INTERNATIONALE PHARMACEUTICA SCIENCIA | April-June 2013 | Vol. 3 | Issue 2 | Available online http://www.ipharmsciencia.com ISSN 2231-5896 ©2013 IPS RESEARCH ARTICLE
Synthesis and SAR of some Novel N-(3-Chloro-2-Oxo-4-substituted (Aryl) Azetidin-1-yl) Isonicotinamide derivatives as Antimicrobial Agents ABSTRACT Objective: The treatment of many infectious diseases are challenging due to resistance to antimicrobial agents. From literature review, Sushil Kumar et al. have synthesized some azetidinones derivatives and screened for antimicrobial activity. To further modify this, this has been planned to synthesize some novel derivatives with various functional groups to derive SAR study. Experimental and Computational work done: In the experiment N(substituted) benzylidene isonicotinohydrazide were reacted with chloroacetyl chloride and triethylamine in presence of 1,4-dioxane to form novel series of N-(3chloro-2-oxo-4-substituted (aryl) azetidin-1-yl) isonicotinamide. The purity of all compounds has been checked by TLC monitoring and the confirmation of the structure has been checked by different spectral analysis like IR, Mass, 1H-NMR and elemental analysis to report the structure of compounds. Result & Discussion: The antibacterial and antifungal activity of synthesized compounds was tested by Disc diffusion method and was screened against S.aureus, B.subtilis and E.coli for antibacterial activity and antifungal activity screened against C.albicans. Compounds 6b and 6e have shown better antimicrobial activity. Conclusion: Study concludes that compounds with electron withdrawing groups like 4-Cl and 2-NO2 on phenyl ring exhibited potent antimicrobial activity.
Dhaval K. Patel*, Chirag S. Rami, Dr. Dhrubo Jyoti Sen and Dr. C. N. Patel Shri Sarvajanik Pharmacy College, Gujarat Technological University, Nr. Arvind Baug, Mehsana-384001, Gujarat, India Date of Submission: 03-04-2013 Date of Acceptance: 28-05-2013 Conflict of interest: Nil Source of support: None
Keywords: Azetidinone, Antimicrobial agents, Zone of Inhibition, MIC.
INTRODUCTION
agents. In recent scenario heterocycles plays a major
The development of new therapeutic agents is
role in drug synthesis. In that respect azetidinone ring
becoming the major interest in many academic and
plays a significant role among other heterocycles. From
industrial research laboratories all over the world with
the literature survey, some Azetidinone derivatives
the aim to discover newer, more potent molecules,
have attracted considerable interest because of their
with higher specificity and reduced toxicity than the
therapeutic and pharmacological properties. Several
existing ones. Microbial infections are associated with
of them have been found to exhibit a wide spectrum of
high rates of attributable morbidity and mortality.
biological effects including Antimicrobial, Antioxidant,
Microbial infections caused by microbial species are
Antitubercular,
common in immune compromised patients and carry
Earlier, Sushil Kumar et al. Synthesized Azetidinone of
significant
1-naphthol and screened for antimicrobial activity.1
treatment
costs
and
mortality.
The
treatment of many infectious diseases are challenging
Antimycobacterial,
O
Cytotoxic
NH N
due to resistance to antimicrobial agents. The various Penicillin and Cephalosporins drugs are already in the market some of them have narrow antimicrobial
O (1a-f)
R
activity. The emerging resistance of some microbial species to some synthetic antimicrobial agents makes it necessary to continue the search for new antimicrobial Address for correspondence
Dhaval K. Patel Email:
[email protected] 96
Where, R: 1a= -H, 1b= -2-Cl, 1c= -3-OH, -4-OCH3, 1d= -4-N(CH3)2, 1e= -4-NO2, 1f= -3-OH (1) Internationale Pharmaceutica Sciencia Apr-June 2013 Vol 3 Issue 2
etc.
Dhaval K. Patel, et al: Synthesis and SAR of some Novel N-(3-Chloro-2-Oxo-4-substituted (Aryl) Azetidin-1-yl) Ar
EXPERIMENTAL
O
Synthesis
O
N-(substituted)
benzylidene
isonicotinohydrazide: A mixture of isoniazid (3)
HN N
of
(2a-b)
(0.02mol, 5gm), substituted aromatic aldehyde (4 a-
Cl
h) (0.02mol, 3.1ml) and 1ml glacial acetic acid in 30ml
O
ethanol was refluxed for 8-10 hrs. The reaction mixture
Where, Ar: 2a= -H, 2b= -4NO2 (2)
was cooled to room temperature. The product formed was separated by filtration and washed successively
In above series compound 1b which has 2-Cl substituent and 1e which has 4-NO2 substituent shown
with water and dried. The obtained product was purified by recrystallization from rectified spirit.2
promising antimicrobial activity having MIC value 1664µg/ml. So, it has been planned to synthesize newer azetidinone analogues by substituting at 1st and 4th position of azetidinone with nicotinyl and substituted aryl ring respectively and to check their activity as antimicrobial agents.
