Phenylacetaldehyde is an aromatic compound found in buckwheat

Buckwheat

Buckwheat refers to a variety of plants in the dicot family Polygonaceae: the Eurasian genus Fagopyrum, the North American genus Eriogonum, and the Northern Hemisphere genus Fallopia. Either of the latter two may be referred to as "wild buckwheat"...

, chocolate

Chocolate

Chocolate is a raw or processed food produced from the seed of the tropical Theobroma cacao tree. Cacao has been cultivated for at least three millennia in Mexico, Central and South America. Its earliest documented use is around 1100 BC...

 and many other foods and flowers.
It is also responsible for the antibiotic activity of maggot therapy

Maggot therapy

Maggot therapy is a type of biotherapy involving the intentional introduction of live, disinfected maggots into the non-healing skin and soft tissue wound of a human or animal for the purpose of cleaning out the...

 and it is also a compound that is added to cigarettes to improve their aroma.

Many insects (Lepidoptera

Lepidoptera

Lepidoptera is a large order of insects that includes moths and butterflies . It is one of the most widespread and widely recognizable insect orders in the world, encompassing moths and the three superfamilies of butterflies, skipper butterflies, and moth-butterflies...

, Hymenoptera

Hymenoptera

Hymenoptera is one of the largest orders of insects, comprising the sawflies, wasps, bees and ants. There are over 130,000 recognized species, with many more remaining to be described. The name refers to the heavy wings of the insects, and is derived from the Ancient Greek ὑμήν : membrane and...

, Coleoptera and Neuroptera

Neuroptera

The insect order Neuroptera, or net-winged insects, includes the lacewings, mantidflies, antlions, and their relatives. The order contains some 6,010 species...

) use this substance for communication.

The aroma of pure substance can be described as: honey-like, sweet, rose, green, grassy.

Phenylacetaldehyde is often contaminated with polystyrene oxide polymer

Polymer

A polymer is a large molecule composed of repeating structural units. These subunits are typically connected by covalent chemical bonds...

 because of the especial lability of the benzylic alpha proton

Alpha carbon

The alpha carbon in organic chemistry refers to the first carbon that attaches to a functional group . By extension, the second carbon is the beta carbon, and so on....

 and the reactivity of the aldehyde. Aldol condensation

Aldol condensation

An aldol condensation is an organic reaction in which an enol or an enolate ion reacts with a carbonyl compound to form a β-hydroxyaldehyde or β-hydroxyketone, followed by a dehydration to give a conjugated enone....

 of the initial dimer gives rise to a range of Michael acceptors and donors.