VOLUM OMAGIAL - Facultatea de Ştiinţe ale Naturii şi Ştiinţe Agricole

Ovidius University Annals of Natural Sciences, Biology – Ecology Series Volume 14, 2010
DINITROPHENYL DERIVATIVES ACTION ON WHEAT GERMINATION
Cristina Amalia DUMITRAS -HUTANU*,
*„Al. I. Cuza” University of Iasi, 11 Carol I,
Iasi-700506, Romania, hutanu_amalia@yahoo.com
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Abstract: Several dinitrophenyl ethers such as 2,4-dinitroanisol, 2,4-dinitrophenetol, 2,4-dinitro-1-
(octadecyloxy) benzene, 3-(2,4-dinitrophenoxy)propane-1,2-diol or other similar compounds have been
synthesized and tested comparatively to some well-known metabolic inhibitors and stimulators within the
germination experiments. As a result, the weight of the resulted plantlets was diminished by 2,4-dinitroanisol and
3-(2,4-dinitrophenoxy)propane-1,2-diol treatments (1.15 g/lot and 32.03 mg/plantlet in the case of 2,4dinitroanisol;
0.11 g/lot and 22.3 mg/plantlet in the case of 3-(2,4-dinitrophenoxy)propane-1,2-diol).
Dinitrophenyl ethers inhibited seed germination, most probably by blocking oxidative phosphorylation. A novel
mechanism of action of these pesticides was discussed. Consequently,the toxicity processes of these pesticidelike
compounds and metabolic inhibitors was discussed in direct relationship with their infrared absorbance and
fluorescence quenching.
Keywords: pesticide toxicity, dinitrophenyl ethers, dintirophenols, wheat germination.
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1. Introduction
Dinitroderivatives, especially the aromatics, are
frequently used as intermediates in the manufacture
of pharmaceuticals, dyes, pesticides and explosives.
They have multiple biological actions, being used as
insecticides, fungicides, herbicides and acaricides [1,
2]. However, Environment Protection Agency in
SUA (EPA) included the dinitrophenols on the list of
national priorities and in concentration of 3-46 mg
dinitrophenol/kg body kill; no antidote is known
(max. admissible dose 70 ppb in water, EPA, 2004).
It is assumed that dinitrophenols hinder the proton
translocation through the mitochondrial inner
membrane and therefore oxidative phosphorylation is
inhibited (ATP is no longer formed and the cells
deprive of essential energy supply). It is also possible
that the dinitrophenols act toxically due to the
inhibition of formation of some triplet states (instable
biradicals) by a resonance process with the triplet
structures in the living cells (A. Szent-Gyorgyi-Nobel
Prize, 1957) [3, 4, 5, 6, 7, 8]. Because the existing
data are inconclusive and do not support a precise
action mechanism of dintrophenyl derivatives on
living organisms, it was necessary to synthesize some
dinitrophenols and dinitrophenyl ethers whose
biological activity should be tested.
The purpose of this paper is to compare the
biological activity of some synthetic compounds
containing the di- and nitrophenyl moiety with that of
some well-known metabolic inhibitors and
stimulators. Because germination experiments are
easy, cheap, fast and spectacular, the testing of the
action of some action of some known and newly
synthesized substances on living organisms will be
performed using germinating cereal seeds [3-5]. The
possible mechanism of toxicity of these chemicals
and pesticides are discussed in the light of the
biostructural theory by Eugen Macovschi as well as
the chemiosmotic theory by Peter Mitchell [6, 7, 8].
2. Material and Methods
Biological material. The wheat samples
(Triticum aestivum), Henika variety, were taken from
the Agricultural Research Station in Suceava. The
1000 seeds weighed 37.2 g and had a residual
humidity of 12%. Chemical reagents. The reagents
used were of analytic purity (Merck, Sigma,
Chimopar) and the solution and the water slurries
were prepared using redistilled water. Thus,
ISSN-1453-1267 © 2010 Ovidius University Press