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Synthesis and Evaluation of Antibacterial Activities of 57-Dihydroxycoumarin Derivatives.

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386
Arch. Pharm. Chem. Life Sci. 2011, 11, 386–393
Full Paper
Synthesis and Evaluation of Antibacterial Activities of
5,7-Dihydroxycoumarin Derivatives
Yi-Ping Chin1, Wei-Jan Huang2, Feng-Lin Hsu2, Yuh-Ling Lin3, and Mei-Hsiang Lin4
1
Department of Microbiology and Immunology, Taipei Medical University, Taipei, Taiwan, ROC
Graduate Institute of Pharmacognosy Science, College of Pharmacy, Taipei Medical University, Taipei,
Taiwan, ROC
3
School of Medicine, Fu Jen Catholic University, Taiwan, ROC
4
School of Pharmacy, College of Pharmacy, Taipei Medical University, Taipei, Taiwan, ROC
2
This study examines the synthesis and antibacterial activities of 5,7-dihydroxycoumarin derivatives,
whose structures were confirmed using analytical and spectral data. Twenty compounds were tested
for their antibacterial activities against five microbial species such as E. coli, S. aureus, K. pneumonia,
P. aeruginosa, and S. typhimurium were studied. Compounds 5 and 12 exhibited the most potent activity
against Staphylococcus aureus with a MIC value of 2.5 mg/mL for each of the compounds.
Keywords: Antibacterial activity / 5,7-Dihydroxycoumarin / Methicillin-resistance / Serratin
Received: August 13, 2010; Revised: November 15, 2010; Accepted: November 26, 2010
DOI 10.1002/ardp.201000233
Introduction
Coumarins belong to a class of phenolic substances, characterized by a benzene moiety fused with a-pyrone rings.
Coumarin derivatives are widely distributed throughout
the plant kingdom; they are structurally diverse and can
be roughly classified into five major groups. Simple coumarins are those with substituents in the benzene ring.
The second group is furocoumarins, containing a five-membered furan ring attached to the coumarin structure with the
furan oxygen in the 7-position. Furocoumarins can be either
linear or angular, based on the position of the attached furan
ring [1]. The third group is pyranocoumarins. They have a sixmembered oxygen heterocyclic ring, and can be found in
either linear or angular forms. The fourth group includes
coumarins substituted in the pyrone ring in either position 3
or 4. The last group is the coumarin dimers, which are usually
made up of two coumarin units linked together. Coumarins
Correspondence: Mei-Hsiang Lin, School of Pharmacy, College of
Pharmacy, Taipei Medical University, 250 Wu-Xing Street, Taipei 110,
Taiwan, ROC.
E-mail: mh100001@tmu.edu.tw
Fax: þ886-2-27361661-3164.
Additional correspondence: Professor Yuh-Ling Lin.
E-mail: yllin054230@mail.fju.edu.tw
ß 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
perform various pharmacological functions involving a number of antibacterial [2, 3], antiviral [4], antitumor [5–9], antiinflammatory [10–14], and DNA-repair properties [15, 16].
Previous studies have focused on the inhibition of bacterial
growth and antifungal activity using naturally occurring
coumarins (e.g., umbelliferone, xanthoxin, herniarin, and
scopoletin) [17–21] and synthetic coumarins and angular
furanocoumarins derived from natural coumarins [22]. A
number of coumarin derivatives (e.g., novobiocin and
analogues) have also been shown to be highly effective antibiotics [23, 24]. Synthetic derivatives of coumarins possessing
antibacterial properties include 3-acyl [2, 25–28], 7-acetohydrazide [29], 3-carbamoyl-4-hydroxycoumarins [28, 30], 6,7-disubstituted, and 6,7,8-tri-substituted coumarin derivatives
[22]. A [7-hydroxy-4-methyl-8-coumarinyl] glycine complex
with metals (Cu(II), Co(II), Ni(II), Zn(II), and Cd(II)) has been
synthesized, demonstrating greater antimicrobial effectiveness than the free ligand [31].
Simple coumarins with two hydroxyls in the benzene are
known for their antifungal properties, and the free 6-OH has
been identified as an important element in antifungal
activity [22]. However, the free hydroxyl group at position
7 of the coumarin nucleus is also important in the antibacterial activity [32]. Coumarins substituted with dihydroxyl
in the benzene ring demonstrate antibacterial activity
Arch. Pharm. Chem. Life Sci. 2011, 11, 386–393
enhanced through the substitution of I and 4-methyl in the
benzene ring [21]. For example, 8-iodo-5,7-dihydroxycoumarin shows strong to very strong antibacterial characteristics with an MIC value in the range of 1.56 mg/mL to
50 mg/mL, whereas 5,7-dihydroxycoumarin displays antibacterial characteristics with an MIC value in the range of
1000 mg/mL to >1000 mg/mL. 7,8-Dihydroxy-4-methylcoumarin exhibits good antibacterial activity with an MIC value
in the range of 100 mg/mL to 500 mg/mL.
