Studies on molecular properties prediction, antitubercular and antimicrobial activities of novel quinoline based pyrimidine motifs

Article abstract of DOI:10.1016/j.bmcl.2014.05.002

In the present study, a series of 3-((6-(2,6-dichloroquinolin-3-yl)-4-aryl- 1,6-dihydro-pyrimidin-2-yl)thio)propanenitriles 5a-o were synthesized and subjected to molecular properties prediction and drug-likeness model score by Molinspiration property calculation toolkit and MolSoft software, respectively. Compound 5m (4-OCH₃) was found to be maximum drug-likeness model score (0.42). Among the screened compounds, 5m showed the most promising antitubercular activity with MIC of 0.20 μg/mL, while compounds 5g, 5k and 5m displayed broad spectrum antibacterial activity against all the bacterial strains. Moreover, compound 5k was found to be the most potent antifungal agent. Further, the results of preliminary MTT cytotoxicity studies on HeLa cells suggested that potent antimicrobial activity of 5g, 5k and 5m was escorted by low cytotoxicity.

Full text of DOI:10.1016/j.bmcl.2014.05.002

Accepted Manuscript
Studies on molecular properties prediction, antitubercular and antimicrobial ac-
tivities of novel quinoline based pyrimidine motifs
N.C. Desai, G.M. Kotadiya, A.R. Trivedi
PII:
S0960-894X(14)00489-2
DOI:
http://dx.doi.org/10.1016/j.bmcl.2014.05.002
BMCL 21615
Reference:
Bioorganic & Medicinal Chemistry Letters
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2 May 2014
Please cite this article as: Desai, N.C., Kotadiya, G.M., Trivedi, A.R., Studies on molecular properties prediction,
antitubercular and antimicrobial activities of novel quinoline based pyrimidine motifs, Bioorganic & Medicinal
Chemistry Letters (2014), doi: http://dx.doi.org/10.1016/j.bmcl.2014.05.002
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Studies on molecular properties prediction, antitubercular and antimicrobial activities
of novel quinoline based pyrimidine motifs
N C Desai*, G M Kotadiya, A R Trivedi
Division of Medicinal Chemistry, Department of Chemistry,
(UGC NON-SAP & DST-FIST Sponsored),
Mahatma Gandhi Campus, Maharaja Krishnakumarsinhji Bhavnagar University,
Bhavnagar 364 002, Gujarat, India
E-mail: dnisheeth@rediffmail.com
Telefax: +91 278 2439852
Abstract
In the present study, a series of 3-((6-(2,6-dichloroquinolin-3-yl)-4-aryl-1,6-dihydro-
pyrimidin-2-yl)thio)propanenitriles 5a-o were synthesized and subjected to molecular
properties prediction and drug-likeness model score by Molinspiration property calculation
toolkit and MolSoft software, respectively. Compound 5m (4-OCH3) was found to be
maximum drug-likeness model score (0.42). Among the screened compounds, 5m showed
the most promising antitubercular activity with MIC of 0.20 µg/mL, while compounds 5g, 5k
and 5m displayed broad spectrum antibacterial activity against all the bacterial strains.
Moreover, compound 5k was found to be the most potent antifungal agent. Further, the
results of preliminary MTT cytotoxicity studies on HeLa cells suggested that potent
antimicrobial activity of 5g, 5k and 5m was escorted by low cytotoxicity.
Keywords: Antimicrobial; Antitubercular; Cytotoxicity; Lipinski ‘Rule of five’; Molecular
properties prediction;
1

