Stilbenoids are hydroxylated derivatives of stilbene. They have a C₆–C₂–C₆ structure. In biochemical terms, they belong to the family of

phenylpropanoid The phenylpropanoids are a diverse family of organic compounds that are synthesized by plants from the amino acids phenylalanine and tyrosine. Their name is derived from the six-carbon, aromatic phenyl group and the three-carbon propene tail of ...

s and share most of their biosynthesis pathway with

chalcones Chalconoids Greek: χαλκός ''khalkós'', "copper", due to its color), also known as ''chalcones'', are natural phenols related to chalcone. They form the central core for a variety of important biological compounds. They show antibacterial, a ...

. Most stilbenoids are produced by plants, and the only known exception is the antihelminthic and antimicrobial stilbenoid, 2-isopropyl-5- ''E'')-2-phenylvinylenzene-1,3-diol, biosynthesized by the Gram-negative bacterium ''

Photorhabdus luminescens ''Photorhabdus luminescens'' (previously called ''Xenorhabdus luminescens'') is a Gammaproteobacterium of the family Morganellaceae, and is a lethal pathogen of insects. It lives in the gut of an entomopathogenic nematode of the family Heteror ...

.''

Chemistry

Stilbenoids are hydroxylated derivatives of stilbene and have a C₆–C₂–C₆ structure. They belong to the family of

s and share most of their biosynthesis pathway with

. Under UV irradiation, stilbene and its derivatives undergo intramolecular cyclization, called stilbene photocyclization to form

dihydrophenanthrene Phenanthrenoids are chemical compounds formed with a phenanthrene backbone. These compounds occur naturally in plants, although they can also be synthesized. Phenanthrols Phenanthrols are any of five isomeric phenols derived from phenanthrene ( ...

s. Oligomeric forms are known as oligostilbenoids.

Types

;Aglycones * Piceatannol in the roots of Norway spruces *

Pinosylvin Pinosylvin is an organic compound with the formula C6H5CH=CHC6H3(OH)2. A white solid, it is related to trans-stilbene, but with two hydroxy groups on one of the phenyl substituents. It is very soluble in many organic solvents, such as acetone. O ...

is a fungal toxin protecting wood from fungal infection, found in trees of the pine family * Pterostilbene in almonds, pine and vaccinium berries *

Resveratrol Resveratrol (3,5,4′-trihydroxy-''trans''-stilbene) is a stilbenoid, a type of natural phenol, and a phytoalexin produced by several plants in response to injury or when the plant is under attack by pathogens, such as bacteria or fungi. Sources ...

in grapes ;Glycosides * Astringin in the bark of Norway spruce * Piceid is a resveratrol derivative in grape juices

Production

Stilbenoids are produced in various plants, for example they are secondary products of heartwood formation in trees that can act as phytoalexins. Another example is

resveratrol Resveratrol (3,5,4′-trihydroxy-''trans''-stilbene) is a stilbenoid, a type of natural phenol, and a phytoalexin produced by several plants in response to injury or when the plant is under attack by pathogens, such as bacteria or fungi. Sources ...

, an antifungal which is found in

grape A grape is a fruit, botanically a berry (botany), berry, of the deciduous woody vines of the flowering plant genus ''Vitis''. Grapes are a non-Climacteric (botany), climacteric type of fruit, generally occurring in clusters. The cultivation of ...

s and which has been suggested to have health benefits. Ampelopsin A and Ampelopsin B are resveratrol dimers produced in

porcelain berry ''Ampelopsis glandulosa'' is a species of plant native to China, Japan, India, Nepal, Myanmar, Vietnam, and the Philippines. Varieties Several varieties are distinguished: * var. ''hancei'' * var. ''kulingensis'' * var. ''glandulosa'' * var ...

. A bacterial stilbenoid, (''E'')-3,5-dihydroxy-4-isopropyl-''trans''-stilbene, is produced by ''

Photorhabdus ''Photorhabdus'' is a genus of bioluminescent, gram-negative bacilli which lives symbiotically within entomopathogenic nematodes, hence the name ''photo'' (which means light producing) and ''rhabdus'' (rod shape). ''Photorhabdus'' is known to be ...

'' which is a bacterial symbiont of insect nematodes called '' Heterorhabditis''. Stilbenoids are secondary metabolites present in Cannabis sativa.

Properties

Phytoalexins have been suggested by some studies to be responsible for resistance to some tree diseases, such as pine wilt.

References

Books