Four substituted coumarins have been tested for antibacterial activity limited to methyl and hydroxyl groups. A few
coumarins were discussed with regard to other substituent
alkyl and aryl simple groups (e.g., allyl, alkyl, methoxy, halogens) substituted in the benzene ring. In this study, we were
interested in the antibacterial activity of 4-alkyl/aryl-6- or 8acyl-5,7-dihydroxycoumarins. In a previous study, 5,7-dihydroxy-4-phenylcoumarin [2, serratin, (Fig. 1)] was isolated
from the aerial parts of Passiflora serratodigitata (Passifloraceae) [33]. However, no antibacterial activity was
observed. Considering the biological aspect of coumarin,
we prepared compound 2 as mentioned in [34] and subsequently tested the antibacterial activities against five
microbial species including E. coli, S. aureus, K. pneumonia,
P. aeruginosa, and S. typhimurium. The results showed moderate
antibacterial activity against Staphylococcus aureus (MIC ¼
160 mg/mL). We synthesized a series of 4-alkyl/aryl-6-acyl5,7-dihydroxycoumarin derivatives (3–21, Figs. 1 and 2)
from phloroglucinol for their antibacterial characteristics.
Out of these, compounds 5 and 12 showed the best
antibacterial activity against Staphylococcus aureus with a
MIC value of 2.5 mg/mL for each of the compounds. In
this study, we described our effort regarding the synthesis
Antibacterial Activities of 5,7-Dihydroxycoumarins
387
Figure 2. Structure of coumarin derivatives 14–21.
of 5,7-dihydroxycoumarin derivatives and investigated their
structure–activity relationship (SAR).
Results and discussion
Chemistry
Compounds 3–13 were obtained as per previous protocols
reported in [35]. It has been documented that the Pechmann
reaction is able to provide an efficient synthesis of benzopyranone moiety from the condensation of phenols with b-keto
esters in the presence of acid [36–38]. We incorporated the
Pechmann reaction in our protocol to prepare coumarin
derivatives 2 and 14–21. The synthesis of the 6-benzoylcoumarins (14–17) was achieved as described in Scheme 1. Monoacylation of phloroglucinol (22) with the appropriate benzoyl
chlorides gave benzoylphloroglucinols (23–26) in 15–37%
Figure 1. Structure of coumarin (1), serratin (2), and derivatives 3–13.
ß 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
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Y.-P. Chin et al.
Arch. Pharm. Chem. Life Sci. 2011, 11, 386–393
Scheme 1. Synthesis of coumarin derivatives 14–17. Reagents and conditions: a) Substituted benzoyl chloride, AlCl3, nitrobenzene,
608C, 15–37%; b) ethyl benzoylacetate, rt, 22–41%.
yields. Compounds 14–17 were obtained by benzoylphloroglucinols (23–26) reaction with either ethyl benzoylacetate or
ethyl propionylacetate in 22–41% yields.
Using the same approach as above, attempts to synthesize
the 6-benzoylcoumarins (29–30) from 40 -CN or 40 -NO2-benzoylphloroglucinols (27–28) failed (Scheme 2). The phloroglucinol
22 reaction with ethyl benzoylacetate gave 4-phenylcoumarin (2) in a 28% yield. Compounds 23–26 were treated
under similar condition as 6-benzoyl-4-phenylcoumarin 18.
This resulted in a 16% yield. In addition, diacetylation of 4phenylcoumarin (2) using acetic anhydride produced acetylated 4-phenylcoumarin 21. Furthermore, the reaction of 21
with appropriate benzoyl chlorides produced selective 5-Obenzoyl-4-phenylcoumarin (19–20).
Biological activity
The antibacterial activity of 5,7-dihydroxycoumarins (2–21) is
shown in Table 1. The MIC values of 2–21 were screened
against five strains of bacteria including, Escherichia coli (EC)
ATCC 25922, Staphylococcus aureus (SA) ATCC 25923, Klebsiella
pneumoniae (KP) ATCC 13883, Pseudomonas aeruginosa (PA) ATCC
27853, and Salmonella typhimurium (ST) ATCC 14028. The
potency was defined as following:
No bioactivity with MIC > 640 mg/mL
Mild bioactivity with MIC in the range of 320–640 mg/mL
Moderate bioactivity with MIC in the range of 160–
319 mg/mL
Good bioactivity with MIC in the range of 80–159 mg/mL
Strong bioactivity with MIC in the range of 10–79 mg/mL
Very strong bioactivity with MIC < 10 mg/mL.
These compounds showed a broad range of antimicrobial
activity. A number of the coumarins exhibited activity
against all five microorganisms, and a few of them were
selectively active against one or two strains. Eight coumarins
(3, 4, 6, 11, 16, 19, 20, and 21) showed mild antibacterial
characteristics in general, with MIC values in the range of
320 mg/mL to >640 mg/mL. Five coumarins (2, 7, 8, 13, and 18)
exhibited moderate antibacterial activity, with MIC values in
ß 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
the range of 160–639 mg/mL. Three coumarins (9, 10, and 14)
displayed good antibacterial activity, with MIC values in the
range of 80–159 mg/mL. Two coumarins (15 and 17) showed
strong antibacterial activity, with MIC values in the range of
10–79 mg/mL. Two coumarins (5 and 12) exhibited very strong
antibacterial activity with MIC values <10 mg/mL.
Coumarin 6 exhibited mild activity only against PS, with a
MIC value of 640 mg/mL. Coumarin 7 showed moderate
activity only against SA, with a MIC value of 160 mg/mL.
