The importance of molecular parameters of quaternary ammonium salts in their antigibberellin (retardant) activity

Article abstract of DOI:10.1023/B:RUBI.0000049778.67576.cc

The importance of six theoretically calculated molecular parameters in the antigibberellin (retardant) activity of quaternary ammonium salts is studied using a regression analysis. A bioassay system based on cell culture of fungus Gibberella fujikuroi is used to determine the activity. In the case of N,N,N-trimethyl-N-(2-hydroxyethyl)ammonium chloride (choline) and N,N,N-triethyl-N-(2-hydroxyethyl)ammonium chloride (N,N,N-triethylcholine) derivatives with linear structure, the polarizability, proton acceptor activity, and lipophilicity of these compounds exert the largest effect on the antigibberellin activity. The antigibberellin activity of more sterically hindered N,N-dialkylpiperidinium salts was mainly defined by the steric parameter, while the polarizability, proton acceptor activity, and (through them) lipophilicity exert a lesser effect. Other parameters are of minor importance for the three groups of compounds studied.

Full text of DOI:10.1023/B:RUBI.0000049778.67576.cc

Russian Journal of Bioorganic Chemistry, Vol. 30, No. 6, 2004, pp. 592–598. Translated from Bioorganicheskaya Khimiya, Vol. 30, No. 6, 2004, pp. 656–662.
Original Russian Text Copyright © 2004 by Gafurov, Grigor’ev, Proshin, Chistyakov, Martynov, Zefirov.
The Importance of Molecular Parameters
of Quaternary Ammonium Salts in Their Antigibberellin
(Retardant) Activity
1
R. G. Gafurov , V. Yu. Grigor’ev, A. N. Proshin, V. G. Chistyakov,
I. V. Martynov, and N. S. Zefirov
Institute of Physiologically Active Substances, Russian Academy of Sciences,
Severnyi proezd 1, Chernogolovka, Moscow oblast, 142432 Russia
Received September 10, 2003; in final form, February 17, 2004
Abstract—The importance of six theoretically calculated molecular parameters in the antigibberellin (retar-
dant) activity of quaternary ammonium salts is studied using a regression analysis. A bioassay system based on
cell culture of fungus Gibberella fujikuroi is used to determine the activity. In the case of N,N,N-trimethyl-N-
(2-hydroxyethyl)ammonium chloride (choline) and N,N,N-triethyl-N-(2-hydroxyethyl)ammonium chloride
(N,N,N-triethylcholine) derivatives with linear structure, the polarizability, proton acceptor activity, and lipo-
philicity of these compounds exert the largest effect on the antigibberellin activity. The antigibberellin activity
of more sterically hindered N,N-dialkylpiperidinium salts was mainly defined by the steric parameter, while the
polarizability, proton acceptor activity, and (through them) lipophilicity exert a lesser effect. Other parameters
are of minor importance for the three groups of compounds studied.
Key words: antigibberellin activity, molecular parameters, quaternary ammonium salts
1
INTRODUCTION
Only limited information is available in literature on
the comparative antigibberellin (retardant) activity of
quaternary ammonium salts in series with monotoni-
cally changing substituents at the nitrogen atom [2–8].
Only two of these publications [2, 4] deal with the
dependence of retardant activity on the molecular prop-
erties of compounds studied. A topological descriptor
1/χ, the so-called index of molecular binding of the first
order, was used to reveal the steric requirements essen-
tial for the manifestation of retardant activity [3]. It was
experimentally shown that the quaternary ammonium
salts of high and moderate activity have 1/χ values in
the range from 2.9 to 4.5 and the compounds with the
values beyond this range are devoid of this activity. The
effect of lipophilicity on the retardant activity of N-(2-
phenoxyethyl)pyridinium bromides substituted at one
of positions (2, 3, or 4) of phenyl group was demon-
strated in a bioassay on rice plantlets [2]. Afterwards, it
The use of quaternary ammonium salts as plant
growth regulators and stress protectors had a profound
impact on the development of intensive biotechnolo-
gies for production of main food and technical crops
[1]. However, the progress in the synthetic, physical,
and biological chemistry of these compounds is of
more general systemic importance. It goes far beyond
the mentioned applied problems and is determined by
the mostly unclear role that is played by quaternary
ammonium salts in functioning the central and periph-
eral nervous system of warm-blooded animals, in the
development of pathologies in these systems, in the
processes of plant photosynthesis, and in some other
physiological processes involved in the maintenance of
homeostasis in living organisms as well as in the pro-
cesses of their exchange with the environment.
was quantitatively shown that the steric factor E0s rather
The determination of quantitative relations between
the physiological activity of low-molecular bioregula-
tors and their structure and physicochemical properties
is one of the ways to computer molecular design and
prediction of physiological activity of new compounds.