The contributory driving force of tuberculosis (TB) is the pathogenic bacterium
Mycobacterium tuberculosis (Mtb).1 According to the global tuberculosis report 2013
published by World Health Organization (WHO), an estimated 8.6 million people developed
TB and 1.3 million died from the disease (including 320,000 deaths among HIV-positive
people) in 2012.2 Furthermore, emergence of new virulent forms of TB such as multi drug
resistant (MDR-TB) and extremely drug resistant (XDR-TB), and its synergy with human
immunodeficiency virus (HIV) has fuelled its epidemic nature.3,4 The development of
antimicrobial resistance contributes greatly to the challenges occurring in the discovery of
new therapies for combating life threatening infectious diseases.5 These reasons mould a
compelling case indicating an urgent need for novel and effective antimicrobial agents to
fight against the MDR infections.
It has been established that heterocyclic moieties play an essential role in designing
newer class of structural entities for medicinal applications. Among them, quinoline and its
derivatives are significant because of their diverse biological activities and their presence in
naturally occurring compounds. They are reported to possess antibiotic,6 antimalarial,7
anticancer,8 anti-inflammatory,9 antihypertensive,10 tyrokinase PDGF-RTK inhibition11 and
anti-HIV12 properties. Amongst the wide array of activities flaunted by quinoline derivatives,
antimicrobial activity is noteworthy. Quinoline derivatives have been reported to exhibit
substantial antitubercular activities and can be considered a promising area for the discovery
of new antitubercular agents.13-15 It is interesting to note that quinoline is a core
pharmacophore in the recently developed antitubercular drugs, viz. bedaquiline (TMC207), a
diarylquinoline,16 mefloquine,17,18 and moxifloxacin.19 Bedaquiline is the first drug with a
novel mechanism of action for TB in more than 40 years and the sole drug specifically
indicated for MDR-TB. It works via inhibition of enzyme adenosine triphosphate (ATP)
synthase, which is the energy source for the bacterium.16 On the other hand, pyrimidines
2

occupy a distinct and unique place in medicinal chemistry due to their presence in several
biologically active natural products.20 In view of wide spectrum biological activities such as
anti-allergic,21 antitumor,22 anti-inflammatory23 and antiparasitic24 activities, exhibited by
synthetic pyrimidine based scaffolds, a number of analogues have garnered considerable
amount of attention. In addition, pyrimidines are potential inhibitors of dihydrofolate
reductase (DHFR), a promising drug target for the development of anti-infective agents.
Although DHFR does not represent a novel target, there is still a large scope for the
development of DHFR inhibitors, particularly with respect to mycobacteria.25,26
Keeping this in view and in continuation of our endeavors towards the development
of anti-infective agents,27-29 it was envisaged that the design and synthesis of new prototypes
which include advantage of dual pharmacophores of quinoline and pyrimidine in single
molecular framework is worth the attempt. In addition, all the title compounds 5a-o were
exposed to molecular properties prediction and drug-likeness model score by Molinspiration
property calculation toolkit and MolSoft software in direction to filter the drugs for biological
screenings.
[Insert Scheme 1 here]
The fifteen new 3-((6-(2,6-dichloroquinolin-3-yl)-4-aryl-1,6-dihydropyrimidin-2-
yl)thio)propanenitriles 5a-o presented in this work were prepared through the synthetic route
illustrated in Scheme 1. The intermediate chalcones 3-(2,6-dichloroquinolin-3-yl)-1-
(aryl)prop-2-en-1-ones 3a-o were synthesized through the Claisen–Schmidt condensation of
equimolar amounts of acetophenone derivatives 2a-o and 2,6-dichloroquinoline-3-
carbaldehyde 1 in accordance with the method described in the literature.30 The starting 2,6-
dichloroquinoline-3-carbaldehyde 1 was furnished through reported method.31 Chalcones
3a-o underwent cyclization reaction with thiourea in ethanolic potassium hydroxide under
reflux condition to furnish quinolyl dihydropyrimidines identified as 6-(2,6-dichloroquinolin-
3

3-yl)-4-aryl-1,6-dihydropyrimidine-2-thiols 4a-o. The structures of intermediates 4a-o were
established by IR spectra which showed the characteristic absorption bands at 2555-2569 and
3306-3318 cm-1 for S-H and N-H stretching respectively, beside disappearance of carbonyl
group stretching due to its involvement in cyclization. 1H NMR spectrum showed besides the
expected aromatic signals, two singlets at δ 9.12-9.21, 11.25-1138 ppm and a doublet at δ
5.26-5.37 ppm for protons of NH, SH and the proton attached to asymmetric carbon
respectively. In the final step, intermediates 4a-o were treated with acrylonitrile in pyridine
followed by the neutralized with hydrochloric acid well-appointed the respective targeted 3-
((6-(2,6-dichloroquinolin-3-yl)-4-aryl-1,6-dihydropyrimidin-2-yl)thio)propanenitriles 5a-o.32
The structures of the final compounds 5a-o were established by IR spectrum which
displayed disappearance of S-H stretching in intermediates 4a-o. Moreover, absorption band
1
appearing between 2241-2254 cm-1 was assigned to CN group and its H NMR spectra
revealed two triplets at δ 3.09-3.17 and 3.22-3.34 ppm for methylene protons attached to
cyanide group and S atom respectively, along with the vanishing of SH group singlet.
Furthermore, 13C NMR spectrum of compound 5a as a representative example displayed,
besides the aromatic signals, four characteristic signals at δ 166.6, 119.2, 54.6 and 47.8 ppm
due to carbon of pyrimidine ring attached to S, cyanide group carbon and two methylene
carbons attached to cyanide group and S atom respectively. The mass spectrum of 5a showed
molecular ion peak at m/z = 438.07 [M+ 79%], in agreement with its proposed structure.
Similarly, the spectral values for all the compounds and their C, H, N analysis is presented in
the supplementary data.
[Insert Table 1 here]
In the development of drugs projected for oral use, good drug absorption and
appropriate drug delivery are very important.33 About 30% of oral drugs flop in development
4

