and vasoconstrictive liability in preclinical models.
- CAS No.
- 611-59-6
- Synonyms
- 1,7-Dimethylxanthine; Paraxanthine; caffeine metabolite 1
- IUPAC
- 1,7-dimethyl-3H-purine-2,6-dione
- Formula
- C₇H₈N₄O₂
- Molecular Weight
- 180.16 g/mol
- Primary Targets
- Adenosine A₁/A₂ᴀ receptors; PDE
- Typical Purity
- ≥98% (HPLC)
- Storage
- 2–8 °C, sealed, light-protected
🟤 Theobromine (3,7-Dimethylxanthine)
The signature alkaloid of cocoa beans — the molecule behind dark chocolate's gentle, slow, vasodilating stimulation. Weaker adenosine antagonism, longer half-life, classic smooth-muscle relaxant pharmacology.
- CAS No.
- 83-67-0
- Synonyms
- 3,7-Dimethylxanthine; diurobromine; xantheose
- IUPAC
- 3,7-dimethyl-3H-purine-2,6-dione
- Formula
- C₇H₈N₄O₂
- Molecular Weight
- 180.16 g/mol
- Primary Targets
- PDE; adenosine receptors (weak); smooth muscle
- Typical Purity
- ≥98% (HPLC)
- Storage
- Room temperature, sealed, dry
Product Technical Specifications
📋 Physicochemical Properties — Head-to-Head
| Parameter | Paraxanthine | Theobromine |
|---|---|---|
| CAS Number | 611-59-6 | 83-67-0 |
| Molecular Formula | C₇H₈N₄O₂ | C₇H₈N₄O₂ |
| Molecular Weight | 180.16 g/mol | 180.16 g/mol |
| Chemical Class | Dimethylated xanthine (1,7-) | Dimethylated xanthine (3,7-) |
| Appearance | White to off-white crystalline powder | White to off-white crystalline powder |
| Melting Point | ~290 °C (decomp.) | ~351–353 °C |
| Water Solubility | Sparingly soluble (~2–4 mg/mL at RT) | Poorly soluble (<1 mg/mL; improves in alkaline/hot media) |
| Solubility Note | Dissolves in dilute alkali; limited DMSO | Dissolves in dilute alkali & hot water |
| Natural Occurrence | Trace; formed endogenously from caffeine | Cocoa (2–3% of dry bean), tea (trace) |
| HS Code | 2939.59 / 2939.99 (alkaloid derivative) | 2939.59 / 2939.99 (alkaloid derivative) |
| Purity | ≥98% (HPLC) | ≥98% (HPLC) |
🔬 Quality Control & Handling
| Item | Paraxanthine | Theobromine |
|---|---|---|
| Purity (HPLC) | ≥98% | ≥98% |
| Identity Testing | NMR, MS, IR, HPLC retention time | NMR, MS, IR, HPLC retention time |
| QC Documents | COA, HPLC chromatogram, NMR, MS, MSDS | COA, HPLC chromatogram, NMR, MS, MSDS |
| Storage | 2–8 °C, sealed, light-protected | RT, sealed, dry |
| Shipping | Ambient / expedited cool option | Ambient |
| Pack Sizes | 1 g / 5 g / 10 g / 100 g / 1 KG | 1 g / 5 g / 10 g / 100 g / 1 KG |
| Stock Status | In stock (1 KG made-to-order) | In stock (1 KG made-to-order) |
| Intended Use | Laboratory research use only — not for human or veterinary use, not for clinical or dietary application | |
Key Molecular Targets & Pathway Nodes
Paraxanthine: Adenosine A₁ receptor · Adenosine A₂ᴀ receptor · Phosphodiesterase (PDE) · cAMP signaling · Lipolysis (HSL/cAMP-dependent) · CYP1A2 metabolite node · Dopamine signaling (indirect)
Theobromine: Phosphodiesterase (PDE) · Adenosine receptors (low affinity) · Smooth muscle relaxation · Vasodilation · Bronchodilation · Diuresis · NO-mediated vascular tone
How They Work: Same Xanthine Scaffold, Opposite Vascular Personalities
Both dimethylxanthines block adenosine A₁/A₂ᴀ receptors, the classic wakefulness mechanism — but paraxanthine retains near-caffeine affinity while theobromine is markedly weaker, requiring higher concentrations for the same antagonism.
