Synthesis of novel mono and bis nitric oxide donors with high cytocompatibility and release activity

Article abstract of DOI:10.1016/j.bmcl.2018.09.009

Four compounds bearing amidoxime functions were synthetized: (1) 2a,b bearing an aromatic amidoxime function, (2) 2c bearing an aliphatic amidoxime function, and (3) 2d bearing aromatic and aliphatic amidoximes functions. The ability of these compounds to

Full text of DOI:10.1016/j.bmcl.2018.09.009

Accepted Manuscript
Synthesis of Novel Mono and Bis Nitric Oxide Donors with High Cytocompat-
ibility and Release Activity
Tanya Sahyoun, Caroline Gaucher, Yi Zhou, Naïm Ouaini, Raphaël Schneider,
Axelle Arrault
PII:
S0960-894X(18)30740-6
https://doi.org/10.1016/j.bmcl.2018.09.009
BMCL 26030
DOI:
Reference:
Bioorganic & Medicinal Chemistry Letters
To appear in:
Received Date:
Revised Date:
Accepted Date:
9 July 2018
4 September 2018
7 September 2018
Please cite this article as: Sahyoun, T., Gaucher, C., Zhou, Y., Ouaini, N., Schneider, R., Arrault, A., Synthesis of
Novel Mono and Bis Nitric Oxide Donors with High Cytocompatibility and Release Activity, Bioorganic &
Medicinal Chemistry Letters (2018), doi: https://doi.org/10.1016/j.bmcl.2018.09.009
This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers
we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and
review of the resulting proof before it is published in its final form. Please note that during the production process
errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Synthesis of Novel Mono and Bis Nitric Oxide Donors with High
Cytocompatibility and Release Activity
Tanya Sahyouna,c, Caroline Gaucherb, Yi Zhoub, Naïm Ouainic, Raphaël Schneiderd*, Axelle
Arraulta*
a
Laboratoire de Chimie Physique Macromoléculaire, Université de Lorraine, CNRS, LCPM, F-54000 Nancy,
France
b Université de Lorraine, CITHEFOR, F-54000 Nancy, France
c Faculty of Sciences, Holy Spirit University of Kaslik, BP446, Jounieh, Mount Lebanon, Lebanon
d Laboratoire Réactions et Génie des Procédés, Université de Lorraine, CNRS, LRGP, F-54000 Nancy, France
Abstract
Four compounds bearing amidoxime functions were synthetized: (1) 2a-b bearing an aromatic
amidoxime function, (2) 2c bearing an aliphatic amidoxime function, and (3) 2d bearing
aromatic and aliphatic amidoximes functions. The ability of these compounds to release NO
was evaluated in vitro using the oxidative metabolism of cytochrome P450 from rat liver
microsomes. Results obtained demonstrate that all amidoximes were able to release NO with
a highest amount of NO produced by the 2a aromatic amidoxime. Moreover, all amidoximes
exhibit cytocompatibility with human aorta smooth muscle cells. Using intracellular S-
nitrosothiol formation as a marker of NO bioavailability, compounds 2a-c were demonstrated
to deliver a higher amount of NO in the intracellular environment than the reference.
Considering that the concentration of the bis-amidoxime 2d was two times lower that than of
2a and 2b, we can assume that 2d is the most potent molecule among the tested compounds
for NO release.
Keywords: Amidoximes; Nitric oxide; Cardiovascular disease; Double donor; Oxidation
Gasotransmitters are endogenously synthesized molecules presenting biological properties.
Until today, three gasotransmitters have been identified.1 The first described and studied
gasotransmitter is nitric oxide (NO).2 NO plays a key role in various physiological processes.
In the nervous system, NO controls the neurotransmission, in the immune system, it also acts
as a defense against bacteria, parasites, and tumor cells, and in the cardiovascular system, it
controls vascular homeostasis including blood pressure.3,4 The second gasotransmitter is
carbon monoxide (CO) which plays a role in the cardiovascular system since it relaxes the
vascular vessels and therefor lowers the blood pressure. CO was also identified as a
S1