In medicinal chemistry, this approach is considered to
be a main avenue to the development of new drugs with
predetermined properties. In the chemistry of bioregu-
lators, this approach is still in its infancy.
than the lipophilicity value predominantly affects the
antigibberellin (retardant) activity upon the introduc-
tion of bulky lipophilic substituents at the nitrogen
atom in piperidinium salts [4]. Until now, there is no
information concerning the influence of other molecu-
lar parameters on the growth-regulating properties of
quaternary ammonium salts.
A convenient express method for such an investiga-
tion is the determination of residual concentration of
gibberellic acid in the cell culture of fungus Gibberella
1
Corresponding author; phone/fax: +7 (095) 785-7024; e-mail:
ravig@icp.ac.ru
1068-1620/04/3006-0592 © 2004 MAIK “Nauka /Interperiodica”

THE IMPORTANCE OF MOLECULAR PARAMETERS
593
Table 1. Antigibberellin activity I of choline (I)–(IX) and N,N,N-triethylcholine (X)–(XVII) derivatives in the assay on a cell
culture of fungus G. fujikuroi
Residual GA3
concentration, mg/ml
Quaternary ammonium
salt (QAS)*
Extent of
inhibition I, %**
Cation
Anion
[(CH3)3NCH2CH2OH]+
[(CH3)3NCH2CH2OH]+
Cl–
CH3CO–2
Cl –
(I)
1.17
1.16
0.80
0.74
0.11
1.16
0.15
0.14
0.08
0.83
0.82
0.51
0.32
0.15
0.82
0.30
0.24
–18
–17
19
24
89
–17
85
86
92
16
17
48
67
85
16
69
76
(II)
[(CH3)3NCH2CH2OCH3]+
[(CH3)3NCH2CH2OC2H5]+
[(CH3)3NCH2CH2OCH2C6H5]+
[(CH3)3NCH2CH2OCOCH3]+
[(CH3)3NCH2CH2Cl]+
(III)
(IV)
Cl –
Cl –
(V)
CH3CO–
(VI)
2
Cl –
Br –
F –
(VII)
(VIII)
(IX)
[(CH3)3NCH2CH2Br]+
[(CH3)3NCH2CH2F]+
[(C2H5)3NCH2CH2OH]+
[(C2H5)3NCH2CH2OH]+
[(C2H5)3NCH2CH2OCH3]+
[(C2H5)3NCH2CH2OC2H5]+
[(C2H5)3NCH2CH2OCH2C6H5]+
[(C2H5)3NCH2CH2OCOCH3]+
[(C2H5)3NCH2CH2Cl]+
Cl –
(X)
CH3CO–2
(XI)
Cl –
Cl –
Cl –
(XII)
(XIII)
(XIV)
(XV)
(XVI)
(XVII)
CH3CO–2
Cl –
Br –
[(C2H5)3NCH2CH2Br]+
–3
* QAS concentration 10 M.
** I = 100(m – n)/m, %; m = 0.99 0.02 mg/ml (m is GA concentration in the absence of salts, n is GA concentration in experiment).
3
3
Negative I values correspond to stimulation of GA biosynthesis.
3
fujikuroi by the method [9, 10] after the incubation with of compounds under study at 1-mM concentration and
the corresponding salt at concentrations of 10–3 to
10−6 M. The antigibberellin activity of the salts is asso-
ciated with an inhibition of conversion of geranylger-
anyl pyrophosphate into copalyl pyrophosphate, an
entkaurene precursor in the cascade of biochemical
reactions of gibberellin biosynthesis. It is well known
that this stage is common in the biosynthesis of gib-
berellins both in fungus G. fujikuroi and green plants
[11–13].
expressed as an extent of inhibition of gibberellin bio-
synthesis by the salts, I = 100(m – n)/m%, where m and
n are the gibberellin concentrations in control and in
experiment, respectively.
