Synthesis and antibiofilm activity of marine natural product-based 4-thiazolidinones derivatives

Article abstract of DOI:10.1016/j.bmcl.2012.09.073

4-Thiazolidinones derivatives of marine bromopyrrole alkaloids were synthesized as potential antibiofilm compounds. Among the synthesized compounds, some showed promising antibiofilm activity. Biological data revealed that 1,3-thiazolidin-4-one derivative

Full text of DOI:10.1016/j.bmcl.2012.09.073

Bioorganic & Medicinal Chemistry Letters 22 (2012) 7131–7134
Contents lists available at SciVerse ScienceDirect
Bioorganic & Medicinal Chemistry Letters
journal homepage: www.elsevier.com/locate/bmcl
Synthesis and antibiofilm activity of marine natural product-based
4-thiazolidinones derivatives
⇑
Rajesh A. Rane , Niteshkumar U. Sahu, Chetan P. Shah
S.P.P. School of Pharmacy and Technology Management, NMIMS University, Vile Parle, Mumbai 400056, India
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 24 July 2012
Revised 17 September 2012
Accepted 19 September 2012
Available online 3 October 2012
4-Thiazolidinones derivatives of marine bromopyrrole alkaloids were synthesized as potential antibio-
film compounds. Among the synthesized compounds, some showed promising antibiofilm activity. Bio-
logical data revealed that 1,3-thiazolidin-4-one derivatives are more potent antibiofilm agents compared
to 1,3-thiazinan-4-ones. Antibiofilm activity of compound 4b, 4c (MIC = 0.78
than standard vancomycin (MIC = 3.125 g/ml) while activity of compound 4d, 4f, 4g and 4h was 2-fold
(MIC = 1.56 g/ml) against Staphylococcus aureus biofilm. Compound 4b–4h showed equal antibiofilm
activity against Staphylococcus epidermidis compared to standard Vancomycin (MIC = 3.125 g/ml).
lg/ml) was 3-fold superior
l
l
Keywords:
l
Bromopyrrole alkaloids
4-Thiazolidinones
Antibiofilm agent
Ó 2012 Elsevier Ltd. All rights reserved.
Nosocomial infections occur worldwide, both in the developed
and developing world. They are a significant burden to patients
and public health. Coagulase-negative staphylococci and Staphylo-
coccus aureus have emerged as predominant cause of hospital ac-
quired infections and can induce a wide spectrum of diseases
associated with morbidity and mortality. Patients at risk include
those with prosthetic devices, intravascular catheters, or other for-
eign bodies in place, and immunocompromised hosts.1 On account
of the inevitable development of resistance, the discovery of new
antimicrobial agents active against not only planktonic bacteria
but also against biofilms that are intrinsically resistant to conven-
tional antibiotics represents an important task.2–5
One approach is to improve the activity of natural anti-micro-
bial substances by synthesis of analog compounds. For this reason,
we turned our attention to naturally produced organohalogens.6
Our interest in halogenated pyrrole derivatives led to synthesis
and antimicrobial evaluation of few analogues of pyoluteorin.7 In
continuation to this we found that bromopyrrole alkaloids; a fam-
ily of marine alkaloids represents a fascinating example of the large
variety of secondary metabolites formed by marine sponges. These
compounds are involved in the sponge’s defense mechanism
against fishes. Also, several pharmacologically important bromo-
pyrrole congeners have been previously described as having anti-
histaminic, antiserotonergic and antineoplastic activity. Further-
more, these natural products also possess antibacterial, antifungal
and anitibiofilm activity.8–10 Most of these compounds are defined
by the signature of bromopyrrole carboxamide with oroidin as
there prototype alkaloid reported for its antibiofilm activity.8
Structure–activity relationship performed on synthetic library of
oroidin derivatives indicated that N-methylation of the pyrrole
ring led to increased antibiofilm activity against medically relevant
Gram-negative
c-proteobacterium Pseudomonas aeruginosa, as
indicated by the most active member of the library, dihydrosven-
trin (DHS)11 (Fig. 1).