Synthesis of N-(3-chloro-2-oxo-4-substituted (aryl)
N-
(0.01mol, 1.5gm) were dissolved in 1, 4-dioxane (10ml) constant
stirring
at
room
temperature.
Triethylamine (1ml) was added slowly followed by
Cl
O
isonicotinamide:
(substituted) benzylidene isonicotinohydrazide (5a-h) with
O
azetidin-1-yl)
drop wise addition of chloro acetyl chloride (1ml). N
Stirring was continued for further 30 min. Thereafter,
NH Aryl
N
the reaction mixture was refluxed for 9-10 hrs. The mixture was allowed to cool at room temperature and
Ar=-C6H5, 4-Cl-C6H4-, 4-OH-C6H4-, 4-OCH3-C6H4-, 4-
filtered to remove insoluble salt. Excess of the solvent
N (CH3)2C6H4-, 2-NO2-C6H4-, -1-Naphthyl, -2-Furyl
was removed and the obtained residue was washed
(6a-h)
with water, dried, and recrystallized from ethanol to
The research objectives of this study are the synthesis
afford N-(3-chloro-2-oxo-4-substituted (aryl) azetidin-
of
1-yl) isonicotinamide (6 a-h).3
azetidinones
derivatives,
characterization
of
synthesized compounds by IR, Mass, NMR spectral analysis
and
to
evaluate
for
antibacterial
and
antifungal agents by finding MIC value. SCHEME OF SYNTHESIS: O
O NH
NH2
+
N (3) Isoniazid
Aryl-CHO
N
CH3CH2OH Glacial acetic acid
Aryl
NH N
(4a-h)
Reflux for 8-10 hours Substituted aromatic aldehyde
(5a-b) ClCH2COCl Triethylamine
Reflux for 9-10 hours
1,4-Dioxane O Cl
O N NH
Aryl
N (6a-h)
Aryl = -C 6H5, 4-Cl-C6H4-, 4-OH-C 6H4-, 4-OCH3-C6H4-, 4-N(CH3)2-C6H4-, 2-NO 2-C6H4-, 1-Naphthyl-, 2-Furyl-
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Dhaval K. Patel, et al: Synthesis and SAR of some Novel N-(3-Chloro-2-Oxo-4-substituted (Aryl) Azetidin-1-yl)
PHYSICAL CHARACTERISTICS OF N-(3-CHLORO-2-OXO-4-SUBSTITUTED (ARYL) AZETIDIN-1YL) ISONICOTINAMIDE DERIVATIVES:O Cl
O N NH
Aryl
N
(6a-h) Comp. No. 6a
-C6H5
Molecular Formula C15H12ClN3O2
6b
4-Cl-C6H4-
C15H11Cl2N3O2
336.17
148-149
28
0.68
6c
4-OH-C6H4-
C15H12ClN3O3
317.73
123-125
32
0.45
6d
4-OCH3-C6H4-
C16H14ClN3O3
331.75
142-143
40
0.68
6e
2-NO2-C6H4-
C15H11ClN4O4
346.73
129-131
27
0.40
6f
1-Naphthyl
C19H14ClN3O2
351.79
138-140
37
0.48
6g
2-Furyl
C13H10ClN3O3
291.69
118-120
30
0.65
6h
4-N(CH3)2C6H4-
C17H17ClN4O2
344.8
115-116
33
0.54
Ar
Molecular Weight Melting Point Yield Rf (g/mol) (%w/w) ( C) 301.73 102-104 35 0.52
Mobile Phase: Ethyl acetate: Hexane (1:1) Table-1: Physicochemical Parameters Spectral characteristics of N-(3-chloro-2-oxo-4-substituted (aryl) azetidin-1-yl) isonicotinamide:O Cl
O N NH
Aryl
N
(6a-h) Comp. No.