due to poor pharmacokinetics.34 Among the pharmacokinetic properties, a low and highly
flexible bioavailability is definitely the main reason for stopping further development of the
drug.35 To qualify the compound as a drug candidate, the computed molecular properties are
shown in Table 1. Lipophilicity (miLogP), molecular weight (MW), number of rotatable
bonds (NROTB), number of hydrogen bond donors (HBD) and number of hydrogen bond
acceptors (HBA) of Lipinski’s rule of five36 were calculated using Molinspiration online
property calculation toolkit.37 The degree of absorption is expressed by the percentage of
absorption (%ABS) and is calculated by using %ABS = 109 - (0.345 × TPSA).38 Molecular
polar surface area (TPSA) is a very valuable parameter for the prediction of drug transport
properties.
Drug-likeness model score (a combined outcome of physicochemical properties,
pharmacokinetics and pharmacodynamics of a compound and is represented by a numerical
value) was computed by MolSoft39 software for the fifteen molecules under study. Computed
drug-likeness scores are presented in Table 1. Compounds having zero or negative value
should not be considered as drug-like candidate. Compounds 5l (3-OCH3) and 5m (4-OCH3)
possessed maximum drug-likeness score of 0.26 and 0.42.
[Insert Table 2 here]
All the compounds were initially screened for their in vitro antimycobacterial activity
against M. tuberculosis H37Rv strain by using Lowenstein-Jensen slope method exactly as
described previously.40 The results of the antitubercular studies are presented in Table 2.
Compounds exhibiting ≥90% inhibition in the initial screen were retested at lower
concentration (MIC) in Lowenstein-Jensen medium to determine the actual MIC. In the
preliminary screening, compounds 5g and 5j-m inhibited Mtb by 90-100%. In the secondary
level, compounds 5g and 5k inhibited Mtb with MIC of 3.12 µg/mL and compound 5m with
5

MIC of 0.20 µg/mL. Among all the screen compounds, compound 5m having 4-OCH3
substituent at the phenyl ring of pyrimidine substitution was found to be the most potent
compound of the series with MIC equivalent to the standard drug isoniazid. The preliminary
in vitro results provide an excellent lead for further development of these molecules as novel
antitubercular agents. It is interesting to note that substituents with electron donating groups
such as methoxy, methyl and hydroxy at para position of phenyl ring demonstrated high
inhibitory activity against Mtb as compared meta substituted derivatives, indicating that the
electronic properties of the substituents have major influence on the antimycobacterial
activity.
[Insert Table 3 here]
All the tested compounds were evaluated for their in vitro antibacterial and antifungal
activity (MIC) by conventional broth microdilution method.41 Bacterial strains
Staphylococcus aureus MTCC 96 and Streptococcus pyogenes MTCC 442 as Gram-positive,
Escherichia coli MTCC 443 and Pseudomonas aeruginosa MTCC 1688 as Gram-negative
and Candida albicans MTCC 227, Aspergillus niger MTCC 282 and Aspergillus clavatus
MTCC 1323 as fungal strains were used. Ciprofloxacin and Griseofulvin were used as
standard drugs. As indicated in Table 3, compounds 5g, 5k and 5m displayed broad spectrum
antibacterial activity against both gram-positive and gram-negative bacteria as compared with
ciprofloxacin. Compounds 5m and 5k were found to be 4-fold more active against S. aureus
and S. pyogens (MIC = 12.5 µg/mL) and compound 5g exhibited 2-fold more potency against
S. aureus and S. pyogens (MIC = 25 µg/mL) compared to the standard drug. While,
compound 5m showed equivalent activity against E. coli and P. aeruginosa and 2-fold more
activity against S. pyogens (MIC = 25 µg/mL). Moreover, compound 5k exhibited 2-fold
inhibition against S. aureus and equivalent inhibition against P. aeruginosa. As observed
6

