Design, synthesis and molecular docking studies of quinazolin-4-ones linked to 1,2,3-triazol hybrids as Mycobacterium tuberculosis H37Rv inhibitors besides antimicrobial activity

Article abstract of DOI:10.1007/s00044-019-02313-9

Quinazolin-4-ones linked to 1,2,3-triazol (10) were identified as inhibitors of the bisphosphonate BPH-700 transcriptional factor from a high throughput screen. A series of 1,4-disubstituted triazoles (10a–j) were synthesized by the Cu-catalyzed azide-alkyne cyclo addition of 5-methoxy-2-nitro-4-(prop-2-yn-1-yloxy) benzamide (6) with various substituted azido benzenes (7) in the presence of CuSO₄ under aerobic conditions followed by click reaction with substituted aldehydes. The target compounds were screened for antitubercular activity against Mycobacterium tuberculosis H₃₇Rv by Broth micro dilution method using Lowenstein Jensen medium (LJ) (MIC < 9 μg/mL). Majority of the compounds 10b, 10d, 10e, 10i and 10j displayed good antitubercular activity with MIC 7–11 μg/mL. Further, 10e exhibited a promising inhibition with MIC 7 μg/mL, compared to the reference drug Rifampicin. Docking studies have been performed to understand the interactions between the synthesized compounds and the active site of pantothenate synthetase Mycobacterium tuberculosis H₃₇Rv organism. The study revealed that the target compounds showed good affinity toward the protein when compared to the standard drug Pefloxacin. Further, 10b was found to interact with three amino acids, viz., Gln92, Arg200, Ser196, as evidenced by the large interaction energy (ΔG = ?8.16 kcal/mol). Besides the above, the synthesized quinazolinone triazoles 10a–j were evaluated for their antibacterial activities against a panel of Gram +ve and Gram –ve bacteria. Among them 10a, 10e, 10 h and 10j showed promising broad spectrum antibacterial activity with inhibition in the range of 19–33-mm diameter of inhibition zone (DIZ).

Full text of DOI:10.1007/s00044-019-02313-9

MEDICINAL
CHEMISTRY
RESEARCH
Medicinal Chemistry Research
https://doi.org/10.1007/s00044-019-02313-9
ORIGINAL RESEARCH
Design, synthesis and molecular docking studies of quinazolin-4-
ones linked to 1,2,3-triazol hybrids as Mycobacterium tuberculosis
H Rv inhibitors besides antimicrobial activity
3
7
1
,2 ●
1 ●
3 ●
2 ●
2 ●
Narendra Kumar Maddali
I. V. Kasi Viswanath* Y. L. N. Murthy*
Rabin Bera Mohamed Takhi
3 ●
3
Nethinti Sundara Rao Vanajakshi Gudla
Received: 23 August 2018 / Accepted: 7 February 2019
©
Springer Science+Business Media, LLC, part of Springer Nature 2019
Abstract
Quinazolin-4-ones linked to 1,2,3-triazol (10) were identified as inhibitors of the bisphosphonate BPH-700 transcriptional
factor from a high throughput screen. A series of 1,4-disubstituted triazoles (10a–j) were synthesized by the Cu-catalyzed
azide-alkyne cyclo addition of 5-methoxy-2-nitro-4-(prop-2-yn-1-yloxy) benzamide (6) with various substituted azido
benzenes (7) in the presence of CuSO under aerobic conditions followed by click reaction with substituted aldehydes. The
4
target compounds were screened for antitubercular activity against Mycobacterium tuberculosis H Rv by Broth micro
3
7
dilution method using Lowenstein Jensen medium (LJ) (MIC < 9 μg/mL). Majority of the compounds 10b, 10d, 10e, 10i and
0j displayed good antitubercular activity with MIC 7–11 μg/mL. Further, 10e exhibited a promising inhibition with MIC 7
1
μg/mL, compared to the reference drug Rifampicin. Docking studies have been performed to understand the interactions
between the synthesized compounds and the active site of pantothenate synthetase Mycobacterium tuberculosis H Rv
37
organism. The study revealed that the target compounds showed good affinity toward the protein when compared to the
standard drug Pefloxacin. Further, 10b was found to interact with three amino acids, viz., Gln92, Arg200, Ser196, as
evidenced by the large interaction energy (ΔG = −8.16 kcal/mol). Besides the above, the synthesized quinazolinone
triazoles 10a–j were evaluated for their antibacterial activities against a panel of Gram +ve and Gram –ve bacteria. Among
them 10a, 10e, 10 h and 10j showed promising broad spectrum antibacterial activity with inhibition in the range of 19–33-
mm diameter of inhibition zone (DIZ).
●
●
●
●
●
Keywords 1,2,3-Triazoles Quinazolinones Antibacterial activity Docking studies Mycobacterium tuberculosis H Rv
37
Pantothenate synthetase (3IVX)
Introduction
Heterocyclic structures are the basic elements of many
pharmaceuticals, agrochemicals and veterinary products.
Quinazolinones are a big family of heterocyclic compounds,
which have been shown to display a broad range of biolo-
gical activity profiles (Jhone 1982), for example, antispasm
(Jatav et al. 2008), anticancer (Murugan et al. 2003),
analgesic activity (Jones et al. 1997), antiviral (Desai et al.
Supplementary information The online version of this article (https://
doi.org/10.1007/s00044-019-02313-9) contains supplementary
material, which is available to authorized users.
*
Y. L. N. Murthy*
murthyyln@gmail.com
1
Department of Chemistry, Koneru Lakshmaiah Education
Foundation (KLEF), Green Fields, Vaddeswaram, Guntur, Andhra
Pradesh 522502, India
1998), anti-inflammatory (Alagarsamy et al. 2003), antic-
ytotoxin (Chandrika et al. 2009), antituberculosis (Viswa-
nadh et al. 2018; Pattan et al. 2006), antibacterial (Nanda
et al. 2007), antifungal (Nagarajan and Kavimani 2010),
antioxidant (Saravanan et al. 2010), antihypertension (Hess
et al. 1968), antiobesity (Sasmal et al. 2012), antipsychotic
(Alvarado et al. 2006), antimalarial (Lakhan and Singh
2
3
United States Pharmacopeia India Pvt. Ltd., IKP Knowledge Park,
Genome valley, Shamirpet, Turkapally village, Medchal District,
Hyderabad, Telangana 500101, India
Department of Organic Chemistry, Andhra University,
Visakhapatnam, Andhra Pradesh 530003, India

Medicinal Chemistry Research
Molecular docking studies were performed at the active
site of pantothenate synthetase protein to study the inter-
action modes of the synthesized compounds. The results of
invitro and insilico studies clearly indicate that quinazoli-
nones containing 1,2,3-triazoles may serve as a potential
new drug candidate in the combat against PDB code, 3IVX
Mycobacterium tuberculosis H Rv organism. Based on the
3
7
literature, we describe how the template was modified to
improve its biological activity resulting in a series of novel
6
-methoxyquinazolin-4(3H)-one-7-substituted-1,2,3-
triazoles.