Ar
Mol. Wt. (g/mol)
6a
-C6H5
301.73
6b
4-Cl-C6H4-
336.17
6c
4-OH-C6H4-
317.73
6d
4-OCH3-C6H4- 331.75
6e
2-NO2-C6H4-
346.73
6f
-1-Naphthyl
351.79
6g
-2-Furyl
291.69
6h
4N(CH3)2C6H4-
344.8
Mass (m/z)
IR (cm-1)
1 H NMR (δ, ppm)
9.18-9.25 (d, 2H, -CH-N=CH), 8.25 (s, 1H, -CONH), 7.92-7.95 (d, 2H, 301.0 (M+), 3055.03 (-NH str.), CH=C=CH), 7.05-7.29 (m, 5H, Ar-H), 5.54-5.62 (d, 1H, -CH), 5.12-5.23 (d, 303.0 (M+2) 1757.08 (C=O str.) H, CH) 335.0 (M+) 9.07-9.11 (d, 2H, -CH-N=CH), 8.12 (s, 1H, -CONH), 7.75-7.80 (d, 2H, 3203.54 (-NH str.), 337.0 (M+2) CH=C=CH), 7.03-7.27 (m, 4H, Ar-H), 5.56-5.59 (d, 1H, -CH), 5.02-5.04 1742.72 (C=O str.) 339.0 (M+4) (d, 1H, -CH) 8.99-9.01 (d, 2H, -CH-N=CH), 8.32 (s, 1H, -CONH), 7.87-7.89 (d, 2H,318.0 (M+), 3101.32 (-NH str.), CH=C=CH), 7.05-7.38 (m, 4H, Ar-H), 5.81-5.88 (d, 1H, -CH), 5.21-5.30 (d, 320.0 (M+2) 1723.40 (C=O str.) 1H, -CH), 4.67 (s, 1H, -OH) 330.0 (M+), 3452.34 (-NH str.), 332.0 (M+2) 1764.01 (C=O str.) 347.0 (M+), 3132.18 (-NH str.), 349.0 (M+2) 1715.63 (C=O str.) 353.1 (M+), 2914.24 (-NH str.), 355.1 (M+2) 1705.98 (C=O str.) 291.0 (M+), 3269.12 (-NH str.), 293.0 (M+2) 1766.88 (C=O str.) 345.1 (M+), 2987.53 (-NH str.), 347.1 (M+2) 1733.63 (C=O str.)
Table-2: Spectral Datas BIOLOGICAL SCREENING:
Gram -Ve microorganism:
Screening of Antibacterial activity:
Escherichia coli
Microorganism used for screening:-
Microbiological Screening:-
Gram +Ve microorganisms:
The microbiological assay is based upon a comparison
Staphylococcus aureus
of inhibition of growth of micro-organisms by
Bacillus subtilis
measured concentrations of test compounds with that
98
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Dhaval K. Patel, et al: Synthesis and SAR of some Novel N-(3-Chloro-2-Oxo-4-substituted (Aryl) Azetidin-1-yl)
produced by known concentration of a standard
Apparatus:-
antibiotic. Two methods generally employed are
All the apparatus like petri dishes, pipettes, glass rods,
turbidometric (tube-dilution) method and cylinder
test-tubes etc. were properly wrapped with papers and
plate (cup-plate) method.
sterilized in hot air oven.
In the turbidometric method inhibition of growth of microbial culture in a uniform dilution of antibiotic in
B. Disc diffusion method:-
a fluid medium is measured. It is compared with the
Preparation of Nutrient Agar medium:-
synthesized compounds. Here the presence or absence
•
Agar
20g
of growth is measured. The cylinder plate method
•
Peptone
10g
depends upon diffusion of antibiotic from a vertical
•
Beef extract
10g
cylinder through a solidified agar layer in a Petri dish
•
Sodium chloride
5g
or plate to an extent such that growth of added micro-
•
Distilled water up to
1000ml
organisms is prevented entirely in a zone around the
(Maintain pH by NaOH: 7pH)
cylinder containing solution of the antibiotics. The
All the ingredients were weighed and added to water.
cup-plate method is simple and measurement of
This solution was heated on water bath for about one
inhibition of microorganisms is also easy.
and half-hour till it became clear. This nutrient media
General
were sterilized by autoclaving at 121°C (15lbs psig) for
Procedure
for
Antimicrobial
Screening:-
15 minutes.