We found that the antigibberellin activity of choline
and N,N,N-triethylcholine acetates (VI) and (XV),
respectively, was the same as that of the corresponding
alcohols. Possibly, a hydrolase system cleaving the
ester bond is present in the active site of biotarget with
which the quaternary ammonium salts interact. At the
same time, choline chloride (I) manifests no antigibber-
ellin activity in contrast to N,N,N-triethylcholine chlo-
ride (IX); on the contrary, it intensifies the gibberellin
biosynthesis. It is not excluded that choline fulfills a
trophic function in the life cycle of the fungus.
RESULTS AND DISCUSSION
We carried out a regression analysis of the contribu-
tion of six theoretically calculated molecular parame-
ters to the antigibberellin activity of quaternary ammo-
nium salts [14], when determining the activity with bio-
Table 2 shows the theoretically calculated values of
assay on the cell culture of fungus G. fujikuroi. The molecular parameters for the two groups of com-
antigibberellin activity of the derivatives of choline (I)– pounds. These values were obtained without conforma-
(IX) and N,N,N-triethylcholine (X)–(XVII) is given in tional study and only for the cations of compounds
Table 1. The activity was calculated by the gibberellin under investigation. The geometric and electron struc-
GA3 concentration in cultural medium in the presence tures of the molecules and partial atomic charges qH
RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY Vol. 30 No. 6 2004

594
GAFUROV et al.
Table 2. Theoretically calculated molecular parameters of choline (I)–(IX) and N,N,N-triethylcholine (X)–(XVII) derivatives*
Cma ax
QAS**
(I)
α, Å3
Ca(0)
qX
Cd
Es
qH
logP
I, %
12.32
12.32
14.16
15.99
23.81
15.79
13.62
14.31
11.60
17.83
17.83
19.66
21.50
29.32
21.29
19.12
19.82
1.54
1.54
1.46
1.49
2.31
1.59
0.39
0.40
0.28
1.54
1.54
1.46
1.49
2.32
1.59
0.39
0.40
1.54
1.54
1.46
1.49
1.25
1.59
0.39
0.40
0.28
1.54
1.54
1.46
1.49
1.49
1.59
0.39
0.40
– 0.310
–0.310
–0.270
–0.278
–0.308
–0.323
–0.010
+0.080
–0.122
–0.326
–0.326
–0.272
–0.279
–0.304
–0.364
–0.026
+0.063
–1.93
–6.38
–6.38
–6.55
–6.67
–7.10
–6.7
0.143
0.143
0.142
0.142
0.142
0.144
0.144
0.143
0.144
0.114
0.114
0.114
0.114
0.112
0.116
0.116
0.115
1.74
1.74
2.31
2.76
4.02
2.61
3.23
3.41
2.81
3.20
3.20
3.77
4.23
5.48
4.07
4.70
4.87
–18
–17
19
24
64
–17
85
86
92
16
17
48
67
85
16
69
76
(II)
–1.93
(III)
0
(IV)
0
(V)
0
(VI)
0
(VII)
(VIII)
(IX)
0
–6.48
–6.55
–6.33
–8.04
–8.04
–8.24
–8.38
–8.91
–8.51
–8.11
–8.19
0
0
(X)
–1.93
(XI)
0
0
0
0
0
0
0
(XII)
(XIII)
(XIV)
(XV)
(XVI)
(XVII)
* Parameters: α, polarizability; Cma ax , maximal proton acceptor factor; C , total proton acceptor factor; q , partial negative charge of
a(0)
X
oxygen or halogen atoms in variable substituent; C , proton donor factor of hydroxyl group; E , steric parameter; logP, lipophilicity; q ,
d
s
H
positive charge of hydrogen atoms of methyl groups; and I, the inhibition extent of gibberellin GA biosynthesis (see Table 1).