Theobromine's pharmacology leans more on phosphodiesterase inhibition and rising intracellular cAMP, driving smooth-muscle relaxation — the molecular basis of its vasodilator and bronchodilator profile.
Preclinical literature reports paraxanthine shows little of caffeine's vasoconstrictive effect, while theobromine is actively vasodilatory — the key reason the two metabolites sit at opposite ends of the hemodynamic spectrum.
⚖️ Pharmacokinetics: The Half-Life Story
| Parameter | Paraxanthine | Theobromine | Caffeine (reference) |
|---|---|---|---|
| Methyl positions | 1,7- | 3,7- | 1,3,7- |
| Origin | Caffeine metabolite (CYP1A2) | Caffeine metabolite + cocoa | Dietary (coffee, tea, etc.) |
| Elimination half-life | ~2–3 h (short) | ~7–8 h (long) | ~4–6 h |
| Adenosine antagonism | High (caffeine-like) | Low | High |
| PDE inhibition | Moderate | Moderate–predominant | Moderate |
| Vascular effect | Reported neutral / non-vasoconstrictive | Vasodilation | Vasoconstriction reported |
| Character in preclinical models | Fast, "clean" alertness | Slow, sustained, smooth-muscle relaxant | Biphasic; tolerance-forming |
This half-life contrast is exactly what current energy-drink, pre-workout and "post-GLP-1 energy slump" research programs are probing: paraxanthine clears quickly (studied for reduced residual stimulation and sleep interference), while theobromine's long tail supports sustained vasodilatory models.
♻️ Downstream Biological Consequences
- Paraxanthine: preserved vigilance and reaction-time readouts in behavioral models; cAMP-dependent lipolysis; investigated as a caffeine substitute with reduced anxiogenic and vascular liability.
- Theobromine: peripheral vasodilation, bronchodilation, mild diuresis; studied in dental enamel-hardness models, airway physiology, and cocoa-flavanol cardiovascular synergy research.
Research Applications & Models
⚡ Pre-Workout & Ergogenic Research
Paraxanthine as a fast-onset, fast-clearance stimulant candidate; head-to-head dosing against caffeine and theacrine in exercise-performance models.🧠 Nootropic & Cognitive Protocols
Alertness, reaction time, and "clean energy / no-crash" study designs comparing short-half-life paraxanthine against parent caffeine.🫀 Cardiovascular & Vascular Function
Theobromine-centered flow-mediated dilation, endothelial function, and blood-pressure-research models; cocoa-flavanol interaction studies.🔄 Caffeine Metabolism & CYP1A2 Studies
Paraxanthine/theobromine ratios as non-invasive probes of CYP1A2 phenotyping and drug–interaction research.😴 Sleep & Chronobiology
Stimulant-residue paradigms: how a 2–3 h half-life compound compares with 7–8 h compounds on sleep-onset and architecture endpoints.🧪 Analytical Reference Standards
Both compounds as certified-style references (COA-backed) for LC-MS/MS quantification in plasma, beverages, and botanical matrices.Key Literature & Landmark Publications
- Fredholm BB, Bättig K, Holmén J, Nehlig A, Zvartau EE. Actions of caffeine in the brain with special reference to factors that contribute to its widespread use. Pharmacological Reviews. 1999;51(1):83–133.
- Lelo A, Birkett DJ, Robson RA, Miners JO. Comparative pharmacokinetics of caffeine and its demethylated metabolites paraxanthine, theobromine and theophylline in man. British Journal of Clinical Pharmacology. 1986;22(2):177–182.