A. Cup Plate Method:-
Preparation of Standard solution:-
• All the Petri dishes were sterilized in oven at 160°C for 1 hour. • Agar media and test solutions were sterilized in autoclave at 121°C at 15psi. • Molten sterile agar was poured in sterile Petri dishes aseptically. • The agar was allowed to cool and the bacterial
The standard drug ampicillin was dissolved in appropriate
quantity
of
water
to
obtain
the
concentration range of 50, 100 and 150µg/ml and the zone of inhibition was checked. Preparation of Test solution:Specified quantity (50mg) of the compound was accurately weighed and dissolved in 50ml of water to
suspension was poured into the Petri dishes
get
aseptically.
dilutions were made with water to obtain the
• Placing the sterile bored in the agar plate by
the
concentration
1000µg/ml
and
further
concentration range of 250µg/ml, 500µg/ml and
borer and solution of the compounds was filled in
750µg/ml and the zone of inhibition was checked.
the bore using pipette (0.1ml) in appropriate four
Preparation of Inoculums:-
quadrants of petri dishes aseptically.
In the aseptic condition from the working culture,
• Petri dishes were be at 37°C for antibacterial
small amount of culture was transferred to about 10-
activity and 24°C for antifungal activity for 24
15ml of sterile normal saline (0.9% NaCl solution).
hours and observed the zone of inhibition.4
This solution was gently mixed and used for the
Antibacterial Screening:-
antibacterial activity. About 0.5ml of inoculums was
Culture:-
added to the sterilized petri dish and melted agar
S.aureus and B.subtilis were used as gram-positive
cooled was added, mixed gently and allowed to
bacteria and E.coli were used as gram negative
solidify. Placing the sterile bored in the agar plate by
bacteria for our study. The master culture were be
borer and solution of the compounds were filled in the
prepared on agar slant of the above nutrient media
bore using pipette (0.1ml) in appropriate four
and kept in refrigerator. The working culture was
quadrants of petridishes aseptically. Petri dishes were
prepared from it by weekly transferred in nutrient
then incubated at 37°C for 24 hours and after which
agar medium.
the zone of inhibition was measured.
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Dhaval K. Patel, et al: Synthesis and SAR of some Novel N-(3-Chloro-2-Oxo-4-substituted (Aryl) Azetidin-1-yl)
Screening of Antibacterial activities of synthesized compounds:Compound Concentration No. (µg/ml)
6a
6b
6c
6d
6e
6f
6g
6h
Ampicillin
250 500 750 1000 250 500 750 1000 250 500 750 1000 250 500 750 1000 250 500 750 1000 250 500 750 1000 250 500 750 1000 250 500 750 1000 50 100 150
Zone of inhibition (mm) Gram+ve Gram-ve S.aureus B.subtilis E.coli 00 00 03 05 04 06 07 06 09 09 08 11 07 09 08 11 13 13 15 17 18 18 21 22 06 06 05 09 08 06 10 09 08 13 14 10 00 03 06 04 05 08 05 08 09 06 10 12 09 10 09 13 14 15 17 19 18 19 23 22 05 00 06 07 05 08 08 06 09 10 08 11 05 04 08 06 04 08 07 06 09 09 07 12 00 00 00 00 00 00 03 04 04 08 05 06 21 25 24 23 28 27 25 30 30
Table-3: Zone of Inhibition (Antibacterial)
Serial dilution of the substance under examination was placed into culture tubes containing suitable medium and inoculated with the test organism. After incubation, the minimum concentration of test compound that inhibited the growth of the organism were observed.4,5 Determination
of
MIC
by
tube
dilution
method:Preparation of Nutrient Broth medium:•
Peptone
10g
•
Beef extract
10g
•
Sodium chloride
•
Distilled water up to
5g 1000ml
All the ingredients were weighed and dissolved in water. This nutrient media were sterilized by autoclaving at 121°C (15lbs psig) for 15 minutes. Procedure:All the synthesized compounds were dissolved separately to prepare a stock solution containing 1000µg/ml and 800µg/ml in water. 1ml of this solution were aseptically transferred to the sterile nutrient broth medium and made up to 10ml with sterile nutrient media, thus 1ml of the resulted solution gives 1000µg/ml. 5ml of the above solution were transferred to 5ml of water to give half the concentration of first. Thus, from 1000µg/ml stock solution, a successive concentration like 500, 250, 125, 62.5 and so were prepared in a similar manner up to 6 dilutions from sixth 5ml of the solution were discarded. Thus, from 800µg/ml stock solution, a successive concentration like 400, 200, 100, 50 and so were prepared in a similar manner up to 6 dilutions from sixth 5ml of the solution were discarded. The
Figure-1: Histogram of Antibacterial Screening MIC OF ANTIBACTERIAL SCREENING:Minimum inhibitory concentration is the lowest concentration antimicrobial compound found to inhibit the growth of particular test organism. MIC of different antimicrobial compounds is determined by
organism. A positive control and a negative control were also prepared to confirm the nutritive property and sterility, respectively of the prepared to confirm nutritive property and sterility, respectively of the prepared medium. The tubes were incubated at 37°C
liquid dilution method. MIC of the synthesized compounds was determined
100
tubes were inoculated with 0.5ml of the test organism culture. The process was repeated with different test
MIC:-
by tube dilution techniques.