with antitubercular activity, high antibacterial potency of 5g, 5k and 5m may be attributed to
the presence of electron donating substituents such as methoxy, methyl and hydroxy at 4th
position of phenyl ring of pyrimidine substitution. In comparison to the standard drug
griseofulvin, the in vitro antifungal activity results indicated that compound 5k substituted
with hydroxy group at 4th position of phenyl ring was found to be the most potent with 4 and
2-fold higher activity against A. niger, A. clavatus (MIC = 25 µg/mL) and C. albicans (MIC
= 250 µg/mL) respectively.
[Insert Table 4 here]
In vitro cytotoxicity of most active antitubercular and antimicrobial compounds 5g,
5k and 5m were evaluated against human cervical cancer cell line (HeLa) by MTT
colorimetric assay.42,43 The IC50 values obtained for these compounds are shown in Table 4.
As seen from Table 4, none of the tested compounds exhibited any significant cytotoxic
effect on HeLa cells, suggesting a great potential for their in vivo use as antimicrobial agents.
In summary, we have conveniently synthesized a novel series of quinoline bearing
pyrimidines and evaluated them for prediction of their molecular properties and drug-likeness
model score by different softwares in order to find suitable molecules for the antitubercular,
antimicrobial and cytotoxic activities with anticipation of generating new structural leads
serving as potent anti-infective agents. Among the screened compounds, compounds 5g, 5k
and 5m with electron donating group/atoms such as methoxy, methyl and hydroxy at fourth
position of phenyl ring attached to pyrimidine ring showed the most promising antitubercular
and antibacterial activity. While, compound 5k with electron donating hydroxyl group at
fourth position was identified as the most promising antifungal agent. The potent
antitubercular and antimicrobial activity of compounds 5g, 5k and 5m were accompanied
with relatively low level of cytotoxicity, which reflect their therapeutic potential for their
7

growth in the field of anti-infective agents. The work reported herein provides an insight into
the development of novel antimicrobial and antitubercular agents effective over a wide range
of pathogenic strains.
Acknowledgements
Authors are thankful to the University Grants Commission, New Delhi and
Department of Science & Technology, New Delhi for financial support under the NON-SAP
and DST-FIST programs respectively. Authors, G M Kotadiya and A R Trivedi are thankful
to UGC, New Delhi for providing ‘Research Fellowships in Science to Meritorious Students’
and ‘Dr. D. S. Kothari Post-Doctoral Fellowship’ respectively.
References
1. Zumla, A.; George, A.; Sharma, V.; Herbert, N.; Baroness Masham of, I. Lancet 2013,
382, 1765.
2. World Health Organization. Global Tuberculosis Report 2013 (WHO, 2013).
3. Lawn, S. D.; Mwaba, P.; Bates, M.; Piatek, A.; Alexander, H.; Marais, B. J.; Cuevas, L.
E.; McHugh, T. D.; Zijenah, L.; Kapata, N.; Abubakar, I.; McNerney, R.; Hoelscher, M.;
Memish, Z. A.; Migliori, G. B.; Kim, P.; Maeurer, M.; Schito, M.; Zumla, A. Lancet.
Infect. Dis. 2013, 13, 349.
4. Prabowo, S.; Gröschel, M.; Schmidt, E. L.; Skrahina, A.; Mihaescu, T.; Hastürk, S.;
Mitrofanov, R.; Pimkina, E.; Visontai, I.; Jong, B.; Stanford, J.; Cardona, P.-J.;
Kaufmann, S. E.; Werf, T. Med. Microbiol. Immunol. 2013, 202, 95.
5. O'Connell, K. M.; Hodgkinson, J. T.; Sore, H. F.; Welch, M.; Salmond, G. P.; Spring, D.
R. Angew. Chem. 2013.
6. Eswaran, S.; Adhikari, A. V.; Shetty, N. S. Eur. J. Med. Chem. 2009, 44, 4637.
7. Nasveld, P.; Kitchener, S. Trans. Royal Soc. Trop. Med. Hyg. 2005, 99, 2.
8