Eight coumarins were active against all five microorganisms;
four of these (18, 19, 20, and 21) had MIC values ranging
between 160 mg/mL and 640 mg/mL; three of these (14, 15,
and 17) had MIC values ranging between 20 mg/mL and
640 mg/mL; and one coumarin 5 had a MIC value of 2.5–
320 mg/mL. Coumarin 5 exhibited very strong antibacterial
activity against SA (MIC ¼ 2.5 mg/mL) and moderate activity
against EC, KP, and PA (MIC ¼ 160 mg/mL). Coumarin 12
displayed very strong bioactivity against the entire range
of bacteria tested, demonstrating MIC values against the
Gram-positive bacterium SA with a MIC value of 2.5 mg/mL.
Against the Gram-negative bacterium EC, the value was
640 mg/mL. MIC values for the other two Gram-negative bacteria were KP 320 mg/mL and PA 80 mg/mL.
From these results, it was also possible to make a number of
correlations regarding the relationship between the structure of the coumarins and their antimicrobial activities.
4-Phenyl substitution appears to enhance bioactivity
with 5,7-dihydroxycoumarin and coumarin 2 .
Protection of 5-hydroxyl and 5,7-dihydroxyl reduces the
antibacterial activity as with coumarin 19, 20, and 21. It
appears that, as far as the antibacterial activity is concerned, 5- and 7-OH are essential, while protected 5-OH
and 7-OH have less bioactivity.
6-(3-Methyl-butyryl)-4-phenyl-5,7-dihydroxycoumarin (3)
and 8-(3-methyl-butyryl)-4-phenyl-5,7-dihydroxycoumarin
(4) both demonstrate mild bioactivity and 6-(3-methylbutyryl)-4-(p-methylphenyl)-5,7-dihydroxycoumarin (13)
enhances bioactivity, showing moderate antibacterial
activity. 6-Benzoyl-4-phenyl-5,7-dihydroxycoumarin (5)
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Arch. Pharm. Chem. Life Sci. 2011, 11, 386–393
Antibacterial Activities of 5,7-Dihydroxycoumarins
389
Scheme 2. Synthesis of coumarin derivatives 18–21. Reagents and conditions: a) 4-Cyano or 4-nitrobenzoyl chloride, AlCl3, nitrobenzene, 608C, 23–29%; b) ethyl benzoylacetate, rt, 28%; c) p-anisoyl chloride, AlCl3, nitrobenzene, 608C, 3 h, 16%; d) acetic anhydride,
sodium acetate, 1608C, 1 h, 86%; e) p-cyanobenzoyl chloride or p-nitrobenzoyl chloride, AlCl3, nitrobenzene, 608C, 3 h, 16%.
displays strong antibacterial activity. This suggests that
introducing a 6-benzoyl group to 4-phenylcoumarin has
a positive influence on antibacterial activity.
It has been found that the antibacterial activity of 6-acyl4-alkyl-5,7-dihydroxycoumarins decreases in the following sequence: 12 > 14 > 9 10 > 7 8 > 11 6 (i.e.,
cyclohexylacyl-4-ethyl > 6-benzoyl-4-ethyl > 6-propionyl4-ethyl acetyl-4-ethyl > 3-methyl-butyryl-4-ethyl phenylacetoyl-4-ethyl > 3,3-dimethyl-butyryl-4-ethyl 3methyl-butyryl-4-methyl).
The antibacterial activity of 4-phenyl-5,7-dihydroxycoumarins substituted in the benzene of the 6-benzoyl
group is not enhanced through the substitution of oCl, p-Br, p-CH3 or p-OH, and the antibacterial activity
ß 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
decreases in the following sequence: 15 > 17 > 18 > 16
(i.e., o-Cl > p-CH3 > p-OH > p-Br). In this study, substitutions with electron-attracting, electron-donating,
hydrophilic and lipophilic substituents on the benzene
of the 6-benzoyl group showed a decrease in bioactivity.
Comparing the bioactivities of compound 5 with compound 14 revealed that compounds with a 4-phenyl
group have a higher level of activity, suggesting that
the p-donor of the benzene makes a greater contribution
to the antibacterial activity than inductive electrondonating ethyl substituent on position 4 of the coumarin.
To conclude, serratin, a naturally occurring coumarin
showing antibacterial activity, is considered an essential
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Y.-P. Chin et al.
Arch. Pharm. Chem. Life Sci. 2011, 11, 386–393
Table 1. Antibacterial activity of coumarin derivatives 2–21 obtained from the standard dilution techniques of various compounds tested
against numerous bacteria.
Compound
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
E. coli
(ATCC 25922)
S. aureus
(ATCC 25923)
K. pneumonia
(ATCC 13883)
P. aeruginosa
(ATCC 27853)
S. typhimurium
(ATCC 14028)
640
>640
320
160
>640
>640
>640
>640
640
>640
640
>640
640
640
640
640
640
640
640
640
160
>640
>640
2.5
>640
>640
160
>640
>640
640
2.5
>640
80
20
>640
40
160
640
320
640
>640
640
>640
160
>640
>640
640
>640
>640
>640
320
>640
640
640
640
640
640
640
640
640
>640
>640
>640
160
640
>640
640
128
128
640
80
160
640
640
640
640
640
640
640
640
>640
640
640
320
>640
160
160
320
>640
>640
>640
640
640
640
640
640
640
640
640
640
Minimum inhibitory concentrations (MICs) are reported in mg/mL.
structure in synthetic coumarins. Twenty coumarins were
synthesized and evaluated for antibacterial activity against
EC, SA, KP, PA, and ST, to investigate their structure–activity
relationship (SAR). Of these twenty coumarins, compound 5
showed good selectivity against SA with very strong activity
(MIC ¼ 2.5 mg/mL). Compound 12 also showed very strong
activity (MIC ¼ 2.5 mg/mL) against SA as well as good activity
(MIC ¼ 80 mg/mL) against PA. This suggests that the cyclohexylacyl group contributed to action against SA and PA,
while the benzoyl group contributed to selectivity for SA.