The present work is of three-fold: (a) to synthesize a
Fig. 1 Design of new hybrid molecules
series of novel antibacterial/antitubercular agents based on
7-((1H-1,2,3-triazol-4-yl) methoxy)-6-methoxyquinazolin-4
(3H)-one framework, (b) biological screening of the syn-
thesized compounds and (c) docking studies to understand
the interactions of compounds with the active site of the
protein.
1
988), antidiabetes (Malamas and Millen 1991), etc. Fur-
thermore, quinazolinones are most common heterocyclic
core in medicinal chemistry research and act as the potent
tyr Pattansine kinase and cellular phosphorylation inhibitors
(
(
Ouyang et al. 2006) various neurodegenerative disorders
Fry et al. 1994) bacterial carbonic anhydrases in patho-
genesis (Elkamhawy et al. 2014) fluorescence for cysteine
Alafeefy et al. 2014) and chemodosimeter for NO (Anand
et al. 2014) used as ligands for benzodiazepine and GABA
receptors in the central nervous system (CNS) (Colotta et al.
(
Results and discussions
Synthesis of the target compounds 10a–j
2
006) or as DNA binders (Doyle and Ross 2003). The
quinazolinone skeleton is present in a variety of biologically
active compounds, among these are several marketed drugs
like Afloqualone, Cloroqualone and Diproqualone (Tiwary
et al. 2015; Arora et al. 2011), and many compounds are in
the development phase as potential new drugs acting against
different targets.
Esterification of vanillic acid (1) using MeOH resulted in
the formation of 4-hydroxy-3-methoxy methylbenzoate (2),
which was treated with propargyl bromide and K CO to
2
3
obtain the required methyl 3-methoxy-4-(prop-2-yn-1-
yloxy) benzoate (3), and followed by nitration gave the
corresponding nitro ester 4 in good yield. The compound 5
formed by base hydrolysis of 4 and further treatment of 5 in
the presence of SOCl , THF and aq. NH at room tem-
1
,2,3-Triazole ring system has found a broad spectrum
of applications in the field of medicinal chemistry due to
some unique features like hydrogen bond formation,
dipole–dipole and π–π stacking interactions, stable to
oxidation/reduction and stable to hydrolysis under acidic/
basic conditions (Mohammed et al. 2015). An exploration
of new and potential antibacterial agents is indispensable
as the problem of multidrug-resistant microorganisms has
reached a disturbing level. Incorporation of heterocycles
and 1,2,3-triazole moiety as well in a single molecular
entity is the current approach for making interesting novel
bioactive molecules (Kumar et al. 2009; Majumdar et al.
2
3
perature (RT) to obtain 5-methoxy-2-nitro-4-(prop-2-yn-1-
yloxy)benzamide (6). To synthesize the precursor molecule
8, which contains 2,3-dihydro-1-benzoxepine and 1,2,3-
triazole pharmacophores, we have decided to explore cop-
per sulfate pentahydrate catalyzed reaction between azides 7
(a–j) and 6 to obtain the desired product 8(a–j) in good
yields. A suitable precursor for the synthesis of target
hybrid molecules 10(a–j), herein, we demonstrate a clean
and convenient click reaction between the electronically
divergent triazole compounds 5-methoxy-2-nitro-4-((1-
phenyl-1H-1,2,3-triazol-4-yl)methoxy)benzamide (8a–j),
substituted aldehydes (9a–j)) in the presence of sodium
dithionite in dimethyl sulfoxide (DMSO) solvent to give the
corresponding target molecules (10a–j) in good yields
(Scheme 1).
2
013; Suresh et al. 2017). This can produce a range of
densely functionalized small molecules required by
researchers working in the area of medicinal and phar-
maceutical chemistry/drug discovery. In this context, we
anticipated that integration of three basic groups can be
selected for the design, synthesis and structure activity
relationship (SAR) studies: quinazolinone core, sub-
stituted phenyl groups and substituted 1,2,3-triazole
moiety (Fig. 1) for the generation of small molecules as
potential antibacterial agents.
After thorough characterization of the synthesized
molecules, the main aim of these investigations is to
examine the anticancer activity to find a potent molecule.
Herein, we present the (i) antituberculosis activity followed
by (ii) antimicrobial activity in detail.

Medicinal Chemistry Research
Scheme 1 Synthesis of novel quinazolinone-1,2,3-triazole analogs
2 h, (b) aq. NH3, THF, 0 °C to RT, 85%; (vi) CuSO4·5H2O (10 mol),
sodium ascorbate (10 mol), tert. butanol, water, RT; (vii) 8 (1 mmol),
Na2S2O4 (2 mmol), DMSO (5 mL), 100 °C
1
0a–j. (i) MeOH, conc. H2SO4, reflux, 8 h, 95%; (ii) propargyl bro-
mide, K2CO3, acetone, reflux, 6 h, 85%; (iii) conc. HNO3, −5 °C,
0%; (iv) THF:H O, 10% NaOH, 6 h, RT, 95%; (v) (a) SOCl , reflux,
9
2
2

Medicinal Chemistry Research
Table 1 Minimum inhibitory concentration (MIC) data for the anti-
mycobacterial activity of target compounds (10a–j) obtained by micro
dilution method toward MTB H Rv clinical isolate of MTB
SAR studies
37
Anti-mycobacterial study
Compound
4 µg/mL
5th day
8 µg/mL
15th day
1
21st day
21st day
The integration of three basic groups selected for the design,
synthesis and SAR studies are: quinazolinone core, sub-
stitution on phenyl groups and substitution on 1,2,3-triazole
moiety. Observation of Table 1 (anti-TB investigations): It
is clear that compound 10e having electron-donating groups
on the phenyl rings exhibit potent activity followed by 10b,
1
1
1
1
1
1
1
1
1
1
0a
0b
0c
NA
9
NA
9
NA
9
NA
9
NA
9
NA
9
NA
9
NA
9
0d
0e
7
7
7
7
10d and 10j. Increase of concentrations does not enhance
0 f
0 g
0 h
0i
NA
16
10
11
9
NA
16
10
11
9
NA
16
17
11
18
1.5
NA
16
17
11
18
1.5
the activity.