The structural and therapeutic diversity coupled with commer-
cial viability of small heterocyclic molecules has fascinated organic
and medicinal chemists. In recent years, 4-thiazolidinones are the
most extensively investigated class of compounds. 4-Thiazolidi-
nones have many interesting activity profiles namely COX-1 inhib-
itors,12 non-nucleoside inhibitors of HIV-RT,13 inhibitors of aldose
reductase,14,15 antidiabetic,16 inhibitors of the bacterial enzyme
MurB and YycG histidine kinase.17,18 Moreover derivatives of 4-
thiazolidinones have been reported for antitubercular, antifungal
and anthelmintic activities.19 Keeping this in a view, 4,5-dibromo-
pyrrole carboxamide moiety was incorporated in to 4-thiazolodi-
none and evaluated for antibiofilm activity. We also investigated
effect of replacement of five member 1,3-thiazolidin-4-one by six
member 1,3-thiazinan-4-one ring and systematic modification of
the substituent on the aromatic ring attached to 4-thiazolidinone
ring. (Fig. 1)
The target compounds were synthesized as illustrated in
Schemes 1 and 2. Trichloroacetylation of respective pyrroles gave
an excellent yield of 1.20 Compound 1 was brominated using bro-
mine in chloroform to give 2.21 Compound 2 was further converted
into corresponding hydrazides 3 by stirring with hydrazine hydrate
at room temperature (Scheme 1). The desired 1,3-thiazolidin-
4-ones /1,3-thiazinan-4-ones were synthesized in the quantitative
yield by one-pot condensation of amine, benzaldehyde, mercapto-
acetic/mercaptopropinoic acid in the ratio 1:2:3. Compound 3
⇑
Corresponding author. Tel.: +91 9224294690; fax: +91 22 26114512.
E-mail address: rajeshrane_uict@yahoo.co.in (R.A. Rane).
0960-894X/$ - see front matter Ó 2012 Elsevier Ltd. All rights reserved.
http://dx.doi.org/10.1016/j.bmcl.2012.09.073

7132
R. A. Rane et al. / Bioorg. Med. Chem. Lett. 22 (2012) 7131–7134
Br
Br
Br
Br
NH
N
H
Br
Br
N
H
O
NH
NH2
OH
O
N
oroidin
Pentabromopseudilin derivative
Pseudomonas aeruginosa biofilms
S. aureus(MIC) 0.005 µg/ml
PAO1 IC50 = 190 [µM]
II
I
Br
Br
Br
Br
H
H
N
H
N
N
NH
NH2
N
N
O
N
N
O
NH2
sventrin
Dihydrosventrin
Pseudomonas aeruginosa biofilms
Pseudomonas aeruginosa biofilms
PAO1 IC50 = 75 [µM]
PAO1 IC50 = 51 [µM]
III
IV
OCH3
O
N
O
O
S
COOH
HO
NH
N
N
O
F
N
S
Ar
N
H3CO
S
F
O
Antitubercular activity :
Antibiofilm activity:
S. epidermidis RP62A : 6.25 µg/ml
M. tuberculosis H37Rv: 0.12 µg/ml
Antibacterial activity againest
Bacillus subtilis and Escherichia coli
Ar = 4-bezyloxyphenyl-
V
VII
VI
Figure 1. Reported bromopyrrole alkaloids and 4-thiazolidinones with antibacterial and antibiofilm activity.
O
position of pyrrole ring resonates between d 6.6 and 6.4. The pro-
ton of substituted aryl ring resonates between 7.9 and 6.4.
CCl3
Cl3C
Cl
N
N
The newly prepared compounds were screened for their mini-
mal inhibitory concentration (MIC), minimal bactericidal concen-
tration (MBC) and antibiofilm concentration assay against
Staphylococcus epidermidis ATCC 12228, Staphylococcus aureus
ATCC29213 and Enterococcus faecalis ATCC 29212 bacterium using
a standard tube-dilution assay (Table 1). MIC assays for the anti-
bacterial activities of the compounds were performed according
to the broth microdilution (in tubes) method of the Clinical and
Laboratory Standards Institute (CLSI) of America.24 MBC of the
K2CO3
O
1
Br2
CHCl3
Br
Br
Br
Br
H2O
Ethanol
NH2NH2
H
N
CCl3
NH2
N
compounds was obtained by sub-culturing 100 ll from each nega-
N
2
O
O
tive (no visible bacterial growth) tube from the MIC assay, onto
substance-free Mueller–Hinton agar plates. The plates were incu-
bated at 37 °C for 24 h, and the MBC was defined as the lowest con-
centration of compounds which produced subcultures growing no
more than five colonies on each plate.