Furthermore, compounds 15 and 17 designed from compound 5 displayed a lower level of bioactivity than compound
5, suggesting o-chloro- and p-methyl-substituents to the 6benzoyl group had a negative contribution on antibacterial
activity. Compounds 15 and 17 were tested against methicillin-resistant Staphyloccocus aureus (MRSA) (Table 2). Compound
15 also showed good activity against MRSA. In many of the
synthesized coumarins, the free 7-OH was found to be an
important contributor to the antibacterial activity [32].
Table 2. Minimum inhibitory concentrations (mg/mL) of coumarin
derivatives 15 and 17 were tested against meticillin-resistant
Staphylococcus aureus (MRSA).
Compound
15
17
S. aureus methicillin resistance
(ATCC 33591)
80
160
ß 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Further experiments regarding antibacterial mechanisms
of these 5,7-dihydroxycoumarins are under way.
Experimental chemistry
General
We measured the melting points in a capillary tube using a
MEL-TEMP II melting point apparatus produced by Laboratory
Devices. We also recorded the nuclear magnetic resonance
(NMR) spectra on Bruker DMX-500 FT-NMR spectrometers.
Similarly we recorded chemical shifts in parts per million
downfield from Me4Si. We determined the IR spectra with a
Perkin-Elmer 1760-X FT-IR spectrometer. We recorded mass
spectra on Jeol JMS-D300 and FINNIGAN TSQ-46C mass spectrometers and obtained high-resolution mass spectrometry
(HRMS) data with a Jeol JMS-HX110 spectrometer. We performed thin layer chromatography (TLC) on Merck (Art. 5715)
silica gel plates and visualized it under UV light (254 nm).
This was done upon treatment with iodine vapor or upon
heating after treatment with 5% phosphomolybdic acid in
ethanol. We also performed Flash column chromatography
with Merck (Art. 9385) 40–63 mm silica gel 60. We prepared
compound 2 abiding by a method reported in the literature
earlier [34].
General procedure for preparing acylphloroglucinols 23–28
Aluminum trichloride (48 mmol) was added to a suspension
of anhydrous phloroglucinol (22, 12 mmol) in nitrobenzene
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Arch. Pharm. Chem. Life Sci. 2011, 11, 386–393
(30 mL) and was stirred for 30 min at room temperature.
Then, acyl chloride (12 mmol) was added and the mixture
was heated to 608C for 2 h. We then allowed the reaction
mixture to cool to room temperature. Thereafter, the mixture was poured into ice water and extracted with ethyl
acetate. We could then extract the organic layer with 10%
NaOH(aq) and neutralized the alkaline layer with concentrated HCl followed by extraction with ethyl acetate. We then
washed the ethyl acetate extract with water and brine. We
dried (MgSO4), filtered, and evaporated the resulting mixture.
We then chromatographed (silica gel, EtOAc/n-hexane 1:5)
the residue to produce solid acylphloroglucinol.
Phenyl(2,4,6-trihydroxyphenyl)methanone 23
Benzoyl chloride (0.46 mL, 4.0 mmol) was the starting
material from which 23 (0.14 g, 15%) was obtained as a yellow
solid. 1H-NMR (500 MHz, DMSO-d6) d 5.83 (s, 2H), 7.42
(t, J ¼ 7.5 Hz, 2H), 7.52 (t, J ¼ 7.4 Hz, 1H), 7.60–7.61
(m, 2H), 9.83 (s, 1H), 10.08 (s, 2H).
Antibacterial Activities of 5,7-Dihydroxycoumarins
391
(4-Nitrophenyl)(2,4,6-trihydroxyphenyl)methanone 28
p-Nitrobenzoyl chloride (0.54 mL, 4.0 mmol) was the starting
material from which 28 (0.37 g, 36%) was obtained as a yellow
solid. 1H-NMR (500 MHz, DMSO-d6) d 5.84 (s, 2H), 7.77 (d,
J ¼ 8.5 Hz, 2H), 8.25 (d, J ¼ 8.5 Hz, 2H), 10.24 (s, 1H), 10.66
(s, 2H); 13C-NMR (125 MHz, DMSO-d6) d 94.65, 104.56, 123.27,
128.97, 146.29, 148.59, 161.22, 164.05, 195.37.
General procedure for preparing 5,7-dihydroxycoumarins
2, 14–20
Concentrated H2SO4 (0.2 mL) was added to a mixture of
acylphloroglucinol (1 mmol) and ethyl benzoylacetate or
ethyl propionylacetate (1.1 mmol) in glacial HOAc (3 mL)
and stirred for 2 h at room temperature. The obtained precipitate was filtered, washed with water, and crystallized
with MeOH to yield the final product.