Molecular docking studies
0j
The three-dimensional crystal structure of pantothenate
synthetase complexed with 2-(2-(benzofuran-2-ylsulfo-
Rifampicin
0.10
0.10
nylcarbamoyl)-5-methoxy-1H-indol-1-yl)acetic
acid
NA not active toward TB isolates
(
3IVX) has been retrieved from protein data bank (Hung
et al. 2009). All the synthesized compounds were docked
against pantothenate synthetase protein by using Auto-
dock 4.2 software (Morris et al. 2009). The docking score,
H-bond interactions and Van der Waal forces were esti-
mated for all the synthesized compounds used in this
study (green color lines). Binding energies were mea-
sured; they consist of Van der Waals forces, hydrogen
bonding, π–π interactions, cation–π interactions, etc. For
each ligand, the docking score in terms of interaction
energy was calculated and is presented in Table 2 along
with the interacting amino acids. The generalized struc-
ture of 3IVX along with the docking ligand is shown in
Antituberculosis activity
The anti-mycobacterium activity of the synthesized com-
pounds was evaluated at different concentrations and at
different time intervals and minimum inhibitory con-
centrations (MICs) were investigated and are presented in
Table 1. The readings were obtained at different intervals to
check the activity against mycobacteria that inhibit the
growth. Thus, all the compounds have the capability to
inhibit the mycobacteria at different concentrations and
Rifampicin was taken as standard/control. H Rv showed
37
no growth in the tubes, whereas in the multidrug-resistant
MDR) strain inoculated tube, it showed visible growth
Table 2 Docking scores (ΔG°, kcal/mol) and the dissociation constant
(
(KI, µM) of all the synthesized compounds 10a–10j with pantothenate
pattern. The MIC values of selected compounds BTDHA-
Ni, BTDHA-Cu, BTDHA-Pd, BDHA-Hg, were determined
for M. tuberculosis H Rv and drug-resistant clinical sample
synthetase protein (3IVX)
Ligands Interacting amino Binding
Dissociation
37
acids
energy ΔG°
kcal/mol)
constant KI (µM)
of M. tuberculosis using broth micro dilution method in
Middlebrook 7H9 medium supplemented with Oleic
Albumin Dextrose Catalase (OADC). The compounds were
tested at the concentrations of 4 and 8 µg/mL. All the
compounds exhibited >90% growth inhibition at the con-
centration of 4–8 µg/mL for 15 and 21 days, respectively.
The screening of the synthesized compounds 10a–j
against TB revealed that some of the compounds exhibited
moderate to good inhibitory activity as it was evident from
their MIC values, and the results are presented in Table 1.
Compounds 10b, 10e and 10j show prominent activity,
compared to other synthesized compounds. The most active
inhibitor of tuberculosis, compound 10e, showed an MIC
value of 7 μg/mL. The data obtained may be useful for the
design of novel anti-TB drugs with the skeleton of quina-
zolinone–triazoles hybrids.
(
1
1
0a
0b
−
−7.13
−8.16
5.96
1.01
Gln92, Ser196,
Arg200
1
1
1
1
1
1
0c
Arg200
Arg200
Arg200
Arg200
Arg200
−7.54
−7.59
−7.11
−7.05
−7.14
−5.95
2.97
2.72
6.14
6.78
5.87
43.33
0d
0e
0 f
0 g
0 h
Gln92, Arg200,
Arg207
1
1
0i
0j
Glu45, Glu189,
Asn199, Arg200
−7.10
6.26
Gln92, Arg200
−8.11
−7.12
1.14
6.15
Pefloxacin Ser196, Arg200

Medicinal Chemistry Research
Fig. 2 Generalized structure of pantothenate synthetase protein (3IVX) along with the docked ligand a and zoomed protein structure with docked
ligand 10b (Fig. 2c)
Fig. 2a. From the data, it is observed that except 10a (the
interaction energy of −7.13 kcal/mol present in Table 2
may be due to the Van der Waal forces and π–π stacking
interactions), all other synthesized compounds showed
strong interaction energies and Arg200 as a common
interacting amino acid. Compounds 10c–10g showed
interaction energies with Arg200 in between −7.05 and
Arg200 and has the binding energy of −7.10 kcal/mol and
the corresponding HB distances are 2.027, 1.854, 2.193
and 1.903 Å (Fig. 2e). Compound 10j showed an inter-
action energy of −8.11 kcal/mol with Gln92 and Arg200,
and HB distances are 1.985 Å and 2.098 Å (Fig. 2f).
Finally, these interaction energies were compared with the
standard drug molecule Pefloxacin where it showed a
binding energy of −7.12 with Arg200 and Ser196. This
indeed suggests that except 10a and 10h, rest of the
synthesized compounds showed equivalent interaction
energies compared with Pefloxacin. In addition, interac-
tion with Gln92 contributes significantly toward the
interaction energy. Overall, docking studies reveal that the
interaction with Gln92, Ser196 and Arg200 is very crucial
in the design of new chemical entities for potent inhibition
of pantothenate synthetase protein and suggested that 10b
−
7.59 kcal/mol with an average hydrogen bond (HB)
distance of ~1.61 Å (Fig. 2b). Compound 10b showed an
interaction energy of −8.16 kcal/mol with Gly92, Ser196
and Arg200 and the corresponding HB distances are
2
.065, 1.942 and 1.939 Å (Fig. 2c). Compound 10h
showed a binding energy of −5.95 kcal/mol with Gln92,
Arg200 and Arg207 and the corresponding HB distances
are 2.12, 2.084 and 1.995 Å (Fig. 2d). Compound 10i
showed interactions with Glu45, Glu189, Asn199 and

Medicinal Chemistry Research
Table 3 Antibacterial activity of
the tested compounds (10a–j) at
a concentration of 1.0 mg/50 µL
and their activity in terms of
diameter of inhibition zone
Compound
P. aeruginosa
−ve)
E. coli
(−ve)
K. pneumoniae
(−ve)
B. subtilis
(+ve)
S. aureus
(+ve)
(
1
1
1
1
1
1
1
1
1
1
0a
0b
0c
0d
0e
0f
30 ± 0.4
13 ± 0.4
25 ± 0.3
NI
NI
11 ± 0.1
18 ± 0.2
18 ± 0.2
33 ± 0.2
26 ± 0.1
24 ± 0.1
10 ± 0.2
11 ± 0.1
10 ± 0.2
16 ± 0.1
35 ± 0.2
15 ± 0.2
21 ± 0.4
11 ± 0.1
16 ± 0.1
NI
12 ± 0.4
18 ± 0.3
10 ± 0.3
20 ± 0.5
28 ± 0.5
17 ± 0.3
NI
14 ± 0.2
12 ± 0.3
18 ± 0.3
24 ± 0.1
16 ± 0.4
28 ± 0.5
17 ± 0.3
25 ± 0.4
16 ± 0.2
32 ± 0.1
(
mm)
21 ± 0.5
12 ± 0.3
21 ± 0.2
19 ± 0.4
14 ± 0.2
33 ± 0.2
19 ± 0.4
28 ± 0.2
29 ± 0.4
22 ± 0.4
26 ± 0.1
33 ± 0.1
0g
0h
0i
19 ± 0.1
28 ± 0.1
36 ± 0.3
37 ± 0.4
0j
Ciprofloxacin 36 ± 0.2
Data are means (n = 3) ± standard deviation of three replicates
NI no inhibition
(
R = chlorophenyl and R = indole) and 10j (R =
2H-chromen-2-one > 4–methyl phenyl>benzo[d] [1,3]
dioxole and 4-chloro, 4-fluoro substitutes on the quinazo-
linone and triazole ring is advisable. In addition, the com-
pounds 10e and 10j (28 and 36 mm zone of inhibition)
showed greater antibacterial activity against S. aureus than
that of reference Ciprofloxacin (37 mm zone of inhibition).