3
Scheme 1. Synthesis of 4,5-dibromo-1-methyl-1H-pyrrole-2-carbohydrazide.
was dissolved in THF and the reaction mixture was cooled to 0 °C,
the corresponding aldehyde was then added drop wise, followed
by mercaptoacetic acid/3-mercaptopropionic acid and 1.2 equiv
of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide, the reaction
mixture was then slowly warmed to room temperature and stirred
at room temperature for another 5–6 h (monitored by TLC for com-
pletion), it was then quenched with water and worked up to give
the desired 1,3-thiazolidin-4-one/1,3-thiazinan-4-one in quantita-
tive yield. (Scheme 2)22,23
In the antibiofilm concentration experiment, overnight culture
of bacterium (Staphylococcus aureus ATCC 29213/Staphylococcus
epidermidis ATCC 12228/Enterococcus faecalis ATCC 29212) was di-
luted 1:10 in TSB (OD 600 = 0.6–0.8), then was diluted 1:200 in
MH. The bacterial suspension was inoculated into the wells of ster-
ile 96-well polystyrene microtiter plates (Falcon) incubated at
37 °C for 6 h. The plates with young biofilm were washed gently
four times with sterile PBS before adding fresh TSB containing
the various concentration compounds, and incubated at 37 °C for
The spectral data (IR, 1H NMR and MS) of all synthesized com-
pounds were in agreement with the proposed structures. The MS of
all the compounds exhibited the (M+) as molecular ion peak, con-
firming the molecular weight. Presence of bromo was confirmed
with the presence of [M+2], [M+4] peaks in mass spectra. The 1H
16 h. The initiate dilution was 200
lM. For all assay standard used
was Vancomycin.25
The synthesized series of compounds showed promising activ-
ity against S. aureus, S. epidermidis and E. faecalis. As indicated in
Table 1, most of synthesized compounds generally showed potent
to moderate antibacterial and antibiofilm activity against activity
all tested gram-positive bacterium. Antibiofilm activity of
NMR spectra of all compounds showed single at
d 4.0–3.8
corresponding to N–CH3 attached to pyrrole core while the amide
N–H proton resonates between d 8.4 and 8.1. Proton at third
compound 4b and 4c (MIC = 0.78 lg/ml) was 3-fold superior to

R. A. Rane et al. / Bioorg. Med. Chem. Lett. 22 (2012) 7131–7134
7133
Br
Br
Br
OH
HS
H
N
Br
O
N
NH2
N
O
S
O
Ar-CHO
N
NH
Ar
O
EDC, THF
4b - 4-methoxyphenyl
4c - 4-nitrophenyl
4d - 2-hydroxy-4-methoxyphenyl
4e - 3-hydroxy-4-methoxyphenyl
4f - 2,5-dihydroxyphenyl
4g - 4-fluorophenyl
4a - phenyl
3
4
4h - 4-chlorophenyl
4i - cinnamyl
Br
Br
Br
Br
HS
OH
H
N
O
NH2
O
N
O
Ar-CHO
NH
Ar
N
N
O
EDC, THF
5a - phenyl
5b - 4-methoxyphenyl
5c - 4-nitrophenyl
S
5
3
5d - 2-hydroxy-4-methoxyphenyl
5e - 3-hydroxy-4-methoxyphenyl
5f - 2,5-dihydroxyphenyl
5g - 4-fluorophenyl
5h - 4-chlorophenyl
5i - cinnamyl
Scheme 2. Synthesis of 1,3-thiazolidin-4-one 4 and 1,3-thiazinan-4-one 5.
Table 1
Antibacterial and antibiofilm test results: (MIC
a,b
l
g/ml)