8. Denny, W. A.; Wilson, W. R.; Ware, D. C.; Atwell, G. J.; Milbank, J. B.; Stevenson, R. J.
U.S Patent, 7064117, 2006.
9. Leatham, P. A.; Bird, H. A.; Wright, V.; Seymour, D.; Gordon, A. Eur. J. Rheumatol.
Inflamm. 1983, 6, 209.
10. Muruganantham, N.; Sivakumar, R.; Anbalagan, N.; Gunasekaran, V.; Leonard, J. T.
Biol. Pharm. Bull. 2004, 27, 1683.
11. Maguire, M. P.; Sheets, K. R.; McVety, K.; Spada, A. P.; Zilberstein, A. J. Med. Chem.
1994, 37, 2129.
12. Trekowski, L.; Mokrosz, J. L.; Honkan, V. A.; Czarny, A.; Cegla, M. T.; Wydra, R. L.;
Patterson, S. E.; Schinazi, R. F. J. Med. Chem. 1991, 34, 1739.
13. de Souza, M. V.; Pais, K. C.; Kaiser, C. R.; Peralta, M. A.; de, L. F. M.; Lourenco, M. C.
Bioorg. Med. Chem. 2009, 17, 1474.
14. Candea, A. L.; Ferreira Mde, L.; Pais, K. C.; Cardoso, L. N.; Kaiser, C. R.; Henriques,
M.; Lourenco, M. C.; Bezerra, F. A.; de Souza, M. V. Bioorg. Med. Chem. Lett. 2009, 19,
6272.
15. Lilienkampf, A.; Mao, J.; Wan, B.; Wang, Y.; Franzblau, S. G.; Kozikowski, A. P. J.
Med. Chem. 2009, 52, 2109.
16. Rustomjee, R.; Diacon, A. H.; Allen, J.; Venter, A.; Reddy, C.; Patientia, R. F.; Mthiyane,
T. C.; De Marez, T.; van Heeswijk, R.; Kerstens, R.; Koul, A.; De Beule, K.; Donald, P.
R.; McNeeley, D. F. Antimicrob. Agents Chemother. 2008, 52, 2831.
17. Ayaprakash, S.; Iso, Y.; Wan, B.; Franzblau, S. G.; Kozikowski, A. P. Chem. Med. Chem.
2006, 1, 593.
18. Bermudez, L. E.; Kolonoski, P.; Seitz, L. E.; Petrofsky, M.; Reynolds, R.; Wu, M.;
Young, L. S. Antimicrob. Agents Chemother. 2004, 48, 3556.
19. Schluger, N. W. Am. J. Respir. Crit. Care Med. 2013, 188, 768.
9

20. Hurst, D. T. An Introduction to the Chemistry and Biochemistry of Pyrimidines, Purines
and Pteridines: John Wiley & Sons Australia, Limited, 1980.
21. Ban, M.; Taguchi, H.; Katsushima, T.; Aoki, S.; Watanabe, A. Bioorg. Med. Chem. 1998,
6, 1057.
22. Wright, G. E.; Gambino, J. J. J. Med. Chem. 1984, 27, 181.
23. Jalander, L. F.; Longquist, J. E. Heterocycles 1998, 48, 743.
24. Srivastava, S. K.; Agarwal, A.; Chauhan, P. M.; Agarwal, S. K.; Bhaduri, A. P.; Singh, S.
N.; Fatima, N.; Chatterjee, R. K. J. Med. Chem. 1999, 42, 1667.
25. Gerum, A. B.; Ulmer, J. E.; Jacobus, D. P.; Jensen, N. P.; Sherman, D. R.; Sibley, C. H.
Antimicrob. Agents Chemother. 2002, 46, 3362.
26. El-Hamamsy, M. H.; Smith, A. W.; Thompson, A. S.; Threadgill, M. D. Bioorg. Med.
Chem. 2007, 15, 4552.
27. Desai, N. C.; Bhatt, N.; Somani, H.; Trivedi, A. Eur. J. Med. Chem. 2013, 67, 54.
28. Desai, N. C.; Rajpara, K. M.; Joshi, V. V. Bioorg. Med. Chem. Lett. 2013, 23, 2714.
29. Desai, N. C.; Rajpara, K. M.; Joshi, V. V. Bioorg. Med. Chem. Lett. 2012, 22, 6871.
30. Shaharyar, M.; Abdullah, M. M.; Bakht, M. A.; Majeed, J. Eur. J. Med. Chem. 2010, 45,
114.
31. Ambika, S.; Singh, R. M. Ind. J. of Chem. 2005, 44B, 1868.
32. Abdelhamid, A. O.; Ismail, Z. H.; Gendy, M. S. E.,; Ghorab, M. M. Phosphorus Sulfur
Silicon 2007, 182, 2409.
33. Hou, T. J.; Xu, X. J. Curr. Pharm. Des. 2004, 10, 1011.
34. De Waterbeemd, H. V.; Gifford, E. Nat. Rev. Drug Discov. 2003, 2, 192.
35. Hou, T.; Wang, J.; Zhang, W.; Xu, X. J. Chem. Inf. Model. 2007, 47, 460.
36. Lipinski, C. A.; Lombardo, L.; Dominy, B. W.; Feeney, P. J. Adv. Drug Deliv. Rev. 2001,
46, 3.
10