5,7-Dihydroxy-4-phenyl-2H-chromen-2-one 2
o-Chlorobenzoyl chloride (0.50 mL, 4.0 mmol) was the starting material from which 24 (0.39 g, 37%) was obtained as a
yellow solid. 1H-NMR (500 MHz, DMSO-d6) d 5.76 (s, 2H), 7.27–
7.43 (m, 4H), 10.63 (s, 1H), 11.69 (s, 2H); 13C-NMR (125 MHz,
DMSO-d6) d 94.58, 104.04, 126.84, 127.01, 128.46, 128.70,
129.72, 142.39, 164.39, 166.55, 196.07.
22 (1.0 g, 7.9 mmol) and ethyl benzoylacetate (1.53 mL,
7.9 mmol) yielded in 2 (0.56 g, 28%), yellow solid. 1H-NMR
(500 MHz, DMSO-d6) d 5.73 (s, 1H), 6.15 (d, J ¼ 2.0 Hz, 2H), 6.25
(d, J ¼ 2.0 Hz, 2H), 7.30–7.36 (m, 5H), 10.10 (s, 1H), 10.38
(s, 2H); 13C-NMR (125 MHz, DMSO-d6) d 94.64, 99.11, 100.56,
110.15, 127.24, 127.38, 127.76, 139.56, 156.00, 156.75, 157.09,
159.89, 161.70; MS (EI, 70 eV) m/z 254 (Mþ), 226 (base
peak); HRMS (EI) calcd. for C15H10O4þ: 254.0574, found
254.0580.
(4-Bromophenyl)(2,4,6-trihydroxyphenyl)methanone 25
6-Benzoyl-4-ethyl-5,7-dihydroxy-2H-chromen-2-one 14
p-Bromobenzoyl chloride (0.90g, 4.0 mmol) was the starting
material from which 25 (0.45 g, 37%) was obtained as a yellow
solid. 1H-NMR (500 MHz, DMSO-d6) d 5.83 (s, 2H), 7.52
(d, J ¼ 8.5 Hz, 2H), 7.62 (d, J ¼ 8.5 Hz, 2H), 9.93 (s, 1H),
10.19 (s, 2H); 13C-NMR (125 MHz, DMSO-d6) d 94.61, 105.41,
125.64, 130.50, 131.22, 139.14, 159.74, 162.40, 195.58.
23 (0.14g, 0.6 mmol) and ethyl propionylacetate (8.3 mL,
0.6 mmol) gave compound 14 (0.05 g, 27%), yellow solid. IR
(neat) 3000–3500, 1667, 1608 cm1; 1H-NMR (500 MHz,
DMSO-d6) d 1.18 (t, 3H), 2.95 (q, 2H), 5.87 (s, 1H), 6.46
(s, 1H), 7.51 (m, 2H), 7.63 (m, 1H), 7.74 (m, 2H), 10.66
(s, 1H), 10.99 (s, 1H); 13C-NMR (125 MHz, DMSO-d6) d 13.88,
28.59, 98.95, 101.24, 107.39, 107.64, 128.87, 129.02, 133.65,
137.27, 153.64, 158.00, 159.48, 160.43, 192.70; MS (EI, 70 eV)
m/z 310 (Mþ), 309 (base peak); HRMS (EI) calcd. for C18H14O5þ:
310.0841, found 310.0850.
(2-Chlorophenyl)(2,4,6-trihydroxyphenyl)methanone 24
p-Tolyl(2,4,6-trihydroxyphenyl)methanone 26
p-Toluoyl chloride (0.54 mL, 4.0 mmol) was the starting
material from which 26 (0.37 g, 36%) was obtained as a yellow
solid. 1H-NMR (500 MHz, DMSO-d6) d 2.34 (s, 3H), 5.84 (s, 2H),
7.23 (d, J ¼ 7.9 Hz, 2H), 7.53 (d, J ¼ 7.9 Hz, 2H), 9.75 (s, 1H),
9.93 (s, 2H); 13C-NMR (125 MHz, DMSO-d6) d 21.09, 94.43,
106.12, 128.65, 128.83, 137.12, 142.21, 158.94, 161.38, 195.01.
4-(2,4,6-Trihydroxybenzoyl)benzonitrile 27
p-Cyanobenzoyl chloride (0.54 mL, 4.0 mmol) was the starting material from which 27 (0.37 g, 36%) was obtained as a
yellow solid. 1H-NMR (500 MHz, DMSO-d6) d 5.83 (s, 2H), 7.68
(d, J ¼ 8.2 Hz, 2H), 7.89 (d, J ¼ 8.2 Hz, 2H), 10.19 (s, 1H), 10.59
(s, 2H); 13C-NMR (125 MHz, DMSO-d6) d 95.75, 105.83, 114.35,
119.53, 129.47, 133.17, 145.13, 161.71, 164.37, 197.09.
ß 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
6-(2-Chlorobenzoyl)-5,7-dihydroxy-4-phenyl-2H-chromen2-one 15
24 (0.39g, 1.5 mmol) was the starting material from which 15
(0.24 g, 41%) was obtained as a yellow solid. Mp: 243–2448C;
IR (neat) 3000–3500, 1687, 1593 cm1; 1H-NMR (500 MHz,
DMSO-d6) d 5.80 (s, 1H), 6.24 (s, 1H), 7.32–7.45 (m, 6H),
7.52–7.57 (m, 3H), 10.97 (s, 1H), 11.47 (s, 1H); 13C-NMR
(125 MHz, DMSO-d6) d 98.78, 100.90, 106.89, 110.90, 127.31,
127.90, 130.03, 130.26, 130.43, 132.24, 139.05, 139.28, 155.38,
155.73, 158.36, 160.06, 161.91, 192.19; MS (EI, 70 eV) m/z 392
(Mþ), 357(base peak); HRMS (EI) calcd. for C22H13ClO5þ:
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Y.-P. Chin et al.