- Smit HJ, Gaffan EA, Rogers PJ. Methylxanthines are the psycho-pharmacologically active constituents of chocolate. Psychopharmacology (Berl). 2004;176(3–4):412–419.
- Monteiro JP, Alves MG, Oliveira PF, Silva BM. Structure-bioactivity relationships of methylxanthines: Trying to keep pace with caffeine. Life Sciences. 2016;178:54–62.
- van Dam RM, Hu FB, Willett WC. Coffee, caffeine, and health. The New England Journal of Medicine. 2020;383(4):369–378.
Available Sizes & Ordering
| Tier | Pack Size | Stock Status | Suitable For | Lead Time |
|---|---|---|---|---|
| Trial | 1 g | In stock | Method validation, screening assays | 1–3 days |
| Lab | 5 g | In stock | In vitro pharmacology, LC-MS standards | 1–3 days |
| Pilot | 10 g | In stock | Animal-model dosing studies | 1–3 days |
| Bulk | 100 g | In stock | Scaled preclinical programs | 3–5 days |
| Industrial | 1 KG | Made to order | Contract research & formulation R&D | 2–3 weeks |
Tiered bulk pricing available on both compounds. Order paraxanthine, theobromine, or both together — paired quotes make comparative studies easier to budget. Contact us →
Frequently Asked Questions (FAQ)
Q1: What is paraxanthine (CAS 611-59-6)?
Paraxanthine (1,7-dimethylxanthine) is the principal metabolite of caffeine in humans — roughly 80% of ingested caffeine is demethylated by CYP1A2 to paraxanthine. It is a white crystalline xanthine powder (C₇H₈N₄O₂, MW 180.16) supplied for laboratory research only, with adenosine-receptor antagonism comparable to caffeine and a shorter half-life.
Q2: Is paraxanthine stronger than caffeine or theobromine?
In adenosine-receptor affinity terms, paraxanthine is close to caffeine and clearly stronger than theobromine. Preclinical and early human-exercise literature suggest paraxanthine may sustain alertness-type readouts while being reported as less vasoconstrictive and potentially less anxiogenic than caffeine — a key reason it is widely discussed as a next-generation stimulant candidate.
Q3: Theobromine vs caffeine — what's the actual difference?
One methyl group: caffeine is 1,3,7-trimethylxanthine; theobromine is 3,7-dimethylxanthine. Theobromine is a much weaker adenosine antagonist, relies more on PDE inhibition, is actively vasodilatory rather than vasoconstrictive, and lasts roughly twice as long (t½ ≈ 7–8 h vs ≈ 4–6 h). It is the main alkaloid of cocoa behind dark chocolate's milder, longer-lasting stimulation.
Q4: Can paraxanthine and theobromine be studied together in the same protocol?
Yes — they are natural co-metabolites of caffeine and share the xanthine scaffold, making them ideal for comparative or stacked-dose experimental designs (e.g., fast onset + sustained tail). Order both from a single supplier to keep lot-to-lot QC consistent across arms.
Q5: Which compound should I choose for vascular vs cognitive endpoints?
For vascular/endothelial and smooth-muscle endpoints (vasodilation, airway, diuresis), theobromine is the standard tool. For CNS alertness, reaction-time, and pre-workout ergogenic endpoints, paraxanthine is the trending candidate. Many labs stock both for crossover designs.
Q6: Do you provide COA, HPLC, NMR, MS and MSDS documentation?
Yes — every lot of both compounds ships with a full QC package (COA, HPLC purity chromatogram, NMR, MS identity, MSDS). Samples for qualifying institutions and companies can be arranged via our quote request page.
Need Paraxanthine (CAS 611-59-6) or Theobromine (CAS 83-67-0) for Your Research?
High-purity ≥98% (HPLC) xanthine research powders, dual-compound sourcing, full QC documentation, and tiered bulk pricing from 1 g to 1 KG. Get a same-day quote for one compound — or a paired quote for both — and keep your comparative study on one consistent, documentation-complete supply chain.
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