science

Leonurine

Leonurine 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 Leonurine rather than just read about it. In short: Leonurine (also known as SCM-198 in research) is a substituted guanidine that has been isolated from Leonotis leonurus, Leonotis nepetifolia, Leonurus japonicus, Leonurus cardiaca (motherwort), Leonurus sibiricus, as well as other plants of family Lamiaceae. Leonurine is easily extracted into water.

Key takeaways

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

Reference excerpt

Leonurine (also known as SCM-198 in research) is a substituted guanidine that has been isolated from Leonotis leonurus, Leonotis nepetifolia, Leonurus japonicus, Leonurus cardiaca (motherwort), Leonurus sibiricus, as well as other plants of family Lamiaceae. Leonurine is easily extracted into water.

Research Leonurine weakly binds to multiple GABA receptor sites including the GABAA receptor. However, it shows much higher affinity as a 5-HT3A receptor antagonist. 5-HT3A antagonists have been shown to help prevent nausea and vomiting as well as the negative effects of serotonin in the gastrointestinal tract. Leonurine can regulate a variety of functions including oxidative stress, inflammation, fibrosis, apoptosis, and metabolic disorder. Leonurine has demonstrated antidepressant-like action and has been shown to increase levels of serotonin, noradrenaline, and dopamine in chronic mild stress studies on mice and inhibits the production of pro-inflammatory cytokines. Leonurine has been investigated as a potential treatment for cardiovascular disorders. It protects against oxidative damage from ischemic stroke and demonstrates neuroprotective activity against focal cerebral ischemia brain injury induced on rats. Leonurine protects mice from pneumonia induced by influenza A. Leonurine has demonstrated anti-cancer activity in vitro and in animal studies.

Metabolites Metabolites of leonurine in rats dosed orally include leonurine-10-O-sulfate (the sulfate conjugate of leonurine), leonurine-10-O-β-D-glucuronide (the glucuronide metabolite of leonurine) and an O-demethylated leonurine analog that has not yet had its structure definitively confirmed.

Chemical synthesis Leonurine can be synthesized starting from eudesmic acid. Reaction with sulfuric acid produces syringic acid. Protection with ethyl chloroformate followed by reaction with thionyl chloride (SOCl2) and then tetrahydrofuran yields 4-carboethoxysyringic acid 4-chloro-1-butyl ester. The chloride is then converted to an amino group via a Gabriel synthesis (with potassium phthalimide) followed by hydrazinolysis (Ing–Manske procedure). The final step is reaction of the amine with S-methylisothiourea hemisulfate salt.

References

Illustrations

Worked examples

Example 1 — a first encounter with Leonurine

Start with the simplest possible case. Write down what Leonurine 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 Leonurine 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 Leonurine 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 Leonurine

In research: Leonurine 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 Leonurine 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: Leonurine is common in secondary-school and first-year university syllabi. It links to neighbouring topics Alkaloids, Benzoate esters, Guanidines, so understanding it makes those chapters shorter.
In everyday life: Look for Leonurine 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 Leonurine in 20 minutes

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

Frequently asked questions

What is Leonurine in simple terms?

Why does Leonurine 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 Leonurine?

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 Leonurine.