science

Glaucine

Glaucine is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Glaucine rather than just read about it. In short: Glaucine, also known as 1,2,9,10-tetramethoxyaporphine and sold under the brand names Glauvent and Tusidil among others, is an aporphine alkaloid, antitussive (cough suppressant), and hallucinogen. It is found in several different plant species in the family Papaveraceae, such as Glaucium flavum, Glaucium oxylobum, and Corydalis yanhusuo, and in other plants such as Croton lechleri in the family Euphorbiaceae.

Key takeaways

Glaucine belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Glaucine to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Glaucine from memory before moving on to harder problems.

Reference excerpt

Glaucine, also known as 1,2,9,10-tetramethoxyaporphine and sold under the brand names Glauvent and Tusidil among others, is an aporphine alkaloid, antitussive (cough suppressant), and hallucinogen. It is found in several different plant species in the family Papaveraceae, such as Glaucium flavum, Glaucium oxylobum, and Corydalis yanhusuo, and in other plants such as Croton lechleri in the family Euphorbiaceae. Glaucine was first described following isolation from Glaucium flavum in 1839 and its chemical structure became known in 1911.

Uses

Medical Glaucine is currently used as an antitussive agent in Iceland, as well as Romania, Bulgaria, Russia and other Eastern European countries. Bulgarian pharmaceutical company Sopharma sells glaucine in tablet form, where a single dose contains 40 mg. It is known to be sold over-the-counter.

Recreational Reports of recreational use of glaucine have been published, and effects include dissociative-type symptoms; feeling detached and "in another world, as well as nausea, vomiting, and dilated pupils. These reports mirror those about the effects of clinical use, which state dissociative-type symptoms as well as lethargy, fatigue, and hallucinations. Investigation of side effects in a clinical setting also reports that the hallucinatory effects manifest as bright and colorful visualizations. They further report that patients perceive their environments clearly yet feel detached from it; "the patient sees and understands everything and is oriented well enough, but cannot take a clear and adequate action". One particular report of recreational use gone awry described the form of distribution as tablets being marketed as a 1-benzylpiperazine (BZP)-free "herbal high" which the patient referred to as "head candy".

Side effects Glaucine may produce side effects such as sedation, sleepiness, fatigue, weakness, nausea, pupil dilation, and hallucinogenic effects such as visual hallucinations and dissociation.

Pharmacology

Pharmacodynamics Glaucine binds to the benzothiazepine site on L-type Ca2+-channels, thereby blocking calcium ion channels in smooth muscle like the human bronchus. Glaucine has no effect on intracellular calcium stores, but rather, does not allow the entry of Ca2+ after intracellular stores have been depleted. Ca2+ influx is a vital component in the process of muscular contraction, and the blocking of this influx therefore reduces the ability of the muscle to contract. In this way, glaucine can prevent smooth muscle from contracting, allowing it to relax. It is a non-competitive selective inhibitor of PDE4 in human bronchial tissue and granulocytes. PDE4 is an isoenzyme that hydrolyzes cyclic AMP to regulate human bronchial tone (along with PDE3). Yet as a PDE4 inhibitor, glaucine possesses very low potency. Glaucine has been found to act on the serotonin 5-HT2 receptors. (S)-Glaucine is partial agonist of the serotonin 5-HT2A and 5-HT2C receptors, whereas (R)-glaucine is a positive allosteric modulator of the serotonin 5-HT2A receptor and possibly of the other two serotonin 5-HT2 receptors. At the serotonin 5-HT2A receptor, (S)-glaucine showed an affinity (Ki) of 966 nM, EC50Tooltip half-maximal effective concentration of 661 nM, and an EmaxTooltip maximal efficacy of 42%, whereas at the serotonin 5-HT2C receptor, it displayed an EC50 of 447 nM and an Emax of 52%. Activation of the serotonin 5-HT2A receptor is notably known to be responsible for the hallucinogenic effects of serotonergic psychedelics like psilocybin, LSD, and mescaline. However, while activation of the serotonin 5-HT2A receptor may be involved, the underlying mechanism of action responsible for the hallucinogenic effects of glaucine remains unknown. Glaucine also shows affinity for the serotonin 5-HT1A and 5-HT7 receptors (Ki = 171 nM and 43 nM, respectively). Both (R)-glaucine and (S)-glaucine antagonize the α1-adrenergic receptor. Glaucine has been demonstrated to be a dopamine receptor antagonist, favoring dopamine D1 and D1-like receptors. Besides actions on monoamine receptors, glaucine inhibits monoamine oxidase A (MAO-A), but its IC50Tooltip half-maximal inhibitory concentration could not be determined due to solubility issues. It has bronchodilator, neuroleptic, and antiinflammatory effects, acting as a PDE4 inhibitor and calcium channel blocker, TLRs plays role in its anti inflammatory effects. Glaucine has been reported to reduce blood pressure and heart rate and to possess anticonvulsant and antinociceptive effects in animals.

Pharmacokinetics The pharmacokinetics of glaucine have been studied in humans and in horses. In addition, the in-vitro human metabolism of glaucine has been studied.

Chemistry

Stereoisomerism Glaucine is a racemic mixture of (S)- and (R)- enantiomers. (S)-Glaucine is the form that mainly occurs in nature. However, while it was originally believed that only (S)-glaucine occurs in nature, (R)-glaucine has since been found in fire poppy (Papaver californicum). The form used in medicine appears to exclusively be the (S) enantiomer and not the racemic mixture or (R)- enantiomer.

Synthesis The chemical synthesis of glaucine has been described.

Analogues Analogues of glaucine include other aporphine alkaloids like apomorphine, boldine, bulbocapnine, nantenine, nuciferine, and pukateine, among many others. Certain synthetic analogues of glaucine such as 2-hydroxy-11-(2-methylallyl)oxynoraporphine are known to act as highly potent and high-efficacy serotonin 5-HT2A and 5-HT2C receptor agonists.

History Glaucine was first described by J. M. Probst via isolation from Glaucium flavum (yellow horned poppy) in 1839. However, its chemical identity was not elucidated until later by other researchers, such as Richard Fischer in 1901 (chemical formula) and J. Gadamer (chemical structure) in 1911. The drug subsequently came to be used medically as an antitussive (cough suppressant) in some Eastern European countries. Glaucine was reported to produce hallucinogenic effects in 1989. Later, it was reported as a novel designer recreational drug in 2008. The drug was found to act as a serotonin 5-HT2A receptor partial agonist and positive allosteric modulator in 2019.

Society and culture

Availability Glaucine is marketed for use as an antitussive (cough suppressant) in Bulgaria, Croatia, and Romania.

Research

… excerpt ends here. Continue reading the full article.

Illustrations

Worked examples

Example 1 — a first encounter with Glaucine

Start with the simplest possible case. Write down what Glaucine claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Glaucine before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Glaucine ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Glaucine

In research: Glaucine appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Glaucine in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Glaucine is common in secondary-school and first-year university syllabi. It links to neighbouring topics 5-HT2A agonists, 5-HT2A receptor positive allosteric modulators, 5-HT2C agonists, so understanding it makes those chapters shorter.
In everyday life: Look for Glaucine outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Glaucine in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Glaucine means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Glaucine out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Glaucine in simple terms?

Why does Glaucine matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Glaucine?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Glaucine.