neurotransmitter. The third and recently studied gasotransmitter is hydrogen sulfide (H2S)
which was discovered to play an important role in neuromodulation and neurotransmission.2, 5
In this study, we focus on the firstly discovered gasotransmitter, NO. In vivo, NO is produced
by oxidation of the guanidine function of L-arginine. In the cardiovascular system, this
oxidation is catalyzed by the endothelial nitric oxide enzyme (eNOS) and occurs in two
steps.6 The first one is the N-hydroxylation of one of guanidino nitrogen atoms of arginine
consuming one mole of NADPH and one mole of dioxygen. The second step is the oxidation
of the intermediate N-hydroxy-L-arginine (NOHA) allowing the breaking of the C=N-OH
bond and producing NO and citrulline (Fig. 1).7 This step consumes 0.5 mole of NADPH and
1 mole ofdioxygen. The L-arginine oxidation resembles a classical P450 dependent
monooxygenation.8 This reaction has been the subject of extensive studies and it has been
demonstrated that the oxidation of NOHA, but also of other arginine-mimetics like
amidoximes, can be performed by cytochromes P450.9
H
H
N
H
N
N
NH2
OH
NH2
NH2
NOS
NOS
R
NO
+
R
R
1/2 NADPH + O2
NADPH + O2
N
O
NH
Arg
NOHA
Citrulline
Fig. 1. In vivo oxidation of L-Arginine by NO Synthases.
Jousserandot et al. were the first to describe the oxidation of some amidoximes by
cytochromes P450, using rat liver microsomes in the presence of NADPH and dioxygen.10,11
Their work focused on the quantification of nitrite ions released by aromatic amidoximes
substituted by para electron-donating substituents, such as Cl, that were demonstrated to
exhibit the highest NO release rates.11 Other studies were devoted to the synthesis of prodrugs
bearing an amidoxime function and on their effects on many diseases like cardiovascular
disease. These reports showed the capacity of seventeen different amidoxime prodrugs to
inhibit platelet aggregation, thrombus formation and to decrease blood pressure in
spontaneously hypertensive rats.12,13 Some aliphatic bis-amidoximes showed the highest
inhibition of thrombus formation while the aromatic mono-amidoxime bearing a p-CF3 group
was demonstrated to be of high efficiency for the decrease of the blood pressure.13
Furthermore, the capacity of some amidoxime functions to induce vasorelaxation of rat aortic
rings after the NO release was also highlighted.14, 15
S2

In this work, the synthesis of mono-amidoximes 2a-c substituted by various electron-
donating groups in the para position and of a bis-amidoxime 2d, bearing one aromatic and one
aliphatic amidoxime function, is described from the corresponding nitriles (Fig. 2).
O
NH2OH.HCl, Na2CO3
EtOH
R
O
R
H2N
HO
Reflux
98, 95%
R= H, CH
3
NC
N
1a, b
2a, b
O
O
NH2
OH
O
NH2OH 50 wt. % in H2O
EtOH
CN
N
N
Reflux
60%
1c
2c
NH2
OH
NH2OH 50 wt. % in H2O
EtOH
O
CN
H2N
HO
Reflux
40%
NC
N
1d
2d
Fig. 2. Synthesis of amidoximes
Nitriles 1a and 1b are commercially available, while 1c and 1d were prepared from the
corresponding bromides by nucleophilic substitution using KCN in DMF. The synthesis of
amidoximes 2 from nitriles 1 was performed either in ethanol using hydroxylamine
hydrochloride associated to Na2CO3 or using an aqueous solution of hydroxylamine and a
protocol adapted from Ovdiichuk et al.16-18 The synthetic conditions are listed in Table 1 in
the Supporting Information. Aromatic nitriles 1a and 1b could easily be converted into
amidoximes 2a19,20 and 2b19,21 using hydroxylamine hydrochloride and Na2CO3. Due to the
lower reactivity of aliphatic nitriles compared to aromatic ones, compound 2c19 could only be
prepared from 1c with a modest yield of 37% under these synthetic conditions. With aliphatic
nitriles, better conversions were obtained using a solution of hydroxylamine in water and
2c22,23 was isolated with 60% yield after column chromatography. Under these reaction
conditions, bis-amidoxime 2d22, 24 was obtained in 40% yield.
The ability of compounds 2 to release NO by oxidation was first evaluated using rat liver
microsomes containing cytochromes P450 in the presence of NADPH and dioxygen (see
Supporting Information). 4-Chlorobenzamidoxime (Fig. 3), which is known to release high
amounts of NO in the presence of cytochrome P450,11 was used as a reference.
S3