37. Molinspiration Cheminformatics, Bratislava, Slovak Republic, Available from:
http://www.molinspiration.com/services/properties.html.
38. Zhao, Y. H.; Abraham, M. H.; Lee, J.; Hersey, A.; Luscombe, N. C.; Beck, G.;
Sherborne, B.; Cooper, I. Pharm. Res. 2002, 19, 1446.
39. Drug-likeness
and
molecular
property
prediction,
available
from:
http://www.molsoft.com/mprop/.
40. Kathrotiya, H. G.; Patel, M. P. Eur. J. Med. Chem. 2013, 63, 675.
41. Hannan, P. C. Vet. Res. 2000, 31, 373.
42. Mosmann, T. J. Immunol. 1983, 65, 55.
43. Alley, M. C.; Scudiero, D. A.; Monks, A.; Hursey, M. L.; Czerwinski, M. J.; Fine, D.L.;
Abbott, B. J.; Mayo, J. G.; Shoemaker, R. H.; Boyd, M. R. Cancer Res. 1988, 48, 589.
11

Captions
Scheme 1 Synthetic route for the preparation of title compounds 5a-o
Table 1 Drug likeness calculations and Lipinski parameters of compounds 5a-o
Table 2 In vitro antitubercular activity of compounds 5a-o against M. tuberculosis H37Rv
Table 3 Results of antibacterial and antifungal screening of compounds 5a-o
Table 4 Levels of cytotoxicity induced by selected compounds on HeLa cells
12

COCH3
R
O
Cl
CHO
Cl
Cl
Ethanol, KOH
Stirring, 24 h
+
R
N
N
Cl
3a-o
1
2a-o
Ethanol, KOH,
Reflux, 6 h,
NH2CSNH2
dil. CH3COOH,
CN
S
SH
N
HN
N
HN
H2C CH
CN
Cl
Cl
Pyridine, dil. HCl,
Reflux, 20 h
R
R
N
Cl
5a-o
N
Cl
4a-o
-R
-R
-R
5a
5b
5c
5d
5e
5f
5g
5h
5i
5k
5l
-H
-3-CH3
-4-CH3
-3-NO2
-4-NO2
-3-OH
-4-OH
-3-OCH3
-4-OCH3
-3-Br
-3-Cl
-4-Cl
-3-F
-4-F
5m
5n
5o
5j
-4-Br
Scheme 1
5a-o
. Synthetic route for the preparation of title compounds
13

