INTERNATIONAL JOURNAL OF ARTIFICIAL INTELLIGENCE
ISSN: 2692-5206, Impact Factor: 12,23
American Academic publishers, volume 05, issue 09, 2025
https://www.academicpublishers.org/journals/index.php/ijai
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IN VITRO STUDY OF THE BIOLOGICAL ACTIVITY OF COMPLEX COMPOUNDS
SYNTHESIZED BASED ON LEVOFLOXACIN
Bozorova Mahbuba Ishquvvatovna
Assistant of the Department of Medical and Biological Chemistry, Termez Branch of Tashkent
State Medical University
Tel: +99891-587-11-60
Ashurov Jamshid Mengnorovich
Professor of the Institute of Bioorganic Chemistry named after O.S.Sadikov, Academy of
Sciences of the Republic of Uzbekistan
To‘rayev Xayit Xudoynazarovich
Professor of the Department of Analytical Chemistry, Termez State University
Abstract.
This study investigates the antibacterial activity of novel metal complexes synthesized
using levofloxacin (LEV) as a ligand. The in vitro antimicrobial effects of these complexes were
evaluated against three clinically significant bacterial strains:
Bacillus subtilis
,
Escherichia coli
,
and
Pseudomonas aeruginosa
. The synthesized copper(II), cobalt(II), and nickel(II) complexes of
levofloxacin were tested using the agar well diffusion method at a fixed concentration of 35
µg/mL. The diameter of the bacterial growth inhibition zones was measured and compared to those
produced by free levofloxacin and the corresponding metal salts. Results demonstrated that the
metal complexes exhibited significantly enhanced antibacterial activity compared to levofloxacin
alone, with the copper complex showing the highest efficacy. These findings suggest that metal
complexation with levofloxacin can improve its antimicrobial potency and may serve as a
promising strategy for developing more effective antibacterial agents..
Keywords:
Levofloxacin, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa bacteria
.
Introduction.
Currently, due to global climate change, increasing pollution of the atmosphere and
environment with various wastes has led to the rise of harmful microorganisms and the diseases
they cause. This situation increases the need for antibiotics, which imposes on scientists in the
fields of chemistry, biology, and pharmaceutical medicine the task of creating new and effective
drugs, reducing their concentration, and increasing the scope of action [1]. Levofloxacin (LEV)
[2-3] is one of the most effective fluoroquinolones, a biologically active compound that is used in
medical practice as a drug, and is included in the group of broad-spectrum fluoroquinolones. It is
used in the clinical treatment of many infections, such as chronic prostatitis, skin and soft tissue
infections, lung and urinary tract infections [4-5]. It is known from the literature that in many
cases, metallocomplex compounds of a particular drug are active relative to the free ligand [6].
From the research, metallocomplexes of LEV containing a pyridine ring, which have certain
bioactive properties, have been synthesized and studied [7-8]. Therefore, the synthesis of LEV-
based metal complexes and the investigation of their bioactivity remain pressing research areas.
INTERNATIONAL JOURNAL OF ARTIFICIAL INTELLIGENCE
ISSN: 2692-5206, Impact Factor: 12,23
American Academic publishers, volume 05, issue 09, 2025
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page 257
Research methodology.
Chemicals, instruments and calculations. In this study, the antibacterial
properties of levofloxacin and its synthesized metal complexes were evaluated in vitro on strains
of Bacillus subtilis-5, Escherichia coli-221, Pseudomonas aeruginosa-225, Staphylococcus aureus-
91, Candida albicans-247 obtained from the microbial culture collection at the Institute of
Microbiology, Academy of Sciences of the Republic of Uzbekistan (ASRUz) [9].
Experimental part.
Antibiotic resistance of microorganisms is currently emerging as a serious
global medical problem. Antibiotic resistance of microorganisms significantly complicates the
treatment of infections. Resistant strains place an excessive burden on the health system, increase
the risk of mortality, and reduce the effectiveness of medical procedures such as surgery and cancer
treatment. Therefore, it is necessary to develop effective antimicrobial therapies, as well as
optimize existing antibiotics using chelation processes [10].
The antibacterial properties of levofloxacin and the synthesized complexes (labeled as Compounds
1-3) were tested in the laboratory of the “Collection of Microorganisms” of the Institute of
Microbiology of the ASRUz. The experiments were conducted in vitro on strains of Bacillus
subtilis, Escherichia coli, and Pseudomonas aeruginosa.