Further, the most active compounds 10a and 10j were found
to have more potent antibacterial activity and the compound
1
2
1
chlorophenyl and R = methyl-2-chromenone) can be
2
potent candidatures for the inhibition against the standard.
Further, all these molecules are competent candidatures
against the recently reported imidazo quinoline-5-
carboxylic acid derivatives where they showed interac-
tion energies between −5.8 and −6.92 kcal/mol (Mohana
Rao et al. 2017).
1
0d exhibited highest bacterial response against Klebsiella
pneumoniae. As for Gram-(‒) strains, the novel compounds
0 g and 10i provided satisfactory potency against E. coli
Antibacterial activity
1
1
0a–j were evaluated for their in vitro antibacterial activity
against Gram-(+) organisms, viz., Bacillus subtilis
MTCC121), Staphylococcus aureus (MTCC96), Gram-(‒)
(MTCC739). Further, the activity of the novel targets
against Gram-(‒) strains was in the order: benzo[d] [1,3]
dioxole > 6-hydroxy-4-methyl-2H-chromen-2-one > 4-
methyl phenyl > 4-chloro phenyl > 7-hydroxy-chromenes.
From the screening results, it is found that some of them are
potentially active with reference to Ciprofloxacin.
(
organisms Escherichia coli (MTCC739), Pseudomonas
aeruginosa (MTCC2453) and Klebsiella species strains by
using standard techniques, and the zones of inhibition
(
millimeters) along with those of the reference drug
Ciprofloxacin for comparison are shown in Table 3. All the
prepared compounds showed potent antibacterial activity
against the tested organisms at a concentration of 1.0 mg/50
µL except 10a, 10d, 10e and 10g, which are inactive
toward E. coli, P. aeruginosa, B. subtilis and S. aureus,
respectively. In vitro assay results revealed that the anti-
bacterial potency of target quinazolinone triazoles 10a, 10e,
SAR studies
Antibacterial activity
From activity results, the final compounds 10h, 10j, 10e and
10c showed good antibacterial activity. Compound 10h,
which has electron-withdrawing trifluoromethylphenyl
group on triazole ring and electron-donating p-chloro phe-
nyl group on quinazolinone, showed good activity on all the
tested strains. Compound 10j having p-chloro phenyl group
on triazole core and 7-hydroxy-4-methyl-chromenes group
on quinazolinone showed good antibacterial activity.
Overall, the SAR studies suggest that the electron-
withdrawing groups on triazole core and electron-donating
groups on quinazolinone ring enhance the antibacterial
activity.
1
0h and 10j showed magnificent broad spectrum activity
against representative Gram-(+) and Gram-(‒) strains. They
generally exhibited good potency in inhibiting the growth of
most tested Gram-(‒) strains such as P. aeruginosa (33 mm
zone of inhibition) and some of the tested Gram-(+) strains
such as S. aureus (MTCC96) (36 mm zone of inhibition).
Comparison of results for 10a, 10d and 10j against all the
strains tested follows the trend: 10j > 10a > 10d and sug-
gests that introduction of the groups 6-hydroxy-4-methyl-

Medicinal Chemistry Research
Experimental section
Materials and methods
in 81% yield (10b, 0.096 g). Remaining target quinazoli-
none–triazole compounds were prepared same as above and
a series of novel hybrids 10a–j was synthesized and char-
1
13
acterized by H NMR, C NMR and mass spectral analysis.
All the substrates, reagents and solvents were obtained from
commercial sources and were of analytical grade and used
7-((1-(4-fluorophenyl)-1H-1,2,3-triazol-4-yl)methoxy)-6-
methoxy-2-(p-tolyl)quinazolin-4(3 H)-one (10a)
1
without any further purification. H NMR (CDCl3 or
13
DMSO-d , 300 MHz) and C NMR (CDCl or DMSO-d ,
6
3
6
1
7
5 MHz) were recorded on NMR spectrometer using TMS
H-NMR (300 MHz, CDCl + DMSO-d ): δ
10.22 (s,
3
6
ppm
as an internal standard. Mass spectra (LCMS) were recorded
on a VG micro mass 70-70H instrument. High-resolution
mass spectra (HRMS) were recorded using electro spray
ionization in Bruker Maxis machine. The purity of the
compounds was checked by TLC on silica gel plates using a
mixture of n-hexane and 30–70% of ethyl acetate.
