International Journal of Applied Engineering Research ISSN 0973-4562 Volume 11, Number 20 (2016) pp. 10075-10078
© Research India Publications. http://www.ripublication.com
10075
4-Hydroxycoumarins: Synthesis, Characterization and Antioxidant Activities
Y. Al-Majedy a,c*, A. Kadhuma, A. Mohamada,b, A. Al-Amieryc
aDepartment of Chemical and Process Engineering, Universiti Kebangsaan Malaysia, Bangi, Selangor 43000, Malaysia. bFuel Cell Institute, Universiti Kebangsaan Malaysia, 43600 Bangi Selangor, Malaysia.
cUniversity of Technology (UOT), Baghdad 10001, Iraq.
Abstract
4-hydroxycoumarins were synthesized and characterized by the
Fourier transformation infrared (FT-IR) and Nuclear magnetic
resonance (1H-NMR) spectroscopies. The scavenging activities
were evaluated by various in vitro antioxidant assays, 1, 1-
diphenyl-2-picrul-hydrazil free radical (DPPH•) and hydrogen
peroxide and we were using (vitamin C) as a reference. All of the
synthesized compounds have shown excellent radical scavenging
activities.
Keywords: Antioxidant activity, 4-hydroxycoumarins,
DDPH, H2O2.
INTRODUCTION
Antioxidants in food play an important role as a health-protecting
factor. Scientific evidence suggests that antioxidants reduce the
risk for chronic diseases including cancer and heart disease.
Primary sources of naturally occurring antioxidants are whole
grains, fruits and vegetables. Plant sourced food antioxidants like
vitamin C, vitamin E, carotenes, phenolic acids, phytate and
phytoestrogens have been recognized as having the potential to
reduce disease risk [1] Coumarins are plant flavonoids widely
distributed in nature, Coumarin (2-oxo-2H-chromene) and its
derivatives represent one of the most important classes of
compounds possessing numerous biological activities [2-4] Some
of these compounds have proven to be active as antibacterial [5-7]
antifungal [8] anti-inflammatory [9], anticoagulant [10], anti-HIV
[11] and antitumor agents[12]. Coumarin derivatives are widely
used as additives in food and cosmetics [13], pharmaceuticals and
optical brighteners [14] and laser dyes [15].Coumarins have also
proven to be an excellent antioxidants as well as antifungal agents
[16]. In continuation of previous studies [17–26], we have
focused on synthesis of new heterocyclic compounds, and testing
their free radical scavenging activity by using DPPH and
hydrogen peroxide free radical scavenging methods.
MATERIALS AND METHODS
All chemicals were supplied by Sigma-Aldrich (Selangor,
Malaysia). FT-IR spectra were obtained on a Nicolet 6700 FT-IR
spectrophotometer (Thermo-Nicolet-Corp., Madison, WI, USA),
in cm−1. NMR spectra were recorded using an AVANCE III 600
MHz spectrometer (Bruker, Billerica, MA, USA), using DMSO
and expressed in δ ppm. CHN microanalysis was performed on an
Elementar Vario El III Carlo Erba 1108 elemental analyzer
(Carlo Erba Reagenti SpA, Rodano, Italy).
Synthesis of compounds 1-11.
All compounds were synthesized according to Al-Amiery
2014 [27].
Antioxidant Activity
DPPH free radical scavenging activity
The antioxidant activity of synthesis compounds and the
standard was assessed on the basis of the radical scavenging
effect of the stable 1, 1-diphenyl-2-picrylhydrazyl (DPPH)-
free radical activity by modified method (Braca et al .2002).
The diluted working solutions of the test compound were
prepared in methanol. Ascorbic acid was used as standard in
1-100 µg/ml solution. 0.002% of DPPH was prepared in
methanol and 1 ml of this solution was mixed with 1 ml of
sample solution and standard solution separately. These
solution mixtures were kept in dark for 30 min and optical
density was measured at 517 nm using Spectrophotometer.