Table 1 Drug likeness calculations and Lipinski parameters of compounds 5a-o
Entry
R
MWa
>500
Volumeb %ABSc TPSAd
NROTBe nONf nOHNHg milogPh nviolationsi
Drug-
likeness
model
score
Rule --
--
--
--
--
5
5
5
5
5
5
≥10
4
≥5
1
≥5.0
≥1
0
--
5a
5b
5c
5d
5e
5f
H
439.371 360.016 87.92
473.816 373.552 87.92
473.816 373.552 87.92
457.361 364.947 87.92
457.361 364.947 87.92
453.398 376.577 87.92
61.075
61.075
61.075
61.075
61.075
61.075
4.884
5.538
5.562
5.024
5.048
5.308
0.06
-0.02
0.07
-0.02
0.06
0.02
3-Cl
4-Cl
3-F
4-F
4
1
1
4
1
1
4
1
1
4
1
1
4
1
1
3-
CH3
5g
5h
5i
453.398 376.577 87.92
61.075
5
6
6
4
7
7
1
1
1
5.332
4.819
4.843
1
0
0
0.10
4-
CH3
3-
484.368 383.35
484.368 383.35
72.11
72.11
106.899
106.899
-0.31
-0.25
NO2
4-
NO2
5j
5k
5l
3-OH 455.37
4-OH 455.37
368.034 80.95
368.034 80.95
81.303
81.303
70.309
5
5
6
5
5
5
2
2
1
4.381
4.405
4.917
0
0
0
0.13
0.18
0.26
469.397 385.562 84.74
469.397 385.562 84.74
3-
OCH3
5m
70.309
6
5
1
4.941
0
0.42
4-
OCH3
5n
5o
3-Br
4-Br
518.267 377.902 87.92
518.267 377.902 87.92
61.075
61.075
5
5
4
4
1
1
5.669
5.693
2
2
-0.22
-0.14
14

a Molecular weight; b Molecular volume; c Percentage absorption; d Topological polar surface area; e Number of
rotatable bonds; f Number of hydrogen bond acceptors;
g Number of hydrogen bond donors; h Lipophilicity; i Number of violations.
15

Table 2 In vitro antitubercular activity of
compounds 5a-o against M. tuberculosis H37Rv
Entry
5a
% Inhibition
MIC (µg/mL)
62
62
42
41
69
81
98
38
56
98
99
97
99
66
58
99
--
5b
--
5c
--
5d
--
5e
--
5f
--
5g
3.12
--
5h
5i
--
5j
100
3.12
12.5
0.20
--
5k
5l
5m
5n
5o
--
Isoniazid
0.20
16

Table 3 Results of antibacterial and antifungal screening of compounds 5a-o
Minimum inhibitory concentration (MIC) µg/mL
Gram positive bacteriaa Gram negative bacteriab Fungic
Entry
-R
Sa
Sp
Ec
Pa
Ca
An
Ac
5a
5b
5c
5d
5e
5f
-H
100
250
250
125
500
100
25
250
500
500
250
500
100
25
500
1000
1000
500
1000
250
50
250
500
500
500
>1000
100
50
1000
>1000
>1000
1000
1000
1000
500
1000
500
500
>1000
1000
500
500
500
>1000
250
25
500
1000
1000
500
500
500
250
>1000
1000
250
25
-3-Cl
-4-Cl
-3-F
-4-F
-3-CH3
-4-CH3
-3-NO2
-4-NO2
-3-OH
-4-OH
-3-OCH3
-4-OCH3
-3-Br
5g
5h
5i
500
1000
100
25
1000
500
100
12.5
100
25
>1000
500
125
50
1000
1000
250
25
>1000
>1000
500
5j
5k
5l
250
50
100
25
250
25
500
500
250
500
1000
--
100
250
1000
500
--
5m
5n
5o
12.5
500
250
50
1000
>1000
500
1000
500
50
>1000
1000
25
1000
500
25
-4-Br
Ciprofloxacin
Griseofulvin
--
--
--
--
--
500
100
100
a Sa: Staphylococcus aureus MTCC 96; Sp: Staphylococcus pyogenes MTCC 442;
b Ec: Escherichia coli MTCC 443; Pa: Pseudomonas aeruginosa MTCC 1688;
c Ca: Candida albicans MTCC 227; An: Aspergillus niger MTCC 282; Ac: Aspergillus clavatus MTCC 1323.
17

Table 4 Levels of cytotoxicity induced by selected compounds on HeLa cells
Compounds
IC50 (µM)
94.20
>100
5g
5k
5m
>100
Doxorubicin
3.24
The known numbers of cells (1.0 × 104) were incubated for 24 h in a 5% CO2 incubator at 37 ºC in the presence
of different concentrations of test compounds. After 24 h of drug incubation the MTT solution was added and
supernatant was discarded and 100 ml DMSO was added in each well and absorbance was recorded at 540 nm
by ELISA reader.
18

19