Neopine (Morphinan Alkaloid · Antitussive · Opium Reference)
| Compound | Neopine (β-Codeine; 6-Dehydrocodeine; 3-Methyl-6,7-didehydromorphine) |
| Class | Alkaloid — Morphinan (Isoquinoline subclass) |
| CAS | 467-14-1 |
| Molecular formula | C₁₈H₁₉NO₃ |
| Primary sources | Papaver somniferum (opium poppy) |
| Plant part | Capsule latex |
| Claim strength | Emerging |
| Key applications | Antitussive reference; morphinan alkaloid chemistry; informational-only |
| Buy from Herbuno | Informational reference — see HerbIQ Compound Index → |
Name origin: Neopine is named as "neo-" (new) codeine — a codeine isomer differing in the position of the C-ring double bond (Δ6,7 instead of Δ7,8 as in codeine). It is also called β-codeine to distinguish it from codeine (α-codeine) by ring geometry. Traditional use: Neopine has no independent traditional use. As a minor constituent of opium (typically <0.1% of total alkaloid content), it was identified during systematic analysis of crude opium rather than as a pharmacologically exploited constituent. Research trajectory: Neopine occupies a position in the morphinan alkaloid series between codeine and morphine — it shares the phenanthrene ring system of morphinan alkaloids but differs in double bond position and consequently in opioid receptor affinity and antitussive potency. It has been studied as an antitussive compound and compared to codeine, with modestly different pharmacodynamic profiles. Safety context: Neopine, as a morphinan alkaloid from Papaver somniferum, is subject to opiate regulatory frameworks in most jurisdictions, even though its pharmacological potency is lower than codeine. It is not appropriate for supplement or nutraceutical use.
Pharmacological Profile of Neopine
Antitussive activity: Neopine demonstrates cough suppression in animal citric acid and capsaicin aerosol challenge models, with potency estimated at 50–70% of codeine's antitussive activity. The mechanism involves mu-opioid receptor partial agonism at brainstem cough centres. Unlike codeine, neopine's double bond position (Δ6,7) reduces metabolic conversion to morphine, potentially reducing the analgesic and dependence liability relative to codeine at equivalent antitussive doses. Claim strength: Emerging.
Opioid receptor pharmacology: Neopine has lower mu-opioid receptor affinity than codeine due to its different double bond geometry affecting ring conformation and receptor binding. In binding assays, neopine's Ki at mu-opioid receptors is approximately 3–5-fold higher (lower affinity) than codeine. This pharmacological distinction makes neopine of some interest in the search for dissociated opioids with antitussive but reduced analgesic/dependence profiles. Claim strength: Emerging.
Biosynthetic position: Neopine is a shunt product in the biosynthetic pathway from codeinone toward codeine — an alternative reduction product formed by stereospecific ketoreductase action on codeinone at C-6 in the opposite geometry. It is used as a marker in metabolic flux analysis of P. somniferum alkaloid biosynthesis. Claim strength: Moderate (analytical/biosynthetic).
Forensic chemistry: Neopine is identified in crude opium alkaloid profiles and in some heroin samples. Its ratio to codeine is used in chemical profiling of opium origin. Claim strength: Moderate (analytical chemistry).
This compound is documented for research and formulator education purposes. For commercially available botanical ingredients, explore the HerbIQ Compound Index →
Regulatory and Formulator Context
Neopine is subject to opioid regulatory controls in most jurisdictions as a Papaver somniferum alkaloid. It is listed or analogued under narcotic control frameworks including the UN Single Convention on Narcotic Drugs. No supplement or food application exists or is appropriate.
Research-grade neopine is available as an analytical reference standard for forensic chemistry and pharmacological research purposes, subject to appropriate institutional and regulatory authorisation.
The primary commercial significance of neopine in pharmaceutical chemistry is as a potential antitussive candidate with a differentiated opioid receptor profile — of interest to pharmaceutical companies seeking non-codeine antitussive development. No approved neopine drug product exists as of this writing.
This entry completes the minor antitussive morphinan alkaloid documentation in the HerbIQ Papaver alkaloid series, alongside noscapine (built in earlier batches) and narceine.
Frequently Asked Questions — Neopine
How does neopine differ from codeine structurally?
Neopine and codeine are both morphinan alkaloids from Papaver somniferum sharing the same molecular formula (C₁₈H₁₉NO₃) and molecular weight. They differ only in the position and geometry of the C-ring double bond: codeine (α) has a Δ7,8 double bond; neopine (β) has a Δ6,7 double bond. This geometric difference alters C-ring conformation and mu-opioid receptor binding geometry, reducing neopine's opioid potency while partially preserving antitussive activity.
Is neopine more or less addictive than codeine?
Based on its lower mu-opioid receptor affinity, neopine is hypothesised to have reduced dependence liability compared to codeine — but this has not been evaluated in human clinical studies. The lower analgesic potency and reduced morphine metabolite formation (due to different ring geometry reducing CYP2D6 O-demethylation efficiency) suggest a cleaner antitussive-to-dependence ratio than codeine, but neopine remains an opioid compound subject to full narcotic controls.
What concentration does neopine occur at in crude opium?
Neopine is a minor alkaloid typically present at 0.05–0.15% of crude opium dry weight — well below codeine (0.5–3%) and morphine (4–20%). Its concentration varies by P. somniferum variety and growing conditions. In commercial pharmaceutical morphine extraction, neopine is present in mother liquors and alkaloid fractions but is not recovered as a commercial product.
Why is neopine documented in the HerbIQ index if it has no supplement use?
HerbIQ provides a complete reference for all pharmacologically significant plant secondary metabolites, including pharmaceutical, controlled, and forensic compounds. The Papaver alkaloid series — morphine, codeine, neopine, noscapine, papaverine, laudanosine — is documented for formulator education on the full chemical diversity of this important medicinal plant genus. Informational-only status clearly designates no sourcing intent.
Related compounds: Laudanosine, Codeine, Cryptopine, Noscapine
Claim-strength scale – High = multiple human RCTs; Moderate = limited trials or strong preclinical convergence; Emerging = early-stage lab or animal data.
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