Cl
H2N
HO
N
Fig. 3. Structure of 4-chlorobenzamidoxime.
After 10 min of incubation with rat liver microsomes and NADPH, supernatants were
collected for nitrite ions quantification using the Griess assay (see Supporting Information).
Four control samples were prepared for each molecule, namely without microsomes, without
amidoximes, without NADPH and finally using nitriles 1 instead of amidoximes 2. The
amount of nitrite ions measured in these controls was subtracted from the values measured
with amidoximes 2. As can be seen from Fig. 4, all compounds 2 generate nitrite ions,
indicating their ability to be oxidized by rat liver microsomes and NADPH. The nitrite ions
-
release was the highest for compounds 2a and 2b (2.4 and 1.5 nmol NO2 /mg P450 for 10
min, respectively). Noteworthy is that these values are higher than that obtained for the
-
reference (1.3 nmol NO2 /mg P450 for 10 min). The modest capacity of compounds 2c and 2d
to produce nitrite ions may originate from their inadequate size/shape that does not allow their
fast oxidation by the enzyme and/or to the lower reactivity of aliphatic amidoximes in the
oxidation reaction. Compound 2a is of high interest due to its high capacity of release NO
compared to the reference.
Fig. 4. Concentration of released nitrite ions from compounds 2 and the reference after a 10
min incubation with microsomes. Results are presented as mean ± SEM of three to five
independent experiments and compared with a One-way ANOVA; * p<0.05 versus reference
S4

We further evaluated the capacity of compounds 2 to release NO in the presence of human
vascular smooth muscle cells (HVSMC). In preliminary experiments, the cytocompatibility of
amidoximes 2 toward the HVSMC was evaluated (see Supporting Information). As shown in
Fig. 5, except 2a which induced the lowest cell viability at 100 µM (74.67% ± 2.03), HVSMC
cells remained alive and active in the presence of amidoximes even used at high
concentration. Further experiments were conducted at the 100 µM concentration to reach NO
releases higher than the limit of detection of the fluorometric method used (vide infra).
Noteworthy is also that the cytotoxicity observed at 100 µM was detected after 24 h-
incubation while the release test requires only a 1 h-incubation.
0.001 M
0.01 M
100
0.1 M
1 M
*
10 M
100 M
50
0
e
c
2a
2c
2b
2d
n
e
r
e
f
Re
Fig. 5. Viability of the smooth muscle cells after 24 h incubation at concentrations ranging
from 0.001 to 100 µM. Results are presented as mean ± SEM of three to four tests and
compared with a two-way ANOVA for compound 2a; * p<0.001 100 µM versus all the
concentrations.
For NO release experiments using amidoximes 2, S-nitrosoglutathione (GSNO),25 a well-
known NO donor, able to deliver bioavailable NO for smooth muscle cells and blood
vessels,26-28 was prepared and used as a reference. HVSMC cells were seeded in 6-wells
plates 48 h before incubation with compounds 2 for 1 h at 37°C. Amidoximes 2a-c and
GSNO were used at 100 µM while compound 2d bearing two amidoxime functions was used
at 50 µM. After washing and lysis of the cells, S-nitrosothiols (RSNO) and nitrite ions were
immediately quantified using a fluorometric method based on the reaction of N2O3 with 2,3-
diaminonaphthlene producing naphthotriazole that emits at 415 nm after excitation at 375 nm
S5

(see Supporting Information).29 The RSNO quantification corresponds to the released NO able
to react with cell proteins thiol groups (intracellular S-nitrosation). 30 Control cells incubated
with PBS containing 0.1% DMSO were under the limit of detection for both RSNO and nitrite
ions. Fig. 6 shows that all compounds induced the formation of RSNO inside the cells. In all
cases, the concentration of nitrite ions was under the limit of quantification of the method.
GSNO, 2a, 2b and 2d produced a significantly higher RSNO intracellular concentration (0.20
± 0.01 µM, 0.21 ± 0.01 µM and 0.17 ± 0.02 µM, respectively) compared to the 4-
chlorobenzamidoxime reference (0.03 ± 0.03 µM). The intracellular S-nitrosation process is
less pronounced for 2c, which contains a similar aliphatic amidoxime function than 2d.
Noteworthy is that compounds 2a, 2b and 2d exhibit a higher potential than GSNO to
generate intracellular RSNO.
Among all new synthesized amidoximes, 2a and 2b seem the most potent since they showed
very high NO release compared to other mono-donors like the reference and GSNO. On the
other hand, 2d is also of high interest since its ability to release NO and thus to increase NO
storage through RSNO formation inside the cells is similar to compounds 2a and 2b but at a
twice lower concentration.
Fig. 6. RSNO intracellular concentration after a 1 h incubation of smooth muscle cells with
100 µM of each compound except 2d that was used at 50 µM. Results are presented as mean
± SEM of three independent experiments and compared with a One-way ANOVA; * p<0.05
versus reference; # p <0.05 versus GSNO (Dunnett’s multiple comparisons post-test).
S6

