chemistry

Gacyclidine

Gacyclidine is a chemistry 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 Gacyclidine rather than just read about it. In short: Gacyclidine (GK-11, OTO-313) is a psychoactive drug which acts as a dissociative via functioning as a non-competitive NMDA receptor antagonist. It is closely related to phencyclidine (PCP), and specifically, is a derivative of tenocyclidine (TCP).

Key takeaways

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

Reference excerpt

Gacyclidine (GK-11, OTO-313) is a psychoactive drug which acts as a dissociative via functioning as a non-competitive NMDA receptor antagonist. It is closely related to phencyclidine (PCP), and specifically, is a derivative of tenocyclidine (TCP). Gacyclidine exhibits neuroprotective effects similar to those of other NMDA receptor antagonists, with the advantage of being substantially less neurotoxic maybe due to its interaction with "non-NMDA" binding sites.

History

Gacyclidine is a psychoactive drug that was used for helping with body trauma in humans. While seeing most tests on animals, it has never used commercially to the degree as other painkillers or psychoactive drugs. While gacyclidine has been used in numerous tests dating back to 2012, these tests did not provide fruitful results that would push the future of the drug into a different direction.

Chemistry The 1,2-addition of 2-methylcyclohexanone (I) with 2-thienyl lithium (II) or 2-thienyl magnesium bromide (III) gives cyclohexanol (IV) as a diastereomeric mixture, which was treated with sodium azide (NaN3) in trichloroacetic acid to yield the azide (V). The reduction of (V) with lithium aluminium hydride (LiAlH4) or Raney nickel in isopropanol affords the corresponding amine (VI), preferentially with the cis-configuration. Finally, this compound is dialkylated with 1,5-dibromopentane (VII) by means of potassium carbonate (K2CO3) in acetonitrile to provide the target compound as a diastereomeric mixture.

Uses Gacyclidine's original purpose was for helping with human body trauma, specifically spine and brain trauma. Tests were done on animals to see how their bodies would react to the different drugs and see how that information could be applied to humans. Gacyclidine is used to reduce damage to the brain or spinal cord, hence a treatment for tinnitus, stroke, trauma, and convulsion. As a psychoactive drug, alteration of perception is what makes this substance of use. A lipid-based intratympanic formulation of gacyclidine (OTO-313) has been studied as a potential therapy for the treatment of tinnitus. A randomized, placebo-controlled Phase II trial found that OTO-313 was safe and well-tolerated but did not demonstrate a significant treatment benefit in unilateral tinnitus relative to placebo (believed to be partly due to a high placebo response). In 2022, the company developing OTO‑313 announced it would stop developing the drug for tinnitus.

Dosage

Testing of gacyclidine was performed on animals in a study. In concluding hours (18-96 h), no necrotic neurons were discovered in animals with dosages of 1, 5, 10, 20 milligrams of gacyclidine. At 20 milligrams the presence of a few cytoplasmic vacuoles were present. In a study conducted to find possible neurotoxicity in dosages, scientists tested the effects of gacyclidine in comparison to dizocilpine and CNS-1102, and finalized more positive effects on animals from gacyclidine. When given MK-801 at dosages of 1 or 5 milligrams of gacyclidine, effects were harmless and behaved similarly to untreated animals. At dosages between 5 and 10 milligrams, the animals began to experience behaviors of tremors, sedation and exophthalmos. With CNS-1102, at all doses tested, the animals exhibited some excitation. At the highest doses (10 and 20 milligrams) they suffered from severe akinesia 1 hour after drug administration. Animals that received 1 or 5 milligrams of gacyclidine or its enantiomers behave similarly to untreated animals. At the highest doses (10 and 20 milligrams), the animals began to show some signs of excitation. For all doses, the recovery period was always better with gacyclidine and its enantiomers than with MK-801 or CNS-1102. The days after the testing, labs observed electron microscopy in the 20-milligram group. During observation small lesions were labeled as cytoplasmic or intramitochondrial vacuoles. In addition, no neuronal or glial alterations, such as astrocytic swelling or microglial activation, were seen that could suggest a short-term toxic event had occurred. Further concluding observations, current evidence indicates that the possibility of a short-term toxicity, would be totally reversible. Likewise, any long-term toxicity would become evident after 4 days. But, the evidence in total strongly suggests that gacyclidine and its enantiomers are, at least, far less neurotoxic than MK-801.

Effects

With the use of this drug, motor skills have significantly improved upon use, as it is the antagonist to the NMDA receptor. Gacyclidine is able to reduce calcium getting into cells. While animal test results showed potential in the rats, human tests showed slight improvement to the condition of patients. Outside of results seen in animals like potential trauma assistance and pain relief, there is little to no proof that there will be any clinical benefits in the future of gacyclidine.

See also Arylcyclohexylamine Memantine Dextrallorphan Dimemorfan

References

External links PubChem. "Gacyclidine". pubchem.ncbi.nlm.nih.gov. Retrieved 2020-10-27.

Illustrations

Gacyclidine: Gacyclidine synthesis — Gacyclidine synthesis

Worked examples

Example 1 — a first encounter with Gacyclidine

Start with the simplest possible case. Write down what Gacyclidine claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In chemistry, 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 Gacyclidine 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 Gacyclidine 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 Gacyclidine

In research: Gacyclidine appears in chemistry 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 Gacyclidine 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: Gacyclidine is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1-Piperidinyl compounds, Arylcyclohexylamines, Dissociative drugs, so understanding it makes those chapters shorter.
In everyday life: Look for Gacyclidine 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 Gacyclidine in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Gacyclidine 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 Gacyclidine out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Gacyclidine in simple terms?

Why does Gacyclidine matter?

Because it connects several chemistry 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 Gacyclidine?

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 Gacyclidine.