Methanol (1 ml) with DPPH solution (0.002%, 1 ml) was
used as blank. The optical density was recorded and %
inhibition was calculated using the formula given below [28]:
(1)
Where Ao is the absorbance of the control reaction and A is
the absorbance in the presence of the samples or standards.
Hydrogen Peroxide Scavenging Activity
A solution of hydrogen peroxide (40mM) was prepared in
phosphate buffer (pH 7.4). Different concentrations (250,
500, and 1000 µg/mL) of synthesized compounds (or
ascorbic acid as control) were added to a hydrogen peroxide
solution (0.6 mL, 40 mM). Absorbance of hydrogen peroxide
at 230 nm was determined after 10min. against a blank
solution containing phosphate buffer without hydrogen
Peroxide [29, 30]. Hydrogen peroxide percentage scavenging
activity was then calculated using the equation 1:
International Journal of Applied Engineering Research ISSN 0973-4562 Volume 11, Number 20 (2016) pp. 10075-10078
© Research India Publications. http://www.ripublication.com
10076
RESULTS AND DISCUSSION
Chemistry
Methyl 2-(coumarin-4-yloxy) acetate (1) was obtained by
refluxing methyl bromoacetate with 4-hydroxycoumarin in
anhydrous acetone in the presence of anhydrous potassium
carbonate. The FT-IR spectrum of this compound showed an
absorption band at 1,723.1 cm-1 (ester C=O carbonyl stretching).
The 1H-NMR spectrum exhibited a singlet at δ 3.63 ppm due to
the three (CH) protons. The reaction of 1 with hydrazine hydrate
afforded hydrazide 2 in good yield. The FT-IR spectrum of
compound 2 showed absorption bands at 3,233.3 and 3,210.0cm-1. 1H-NMR spectrum exhibited a singlet at δ 4.45 ppm due to the
two (CH2) (hydrazide (NH-NH) protons and a singlet due to the
single NH proton at δ 8.21 ppm. The reaction of compound 2 with
various carbonyl compounds (2-methylbenzaldehyde, 4-
aminoantipyrine and ethyl methyl ketone) yielded the new Schiff
bases N'-(2-methylbenzylidene)-2-[(coumarin-4-yl)oxy]aceto
hydrazide (3), N'-[4-amino-1,5-dimethyl-2-phenyl1H-pyrazol-
3(2H)-ylidene]-2-[(coumarin-4-yl)oxy]acetohydrazide (4) and N'-
(butan-2-ylidene)-2[(coumarin-4-yl)oxy]acetohydrazide (5),
respectively. Schiff bases 3, 4 and 5 were cyclized by reaction
with mercaptoacetic acid to yield novel coumarin compounds N-
[4-oxo-2-(O-tolyl)thiazolidin3-yl]-2-[(coumarin-4-
yl)oxy]acetamide (6), N-(4-amino-2,3-dimethyl-8-oxo-1-phenyl-
6-thia-1,2,9triazaspiro[4.4]non-3-en-9-yl)-2-[(coumarin-4-
yl)oxy]acetamide (7) and N-(2-ethyl-2-methyl-4oxothiazolidin-3-
yl)-2-[(coumarin-4-yl)oxy]acetamide (8), respectively. The FT-IR
spectrum of compound 6 showed absorption bands at 3,191.4
cm−1 (NH) and 1,715.6 cm−1 (C=O, lactone) as well as 1,695 and
1,677 cm−1 (C=O, amide). The 1H-NMR spectrum exhibited a
singlet due to the (S-CH) proton at δ 4.88 ppm and another singlet
due to the (O-CH) proton at δ 5.11 ppm (2H). For compound 7,
the FT-IR spectrum showed absorption bands at 3,388.3 cm−1for
NH2 and 3,189.1 cm-1 for (N-H) and the( C=N) bands disappeared
due to cyclization. The 1H-NMR spectrum exhibited a doublet
due to the two protons at δ 4.89 and δ 4.12 ppm and singlet due to
the single S-CH proton at δ 3.89 ppm. For compound 8, the FT-IR