392.0446, found 392.0450;
394.0417, found 394.0427.
Arch. Pharm. Chem. Life Sci. 2011, 11, 386–393
calcd.
for
C22H1337ClO5þ:
6-(4-Bromobenzoyl)-5,7-dihydroxy-4-phenyl-2Hchromen-2-one 16
25 (0.45g, 1.5 mmol) was the starting material from which 16
(0.14 g, 22%) was obtained as a yellow solid. Mp: 273–2748C;
IR (neat) 3000–3500, 1703, 1604 cm1; 1H-NMR (500 MHz,
DMSO-d6) d 5.78 (s, 1H), 6.33 (s, 1H), 7.37 (m, 5H), 7.74 (m,
4H), 10.57 (s, 1H), 10.83 (s, 1H); 13C-NMR (125 MHz, DMSO-d6) d
98.82, 100.57, 106.76, 110.61, 127.36, 127.41, 127.86, 127.96,
131.03, 132.05, 136.42, 139.39, 153.77, 156.00, 157.94, 159.01,
159.07, 191.67; MS (EI, 70 eV) m/z 435 (Mþ, base peak); HRMS
(EI) calcd. for C22H13BrO5þ: 435.9931, found 435.9941.
5,7-Dihydroxy-6-(4-methylbenzoyl)-4-phenyl-2Hchromen-2-one 17
26 (0.36g, 1.5 mmol) was the starting material from which 17
(0.11 g, 29%) was obtained as a yellow solid. Mp: 265–2668C;
IR (neat) 3000–3500, 1706 cm1; 1H-NMR (500 MHz, DMSO-d6)
d 2.34 (s, 3H), 5.76 (s, 1H), 6.33 (s, 1H), 7.33–7.38 (m, 7H), 7.70
(d, J ¼ 8.1 Hz, 2H), 10.47 (s, 1H), 10.71 (s, 1H); 13C-NMR
(125 MHz, DMSO-d6) d 21.26, 98.79, 100.44, 107.55, 110.47,
127.33, 127.41, 127.91, 129.26, 129.44, 134.95, 139.45, 144.22,
153.55, 156.02, 157.50, 158.88, 159.12, 192.05; MS (EI, 70 eV)
m/z 372 (Mþ), 371 (base peak); HRMS (EI) calcd. for C23H16O5þ:
372.0992, found 372.0985.
5,7-Dihydroxy-6-(4-hydroxybenzoyl)-4-phenyl-2Hchromen-2-one 18
2 (0.56g, 2.2 mmol) was the starting material from which 18
(0.13 g, 16%) was obtained as a yellow solid. Mp: 266–2678C;
IR (neat) 3000–3500, 1683 cm1; 1H-NMR (500 MHz, DMSO-d6)
d 5.72 (s, 1H), 6.31 (s, 1H), 6.85 (d, J ¼ 8.1 Hz, 2H), 7.34–7.37
(m, 5H), 7.66 (d, J ¼ 8.1 Hz, 2H), 10.43 (s, 1H), 10.48 (s, 1H),
10.67 (s, 1H); 13C-NMR (125 MHz, DMSO-d6) d 98.86, 100.45,
107.98, 110.46, 127.36, 127.41, 127.86, 127.96, 131.03, 132.05,
136.42, 139.39, 153.77, 156.00, 157.94, 159.01, 159.07, 191.67;
MS (EI, 70 eV) m/z 374 (Mþ), 373 (base peak); HRMS (EI) calcd.
for C22H14O6þ: 374.0785, found 374.0776.
7-Hydroxy-2-oxo-4-phenyl-2H-chromen-5-yl 4cyanobenzoate 19
2 (0.50 g, 2.0 mmol) and p-cyanobenzoyl chloride (0.34 g,
2.0 mmol) reacted to form compound 19 (0.12 g, 15%), yellow
solid. Mp: 241–2428C; IR (neat) 3000–3500, 2228, 1738,
1703 cm1; 1H-NMR (500 MHz, DMSO-d6) d 5.95 (s, 1H), 6.67
(d, J ¼ 2.4 Hz, 1H), 6.80 (t, J ¼ 7.7 Hz, 1H), 6.82 (d, J ¼ 2.4 Hz,
1H), 7.06 (t, J ¼ 7.7 Hz, 2H), 7.21 (d, J ¼ 7.7 Hz, 2H), 7.59
(d, J ¼ 8.2 Hz, 2H), 7.83 (d, J ¼ 8.2 Hz, 1H), 11.06 (s, 1H);
13
C-NMR (125 MHz, DMSO-d6) d 101.48, 104.96, 108.49,
113.42, 115.70, 117.98, 126.85, 127.81, 128.07, 130.14,
ß 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
131.32, 132.02, 137.50, 148.16, 153.36, 155.94, 159.05,
161.18, 162.66; MS (EI, 70 eV) m/z 383 (Mþ), 130 (base peak);
HRMS (EI) calcd. for C23H13NO5þ: 383.0788, found 383.0793.
