Cutin is one of two wax

Wax

thumb|right|[[Cetyl palmitate]], a typical wax ester.Wax refers to a class of chemical compounds that are plastic near ambient temperatures. Characteristically, they melt above 45 °C to give a low viscosity liquid. Waxes are insoluble in water but soluble in organic, nonpolar solvents...

y polymers that are the main components of the plant cuticle

Plant cuticle

Plant cuticles are a protective waxy covering produced only by the epidermal cells of leaves, young shoots and all other aerial plant organs without periderm...

, which covers all aerial surfaces of plant

Plant

Plants are living organisms belonging to the kingdom Plantae. Precise definitions of the kingdom vary, but as the term is used here, plants include familiar organisms such as trees, flowers, herbs, bushes, grasses, vines, ferns, mosses, and green algae. The group is also called green plants or...

s. The other major cuticle polymer is cutan

Cutan

Cutan is one of two polymers which occur in the cuticle of some plants. The other and better-known polymer is Cutin. Cutan is believed to be a hydrocarbon polymer, whereas cutin is a polyester, but the structure and synthesis of cutan are not yet fully understood...

, which is much more readily preserved

Taphonomy

Taphonomy is the study of decaying organisms over time and how they become fossilized . The term taphonomy was introduced to paleontology in 1940 by Russian scientist Ivan Efremov to describe the study of the transition of remains, parts, or products of organisms, from the biosphere, to the...

 in the fossil record,. Cutin consists of omega hydroxy acid

Omega hydroxy acid

Omega hydroxy acids are a class of naturally occurring straight-chain aliphatic organic acids n carbon atoms long with a carboxyl group at position 1 and a hydroxyl at position n. The C16 and C18 omega hydroxy acids 16-hydroxy palmitic acid and 18-hydroxy stearic acid are key monomers of cutin in...

s and their derivatives, which are interlinked via ester

Ester

Esters are chemical compounds derived by reacting an oxoacid with a hydroxyl compound such as an alcohol or phenol. Esters are usually derived from an inorganic acid or organic acid in which at least one -OH group is replaced by an -O-alkyl group, and most commonly from carboxylic acids and...

 bonds, forming a polyester polymer of indeterminate size.

There are two major monomer

Monomer

A monomer is an atom or a small molecule that may bind chemically to other monomers to form a polymer; the term "monomeric protein" may also be used to describe one of the proteins making up a multiprotein complex...

 families of cutin, the C16 and C18 families. The C16 family consists mainly of 16-hydroxy palmitic acid

Palmitic acid

Palmitic acid, or hexadecanoic acid in IUPAC nomenclature, is one of the most common saturated fatty acids found in animals and plants. Its molecular formula is CH314CO2H. As its name indicates, it is a major component of the oil from palm trees . Palmitate is a term for the salts and esters of...

 and 9,16- or 10,16-dihydroxypalmitic acid. The C18 family consists mainly of 18-hydroxyoleic acid

Oleic acid

Oleic acid is a monounsaturated omega-9 fatty acid found in various animal and vegetable fats. It has the formula CH37CH=CH7COOH. It is an odorless, colourless oil, although commercial samples may be yellowish. The trans isomer of oleic acid is called elaidic acid...

, 9,10-epoxy-18-hydroxystearic acid

Stearic acid

Stearic acid is the saturated fatty acid with an 18 carbon chain and has the IUPAC name octadecanoic acid. It is a waxy solid, and its chemical formula is CH316CO2H. Its name comes from the Greek word στέαρ "stéatos", which means tallow. The salts and esters of stearic acid are called stearates...

, and 9,10,18-trihydroxystearate.

Cutin is sometimes confused with suberin

Suberin

Suberin is a waxy substance found in higher plants. Suberin is a main constituent of cork, and is named after the Cork Oak, Quercus suber.-Anatomy and physiology:...

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