spectrum showed absorption bands at 3,199.0 cm−1 (NH) as well
as 1,691 and 1,685 cm−1 (C=O, amide); the (C=N) bands
disappeared due to cyclization. The 1H-NMR spectrum exhibited
a doublet due to the(S-CH2). Proton at δ 3.86 and δ 8.02 ppm, and
a singlet due to the (NH) proton. Another three novel compounds
were synthesized by the cyclization of Schiff bases 3, 4 and 5
with maleic anhydride to yield N-[4,7-dioxo-2-(O-tolyl)-1,3-
oxazepin-3(2H,4H,7H)-yl]-2-[(coumarin4-yl)oxy] acetamide (9),
N-[2-(4-amino-1,5-dimethyl-2-phenyl-2,3-dihydro-1H-pyrazol-3-
yl)4,7dioxo-1,3-oxazepin-3(2H,4H,7H)-yl]-2-[(coumarin-4-
yl)oxy] acetamide (10) and N-[2-ethylmethyl4,7-dioxo-1,3-
oxazepin-3(2H,4H,7H)-yl]-2-[(coumarin-4-yl)oxy] acetamide
(11), respectively. For compound 9, the FT-IR spectrum showed
absorption bands at 3,196.2 cm−1(NH) and 1,667.9 cm-1 for the
amide as well as 1,755 and 1,745 cm−1 for carbonyls. The 1H-
NMR spectrum exhibited a singlet at δ 5.38 ppm due to the two
O-CH protons. For compound 10, the FT-IR spectrum of showed
absorption bands at 2,981.4 cm−1. (C-H, aliphatic), 1,765 and
1,734 cm−1 for the carbonyls, and 1,678 cm−1 for the amide. The 1H-NMR spectrum exhibited a singlet δ 4.89 ppm due to the two
(O-CH) protons at. For compound 11, the FT-IR spectrum of
showed absorption bands at 3,199 cm-1. The (NH) and 1,669.2
cm−1 for the amides as well as 1,758 and 1,733 cm−1 for the
carbonyls. The 1H-NMR spectrum exhibited a singlet due to
the two (O-CH2) protons at δ 4.65 ppm.
Antioxidant Activities
Free radicals have been a subject of critical interest among
researchers in the previous decade. The wide range of free
radical effects in biological systems has garnered interest
from many specialists. It has been demonstrated that free
radicals assume an important role in the pathogenesis of
specific diseases and aging [31-33]. Numerous synthetic
cancer prevention agents have presented toxic and/or
mutagenic effects; thus, naturally occurring antioxidants have
been considered. Synthesized coumarins 6–11 were screened
for in vitro scavenging activity utilizing DPPH and hydrogen
peroxide. These tested coumarins showed high scavenging
activity (Figure 1 and 2).
Figure 1. Showed that the six synthesized compounds (6-11)
demonstrated a strong scavenging activity against DPPH.
0
10
20
30
40
50
60
70
80
90
100%
inh
ibit
ion
concentration
250 μg/mL500 μg/mL750 μg/mL1000 μg/mL
Figure 1.
Figure 2. Showed that the six synthesized compounds (6-11)
demonstrated a strong scavenging activity against H2O2.
Figure 2.
International Journal of Applied Engineering Research ISSN 0973-4562 Volume 11, Number 20 (2016) pp. 10075-10078
© Research India Publications. http://www.ripublication.com
10077
ACKNOWLEDGEMENTS
The acknowledgement for funding to Universiti Kebangsaan Malaysia.
REFERENCES
[1] Miller, F. Rigelhof, L. Marquart, A. Prakash and M.
Kanter, Cereal Foods World. 2000, 45(2), 59-63.
[2] El-Agrody, A.; Abd El-Latif, M.; El-Hady, N.; Fakery
A.and Bedair, A.2001 Hetero aromatization with 4-
hydroxycoumarin Part II: Synthesis of some new
pyrano[2,3d]pyrimidines,[1,2,4]triazolo[1,5c]pyrimidines
and pyrimido[1,6-b][1,2,4]triazine derivatives. Molecules,
6, 519–527.