S. No.
Ar
S. aureus MBC S.epidermidis
E. faecalis
g/ MBC(MIC)
mL
S. aureus
g/ antibiofilm
concentration
S. epidermidis antibiofilm E. faecalis antibiofilm
(MIC)
lg/mL
MBC (MIC)
mL
l
l
concentration (lg/mL)
concentration (lg/mL)
(lg/mL)
4a
4b
4c
4d
Phenyl
6.25 (1.56)
6.25 (0.78)
6.25 (0.78)
6.25 (0.78)
6.25 (3.125)
3.125 (1.56)
6.25 (1.56)
3.125 (1.56)
25 (12.5)
25 (6.25)
25 (12.5)
25 (12.5)
3.125
0.78
0.78
1.56
12.5
12.5
6.25
12.5
12.5
4-Methoxyphenyl
4-Nitrophenyl
2-Hydroxy-4-
methoxyphenyl
3-Hydroxy-4-
methoxyphenyl
2,5-Dihydroxyphenyl
4-Fluorophenyl
4-Chlorophenyl
Cinnamyl
3.125
3.125
3.125
4e
6.25 (1.56)
6.25 (1.56)
12.5 (3.125)
3.125
3.125
12.5
4f
3.125 (0.78)
3.125 (0.78)
3.125 (0.78)
12.5 (6.25)
6.25 (12.5)
6.25 (3.125)
6.25 (3.125)
6.25 (3.125)
3.125 (1.56)
3.125 (1.56)
3.125 (1.56)
12.5 (25)
12.5 (6.25)
12.5 (6.25)
12.5 (6.25)
12.5 (6.25)
12.5 (6.25)
12.5 (3.12)
25 (12.5)
12.5 (25)
100 (50)
100 (50)
50(50)
1.56
1.56
1.56
6.125
12.5
6.25
3.125
3.125
3.125
6.25
12.5
12.5
12.5
12.5
12.5
6.25
25
25
25
25
4g
4h
4i
5a
5b
5c
5d
Phenyl
4-Methoxyphenyl
4-Nitrophenyl
2-Hydroxy-4-
methoxyphenyl
3-Hydroxy-4-
methoxyphenyl
2,5-Dihydroxyphenyl
4-Fluorophenyl
4-Chlorophenyl
Cinnamyl
6.25
6.25
12.5
12.5
50 (25)
5e
6.25 (3.125)
12.5 (6.25)
50 (25)
6.25
12.5
25
5f
5g
5h
12.5 (3.125)
12.5 (3.125)
12.5 (3.125)
50 (12.5)
12.5 (6.25)
12.5 (6.25)
12.5 (6.25)
12.5 (6.25)
3.125 (1.56)
50 (25)
50 (25)
50 (25)
50 (25)
6.25
6.25
6.25
25
3.125
12.5
12.5
12.5
25
25
25
25
50
5i
Standardc
3.125 (1.56)
6.25 (3.125)
3.125
3.125
a
b
c
The initiate dilution was 200 lM.
The MIC values are given in bracket and MBC out of bracket.
For all assay standard used was Vancomycin.
that of standard Vancomycin (MIC = 3.125
compound 4d, 4f, 4g and 4h was 2-fold (MIC = 1.56
of standard against S. aureus. Compound 4b–4h showed equal anti-
biofilm activity against S. epidermidis compared to standard Vanco-
l
g/ml) while activity of
g/ml) to that
ison to 5a–5i against all tested bacterial pathogens indicated that
replacement of five member 1,3-thiazolidin-4-one ring by six
member 1,3-thiazinan-4-one leads to decrease in antibacterial
and antibiofilm activity. Biological activities shown by derivatives
4i and 5i revealed that replacement of aryl ring by cinnamyl moi-
ety lead to decrease in antibacterial and antibiofilm activities.
In conclusion, 18 new 4-thiazolidinone derivatives of marine
bromopyrrole alkaloids were synthesized and evaluated for their
l
mycin (MIC = 3.125
(4a–4i) showed moderate antibiofilm activity against E. faecalis
(MIC = 6.25–12.5 g/ml) compared to standard Vancomycin. Better
antibiofilm and antibacterial activities shown by 4a–4i in compar-
lg/ml). All 1,3-thiazolidin-4-one derivatives
l

7134
R. A. Rane et al. / Bioorg. Med. Chem. Lett. 22 (2012) 7131–7134
5. Rodrigues, C.; Takita, M.; Coletta-Filho, H.; Olivato, J.; Caserta, R.; Machado, M.;
De Souza, A. Appl. Microbiol. Biotechnol. 2008, 77, 1145.
6. Gribble, G. W. Chemosphere 2003, 52, 289.
antibacterial and antibiofilm activity. The synthesized hybrids
showed promising activity against S. aureus and S. epidermidis.
Biological data revealed that 1,3-thiazolidin-4-one derivatives
are more potent antibiofilm agents in comparison to 1,3-thiaz-
inan-4-ones. Compound 4b–4h showed equal antibiofilm activity
against S. epidermidis compared to standard Vancomycin
7. Rane, R. A.; Telvekar, V. N. Bioorg. Med. Chem. Lett. 2010, 20, 5681.
8. Aiello, A.; Fattorusso, E.; Menna, M.; Taglialatela-Scafati, O. Modern Alkaloids
Structure, Isolation, Synthesis and Biology; Wiley-VCH, 2008, p. 271.
9. Tasdemir, D.; Topaloglu, B.; Perozzo, R.; Brun, R.; O’Neill, R.; Carballeira, N. M.;
Zhang, X.; Tonge, P. J.; Linden, A.; Ruedi, P. Bioorg. Med. Chem. 2007, 15, 6834.
10. Xiong, S.; Pang, H.; Fan, J.; Ge, F.; Yang, X.; Liu, Q.; Liao, X.; Xu, S. J. Pharmacol.
2010, 159, 909.
