ISSN 1021-4437, Russian Journal of Plant Physiology, 2007, Vol. 54, No. 3, pp. 287–301. © Pleiades Publishing, Ltd., 2007.
Published in Russian in Fiziologiya Rastenii, 2007, Vol. 54, No. 3, pp. 325–341.
While polyamines ubiquitous to pro- and eukary-
otes are an attractive focus of intensive research rele-
vant to normal and stress plant physiology [1–7],
including apoptosis , their phenyl derivatives, the
phenylamides, are of a more limited interest. Until
recently, phenylamides have been considered as plant-
speciﬁc secondary metabolites, and evidence in favor
of their involvement in plant development and defense
against environmental challenges has been accumulat-
ing [9–11]. Surprisingly, it has been reported that plant
phenylamides are remarkably similar in general struc-
ture to phenylamides found in insect toxins [12, 13].
Hence, these molecules could play the role of a com-
mon tool employed in defense strategies of various
organisms, thus justifying enhanced further research
efforts to elucidate the scope and mechanisms of their
In this review, a brief outline on the occurrence, dis-
tribution, localization, metabolism, as well as chemical
structure and properties of phenylamides underlying
their physiological functions will be presented, with an
emphasis on their involvement in the developmental
and stress-defense phenomena in plants.
CHEMICAL STRUCTURE, PROPERTIES,
Phenylamides (PhA) are low-molecular products of
covalent bonding between carboxylic groups of
hydroxycinnamic acids and amine groups of aliphatic
di- and polyamines
or aromatic (aryl) monoamines
(Fig. 1). In plants, the most widely distributed acidic
parent compounds of PhA are caffeic, ferulic, and
-coumaric acids (Fig. 2) while the aliphatic
polyamines putrescine, spermidine, and spermine and
the arylmonoamines tyramine and tryptamine (Fig. 2)
are reported as the predominant amine components of
PhA [9, 14].
One or both primary amino groups of aliphatic
polyamines may interact with hydroxycinnamic acids,
thus giving rise to mono- or di-substituted PhA deriva-
tives, respectively; the formulae of mono- and di-feru-
loylputrescine, largely presented in plants, are given in
Fig. 3. Iminogroups of polyamines can also interact
with these acids; trisubstituted derivatives of spermi-
dine such as
have been identiﬁed in ﬂowers of plants belonging to
the Rosaceae family , as well as in
-dicaffeoylspermidine (Fig. 3),
-coumaroylspermidine . Notewor-
thy, as seen from above, amine and imine functional-
ities in one polyamine molecule can be substituted by
different hydroxycinnamic acids. Moreover, amine
For brevity, only the term “polyamines” will be further used.
Phenylamides in Plants
A. M. Edreva
, V. B. Velikova
, and T. D. Tsonev
Acad. D. Kostoff Institute of Genetics, Bulgarian Academy of Sciences, Tsarigradsko sh. 13 km, Soﬁa, 1113 Bulgaria;
Acad. M. Popov Institute of Plant Physiology, Bulgarian Academy of Sciences, Soﬁa, Bulgaria
Received July 20, 2006
—Phenylamides, secondary metabolites, conjugates of aliphatic polyamines or arylmonoamines and
hydroxycinnamic acids, combining the properties of both parent compounds, are a subject of increasing inter-
est, as follows from their ubiquitous distribution and multiplicity of functions. In this paper the occurrence, dis-
tribution, localization, metabolism, as well as chemical structure and properties of phenylamides underlying
their physiological functions are brieﬂy reviewed, with an emphasis on their involvement in the developmental
and stress-defense phenomena of plants. Basic knowledge on phenylamides is supplemented with recent data
pointing to the structural similarity of plant phenylamides with those found in insect toxins. This ﬁnding chal-
lenges the view of phenylamides as plant-speciﬁc molecules and suggests their role as a common defense tool
in various organisms.
Key words: phenylamides - classiﬁcation - occurrence - metabolism - functions - stress resistance
PAL—phenylalanine ammonia-lyase; TYDC—tyrosine decar-
boxylase; TMV—tobacco mosaic virus; THT—tyramine hydroxy-
cinnamoil transferases; PRs—pathogenesis-related proteins.
The text was submitted by the authors in English.