1H, NH), 8.04 (s, 1H, ArH), 7.78 (d, 2H, J = 7.15 Hz,
ArH), 7.69 (m, 2H, ArH), 7.45 (d, 2H, J = 7.15 Hz, ArH),
7.30 (s, 1H, ArH), 7.24 (m, 2H, ArH), 7.10 (s, 1H, ArH),
5.60 (s, 2H, OCH ), 5.35 (s, 2H, OCH ), 3.86 (s, 3H, CH );
2
3
3
1
3
C-NMR (125 MHz, DMSO-d ): δ
161.57, 153.32,
6
ppm
152.81 (d, 1JCF = 245.4 Hz), 150.23, 148.52 (d, 3JCF =
.0 Hz), 144.55, 142.38, 139.84, 138.25 (d, 4JCF = 3.0
9
General procedure for the synthesis of 4-((1-(4-
chlorophenyl)-1H-1,2,3-triazol-4-yl) methoxy)-5-
methoxy-2-nitrobenzamide (8b)
Hz), 133.26, 130.69, 128.17, 127.91, 127.79, 126.77,
125.24, 114.09, 109.43, 61.76, 60.11, 36.05; ESI-MS: m/z
+
457.16 (M + H) ; HRMS-ESI (m/z) [M] + calcd for
C H FN O 457.1550, found 457.1551.
2
5
20
5
3
To a solution mixture of t-butanol/H O in a ratio of 1:1 (15
2
mL), compound 5-methoxy-2-nitro-4-(prop-2-yn-1-yloxy)
benzamide 6 (1 g, 4 mmol) was added, followed by addition
of CuSO ·5H O (0.085 g, 0.4 mmol) and sodium ascorbate
7-((1-(4-chlorophenyl)-1H-1,2,3-triazol-4-yl)-methoxy)-2-
(1H-indol-3-yl)-6-methoxyquinazolin-4(3H)-one (10b)
4
2
1
(
0.16 g, 0.8 mmol). The reaction was stirred at ambient
H NMR (300 MHz, DMSO-d ): δ
12.10 (s, 1H, NH),
ppm
6
temperature for 10 min. A solution of substituted 1-azido-4-
chlorobenzene 7b (0.58 g, 4 mmol) in t-BuOH was added
drop wise to the reaction mixture and stirred at RT for 6 h.
After completion of the reaction, it is diluted with DCM (30
mL) and washed with water (2 × 15 mL), dried over anhy-
drous sodium sulfate and the solvent was evaporated under
vacuo, which resulted in the crude material that was
recrystallized using EtOH to get pure compound 4-((1-(4-
8.24 (d, 1H, J = 8.30 Hz, ArH), 8.16 (s, 1H, NH), 7.98 (s,
1H, ArH), 7.83–7.76 (m, 4H, ArH), 7.68–7.61 (m, 1H,
ArH), 7.50 (s, 1H, ArH), 7.42–7.32 (m, 2H, ArH), 7.26 (d,
1H, J = 7.93 Hz), 6.95 (d, 1H, J = 8.30 Hz), 5.50 (s, 2H,
1
3
OCH ), 3.90 (s, 3H, OCH ); C NMR (125 MHz, DMSO-
2
3
d6): δppm 161.53, 153.28, 150.67, 150.17, 149.74, 148.45,
147.64, 144.62, 142.22, 132.97, 127.78, 126.63, 125.51,
125.14, 122.32, 113.96, 109.40, 108.26, 105.06, 61.74,
+
+
chlorophenyl)-1H-1,2,3-triazol-4-yl)methoxy)-5-methoxy-
52.57. ESI-MS: m/z 498 (M + H) , 500 (M + 2 H) .
1
HRMS-ESI (m/z) [M + Na]+ calcd for C H ClN O Na
2
-nitrobenzamide 8b in 83% yield (1.52 g). H NMR (300
2
6
19
6
3
MHz, CDCl + DMSO-d ): δ 8.80 (s, 2H, NH), 7.80 (s,
521.1105, found 521.1106.
3
6
ppm
1
H, ArH), 7.39 (d, 2H, J = 8.30 Hz, ArH), 7.24 (d, 2H, J =
8
.30 Hz, ArH), 7.01 (s, 1H, ArH), 5.20 (s, 2H, OCH ), 3.91
2-(benzo[d][1,3]dioxol-5-yl)-7-((1-(4-fluorophenyl)-1H-1,2,3-
triazol-4-yl)methoxy)-6-methoxyquinazolin-4(3H)-one (10c)
2
1
3
(
s, 3H, OCH3); C-NMR (75 MHz, CDCl + DMSO-d ):
3
6
δppm 167.96, 152.65, 149.45, 146.91, 141.87, 138.19,
1
1
5
36.02, 127.85, 126.90, 122.91, 120.94, 113.72, 111.47,
3.17, 55.88; ESI-MS: m/z 403 (M + H) .
H NMR (300 MHz, DMSO-d ): δ
11.27 (s, 1H, NH),
ppm
6
+
8.40 (s, 1H, ArH), 7.79 (d, 2H, J = 8.12 Hz, ArH), 7.73 (s,
H, ArH), 7.37–7.51 (d, 1H, J = 7.51 Hz, ArH), 7.36–7.23
(m, 4H, ArH), 7.07 (s, 1H, ArH), 6.14 (s, 2H, OCH ), 5.67
1
General procedure for the synthesis of title
compounds 10a–j
2
1
3
(s, 2H, OCH ), 5.33 (s, 3H, OCH ); C-NMR (125 MHz,
2
3
DMSO-d ): δ
161.48, 153.25 (d, 1JCF = 248.5 Hz),
6
ppm
To a stirred solution of compound 8b (0.10 g, 0.22 mmol)
and 1H-indole-3-carbaldehyde (9b) (0.036 g, 0.242 mmol)
in DMSO (3 mL), sodium dithionite was added (0.087 g,
150.11, 149.67, 148.36, 147.60 (d, 3JCF = 9.1 Hz), 144.60,
142.31, 138.27 (d, 4JCF = 3.5 Hz), 133.24, 130.67, 128.14,
127.88, 126.72, 126.60, 125.26, 122.32, 113.91, 109.29,
0
.44 mmol) and the reaction mixture was heated at 100 °C
108.19, 107.22, 61.67, 55.59; ESI-MS: m/z 487.13 (M + H)
+
for 3 h. After completion, the reaction mixture was poured
in ice/water, resulted precipitate was filtered out and
recrystallized from EtOH to get pure white crystalline solid
.
HRMS-ESI (m/z) [M] + calcd for C H FN O
25 18 5 5
487.1292, found 487.1294.