7-Hydroxy-2-oxo-4-phenyl-2H-chromen-5-yl 4nitrobenzoate 20
2 (0.92g, 3.6 mmol) and p-nitrobenzoyl chloride (0.68 mL,
3.6 mmol) gave compound 20 (0.24 g, 16%), yellow solid.
Mp: 260–2618C; IR (neat) 3000–3500, 1736, 1702 cm1; 1HNMR (500 MHz, DMSO-d6) d 5.96 (s, 1H), 6.70 (d, J ¼ 2.4 Hz,
1H), 6.80 (t, J ¼ 7.7 Hz, 1H), 6.83 (d, J ¼ 2.4 Hz, 1H), 7.06
(t, J ¼ 7.7 Hz, 2H), 7.22 (d, J ¼ 7.7 Hz, 2H), 7.71 (d,
J ¼ 8.2 Hz, 2H), 8.17 (d, J ¼ 8.2 Hz, 1H), 11.07 (s, 1H);
13
C-NMR (125 MHz, DMSO-d6) d 101.56, 104.98, 108.52,
113.46, 123.06, 126.90, 127.90, 126.85, 127.81, 128.07, 130.14,
131.32, 132.02, 137.50, 148.16, 153.36, 155.94, 159.05, 161.18,
162.66; MS (EI, 70 eV) m/z 403 (Mþ), 150 (base peak); HRMS (EI)
calcd. for C22H13NO7þ: 403.0687, found 403.0697.
2-Oxo-4-phenyl-2H-chromene-5,7-diyl diacetate 21
Initially, a mixture of 2 (0.2 g, 0.80 mmol) and sodium
acetate (19 mg, 0.24 mmol) in acetic anhydride (1.0 mL)
refluxed for 1 h, and then the reaction mixture cooled to
room temperature. The mixture was poured into water and
extracted with ethyl acetate. The ethyl acetate extract was
thereafter washed with water and brine, dried (MgSO4), filtered, and evaporated to give 21 (0.23 g, 86%) as white solid.
Mp: 184–1858C; IR (neat) 1772, 1734 cm1; 1H-NMR
(500 MHz, CDCl3) d 1.33 (s, 3H), 2.33 (s, 3H), 6.20 (s, 1H),
6.76 (d, J ¼ 2.4 Hz, 1H), 7.15 (d, J ¼ 2.4 Hz, 1H), 7.31–7.33
(m, 2H), 7.45–7.48 (m, 3H); 13C-NMR (125 MHz, CDCl3) d 19.44,
21.10, 108.72, 110.60, 113.62, 117.48, 127.66, 128.36, 128.73,
137.65, 147.85, 152.79, 153.00, 155.34, 159.29, 168.17, 168.61;
MS (EI, 70 eV) m/z 338 (Mþ), 226 (base peak); HRMS (EI) calcd.
for C19H14O6þ: 338.0790, found 338.0785.
Biological activity evaluation
General procedure for minimum inhibitory
concentration (MICs)
We used microtiter plates to determine the MICs for bacteria
of 2–21. A 2-fold serial dilution of the tested compound in
Mueller-Hinton broth or yeast nitrogen base with glucose
(YNBG) broth was added to the test organism. The microtiter
plates were then incubated for 16–20 h [39] and the test tubes
were capped at 378C for 48 h [40]. The tested bacteria grew in
Muller-Hinton broth for 4 h and were diluted to OD600 ¼ 0.1.
Microtiter plates thereafter were covered with a sterile lid
and incubated at 378C for 18–20 h. The MICs were determined by examining the wells for bacterial growth at
OD600. We found that growth was present in the medium
control and absent in the inoculum control [39]. The MIC
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Arch. Pharm. Chem. Life Sci. 2011, 11, 386–393
values were defined as the lowest drug concentration of the
agent that prevented the growth of the test organism.
This study was supported by the National Science Council, Taiwan (96–
2113-M-038–002). We are thankful to Sun, S.-Y., Instrumentation Center,
National Taiwan University, for assistance in MS Experiments.
The authors have declared no conflict of interest.
References
[1] G. J. Keating, R. O’Kennedy, The chemistry and occurrence
of coumarins, in Coumarins: biology, applications and mode of
action (Eds.: R. O’Kennedy, R. D. Thornes), Wiley, Chichester,
UK 1997, pp. 23–66.
[2] B. Musicki, A. M. Periers, P. Laurin, D. Ferroud, Y. Benedetti,
S. Lachaud, F. Chatreaux, J. L. Haesslein, A. Iltis, C. Pierre,
J. Khider, N. Tessot, M. Airault, J. Demassey, C. DupuisHamelin, P. Lassaigne, A. Bonnefoy, P. Vicat, M. Klich,
Bioorg. Med. Chem. Lett. 2000, 10, 1695.
[3] G. Appendino, E. Mercalli, N. Fuzzati, L. Arnoldi, M. Stavri,
S. Gibbons, M. Ballero, A. Maxia, J. Nat. Prod. 2004, 67, 2108.
[4] D. Yu, M. Suzuki, L. Xie, S. L. Morris-Natschke, K. H. Lee, Med.
Res. Rev. 2003, 23, 322.
[5] D. Egan, R. O’Kennedy, E. Moran, D. Cox, E. Prosser, R. D.
Thornes, Drug Metab. Rev. 1990, 22, 503.
[6] L. M. Wattenburg, L. K. T. Lam, A. V. Fladmoe, Cancer Res.