3
** The numbering of compounds according to Table 1.
were calculated using the semiempirical quantum fivefold increases upon the transition from alcohols to
chemical AM1 method realized in the HYPERCHEM
program complex, version 4.5 [15]. The three-dimen-
sional structures generated by the program were used as
starting points in the final optimization. The additive
values of the polarizability α, total values of the proton
acceptor activity Ca(0), maximal values of the proton
ethers and halogen derivatives. In this case, the lipophi-
licity also exhibits a symbate increase by approxi-
mately 1.5 orders of magnitude. On the other hand, the
values of proton acceptor activity Cma ax are significantly
reduced in the same direction. The partial negative
charge qX on halogen atoms in variable substituents is
by one order of magnitude lower than that on oxygen
atoms. Halides (VII), (VIII), (IX), (XVI), and (XVII)
having maximal qX values are strong inhibitors of gib-
berellin biosynthesis. The value of steric factor ES
changes less than by unity. The qH values are practically
constant within each series. However, they change
approximately by 40% when passing from choline to
N,N,N-triethylcholine derivatives. Thus, the polariz-
acceptor parameter Cma ax for the oxygen and halogen
atoms (the centers of maximal nucleophilicity) in the
variable substituent of the compounds, and the value of
proton donor factor Cd of hydroxy group were calcu-
lated using the HYBOT PLUS program [16] without
taking into consideration ionization of the molecules.
Steric parameters Es characterizing the screening of
quaternary nitrogen atom were determined by the
method proposed in [17]. The lipophilicity values
logP (the distribution coefficient in the n-octanol– ability α, the value of proton acceptor factor Cma ax , and
water system) were calculated by the method [18]
based on the use of information on the molecular polar-
the lipophilicity P, derived from them, are the major
factors in the formation of antigibberellin activity of the
salts under study.
izability α and their total proton acceptor activity Ca(0)
:
logP = 0.26α–1.0 Ca(0)
.
A regression analysis carried out using the SVD
program [19] gave the following equations for the
One can see from Table 2 that the antigibberellin
activity of both groups of compounds approximately dependence of inhibition extent I on the molecular
RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY Vol. 30 No. 6 2004

THE IMPORTANCE OF MOLECULAR PARAMETERS
595
R1
R2
Table 3. Antigibberellin activity and molecular parameters of N,N-dialkylpiperidinium chlorides
(XXIX)*
Cl– (XVIII)–
+
N
pJi50
Cma ax
QAS
R1
R2
α, Å3
Ca(0)
Es
logP
(XVIII)
(XIX)
(XX)
CH3
CH3
CH3
5.95
5.41
4.28
4.85
3.62
4.15
2.98
3.68
3.00
3.00
4.55
5.25
14.58
20.09
23.76
18.89
20.72
20.72
24.39
38.21
22.56
28.55
28.55
22.53
0.00
0.00
0.00
1.46
1.46
1.49
1.46
2.73
1.46
1.87
2.32
0.32
0.00
0.00
0.00
1.46
1.46
1.49
1.46
1.49
1.46
1.46
1.49
0.32
–7.09
–8.15
–9.10
–8.02
–8.64
–8.19
–9.12
–10.25
–8.92
–9.71
–8.50
–8.66
3.88
5.34
6.32
3.56
4.05
4.02
5.03
7.43
4.54
5.72
5.27
5.67
C4H9
C4H9
C3H7
CH3
(XXI)
C2H4OCH3
(XXII)
(XXIII)
(XXIV)
(XXV)
(XXVI)
(XXVII)
C2H5
C2H4OCH3
CH3
C2H4OC2H5
C2H4OCH3
C4H9
CH2C6H5
C3H7
CH2CH2–OCH2C6H5
C2H4OCH3
CH2C6H5
C2H4OCH3
(XXVIII) CH3
(XXIX) CH3
CH2CH2–OCH2C6H5
C6H5
* For the parameter definitions, see Table 2. pJi50 are equally effective concentrations of QASs that inhibit the gibberellin biosynthesis
by 50% (taken as common logarithms).
parameters of studied compounds. For choline and its
derivatives:
The correlation trends become apparent only in
series (clusters) of compounds uniform in their chemi-
cal structures. The structural criterion for the cluster is
the alkyl substituents in the parent ternary amine: cho-
line derivatives make up one cluster and N,N,N-triethyl-
choline derivatives, another. The steric factor Es is of
minor importance in this case. The reason is the linear
structure of these compounds that allows a free rotation
of separate regions of the molecules around C–C bonds
and, thereby, not preventing the formation of conforma-
tion necessary for the interaction of this molecule with
the biotarget binding site. Moreover, the inclusion of Es
term into the regression equations (A)–(D) seriously
impairs the correlation parameters.
