177
11
Feruloyl-CoA is also the precursor for the three main monolignols, coniferyl alcohol,
sinapyl alcohol and coumaryl alcohol, which are synthesized in the cytosol with added glucose moieties to make them water soluble and to reduce their toxicity. The glucosides are
transported through the cell membrane to the apoplast or stored in the vacuole (Dima et al.
2015). Phenylpropenes such as chavicol, eugenol, methyleugenol and estragole are derived
from coniferyl alcohols via coniferyl acetate and often found in trichomes (peltate glands)
as part of the essential oils (Gang et al. 2001) (see 7 Box 10.2). By oxidative dimerization of
coniferyl alcohols, lignans are formed. Secoisolariciresinol and matairesinol, lignans from
the seeds of linum (flaxseed), are digested in the intestine to enterolactone and enterodiol,
which have been proven to be efficient ligands for the G-protein-coupled oestrogen receptor (GPER) (Ren et al. 2016). Podophyllotoxin (PTOX) is isolated from roots of Podophyllum sp. and binds to tubulin thereby inhibiting the formation of microtubuli. This attribute
makes it valuable for chemotherapy. The main flux of this pathway is from the monolignols
to lignin. To form lignin the alcohols form multimers in the apoplast. Lignins are 20–30%
of a plant’s tissue, leading to the fortification of cell walls, especially of the xylem. Extensive
incorporation of lignin leads to the death of the cells.
References
Austin MB, Noel JP (2003) The chalcone synthase superfamily of type III polyketide synthases. Nat Prod
Rep 20:79–110. https://doi.org/10.1039/b100917f
Baldwin IT (2010) Plant volatiles. Curr Biol 20:R392–R397. https://doi.org/10.1016/j.cub.2010.02.052
Bourgaud F, Hehn A, Larbat R, Doerper S, Gontier E, Kellner S, Matern U (2006) Biosynthesis of coumarins
in plants: a major pathway still to be unravelled for cytochrome P450 enzymes. Phytochem Rev
5:293–308. https://doi.org/10.1007/s11101-006-9040-2
Brunetti C, Guidi L, Sebastiani F, Tattini M (2015) Isoprenoids and phenylpropanoids are key components
of the antioxidant defense system of plants facing severe excess light stress. Environ Exp Bot 119:54–
62. https://doi.org/10.1016/j.envexpbot.2015.04.007
Carvalho AA, Andrade LN, de Sousa EB, de Sousa DP (2015) Antitumor phenylpropanoids found in essential oils. Biomed Res Int 2015:392674. https://doi.org/10.1155/2015/392674
Cheynier V, Comte G, Davies KM, Lattanzio V, Martens S (2013) Plant phenolics: recent advances on their
biosynthesis, genetics, and ecophysiology. Plant Physiol Biochem 72:1–20. https://doi.org/10.1016/j.
plaphy.2013.05.009
Colquhoun TA, Clark DG (2011) Unraveling the regulation of floral fragrance biosynthesis. Plant Signal
Behav 6:378–381. https://doi.org/10.4161/psb.6.3.14339
de Cassia da Silveira ESR, Andrade LN, Dos Reis Barreto de Oliveira R, de Sousa DP (2014) A review on antiinflammatory activity of phenylpropanoids found in essential oils. Molecules 19:1459–1480. https://
doi.org/10.3390/molecules19021459
Dima O, Morreel K, Vanholme B, Kim H, Ralph J, Boerjan W (2015) Small glycosylated lignin oligomers are
stored in Arabidopsis leaf vacuoles. Plant Cell 27:695–710. https://doi.org/10.1105/tpc.114.134643
Falcone Ferreyra ML, Rius SP, Casati P (2012) Flavonoids: biosynthesis, biological functions, and biotechnological applications. Front Plant Sci 3:222. https://doi.org/10.3389/fpls.2012.00222
Take Home Message
5 Phenylpropanoids are synthetized via aromatic amino acids (Shikimate pathway). Many of them act as precursors for alkaloids.
5 Phenylpropanoids are important for plants (stability, pollinators and protection against biotic and abiotic stresses), but few have been shown to interact
with human receptors. One example is hispidol, which is a selective adenosine
receptor antagonist.