Medicinal Chemistry Research
2
-(benzo[d][1,3]dioxol-5-yl)-7-((1-(4-chlorophenyl)-1H-1,2,3-
2H, J = 8.10 Hz, ArH), 7.55 (d, 2H, J = 8.10 Hz), 7.32–
triazol-4-yl)methoxy)-6-methoxyquinazolin-4(3H)-one (10d)
7.49 (m, 2H, ArH), 7.18 (s, 1H, ArH), 6.94 (s, 1H, ArH),
1
3
5
.55 (s, 2H, OCH ), 5.07 (s, 3H, OCH ); C-NMR (125
2
3
1
H NMR (300 MHz, DMSO-d ): δppm 11.38 (s, 1H, NH),
MHz, CDCl + DMSO-d ): δ 167.88, 152.85, 146.96,
6
3
6
ppm
7
.79 (s, 1H, ArH), 7.72–7.65 (m, 3H, ArH), 7.57 (m, 2H,
142.15, 140.89 (q, 2JCF = 30.1 Hz), 139.10, 138.61 (q,
3JCF = 4.2 Hz), 128.11 (q, 1JCF = 251.6 Hz), 127.65,
125.33, 125.31, 124.43, 122.41, 117.28, 110.57, 62.27,
ArH), 7.49–7.41 (m, 2H, ArH), 7.32–7.27 (d, 1H, J = 7.5
Hz, ArH), 7.00 (m, 1H, ArH), 6.10 (s, 2H, OCH ), 5.37 (s,
2
13
+
+
2
H, OCH ), 3.99 (s, 3H, OCH ); C NMR (75 MHz,
56.07; ESI-MS: m/z 527.1 (M + H) , 528.1 (M + 2 H) .
HRMS-ESI (m/z) [M] + calcd for C H ClF N O Na
2
3
DMSO-d ): δ 161.43, 153.29, 150.10, 149.65, 148.38,
6
25 17
3
5
3
1
1
6
47.68, 147.57, 144.59, 142.13, 136.74, 128.28, 127.91,
27.85, 126.59, 124.67, 122.29, 121.15, 112.16, 109.28,
9.95, 61.72, 55.54; ESI-MS: m/z 503.10 (M + H) .
550.0870, found 550.0873.
+
6-methoxy-7-((1-(4-(trifluoromethyl)phenyl)-1H-1,2,3-
HRMS-ESI (m/z) [M + Na] + calcd for C H ClN O Na
triazol-4-yl)methoxy)-2-(3,4,5-trimethoxyphenyl)quinazolin-
4(3H)-one (10h)
25
18
5
5
5
26.0894, found 526.0896.
1
2
1
-(benzo[d][1,3]dioxol-5-yl)-7-((1-(2,5-dimethoxyphenyl)-
H-1,2,3-triazol-4-yl)methoxy)-6-methoxyquinazolin-4(3H)-
H NMR (300 MHz, DMSO-d ): δ
12.19 (s, 1H, NH),
ppm
6
7.85 (s, 1H, ArH), 7.64–7.47 (m, 5H, ArH), 7.43 (d, 2H, J
one (10e)
= 7.5 Hz, ArH), 7.21 (d, 1H, J = 7.8 Hz, ArH), 5.38 (s, 2H,
1
3
OCH ), 3.98 (s, 9H, OCH ), 3.85 (s, 3H, OCH ); C NMR
2
3
3
1
H-NMR (300 MHz, DMSO-d ): δ 11.97 (s, 1H, NH), 7.70
(75 MHz, CDCl ) δ: 167.3, 153.3, 145.3, 144.3, 142.7,
6
3
(
7
5
s, 1H, ArH), 7.62 (s, 1H, ArH), 7.51 (s, 2H, ArH), 7.36–
135.4, 134.5, 132.4, 128.6, 128.4, 127.2, 126.6, 124.8,
123.9, 122.5, 122.0, 121.3, 120.5, 118.0, 54.7, 52.1, 46.38;
ESI-MS: m/z 583 (M + H) . HRMS-ESI (m/z) [M + Na] +
.29 (m, 2H, ArH), 7.20 (s, 1H, ArH), 7.15 (s, 2H, ArH),
.93 (s, 2H, OCH ), 5.43 (s, 2H, OCH ), 3.86 (s, 6H,
+
2
2
13
OCH ), 3.73 (s, 3H, OCH ); C-NMR (75 MHz, DMSO-
calcd for C H F N O Na 606.1576, found 606.1578.
3
3
28 24
3
5
6
d6): δ 161.46, 159.29, 153.26, 150.61, 150.51, 148.64,
1
1
5
44.45, 142.19, 134.06, 132.92, 129.64, 127.73, 125.46,
19.75, 117.23, 114.25, 112.13, 109.56, 105.07, 61.75,
5.61, 52.25, 34.19, 30.95; ESI-MS: m/z 530.00 (M + H) .
7-((1-(4-chlorophenyl)-1H-1,2,3-triazol-4-yl)methoxy)-2-(6-
hydroxy-2-oxo-2H-chromen-7-yl)-6-methoxyquinazolin-4
(3H)-one (10i)
+
HRMS-ESI (m/z) [M + Na] + calcd for C H N O Na
27
23
5
7
1
5
52.1495, found 552.1495.
H-NMR (300 MHz, DMSO-d ): δ
11.88 (s, 1H, NH),
6
ppm
8.65 (d, 1H, J = 6.75 Hz, ArH), 8.49 (s, 1H, ArH), 8.40–
2
-(benzo[d][1,3]dioxol-5-yl)-6-methoxy-7-((1-(3,4,5-
8.36 (m, 2H, ArH), 8.02 (s, 1H, ArH), 7.56–7.42 (m, 3H,
trimethoxyphenyl)-1H-1,2,3-triazol-4-yl) methoxy)
quinazolin-4(3H)-one (10f)
ArH), 7.36 (s, 1H, ArH), 7.21 (s, 1H, ArH), 7.09 (s, 1H,
ArH), 5.67 (s, 1H, OH), 5.36 (s, 2H, OCH ), 3.85 (s, 3H,
2
1
3
OCH3); C-NMR (75 MHz, DMSO-d ): δ
161.33,
6
ppm
1
H NMR (300 MHz, DMSO-d ): δppm 8.23 (s, 1H, NH),
153.43, 149.42, 147.93, 144.29, 142.50, 138.30, 136.83,
133.36, 130.79, 129.08, 128.27, 127.96, 126.84, 125.32,
122.77, 120.93, 113.33, 112.11, 108.41, 107.95, 61.85,
6
7
.98 (s, 1H, ArH), 7.70–7.51 (m, 4H, ArH), 7.43 (d, 2H, J
=
8.12 Hz, ArH), 7.28 (s, 1H, ArH), 5.71 (s, 2H, OCH2),
+
+
5
.42 (s, 2H, OCH ), 3.94 (s, 9H, OCH ), 3.82 (s, 3H,
52.17; ESI-MS: m/z 543.09 (M + H), 545 (M + 2H).