One can see from the slopes at variables in equations
(A) and (C) that the inhibiting capacity of choline
derivatives is more sensitive to the proton acceptor
activity Cma ax than that of N,N,N-triethylcholine deriva-
tives. This is related to a smaller volume of molecule in
the case of choline derivatives and, respectively, to a
higher density of unshared electron pairs of oxygen and
halogens at the negative end of molecular dipole.
I = 38.3 + 5.64α – 68.7Camax
(A)
(N = 6; R = 0.991; SD = 6.0)
or
I = 32.7logP – 40.1Camax
(B)
(N = 6; R = 0.971; SD = 9.3),
where N is the number of compounds; R, coefficient of
linear correlation, and SD, standard deviation.
For N,N,N-triethylcholine and its derivatives, taking
into account the proton donor factor Cd of hydroxyl
group:
I = 4.04α – 19.0Cma ax + 13.9Cd
(C)
(N = 6; R = 0.980; SD = 6.4)
or
I = 15.5logP – 2.19Cma ax + 15.7Cd
The molecular parameters of N,N-dialkylpiperidin-
ium chlorides (XVIII)–(XXIX) are given in Table 3.
The retardant activities of these compounds were deter-
mined as the values of equally effective concentrations
Ji50 that inhibit the gibberellin biosynthesis by 50% in
comparison with control. These concentrations are rep-
resented as negative logarithm values pJi50 . In this case,
(D)
(N = 6; R = 0.985; SD = 5.7).
The information on the antigibberellin activity of
choline salts (I) and (II) and acetates of choline (VI)
and N,N,N-triethylcholine (XV) were excluded from the
consideration because of anomalous behavior of these
compounds in the bioassay used in this work.
RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY Vol. 30 No. 6 2004

596
GAFUROV et al.
in contrast to the choline and N,N,N-triethylcholine
Acetates and chlorides of choline (I) and (II),
derivatives, the antigibberellin activity is substantially N,N,N-triethylcholine (X) and (XI), acetates of their
determined not only by the polarizability α, the proton acetyl esters (VI) and (XV), as well as chlorides of
acceptor activity Cma ax , and/or the lipophilicity logP ,
N,N,N-trimethyl-N-(2-chloroethyl)ammonium (chloro-
choline c hloride, crystalline) (VII) and N,N,N-triethyl-
but also by the steric factor Es; moreover, its contribu-
tion is the largest. The regression equations take the
form:
N-(2-chloroethyl)ammonium (XVI), bromides of
N,N,N-trimethyl-N-(2-bromoethyl)ammonium (VIII)
and
N,N,N-triethyl-N-(2-bromoethyl)ammonium
(XVII) were the commercial products from Fluka.
N,N,N-Triethyl-N-(2-benzyloxyethyl)ammonium chlo-
ride (XIV) was obtained by method [20]. N,N-Dialkyl-
piperidinium chlorides were obtained by the proce-
dures described in [4]. The methods of preparation of
other compounds are described below.
pJi50 = 14.93 + 0.41α – 0.833Camax + 1.52Es
(N = 12; R = 0.946; SD = 0.38)
(E)
(F)
or
pJi50 = 15.65 + 0.84logP + 1.81Es
(N = 12; R = 0.943; SD = 0.37).
N,N,N-Trimethyl-N-(2-methoxyethyl)ammonium
chloride (III). A mixture of trimethylamine (5.9 g,
0.1 mol), 2-chloroethylmethyl ether (9.45 g, 0.1 mol),
and ethanol (20 ml) was heated in an autoclave tube at
180°ë for 2.5 h and evaporated to a minimal volume in
a vacuum. The precipitated crystals were filtered,
washed with acetone, and recrystallized to give (III);
colorless hygroscopic crystals; yield 14.3 g (93%); mp
169–172°ë (acetonitrile); 1H NMR (δ, ppm): 3.19 (9 H,
s, 3 CH3), 3.40 (2 H, s, CH2), 3.57–3.64 (3 H, t, CH3),
3.85–3.96 (2 H, m, CH2). Found, %: C 46.72, H 10.75,
N 8.17, Cl 23.21. Calculated for C6H16NOCl, %: C
46.88, H 10.82, N 8.35, Cl 23.06.