References
11
Feruloyl-CoA is also the precursor for the three main monolignols, coniferyl alcohol,
sinapyl alcohol and coumaryl alcohol, which are synthesized in the cytosol with added glucose moieties to make them water soluble and to reduce their toxicity. The glucosides are
transported through the cell membrane to the apoplast or stored in the vacuole (Dima et al.
2015). Phenylpropenes such as chavicol, eugenol, methyleugenol and estragole are derived
from coniferyl alcohols via coniferyl acetate and often found in trichomes (peltate glands)
as part of the essential oils (Gang et al. 2001) (see 7 Box 10.2). By oxidative dimerization of
coniferyl alcohols, lignans are formed. Secoisolariciresinol and matairesinol, lignans from
the seeds of linum (flaxseed), are digested in the intestine to enterolactone and enterodiol,
which have been proven to be efficient ligands for the G-protein-coupled oestrogen receptor (GPER) (Ren et al. 2016). Podophyllotoxin (PTOX) is isolated from roots of Podophyllum sp. and binds to tubulin thereby inhibiting the formation of microtubuli. This attribute
makes it valuable for chemotherapy. The main flux of this pathway is from the monolignols
to lignin. To form lignin the alcohols form multimers in the apoplast. Lignins are 20–30%
of a plant’s tissue, leading to the fortification of cell walls, especially of the xylem. Extensive
incorporation of lignin leads to the death of the cells.
References
Austin MB, Noel JP (2003) The chalcone synthase superfamily of type III polyketide synthases. Nat Prod
Rep 20:79–110. https://doi.org/10.1039/b100917f
Baldwin IT (2010) Plant volatiles. Curr Biol 20:R392–R397. https://doi.org/10.1016/j.cub.2010.02.052
Bourgaud F, Hehn A, Larbat R, Doerper S, Gontier E, Kellner S, Matern U (2006) Biosynthesis of coumarins
in plants: a major pathway still to be unravelled for cytochrome P450 enzymes. Phytochem Rev
5:293–308. https://doi.org/10.1007/s11101-006-9040-2
Brunetti C, Guidi L, Sebastiani F, Tattini M (2015) Isoprenoids and phenylpropanoids are key components
of the antioxidant defense system of plants facing severe excess light stress. Environ Exp Bot 119:54–
62. https://doi.org/10.1016/j.envexpbot.2015.04.007
Carvalho AA, Andrade LN, de Sousa EB, de Sousa DP (2015) Antitumor phenylpropanoids found in essential oils. Biomed Res Int 2015:392674. https://doi.org/10.1155/2015/392674
Cheynier V, Comte G, Davies KM, Lattanzio V, Martens S (2013) Plant phenolics: recent advances on their
biosynthesis, genetics, and ecophysiology. Plant Physiol Biochem 72:1–20. https://doi.org/10.1016/j.
plaphy.2013.05.009
Colquhoun TA, Clark DG (2011) Unraveling the regulation of floral fragrance biosynthesis. Plant Signal
Behav 6:378–381. https://doi.org/10.4161/psb.6.3.14339
de Cassia da Silveira ESR, Andrade LN, Dos Reis Barreto de Oliveira R, de Sousa DP (2014) A review on antiinflammatory activity of phenylpropanoids found in essential oils. Molecules 19:1459–1480. https://
doi.org/10.3390/molecules19021459
Dima O, Morreel K, Vanholme B, Kim H, Ralph J, Boerjan W (2015) Small glycosylated lignin oligomers are
stored in Arabidopsis leaf vacuoles. Plant Cell 27:695–710. https://doi.org/10.1105/tpc.114.134643
Falcone Ferreyra ML, Rius SP, Casati P (2012) Flavonoids: biosynthesis, biological functions, and biotechnological applications. Front Plant Sci 3:222. https://doi.org/10.3389/fpls.2012.00222
Take Home Message
5 Phenylpropanoids are synthetized via aromatic amino acids (Shikimate pathway). Many of them act as precursors for alkaloids.
5 Phenylpropanoids are important for plants (stability, pollinators and protection against biotic and abiotic stresses), but few have been shown to interact
with human receptors. One example is hispidol, which is a selective adenosine
receptor antagonist.
References