HRMS-ESI (m/z) [M] + calcd for C H ClN O 543.0946,
2
3
1
3
OCH3); C NMR (75 MHz, DMSO-d ): δppm 161.48,
6
27 18
5
6
1
1
1
5
53.26, 152.96, 150.15, 149.69, 148.39, 147.60, 144.61,
42.22, 137.30, 131.18, 126.60, 125.02, 122.38, 113.91,
09.29, 108.21, 107.29, 105.74, 105.12, 101.76, 61.70,
found 543.0947.
7-((1-(4-chlorophenyl)-1H-1,2,3-triazol-4-yl)methoxy)-2-(6-
hydroxy-4-methyl-2-oxo-2H-chromen-7-yl)-6-
methoxyquinazolin-4(3H)-one (10j)
+
9.92, 55.81, 55.60, 53.12; ESI-MS: m/z 559.00 (M + H) .
HRMS-ESI (m/z) [M + Na] + calcd for C H N O Na
28
25
5
8
5
82.1601, found 582.1602.
1
H NMR (300 MHz, DMSO-d ): δ
10.13 (s, 1H, NH),
ppm
6
2
-(4-chlorophenyl)-6-methoxy-7-((1-(4-(trifluoromethyl)
8.89 (s, 1H, ArH), 8.37 (s, 1H, ArH), 7.78 (m, 2H, ArH),
7.44 (d, 2H, J = 8.53 Hz, ArH), 7.37 (s, 1H, ArH), 7.06 (d,
2H, J = 8.08 Hz), 6.73 (s, 1H, ArH), 5.66 (s, 1H, OH), 5.39
phenyl)-1H-1,2,3-triazol-4-yl)methoxy)quinazolin-4(3H)-one
10g)
(
13
(
s, 2H, OCH ), 3.94 (s, 3H, OCH ), 3.75 (s, 3H, CH ); C-
2
3
3
1
H-NMR (300 MHz, DMSO-d ): δppm 11.63 (s, 1H, NH),
NMR (75 MHz, DMSO-d ): δ
161.51, 153.28, 152.78,
6
6
ppm
8
.40 (s, 1H, ArH), 8.29 (d, 2H, J = 8.10 Hz, ArH), 7.95 (d,
150.19, 148.49, 144.51, 142.36, 140.51, 139.82, 128.77,

Medicinal Chemistry Research
1
1
5
28.67, 127.74, 125.62, 125.34, 125.08, 114.07, 109.47,
tuberculosis spp. LJ medium is most widely used for
tuberculosis culture. LJ medium containing glycerol favours
the growth of inhibition.
+
05.08, 61.74, 56.01, 55.58; ESI-MS: m/z 557 (M + H) ,
+
58 (M + 2H) . HRMS-ESI (m/z) [M + Na] + calcd for
C H ClN O Na 580.1000, found 580.1002.
2
8
20
5
6
Middlebrook medium preparation
Antibacterial activity
Middlebrook 7H9 Broth is a liquid growth medium spe-
cially used for culture of Mycobacterium, notably M.
tuberculosis. 7H9 supports the growth of mycobacterial
species, which is supplemented with nutrients such as gly-
cerol, oleic acid, albumin and dextrose. The medium is used
for the preparation of inocula for anti-mycobacterial assays.
7H9 broth supports the growth of mycobacterial species
when supplemented with nutrients such as glycerol, oleic
acid, albumin and dextrose, except for M. tuberculosis,
which is inhibited by glycerol. Cultures should be read
within 5–7 days after inoculation and once a week thereafter
for up to 8 weeks. Middlebrook broth is commonly used in
the preparation of inocula for antimicrobial assays, bio-
chemical tests (arylsulfatase and tellurite reduction) and for
maintenance of stock strains.
A collection of three organisms were used for this study of
clinical isolates, including Gram-(+) organisms such as B.
subtilis (MTCC121) and S. aureus (MTCC96), and Gram-
(−) strains E. coli (MTCC739), P. aeruginosa (MTCC2453)
and Klebsiella species strains were obtained from Micro-
biology laboratory of Global Hospital, Hyderabad. All
strains were tested for purity by standard microbiological
methods. The bacterial stock cultures were maintained on
Mueller Hinton Agar (MHA) slants and stored at 4 °C.
Determination of antibacterial activity
An agar-well diffusion method was employed for evaluation
of antibacterial activity. (Clinical and Laboratory Standards
Institute 2007; Kavanagh 1972; Banothu et al. 2017). The
bacterial strains were reactivated from stock cultures by
transferring into Mueller Hinton Broth (MHB) and incu-
Drug concentrations
6
bating at 37 °C for 18 h. A final inoculum containing 10
Preparation of stock solution: 50 mg of Isoniazid was pre-
pared by adding 5 mL of sterile distilled water. Working
solution: 0.5 mL from the stock solution is taken and 24.5
mL of distilled water is added and 0.1 mL of the drug is
added to the medium (con. 0.2 µg/mL).
6
colony forming units (1 × 10 CFU/mL) was added asepti-
cally to MHA medium and poured into sterile Petri dishes.
Different test compounds at a concentration of 1.0 mg/50 μL
were added to wells (8 mm in diameter) punched on agar
surface. Plates were incubated overnight at 37 °C and dia-
meter of inhibition zone (DIZ) around each well was
measured in millimeters. Experiments were performed in
triplicates. Antibiotic such as Ciprofloxacin at a con-
centration of 1 mg/50 μL was used as a positive reference to
determine the sensitivity of microorganisms tested. DMSO
was used as a negative control.
Drug dilution
The compounds (1 mg) are dissolved in 1 mL of DMSO
(con. 1 mg/mL), test samples were further diluted to attain
final concentrations of 1000 µg/mL, 500 µg/mL, 250 µg/
mL, 125 µg/mL, 62 µg/mL, 31 µg/mL, 15 µg/mL, 8 µg/mL
and 4 µg/mL. Step-1: label the test tubes as 1, 2, 3, 4, 5, 6,
7, 8, 9, 10. For MTB H Rv (set A) and MDR strain (set
Material and methods
3
7
B) separately. Step-2: take 2 mL of the stock solution in
test tube no. 1 (in each set), concentration 1000 µg/mL.
