chemistry

Linalool

Linalool 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 Linalool rather than just read about it. In short: Linalool (), also called linalol (), is either of two enantiomers of a naturally occurring terpene alcohol found in many flowers and spice plants. Together with geraniol, nerol, and citronellol, linalool is one of the rose alcohols.

Key takeaways

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

Reference excerpt

Linalool (), also called linalol (), is either of two enantiomers of a naturally occurring terpene alcohol found in many flowers and spice plants. Together with geraniol, nerol, and citronellol, linalool is one of the rose alcohols. Linalool has multiple commercial applications, the majority of which are based on its pleasant scent (floral, with a touch of spiciness). A colorless oil, linalool is classified as an acyclic monoterpenoid. In plants, it is a metabolite, a volatile oil component, an antimicrobial agent, and an aroma compound. Linalool has uses in manufacturing of soaps, fragrances, food additives as flavors, household products, and insecticides. Esters of linalool are referred to as linalyl, e.g. linalyl pyrophosphate, an isomer of geranyl pyrophosphate. The word linalool is based on linaloe (, a type of wood) and the suffix -ol. In food manufacturing, it may be called coriandrol.

Occurrence

Both enantiomeric forms are found in nature: (S)-linalool (dextro-linalool) is found, for example, as a major constituent of the essential oils of coriander (Coriandrum sativum L.), cymbopogon (Cymbopogon martini var. martinii), and sweet orange (Citrus sinensis) flowers. (R)-linalool (laevo-linalool) is present in lavender (Lavandula officinalis), bay laurel (Laurus nobilis), and sweet basil (Ocimum basilicum), among others. Each enantiomer evokes distinct neural responses in humans, so each is classified as possessing distinct scents. (S)-(+)-Linalool is perceived as sweet, floral, petitgrain-like (odor threshold 7.4 ppb) and the (R)-form as more woody and lavender-like (odor threshold 0.8 ppb). Over 200 species of plants produce linalool, notably from the families Lamiaceae (mint and other herbs), Lauraceae (laurels, cinnamon, rosewood), and Rutaceae (citrus fruits), but also birch trees and other plants, from tropical to boreal climate zones.

Aniba rosaeodora Lavandula Cinnamomum tamala Cannabis sativa Basil Solidago (goldenrod) Artemisia vulgaris (mugwort) Humulus lupulus (hop) It was first synthesized in the laboratory of Leopold Ružička in 1919.

Production Linalool is produced commercially from several terpenes and terpenoid precursors, which are often components of terpentine. 2-Pinanol, derived from pinene, gives linalool upon pyrolysis.

Biosynthesis In higher plants linalool is formed by rearrangement of geranyl pyrophosphate (GPP). With the aid of linalool synthase (LIS), water attacks to form the chiral center. LIS appears to show a limonene synthase-type catalysis through a simplified "metal-cofactor-binding domain [where the majority] of the residues involved in substrate...binding [are] in the C-terminal part of the protein" suggesting stereoselectivity and the reasoning behind why some plants have varying levels of each enantiomer.

Odor and flavor Linalool has complex odor and flavor properties. Its odor is similar to floral, spicy wood, somewhat resembling French lavender plants, bergamot oil or lily of the valley. It has a light, citrus-like flavor, sweet with a spicy tropical accent. The aroma of the racemic mixture is described as citrus, floral, sweet, bois de rose, woody, green, blueberry, orange, terpenic, waxy, and rose. The aroma of the laevo enantiomer is described as fresh, floral, woody, natural, and lavender, whilst the dextro enantiomer is described as sweet, floral, petitgrain, and lavender. Linalool is used as a scent in perfumed hygiene products and cleaning agents, including soaps, detergents, shampoos, and lotions. It exhibits antimicrobial and antifungal properties.

Chemical derivatives Linalool is hydrogenated to give dihydro- and tetrahydrolinalool, which are fragrances that are more resilient toward oxidants, as might be found in household cleaning products. Linalyl acetate, a popular scent, is produced by esterification of linalool (as well as occurring naturally). Isomerization of linalool gives geraniol and nerol.

Safety Linalool can be absorbed by inhalation of its aerosol and by oral intake or skin absorption, potentially causing irritation, pain and allergic reactions. Some 7% of people undergoing patch testing in Europe were found to be allergic to the oxidized form of linalool. The US Food and Drug Administration (FDA) lists linalool in the Code of Federal Regulations under substances generally recognized as safe, synthetic flavoring substances and adjuvants.

Illustrations

Linalool: Linalool biosynthesis pathway. Abbreviations used: geranyl diphosphate synthase (GDS), pyrophosphate ester (OPP), isopentenyl pyrophosphate (IPP), dimethylallyl pyrophosphate (DMAPP), geranyl pyrophosphate (GPP). Stereogenic centers are indicated by an asterisk. — Linalool biosynthesis pathway. Abbreviations used: geranyl diphosphate synthase (GDS), pyrophosphate ester (OPP), isopentenyl pyrophosphate (IPP), dimethylallyl pyrophosphate (DMAPP), geranyl pyrophosphate (GPP). Stereogenic centers are indicated by an asterisk.

Worked examples

Example 1 — a first encounter with Linalool

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

In research: Linalool 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 Linalool 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: Linalool is common in secondary-school and first-year university syllabi. It links to neighbouring topics Alkene derivatives, Alkenols, Flavors, so understanding it makes those chapters shorter.
In everyday life: Look for Linalool 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 Linalool in 20 minutes

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

Frequently asked questions

What is Linalool in simple terms?

Why does Linalool 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 Linalool?

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 Linalool.