[3] Rositca, D.N.; Vayssilov, G.N.; Rodios, N.and Bojilova,
A. Regio.2002 stereoselective [2+2] photodimerization of
3-substituted 2-alkoxy-2-oxo-2H-1,2-
benzoxaphosphorines. Molecules, 7, 420–432.
[4] Flašík, R.; Stankovičová, H.; Gáplovský, A.and
Donovalová, 2009.J. Synthesis and study of novel
coumarin derivatives potentially utilizable as memory
media. Molecules, 14, 4838–4848.
[5] Kovalenko, S.; Bylov, I.; Sytnik, K.; Chernykh, V.and
Bilokin, Y. 2000.A new pathway to 3-hetaryl-2oxo-2H-
chromenes: On the proposed mechanisms for the reaction
of 3-carbamoyl-2iminochromenes with dinucleophiles.
Molecules, 5, 1146–1165.
[6] El-Saghier, A.; Khodairy, A.and Khodiyar, A. 2000.New
synthetic approaches to condensed and spiro coumarins:
Coumarin-3-thiocarboxamide as building block for the the
synthesis of condense and spiro coumarins. Phosphorus
Sulfur. , 160, 105–119.
[7] Al-Amiery, A.A.; Al-Bayati, R.; Saour, K.and Radi,
M.2012. Cytotoxicity, antioxidant and antimicrobial
activities of novel 2-quinolone derivatives derived from
coumarins. Res. Chem. Intermediat. 38, 559–569.
[8] Azizian, J.; Mohammadi, A.; Bidar, I.and Mirazaei,
P.2008 KAl(SO4)2·12H2O (alum) a reusable catalyst for
the synthesis of Some 4-substituted coumarins via
Pechmann reaction under solvent-free conditions. Montash.
Chem. 139, 805–808.
[9] Satyanarayan, V.S.; Sreevani, P.,and Sivakumar, A.2008
Synthesis and antimicrobial activity of new Schiff bases
containing coumarin moiety and their spectral
characterization. Arkivoc . 17, 221–233.
[10] Garazd, M.M.; Muzychka, O.V.; Voyk, A.I.; Nagorichna,
I.V.,and Ogorodniichuk, A.S.2007. Modified coumarins.
27. Synthesis and antioxidant activity of 3-substituted 5, 7-
dihydroxy-4methylcoumarins. Chem. Nat. Compd., 43,
19–23.
[11] Smitha, G.,and Sanjeeva, R.2004. ZrCl4-catalyzed
Pechmann reaction: Synthesis of coumarins under solvent-
free conditions. Synth. Commun. . 34, 3997–4003.
[12] Kotali, A.; Lafazanis, I,and Harris, P.2008. Synthesis of
6,7-diacylcoumarins via the transformation of a hydroxy
into a carbonyl group. Synth. Commun. .38, 3996–4006.
[13] Nofal, Z.M.; El-Zahar,M,and Abd El-Karim, S.2000.
Novel coumarin derivatives with expected biological
activity. Molecules, 5, 99–113.
[14] Kennedy, R.O,and Thornes, R.D.1997. Coumarins:
Biology, Applications and Mode of Action; John
Wiley and Sons: Chichester, UK.
[15] Zabradnik, M. 1992.The Production and Application
of Fluorescent Brightening Agents; John Wiley and
Sons: New York, NY, USA.
[16] Al-Amiery, A.A.; Al-Majedy, Y.K.; Kadhum, A.A.H.;
Mohamad, A.B. Novel macromolecules derived from
coumarin: Synthesis and antioxidant activity. Sci. Rep.
2015, 5, 11825.
[17] Al-Amiery, A.A.; Al-Majedy, Y.K.; Abdulreazak, H.;
Abood, H. Synthesis, characterization, theoretical
crystal structure, and antibacterial activities of some
transition metal complexes of the thiosemicarbazone.
Bioinorg. Chem. Appl. 2011, 2011, 1–6.
[18] Kadhum, A.A.H.; Mohamad, A.B.; Al-Amiery, A.A.;
Takriff, M.S. Antimicrobial and antioxidant activities
of new metal complexes derived from 3-
aminocoumarin. Molecules 2011, 16, 6969–6984.