In the experiments, the antimicrobial activity of LEV, Cu-complex, Co-complex and Ni-
complexes was evaluated using the “agar well diffusion” method. LEV, Cu-complex, Co-complex
and Ni-complexes were used in the tests at the same concentration of 35 µg/ml. Levofloxacin was
chosen as the control. Microorganisms were incubated at 28°C for 2 days, and then the inhibitory
effect of synthetic compounds and antibiotics was evaluated by measuring the growth inhibition
zone. All experiments were repeated five times, and statistical analysis was conducted with a
significance level of P=0.05. In the study, standard strains of Bacillus subtilis, Escherichia coli and
Pseudomonas aeruginosa were obtained from the collection of the Institute of Microbiology in
Tashkent.
Antibacterial activity tests of the synthesized Cu-complex showed that the biological effect of the
complex was significantly enhanced against LEV (Table 1, Figure 1). According to the data
obtained, the activity of the complex against gram-negative Escherichia coli bacteria was 45%
higher than that of levofloxacin.
1-jadval
Antimicrobial activity of levofloxacin (LEV) and complex compounds synthesized on its
basis (3-5 days)
№
Sample
Antagonistic activity d (growth inhibition zone),
mm
Escherichia coli
Bacillus
subtilis
Pseudomonas
aeruginosa
0001
LEV (control)
20 ± 0,43
18 ± 0,41
16 ± 0,35
0002
CuSO
4
∙5H
2
O
16 ± 0,35
15 ± 0,65
15 ± 0,84
0003
[LEVH
3
]
2
[Cu
3
Cl
9
(H
2
O)
2
]Cl
29 ± 0,62
27 ± 0,26
26 ± 0,75
0001
LEV (control)
20 ± 0,43
18 ± 0,41
16 ± 0,35
0004
CoCl
2
∙2H
2
O
08 ± 0,25
07 ± 0,25
07 ± 0,15
0005
[LEVH
2
]
2
∙[CoCl
4
]∙2H
2
O
27 ± 0,41
24 ± 0,15
23 ± 0,65
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0001
LEV (control)
20 ± 0,43
18 ± 0,41
16 ± 0,35
0006
NiSO
4
∙7H
2
O
12 ± 0,36
10 ± 0,23
9 ± 0,95
0007
[Ni(LEV)
2
EDA]∙7H
2
O
28 ± 0,55
26 ± 0,91
24 ± 0,10
In this study, Levofloxacin was selected as the control substance. At the same time, the results of
the desired metal salts and complex compounds were studied together and compared. Metal salts
showed a very poor result compared to LEV. However, our complex compounds showed a better
result compared to LEV. For example: The activity results obtained for complexes with copper,
cobalt and nickel metals against the gram-negative bacterium Escherichia coli were improved by
45%, 35% and 40% compared to the activity of levofloxacin, respectively. The activity of these
complexes against Bacillus subtilis was improved by 50%, 33.3% and 44.4% compared to the
activity of the ligand (LEV), respectively, while the activity against Pseudomonas aeruginosa was
improved by 62.5%, 43.75% and 50% compared to the activity of the ligand (LEV). These findings
confirm that the antibacterial activity of organic compounds can be enhanced through metal
complexation.
Escherichia coli
Bacillus subtilis
Pseudomonas aeruginosa
Figure 1. Antibacterial activity of the cobalt complex against Bacillus subtilis, Escherichia
coli, and Pseudomonas aeruginosa.
Although the antimicrobial effect of the Cu complex is similar to that of the Co complex and Ni
complex, the result suggests that the presence of metal ions contributes significantly to the
enhanced antimicrobial properties of the complexes..
The results obtained indicate that the antibacterial activity of the metal complexes is higher than
that of levofloxacin. The activity of the copper complex against the bacteria Bacillus subtilis,
Escherichia coli and Pseudomonas aeruginosa is significantly higher than that of the cobalt and
nickel complexes.
The antibacterial activity of Cu, Co, and Ni complexes, respectively, is higher than that of
levofloxacin, indicating that they may be more effective than traditional antibiotics in treating
infections caused by various microbes.
Conclusion.
As a result of the studies conducted, Levofloxacin was selected as the control
substance and the results of the desired metal salts and complex compounds were compared. Metal
INTERNATIONAL JOURNAL OF ARTIFICIAL INTELLIGENCE
ISSN: 2692-5206, Impact Factor: 12,23
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salts showed very poor results compared to LEV, but our complex compounds showed better
results compared to LEV.
It can be concluded that the antibacterial activity of the synthesized metal complexes exceeds that
of levofloxacin alone, indicating that they may be more effective than traditional antibiotics in
treating infections caused by various microbes.
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