In summary, a series of mono- and bis-amidoximes were synthesized and tested for their
capacity to release NO. Using rat liver microsomes, only the aromatic mono-amidoximes 2a-
b showed high ability to release NO in the presence of cytochromes P450, while the aliphatic
mono-amidoxime 2c and the bis-amidoxime 2d exhibit weaker NO liberation capacity. All of
the studied amidoximes were demonstrated to be cytocompatible with human vascular smooth
muscle cells and were further tested for their ability to deliver NO inside the cells.
Amidoximes 2a, 2b and 2d showed a high capacity to form intracellular RSNO indicating that
these compounds were able to enter the cells and to be oxidized by the P450 of smooth
muscle cells. The lowest delivery of NO inside the cells was observed with aliphatic
amidoxime 2c. Among the amidoximes able to form a high amount of intracellular RSNO,
bis-amidoxime 2d is of high potential since its concentration was two times lower than that of
other amidoximes. This makes new bis-amidoxime 2d of interest since it should allow to
halve the drug dosage and thus to reduce the potential secondary effects. Results obtained
with mono-amidoximes 2a-b show their high capability of being used as NO donors and these
compounds are among the best existing mono-NO-donors reported to date.
Acknowledgments
The authors thank the Agence Universitaire de la Francophonie (AUF) middle east for
financial support of this work. The authors also thank Olivier Fabre for NMR analysis and
Isabelle Fries for the cytocompatibility tests.
A. Supplementary data
Supplementary data associated with this article can be found, in the online version, at
https://doi.org/
S7

References and notes
1.
Steiger, A.K.; Zhao, Y.; Pluth, M.D. Antioxid Redox Signal. 2018, 28, 1516.
2.
Fagone, P.; Mazzon, E.; Bramanti, P.; Bendtzen, K.; Nicoletti, F. Eur. J. Pharmacol. 2018, 834,
92.
3.
Schröder, A.; Kotthaus, J.; Schade, D.; Clement, B.; Rehse, K. Arch. Pharm. 2010, 343, 9.
Snyder, S.H.; Bredt, D.S. Sci. Am. 1992, 266, 68.
4.
5.
Shefa, U.; Yeo, S.G.; Kim, M.S.; Song, I.O.; Jung, J.; Jeong, N.Y.; Huh, Y. BioMed Res. Int. 2017,
2017.
6.
Sennequier, N.; Boucher, J.-L.; Battioni, P.; Mansuy, D. Tetrahedron Lett. 1995, 36, 6059.
Mansuy, D.; Boucher, J.-L. Free Radical Biol. Med. 2004, 37, 1105.
Mansuy, D.; Boucher, J.-L.; Clement, B. Biochimie 1995, 77, 661.
7.
8.
9.
Fylaktakidou, K. ; Hadjipavlou-Litina, D.; Litinas, K.; Varella, E.; Nicolaides, D.
Curr. Pharm. Design 2008, 14, 1001.
10. Jousserandot, A.; Boucher, J.-L.; Desseaux, C.; Delaforge, M.; Mansuy, D. Bioorg. Med. Chem.
Lett. 1995, 5, 423.
11.
Jousserandot, A.; Boucher, J.-L.; Henry, Y.; Niklaus, B.; Clement, B.; Mansuy, D. Biochemistry
1998, 37, 17179.
12.
13.
14.
15.
Rehse, K.; Bade, S.; Harsdorf, A.; Clement, B. Arch. Pharm. 1997, 330, 392.
Rehse, K.; Brehme, F. Arch. Pharm. 1998, 331, 375.
Vetrovsky, P. J. Pharmacol. Exp. Ther. 2002, 303, 823.
Chalupsky, K.; Lobysheva, I.; Nepveu, F.; Gadea, I.; Beranova, P.; Entlicher, G.; Stoclet, J.-C.;
Muller, B. Biochem. Pharmacol. 2004, 67, 1203.
16. Ovdiichuk, O.; Hordiyenko, O.; Medviediev, V.; Shishkin, O.; Arrault, A. Synthesis
2015, 47, 2285.
17.
18.
Ovdiichuk, O.; Hordiyenko, O.; Arrault, A. Tetrahedron 2016, 72, 3427.
Ovdiichuk, O.; Hordiyenko, O.; Fotou, E.; Gaucher, C.; Arrault, A.; Averlant-Petit,
M.-C. Struct. Chem. 2017, 28, 813.
19. General protocol for the synthesis of mono amidoximes. To a stirred solution of nitrile
1 (4 mmol) in ethanol (40 mL), were added hydroxylamine hydrochloride and sodium
carbonate (see Table 1 for details). The mixture was heated to reflux for 48 h. After cooling to
room temperature, the solvent was evaporated and the residue was extracted with ethyl acetate
(2 x 30 mL). The organic phase was washed with water (30 mL), dried over MgSO4 and
S8

