chemistry

S-Allylcysteine

S-Allylcysteine 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 S-Allylcysteine rather than just read about it. In short: S-Allylcysteine (SAC) is an organosulfur compound that has the formula HO2CCH(NH2)CH2SCH2C=CH2. It is the S-allylated derivative of the amino acid cysteine.

Key takeaways

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

Reference excerpt

S-Allylcysteine (SAC) is an organosulfur compound that has the formula HO2CCH(NH2)CH2SCH2C=CH2. It is the S-allylated derivative of the amino acid cysteine. As such only the L-enantiomer is significant biologically. SAC constituent of aged garlic. A number of related compounds are found in garlic, including the disulfide S-"allylmercaptocysteine" (SAMC, HO2CCH(NH2)CH2SSCH2C=CH2) and γ-glutamyl-S-allylcysteine" (GSAC). Allylcysteine is of interest for its potential medicinal properties. and as a chemopreventive.

Occurrence and formation SAC is present in low concentrations in fresh garlic but accumulates significantly during controlled ageing. The conversion of γ-glutamyl-S-allylcysteine (GSAC) to SAC occurs progressively over extended ageing periods, typically ranging from 10 to 20 months under controlled conditions. This accumulation is one reason aged garlic extract preparations have a substantially different compound profile compared to raw garlic, garlic powder, or garlic oil.

Pharmacokinetics SAC is water-soluble and demonstrates substantially higher bioavailability compared to allicin and allicin-derived compounds, which are chemically unstable and degrade rapidly following formation. SAC has been detected in human plasma following oral administration of aged garlic extract preparations, suggesting meaningful systemic absorption.

Use as a standardisation marker Because SAC concentration in aged garlic extract is predictably related to ageing duration and conditions, it is commonly used as a quality and standardisation marker in both research preparations and commercial aged garlic extract supplements. Standardisation for SAC content allows for more consistent comparisons across studies and products than is possible with raw garlic or allicin-based preparations.

Cardiovascular research SAC has been investigated in the context of cardiovascular health, primarily through studies using standardised aged garlic extract preparations in which SAC serves as a marker compound. Multiple randomised controlled trials have examined aged garlic extract in relation to blood pressure markers, arterial stiffness and vascular function, typically over study periods of 8 to 24 weeks. A systematic review and meta-analysis of randomised controlled trials concluded that aged garlic extract preparations were associated with reductions in systolic and diastolic blood pressure in adults with elevated baseline values, though the authors noted variability across studies. Research has also examined aged garlic extract in relation to arterial stiffness and endothelial function. One randomised controlled trial found reductions in central blood pressure and pulse wave velocity — markers of arterial stiffness — following 12 weeks of aged garlic extract supplementation in adults with uncontrolled hypertension. These findings are specific to standardised aged garlic extract preparations used under controlled research conditions and should not be generalised to raw garlic or other garlic supplement forms.

See also Alliin, the S-oxide of allyl cysteine S-1-Propenyl-L-cysteine

References

External links S-allyl-laevo-cysteine, [thegoodscentscompany.com](http://thegoodscentscompany.com)

Illustrations

Worked examples

Example 1 — a first encounter with S-Allylcysteine

Start with the simplest possible case. Write down what S-Allylcysteine 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 S-Allylcysteine 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 S-Allylcysteine 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 S-Allylcysteine

In research: S-Allylcysteine 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 S-Allylcysteine 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: S-Allylcysteine is common in secondary-school and first-year university syllabi. It links to neighbouring topics Allyl compounds, Alpha-Amino acids, Antioxidants, so understanding it makes those chapters shorter.
In everyday life: Look for S-Allylcysteine 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.

Ask Teacher Smith questions about this articleOpens your AI tutor with a question about “S-Allylcysteine” →

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study S-Allylcysteine in 20 minutes

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

Frequently asked questions

What is S-Allylcysteine in simple terms?

S-Allylcysteine (SAC) is an organosulfur compound that has the formula HO2CCH(NH2)CH2SCH2C=CH2. It is the S-allylated derivative of the amino acid cysteine.

Why does S-Allylcysteine 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 S-Allylcysteine?

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 S-Allylcysteine.