Step-3: transfer 1 mL of the solution into test tube no. 2
(in each set) and dilute it with 1 mL of Dimethylforma-
mide (DMF) (in each set). Now the concentration
becomes one half to the first test tube (no. 1), i.e., 500 µg/
mL. Step-4: mix well the contents in the test tube, and
transfer 1 mL of the solution from test tube no. 2 into test
tube no. 3; add 1 ml of DMF to test tube no. 3 as men-
tioned in Step-3. We get the concentration 250 µg/mL
Anti-mycobacterial agents
Test drug included Rifampicin, obtained by Sigma. The
stock solution was prepared according to CDC (1985)
recommendations. The following concentrations were used
for the screening antimicrobial agents: Rifampicin: 0.25 to
1
6. All drugs were kept as a stock suspension of 1% in
distilled water except for Rifampicin that was dissolved in
methanol, and stored at −25 °C.
(
test tube no. 3). Step-5: repeat the dilution as mentioned
Lowenstein–Jensen medium preparation
in Steps 3 and 4 up to test tube no. 9 and discard the 1 mL
of solution from test tube no. 9. Step-6: the test tube no.
10 remains as control (only DMSO).
Lowenstein–Jensen (LJ) medium is used with fresh egg and
glycerol for the isolation and differentiation of M.

Medicinal Chemistry Research
Bacterial strains and cultures
Culture inoculation
All the clinical samples were collected from District
Tuberculosis Center, MGM hospital, Warangal, and
inoculated onto the LJ solid medium and incubated for
Each tube was inoculated with 0.01 mL of bacterial sus-
pension (0.5 McFarland standard). The medium without
antimicrobial agents was inoculated with the same suspen-
sion and with a 100-fold diluted suspension, as a growing
control. The tubes were sealed and incubated at 37 °C for
28 days in a moisturized incubator. The tubes were
rechecked for growth of non-tuberculosis matter (NTM) on
the third and fifth day, respectively. The presence of tur-
bidity/growth of mycobacterium was checked at seventh,
14th and 21st days, respectively (the mean time for
detecting the growth of mycobacterium is 7–21 days)
(Ahmet et al. 2004). The MIC values were recorded on days
14 and 21. Slides were prepared from each well for acid-fast
staining. No organisms other than acid-fast bacilli were
observed.
8
weeks at Department of Microbiology, Sri Shivani Col-
lege of Pharmacy; cultures were identified as M. tubercu-
losis based on morphological and biochemical methods.
Fifty clinical isolates were preserved. Mono resistant strain
of M. tuberculosis was identified by testing drug suscept-
ibility for isoniazid (H) and it was taken as test strain and M.
tuberculosis H Rv taken as a control strain for testing anti-
3
7
mycobacterial activity of compounds. The bacterial strains
were stored in trypticase soy broth containing glycerol at
−
70 °C. All the strains were recovered on LJ medium for
2
1–28 days at 37 °C.
Preparation of inoculums
Determination of MIC
The isolates grown on LJ medium were sub-cultured in
Middlebrook 7H9 broth (Gupta et al. 2011; Camacho
et al. 2011; Issar 2003) supplemented with OADC at 37 °
C for 15–21 days. The bacterial suspension was homo-
genized by vortex shakeup and the turbidity was adjusted
in agreement with tube which is the scales of McFarland
The evaluation of in vitro anti-mycobacterial activity of the
compounds was performed against M. tuberculosis H Rv
37
and MDR strain. The dilutions were carried out in the broth
medium, i.e., Middlebrook 7H9 medium (Himedia, Mum-
bai) supplemented with OADC (Himedia, Mumbai) was
used to determine the MIC method. The compounds were
dissolved as tabulated in Table 3. The inoculum was pre-
pared by transferring colonies from the culture to sterile
water. The cell density was adjusted to 1 McFarland stan-
6
no. 1 (3.2 × 10 cfu/mL). The inoculum was prepared
diluting the bacterial suspension in the proportion of 1:20
in Middlebrook 7H9 broth medium. This diluted suspen-
sion (100 μL) was used to inoculate. The mycobacteria
were grown in Middlebrook 7H9 medium (HiMedia,
India) supplemented with 10% ADC (HiMedia, India).
Log phase cultures were centrifuged, washed twice with
sterile saline and adjusted to McFarland standard corre-
8
dard (10 cells/mL). The final inoculum was made by
1:1000 dilution of the suspension with sterile water. Iso-
niazid was used as the drug control for the compounds. The
controls used are drug-free media for sterility check and the
media inoculated with M. tuberculosis H Rv and MDR
7
sponding to 1 × 10 cfu/mL. The size of inoculum was
3
7
confirmed by plating serial dilutions on Middlebrook
strain for the growth patterns in drug-inoculated tubes. The
tubes were incubated at 37 °C. The determination of results
was performed visually after 3 days of static incubation at
37 °C, after 6 days static incubation at 37 °C and 21 days of
static incubation at 37 °C. The MICs were defined as the
lowest concentration of the compound at which no visible
bacterial growth was observed.
7
1
H11 media (HiMedia, India) plates supplemented with
0% OADC (HiMedia, India). The plates were incubated
for 4 weeks prior to CFU enumeration.
Broth dilution method
The MIC for M. tuberculosis H Rv and drug-resistant
37
clinical sample of M. tuberculosis was determined using a
broth micro dilution method (Delogu et al. 2013; Zhang
et al. 2011; Vanderberg 2007) in Middlebrook 7H9 medium
Docking studies
The ligands were sketched in Sybyl6.7 and saved it in.
mol2 format (Gunda et al. 2015). All the sketched
molecules were converted to energy minimized 3D
structures by using Gasteiger-Huckel charges for in silico
protein–ligand docking using autodock Tools (Banu et al.
2018). Each molecule was docked separately. Initially the
molecule was loaded, torsions were set and saved it in
PDBQT format. All the hetero atoms were removed
from the 3IVX.PDB (crystal structure of pantothenate
2
supplemented with OADC, with a final inoculum of 5 × 10
cells/mL. The compounds were dissolved in DMF (1.25
mg/mL) and used as a stock solution. Concentrations ran-
ging from 1 to 1000 µg/mL were used to assess the effec-
tiveness of the compounds. Microtiter tubes were incubated
at 37 °C for 72 h. The MIC value represents the lowest
dilution of the compound at which no bacterial growth was
detected.

Medicinal Chemistry Research
synthetase in complex with 2-(2-(benzofuran-2-ylsulfo-
nyl carbamoyl)-5-methoxy-1H-indol-1-yl) acetic acid)
References
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1
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