The determining effect of the steric factor Es is
apparently related to the fact that the quaternary nitro-
gen atom is built into piperidine ring. This restricts con-
formational freedom of the molecule upon its interac-
tion with the active site of receptor and imposes more
stringent requirements upon the properties that are
imposed on the molecule by the substituents R1 and R2.
The consideration of (I)–(XVII) as molecular bio-
chemical probes leads to the conclusion that, in addi-
tion to an anionic site and a hydrophobic region, the
active site of kaurene synthase of fungus G. fujikuroi
seems to contain a proton donor fragment, which inter-
acts with nucleophilic atoms and groups in the variable
substituents of retardant molecules.
Thus, we carried out a regression analysis of the
contribution of six theoretically calculated molecular
parameters to the antigibberellin (retardant) activity of
quaternary ammonium salts. Experimentally, this activ-
ity was determined by a bioassay on the cell culture of
fungus G. fujikuroi. In the case of choline and N,N,N-
triethylcholine derivatives with linear structures, the
antigibberellin activity of these compounds was found
to be mostly affected by the polarizability, the proton
acceptor factor, and the lipophilicity derived from the
two factors. The activity of sterically more hindered
N,N-dialkylpiperidinium salts is mainly determined by
the steric factor; the polarizability, the proton acceptor
factor, and the derived lipophilicity contribute to the
activity to a lesser extent.
N,N,N-Trimethyl-N-(2-ethoxyethyl)ammonium
chloride (IV) was similarly obtained from trimethyl-
amine (5.9 g, 0.1 mol) and 2-chlorodiethyl ether
(10.85 g, 0.1 mol); yield 11.7 g (70%); colorless hygro-
1
scopic crystals; mp 162–164°ë; H NMR (δ, ppm):
1.20 (3 H, t, CH3), 3.20 (9 H, s, 3 CH3), 3.8 (2 H, t,
CH2), 4.0 (2 H, quintet, CH2), 4.2 (2 H, t, CH2). Found,
%: C 49.78, H 10.56, N 7.79, Cl 20.61. Calculated for
C7H18NOCl, %: C 50.12, H 10.82, N 8.35, Cl 21.14.
N,N,N-Trimethyl-N-(2-benzyloxyethyl)ammonium
chloride (V). Choline (13.95 g, 0.1 mol) was mixed at
10–15°C with a solution of sodium hydroxide (8 g,
0.2 mol) in water (8 ml), N,N,N-triethyl-N-benzylam-
monium chloride (0.68 g, 3 mmol, used as a catalyst of
interphase transfer), and benzyl chloride (12.65 g,
0.1 mol). After stirring at 70–90°C for 1 h and cooling
to 15–20°C, water (100 ml) was added to the mixture
for dissolving the precipitate of sodium chloride, and
the organic layer was extracted with n-butanol (2 ×
100 ml). The butanol layer was separated, shook with
anhydrous magnesium sulfate to remove the residual
water, filtered, and evaporated in a vacuum. The residue
was then diluted with ethyl acetate (100 ml), and the
precipitated crystals were filtered and recrystallized
from a 1 : 1 acetone–acetonitrile mixture to give
10.04 g (43%) of (V) as colorless crystals; mp 150–
EXPERIMENTAL
1H NMR spectra were registered on a Bruker DPX-
200 NMR spectrometer (Germany) at working fre-
quency of 200 MHz in D2O using the chemical shift
(δ 4.8 ppm relative to Me4Si) of proton signal of resid-
ual 1H2O in D2O as an internal signal. UV spectra were
measured on a Perkin Elmer 550 UV spectrometer. The
elemental analysis was carried out on an automated
Carlo Erba 1106 CHN analyzer. Melting points were
determined on a Boetius hot plate.
1
152°C; H NMR (δ, ppm): 3.08 (9 H, s, CH3), 3.53
(2 H, m, CH2), 3.86–3.98 (2 H, m, CH2), 4.56 (2 H, s,
CH2), 7.4 (5 H, s, C6H5). Found, %: C 62.81, H 8.56, N
6.03, Cl 15.34. Calculated for C12H20NOCl, %: C
RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY Vol. 30 No. 6 2004

THE IMPORTANCE OF MOLECULAR PARAMETERS
597
62.72, H 8.77, N 6.10, Cl 15.45. Picrate: yellow crys- ethyl)ammonium iodide (30.13 g, 0.1 mol) in water
tals; mp 95.0–97.5°C (ethanol).