finally concentrated under vacuum. Amidoximes 2 were purified by flash chromatography
using methanol/dichloromethane (10/90) as eluent.
20.
4-Hydroxybenzamidoxime: Yellow-brown powder. C7H8N2O2. Yield: 596 mg (98%);
mp 150.1°C; TLC: Rf = 0.15 (CH2Cl2/MeOH, 90:10) [silica gel]. 1H NMR (300 MHz,
DMSO-d6, 25°C): δ = 9.57 (s, 1H, =N-OH), 9.33 (s, 1H, OH), 7.49-7.46 (m, 2H, Har), 6.74-
6.72 (m, 2H, Har), 5.61 (s, 2H, NH2). 13C NMR (75 MHz, DMSO-d6, 25°C): δ = 158.1, 150.8,
126.7, 124.1, 114.7. IR (neat): 3434 (br), 3319 (br), 3211 (br), 1645 (m), 1609 (m), 1509 (m),
1277 (m), 1247 (m). 1134 (m). HRMS (ESI, m/z): MH+, found 153.0688. C7H9N2O2 requires
153.0659.
21.
4-Methoxybenzamidoxime: White powder. C8H10N2O2. Yield: 631 mg (95%); mp
120.2°C; TLC: Rf = 0.15 (CH2Cl2/MeOH, 90:10) [silica gel]. 1H NMR (300 MHz, DMSO-d6,
25°C): δ = 9.42 (s, 1H, OH), 7.62-7.59 (m, 2H, Har), 6.93-6.90 (m, 2H, Har), 5.70 (s, 2H,
NH2), 3.77 (s, 3H, CH3). 13C NMR (75 MHz, DMSO-d6, 25°C): δ = 159.8, 150.5, 126.7,
125.7, 113.4, 55.1. IR (neat): 3443 (s), 3353 (s), 2968 (w), 2841 (w), 1646 (s), 1608 (m), 1518
(s), 1413 (m), 1386 (m), 1303 (m), 1243 (s), 1175 (m), 1033 (m), 925 (m), 835 (s). (ESI, m/z):
MH+, found 167.0836. C8H11N2O2 requires 167.0815.
22.
General protocol of the bis-amidoximes and aliphatic amidoxime synthesis: To a
stirred solution of nitrile 1 in ethanol (40 mL), was added an aqueous hydroxylamine solution
(50 wt. % in H2O). The reaction was heated to reflux for 24 h. After cooling to room
temperature, the solvent was evaporated and the residue was extracted with ethyl acetate (2 x
30 mL). The organic phase was washed with water, dried over MgSO4 and finally
concentrated under vacuum. The product was purified by flash chromatography using
methanol/dichloromethane (10/90) as eluent.
23.
N-hydroxy-5-phenoxy-pentanamidine: Black purple powder. C11H16N2O2. Yield: 583
mg (70%); mp 96.5°C; TLC: Rf = 0.15 (CH2Cl2/MeOH, 90:10) [silica gel]. 1H NMR (300
MHz, DMSO-d6, 25°C): δ = 8.70 (s, 1H, OH), 7.30-7.24 (m, 2H, Har), 6.93-6.88 (m, 3H, Har),
5.32 (s, 2H, NH2), 3.95 (t, J = 6.2 Hz, 2H, O-CH2), 2.02 (t, J = 7.2 Hz, 2H, CH2), 1.73-1.61
(m, 4H, (CH2)2). 13C NMR (75 MHz, DMSO-d6, 25°C): δ = 158.6, 152.6, 129.4, 120.3, 114.4,
67.0, 30.4, 28.2, 22.9. IR (neat): 3475 (br), 3361 (br), 3229 (br), 2926 (w), 2871 (w), 1681
(w), 1589 (w), 1498 (w), 1475 (w), 1296 (w), 1255 (m), 751 (w), 660 (m). (ESI, m/z): MH+,
found 209.1323. C11H17N2O2 requires 209.1285.
24.
N-Hydroxy-4-[4-(N-hydroxycarbamimidoyl)-butoxy]-benzamidine: Green powder.
C12H18N4O3. Yield: 330 mg (40%); mp 166.6°C; TLC: Rf = 0.15 (CH2Cl2/MeOH, 90:10)
[silica gel]. 1H NMR (300 MHz, DMSO-d6, 25°C): δ = 9.42 (s, 1H, OH), 8.72 (s, 1H, OH),
S9