[19] Al-Amiery, A.A.; Al-Bayati, R.I.H.; Saour, K.Y.;
Radi, M.F. Cytotoxicity, antioxidant and antimicrobial
activities of novel 2-quinolone derivatives derived
from coumarins. Res. Chem. Intermed. 2011, 38, 559–
569.
[20] Al-Amiery, A.A.; Antimicrobial and antioxidant
activities of new metal complexes derived from (E)-3-
((5-phenyl-1,3,4-oxadiazol-2-
ylimino)methyl)naphthalen-2-o, Medicinal Chemistry
Research, 2012, 21, 3204-3213
[21] Kadhum, A.A.H.; Al-Amiery, A.A.; Musa, A.Y.;
Mohamad, A. The antioxidant activity of new
coumarin derivatives. Int. J. Mol. Sci. 2012, 12, 5747–
5761.
[22] Al-Amiery, A.; Kadhum, A.; Obayes, H.; Mohamad,
A. Synthesis and Antioxidant Activities of Novel 5-
Chlorocurcumin, Complemented by Semiempirical
Calculations. Bioinorg. Chem. Appl. 2013, 2013, 1–7.
[23] Al-Amiery, A.; Musa, A.; Kadhum, A.; Mohamad, A.
The Use of Umbelliferone in the Synthesis of New
Heterocyclic Compounds. Molecules 2011, 16, 6833–
6843.
[24] Kadhum, A.A.H.; Al-Amiery, A.A.; Shikara, M.;
Mohamad, A. Synthesis, Structure elucidation and
DFT studies of new thiadiazoles. Int. J. Phys. Sci.
2011, 6, 6692–6697.
[25] Al-Amiery AA. Synthesis and antioxidant,
antimicrobial evaluation, DFT studies of novel metal
complexes derivate from Schiff base. Res Chem
Intermed. 2012;38:745–759
[26] Al-Majedy, AAH Kadhum, AA Al-Amiery and AB
Mohamad.2014. Synthesis and Characterization of
Some New 4-Hydroxy-coumarin Derivatives.
Molecules 19 (8), 11791-11799.
[27] Braca A, Sortino C, Politi M et al.2002. Anti-oxidant
activity of flavonoids from Licania licaniaeflora . J
Ethnopharmacol 79: 379381.
[28] Bors W, Saran M, Elstner EF. Screening for plant anti-
oxidants. In: Linskens HF, Jackson JF. eds.
1999.Modern Methods of Plant Analysis-Plant Toxin
International Journal of Applied Engineering Research ISSN 0973-4562 Volume 11, Number 20 (2016) pp. 10075-10078
© Research India Publications. http://www.ripublication.com
10078
Analysis-New Series, Vol 13. Springer, Berlin; pp. 277-
295.
[29] Duh, Y.-Y. Tu, and G.-C. Yen, 1999. “Antioxidant
Activity of Water Extract of Harng Jyur (Chrysanthemum
morifolium Ramat),” LWT—Food Science and
Technology, vol. 32, no. 5, pp. 269–277, .
[30] Chen, M. Wang, R. T. Rosen, and C.-T. Ho, 1999.“2,2-
Diphenyl-1-picrylhydrazyl radical-scavenging active
components from Polygonum multiflorum Thunb,” Journal
of Agricultural and Food Chemistry, vol. 47, no. 6, pp.
2226–2228.
[31] Naama j, Alwan G, Obayes H, Al-Amiery A, Al-Temimi
A, Kadhum A, et al. 2013. Curcuminoids as antioxidants
and theoretical study of stability of curcumin isomers in
gaseous state. Research on Chemical Intermediates. 39(9):
4047.
[32] Kadhum A, Al-Amiery A, Musa A.and Mohamad A.
2011.The Antioxidant Activity of New Coumarin
Derivatives. Int J Mol Sci., 12(9): 5747-5761.
[33] Pal R, Hooda M, Bhandari A.and Singh J.
2012.Antioxidant potential and free radicals scavenging
activity by pod extracts of acacia senegal willd, IJPCBS. ,
2(4): 500-506.
Top Related