(50 ml) was passed through the column at the rate of
2 ml/min with subsequent elution with water (200 ml)
at a rate 5 ml/min. The collected solution was evapo-
rated in a vacuum to dryness to yield 20.71 g (98.7%)
of a colorless viscous liquid partly crystallizing at –5 to
0°C. Found, %: C 56.97, H 11.75, N 6.36, Cl 16.81.
Calculated for C10H24ClNO, %: C 57.24, H 11.53, N
6.68, Cl 16.2.
N,N,N-Trimethyl-N-(2-fluoroethyl)ammonium
fluoride (IX). A mixture of choline chloride (3.2 g,
0.023 mol), nitromethane (30 ml), and sulfur tetrafluo-
ride (5.06 g, 0.046 mol) was heated in an autoclave test
tube at 85°C for 8 h. The test tube was cooled in a dry
ice bath, and the exhaust gases were passed through a
Tishchenko absorption vessel containing alkali. The
test tube was unsealed at room temperature and the
solution was evaporated at residual pressure of 1–2 mm
of mercury. The solid residue was recrystallized from a
1 : 1 acetone–ethyl acetate mixture to give colorless
crystals of (IX); yield 2.44 g (85%); mp above 360°C;
N,N,N-Triethyl-N-(2-methoxyethyl)ammonium
chloride (XII) was similarly obtained from N,N,N-tri-
ethyl-N-(2-methoxyethyl)ammonium iodide (14.15 g,
0.05 mol) in 10.42 g (99.3%) yield as a colorless vis-
cous liquid slowly crystallizing at –5 to 0°C. Found, %:
C 54.94, H 11.67, N 6.96, Cl 17.88. Calculated for
C9H22ClNO, %: C 55.21, H 11.33, N 7.15, Cl 18.13.
1
UV spectrum: λ 192 nm (C–F bond); H NMR spec-
trum (δ, ppm): 3.20 (9 H, s, CH3), 3.80 (2 H, quintet,
CH2), 4.0 (2 H, m, CH2). Found, %: C 42.23, H 9.55, N
9.64, F 26.28. Calculated for C5H13NOF2, %: C 42.40,
H 9.25, N 9.89, F 26.83.
The experiments on a cell culture of fungus
G. fujikuroi were carried out three times in three repli-
cas. The results were statistically treated applying Stu-
N,N,N-Triethyl-N-(2-ethoxyethyl)ammonium dent’s criterion; p < 0.01 for the differences exceeding
iodide. A mixture of anhydrous 2,5,8-trioxanonane 8% of the value in the control (water). A GA3 concen-
(diglyme) (100 ml), diethylaminoethanol (11.7 g,
0.1 mol), and sodium metal (2.3 g. 0.1 g-at.) was heated
at 110°C for 30 min with protection from moisture until
complete dissolution of sodium and cessation of hydro-
gen liberation. The mixture was cooled, mixed with
ethyl iodide (31.2 g, 0.2 mol), and heated at 60°ë for
2 h. The precipitated crystals were filtered and washed
with acetone (100 ml) for the removal of sodium iodide
to yield 24.10 g (80%) of the title compound; colorless
tration in culture medium (m) was 0.99 0.02 mg/ml.
ACKNOWLEDGMENTS
We dedicate this paper to the cherished memory of
Academician G.S. Muromtsev (Russian Academy of
Agricultural Sciences), who participated as a collabora-
tor at the beginning of this work. We are grateful to
A.V. Kokurin for his help in biological experiments.
1
crystals yellowing in air; mp 93–95°ë (acetone); H
NMR spectrum (δ, ppm): 1.20 (3 H, t, CH3), 1.40 (9 H,
t, 3 CH3), 3.70 (6 H, q, 3 CH2), 3.8 (2 H, t, CH2), 4.00
(2 H, q, CH2), and 4.20 (2 H, t, CH2). Found, %: C
40.23, H 8.26, N 4.49. Calculated for C10H24NIO, %: C
39.86, H 8.03, N 4.65.
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