7.60-7.57 (m, 2H, Har), 6.94-6.89 (m, 2H, Har), 5.69 (s, 2H, NH2), 5.38 (s, 2H, NH2), 3.98 (t, J
= 6.0 Hz, 2H, O-CH2), 2.02 (t, J = 7.1 Hz, 2H, CH2), 1.73-1.61 (m, 4H, (CH2)2). 13C NMR (75
MHz, DMSO-d6, 25°C): δ = 159.2, 152.8, 150.6, 126.7, 125.6, 113.9, 67.2, 30.3, 28.1, 22.9.
IR (neat): 3452 (br), 3303 (br), 2941 (w), 2869 (w), 1679 (s), 1627 (s), 1522 (m), 1393 (m),
1306 (w), 1260 (m), 1180 (m), 920 (w), 843 (w). (ESI, m/z): MNa+, found 289.1291.
C12H18N4NaO3 requires 289.1271.
25.
31.
26.
Parent, M.; Dahboul, F.; Schneider, R.; Clarot, I.; Maincent, P. Curr. Pharm. Anal. 2013, 9,
Belcastro, E.; Wu, W.; Fries-Raeth, I.; Corti, A.; Pompella, A.; Leroy, P.; Lartaud, I.;
Gaucher, C. Nitric Oxide 2017, 69, 10.
27. Wu, W.; Perrin-Sarrado, C.; Ming, H.; Lartaud, I.; Maincent, P.; Hu, X.-M.; Sapin-Minet, A.;
Gaucher, C. Nanomedicine: Nanotechnology, Biology and Medicine 2016, 12, 1795.
28. Dahboul, F.; Leroy, P.; Maguin Gate, K.; Boudier, A.; Gaucher, C.; Liminana, P.; Lartaud, I.;
Pompella, A.; Perrin-Sarrado, C. PLoS ONE 2012, 7, e43190.
29. Wu, W. ; Gaucher, C.; Diab, R.; Fries, I.; Xiao, Y.-L.; Hu, X.-M.; Maincent, P.; Sapin-
Minet, A. Eur. J. Pharm. Biopharm. 2015, 89, 1.
30. Nagababu, E.; Rifkind, J.M. Cell Biochem. Biophys. 2013, 67, 385.
Graphical Astract
Synthesis of Novel Mono and Bis Nitric Oxide Donors with High Cytocompatibility and
Release Activity
Tanya Sahyoun, Caroline Gaucher, Yi Zhou, Naïm Ouaini, Raphaël Schneider, Axelle Arrault
0.25
0.20
0.15
Incubation with Human
Vascular Smooth Muscle Cells
0.10
NO
+
0.05
0.00
f
e
O
2a
2c
2b
2d
R
N
GS
Highlights
Ref : 4-chlorobenzamidoxime
 A series of aromatic and aliphatic mono-amidoximes and bis-amidoximes were
synthesized.
 Amodoximes were tested for their NO release ability on rat liver microsomes and
human vascular cells.
S10

 Amidoximes are cytocompatible with human vascular smooth muscle cells.
 Mono-amidoximes 2a and 2b exhibit high NO release.
 Bis-amidoxime 2d releases the same amount of NO than 2a and 2b at a twice lower
concentration.
S11