11. Richards, J.; Ballard, T.; Huigens, R.; Melander, C. ChemBioChem 2008, 9, 1267.
12. Look, G. C.; Schullek, J. R.; Homes, C. P.; Chinn, J. P.; Gordon, E. M.; Gallop, M. A.
Bioorg. Med. Chem. Lett. 1996, 6, 707.
13. Barreca, M. L.; Chimirri, A.; Luca, L. D.; Monforte, A.; Monforte, P.; Rao, A.;
Zappala, M.; Balzarini, J.; De Clercq, E.; Pannecouque, C.; Witvrouw, M. Bioorg.
Med. Chem. Lett. 2001, 11, 1793.
14. Maccari, R.; Corso, A. D.; Giglio, M.; Moschini, R.; Mura, U.; Ottana, R. Bioorg.
Med. Chem. Lett. 2011, 21, 200.
(MIC = 3.125
low as 0.78
l
g/ml). The antibiofilm activity at concentrations as
lg/ml shown by compounds 4b and 4c and 1.56 g/
l
ml by compound 4d, 4f, 4g and 4h against S. aureus indicates that
these compounds can act as leads for development of newer anti-
biofilm agent. Further studies on these compounds and optimiza-
tion of their structures leading to novel analogues with superior
biological properties are ongoing in our laboratories.
15. Ottana, A.; Maccari, R.; Giglio, M.; Corso, A. D.; Cappiello, M.; Mura, U.;
Cosconati, S.; Marinelli, M.; Novellino, E.; Sartini, S.; La-Motta, C.; Settimo, F. D.
Eur. J. Med. Chem. 2011, 46, 2797.
Acknowldgement
16. Kini, D.; Ghate, M. Eur. J. Chem. 2011, 8, 386.
RAR thanks Professor R. S. Gaud and Professor Anil Thaker for
providing facility to carry out these experiments.
17. Anders, C. J.; Bronson, J. J.; D’Andrea, S. V.; Deshpande, S. M.; Falk, P. J.; Grant-
Young, K. A.; Harte, W. E.; Ho, H.; Misco, P. F.; Robertson, J. G.; Stock, D.; Sun, Y.;
Walsh, A. W. Bioorg. Med. Chem. Lett. 2000, 10, 715.
18. Schreiber, M.; Res, J.; Matter, A. Curr. Opin. Cell Biol. 2009, 21, 325.
19. Jain, A. K.; Vaidya, A.; Ravichandran, V.; Kashaw, S. K.; Agrawal, R. K. Bioorg.
Med. Chem. 2012, 20, 3378.
20. Bailey, D. M.; Johnson, R. E.; Salvador, J. U. J. Med. Chem. 1973, 16, 1298.
21. Linington, R. G.; Williams, D. E.; Tahir, A.; Soest, R.; Andersen, R. J. Org. Lett.
2003, 5, 2735.
22. Srivastava, T.; Haq, W.; Katti, S. B. Tetrahedron 2002, 58, 7619.
23. Ramani, A. V.; Monika, A.; Indira, V. L.; Karyavardhi, G.; Venkatesh, J.;
Jeankumar, V. U.; Manjashetty, T. H.; Yogeeswari, P.; Sriram, D. Bioorg. Med.
Chem. Lett. 2012, 22, 2764.
Supplementary data
Supplementary data associated with this article can be found, in
the online version, at http://dx.doi.org/10.1016/j.bmcl.2012.
09.073.
References and notes
24. Methods for Dilution Antimicrobial Susceptibility Tests for Bacteria That Grow
Aerobically; Approved Standard, M7-A7, 7th ed.; Wayne, PA, USA, 2006; p 26.
25. Pan, B.; Huang, R.; Han, S.; Qu, D.; Zhu, M.; Wei, P.; Ying, H. Bioorg. Med. Chem.
Lett. 2010, 20, 2461.
1. Costerton, J. W.; Lewandowski, Z.; Caldwell, D. E.; Korber, D. R.; Lappinscott, H.
M. Annu. Rev. Microbiol. 1995, 49, 711.
2. Beech, I. B.; Sunner, J. A.; Hiraoka, K. Int. Microbiol. 2005, 8, 157.
3. Flemming, H. C.; Griebe, T.; Schaule, G. Water Sci. Technol. 1996, 34, 517.
4. Lahtinen, T.; Kosonen, M.; Tiirola, M.; Vuento, M.; Oker-Blom, C. J. Ind.
Microbiol. Biotechnol. 2006, 33, 734.