1979, 39, 1651.
[7] G. Feur, L. A. Kellen, K. Kovacs, Oncology 1976, 33, 35.
[8] U. S. Weber, B. Steffen, C. P. Siegers, Res. Commun. Mol. Pathol.
Pharmacol. 1998, 99, 193.
[9] A. Lorico, B. H. Long, Eur. J. Cancer 1993, 29A, 1985.
[10] K. C. Fylaktakidou, D. J. Hadjipavlou-Litina, K. E. Litnas, D. N.
Nicolaides, Curr. Pharm. Des. 2004, 10, 3813.
[11] C. H. Lin, C. W. Chang, C. C. Wang, M. S. Chang, L. L. Yang,
J. Pharm. Pharmacol. 2002, 54, 1271.
[12] A. Murakami, Y. Nakamura, T. Tanaka, K. Kawabata,
D. Takahashi, K. Koshimizu, H. Ohigashi, Carcinogenesis
2000, 21, 1843.
[13] C. C. Wang, J. E. Lai, L. G. Chen, K. Y. Yen, L. L. Yang, Bioorg.
Med. Chem. 2000, 8, 2701.
[14] A. M. Silvan, M. J. Abad, P. Bermejo, M. Sollhuber, A. Villar,
J. Nat. Prod. 1996, 59, 1183.
[15] P. I. Bauer, E. Kirsteen, G. Varadi, L. J. Young, A. Hakam, J. A.
Comstock, E. Kun, Biochemie 1995, 77, 374.
[16] M. Lee, M. C. Roldan, M. K. Haskell, S. R. McAdam, J. A.
Hartley, J. Med. Chem. 1994, 37, 1208.
ß 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Antibacterial Activities of 5,7-Dihydroxycoumarins
393
[17] L. Jurd, J. Corse, A. D. King, H. Bayne, K. Mihara,
Phytochemistry 1971, 10, 2971.
[18] L. Jurd, J. Corse, A. D. King, H. Bayne, K. Mihara,
Phytochemistry 1971, 10, 2965.
[19] M. C. Recio, J. L. Rios, A. Villar, Phytother. Res. 1989, 3,
117.
[20] T. Ojala, S. Remes, P. Haansuu, H. Vuorela, R. Hiltunen,
K. Haahtela, P. Vuorela, J. Ethnopharmacol. 2000, 73, 299.
[21] T. Smyth, V. N. Ramachandran, W. F. Smyth, Int. J. Antimicrob.
Agents 2009, 33, 421.
[22] S. Sardari, Y. Mori, K. Horita, R. G. Micetich, S. Nishibe,
M. Daneshtala, Bioorg. Med. Chem. 1999, 7, 1933.
[23] P. Laurin, M. Klich, C. Dupis-Hamelin, P. Mauvais,
P. Lassaigne, A. Bonnefoy, B. Musicki, Bioorg. Med. Chem.
Lett. 1999, 9, 2079.
[24] Z. Ivezic, M. Trkovnik, PCT Int. Appl., W02003029237, 2003,
p. 41.
[25] Y. Inoue, H. Kondo, M. Taguchi, Y. Jinbo, F. Sakamoto,
G. Tsukamoto, J. Med. Chem. 1994, 37, 586.
[26] A. M. Craciun, M. M. C. L. Groenen-van Dooren,
H. H. W. Thijssen, C. Vermeer, Biochim. Biophys. Acta 1998,
1380, 75.
[27] D. Zavrnsik, F. Basic, F. Becic, E. Becis, S. Jazic, Period. Biol.
2003, 105, 137.
[28] S. Moran, Crop Protect. 2001, 20, 529.
[29] V. S. V. Satyanarayana, P. Sreevani, A. Sivakumar, V.
Vijayakumar, ARKIVOC 2008, xvii, 221.
[30] B. Yang, J. Sutcliffe, C. J. Dutton, (Pfizer Inc, USA) US
5985912, 1999, Chem. Abstr. 1999, 131, 322536.
[31] K. B. Gudasi, M. S. Patil, R. S. Vadavi, Eur. J. Med. Chem. 2008,
43, 2436.
[32] A. Dini, E. Ramundo, P. Saturnino, A. Scimone, I.
Stagnod’Alcontres, Boll. Soc. Ital. Biol. Sperimentale 1992, 66,
453.
[33] A. Ulubelen, Phytochemistry 1982, 21, 1145.
[34] S. G. Cao, Helv. Chim. Acta 1998, 81, 1404.
[35] C. M. Lin, S. T. Huang, F. W. Lee, H. S. Kuo, M. H. Lin, Bioorg.
Med. Chem. 2006, 14, 4402.
[36] H. V. Pechmann, C. Duisberg, Ber. 1883, 16, 2119.
[37] A. G. Osborne, Tetrahedron 1981, 37, 2021.
[38] J. E. T. Corrie, J. Chem. Soc, Perkin Trans. 1990, 1, 2151.
[39] I. Phillips, J. D. Willians, R. Wise, in Laboratory Methods in
Antimicrobial Chemotherapy (Ed.: L. Garrod), Churchill
Livingston, Edinburgh 1978, p. 3.
[40] D. W. Warnock, in Medical Mycology: A Practical Approach (Eds.:
E. G. V. Evans, M. D. Richardson), Oxford University,
New York 1989, p. 235.
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