tubes were mixed well after each addition. All the
for 48hours. The presence or absence of growth of organisms
were
observed
after
incubation.4,5
Internationale Pharmaceutica Sciencia Apr-June 2013 Vol 3 Issue 2
Dhaval K. Patel, et al: Synthesis and SAR of some Novel N-(3-Chloro-2-Oxo-4-substituted (Aryl) Azetidin-1-yl) Minimum Inhibitory Concentrations (µg/ml) Comp. No. 6a 6b 6c 6d 6e 6f 6g 6h Ampicillin
S.aureus (MTCC 96)
B.subtilis (MTCC121)
E.coli (MTCC521)
500 150 250 500 125 250 250 750 50
500 125 250 250 125 500 250 750 12.5
250 125 250 250 125 250 150 750 12.5
Table-4: MIC (Antibacterial)
Figure-2: Histogram of MIC (Antibacterial Screening) DISCUSSION:All
synthesized
sterilized in hot air oven. compounds
were
screened
for
Cup Plate method:-
antibacterial activity by disc diffusion method at
Preparation of
different
medium:-
concentration
ranges
from
250
to
Sabouraud
1000µg/ml. Compounds 6b and 6e have shown
•
Dextrose
4g
highest zone of inhibition against S.aureus having
•
Peptone
1g
MIC 150 and 125µg/ml respectively. Compound 6b
•
Agar
2g
and 6e have shown highest inhibition against
•
Distilled water up to 100ml
Dextrose
Agar
B.subtilis. Compounds 6b and 6e have shown
(Final pH 5.6 ±0.2 at 25°C)
highest zone of inhibition while other compounds
All the ingredients were weighed and added to water.
shown
All
This solution was heated on water bath for about one
synthesized compounds were found to be less potent
and half-hour till it became clear. This nutrient media
compared to the standard drug Ampicillin.
were sterilized by autoclaving at 121°C (15lbs psig) for
moderate
activity
against
E.coli.
15 minutes. SCREENING OF ANTIFUNGAL ACTIVITY:-
Preparation of Standard solution:-
Antifungal Screening:-
The standard drug Fluconazole were dissolved in
Culture:-
appropriate
The synthesized compounds were screened for their
concentration range of 50, 100 and 150µg/ml and the
antifungal activity against fungi Candida albicans.
zone of inhibition were checked.
Apparatus:-
Preparation of Test solution:-
All the apparatus like petri dishes, pipettes, glass rods,
Specified quantity (50mg) of the compound were
quantity
of
water
to
obtain
test-tubes etc. were properly wrapped with papers and Internationale Pharmaceutica Sciencia Apr-June 2013 Vol 3 Issue 2
101
the
Dhaval K. Patel, et al: Synthesis and SAR of some Novel N-(3-Chloro-2-Oxo-4-substituted (Aryl) Azetidin-1-yl)
accurately weighed and dissolved in 50ml of water to get
the
concentration
1000µg/ml
and
further
dilutions were made with water to obtain the concentration range of 250µg/ml, 500µg/ml and 750µg/ml and the zone of inhibition were checked. Preparation of Inoculums:In the aseptic condition from the working culture, small amount of culture were transferred to about 10-15ml of sterile normal saline (0.9% NaCl solution). This solution were gently mixed and used for the antifungal activity. About 0.5ml of inoculums was added to the sterilized petri dish and melted agar cooled were added, mixed gently and allowed to solidify. Placing the sterile bored in the agar plate by borer and solution of the compounds were filled in the bore using pipette (0.ml) in appropriate four quadrants of petridishes aseptically. Petri dishes were then incubated at 27°C for 24 hours and after which
Figure-3: Histogram of Antifungal Screening Determination
of
MIC
by
tube
dilution
method:Preparation of Sabouraud Dextrose medium:•
Peptone
10 g
•
Dextrose
20 g
•
Distilled water up to 1000 ml
All the ingredients were weighed and added to water. This nutrient media were sterilized by autoclaving at 121°C (15lbs psig) for 15 minutes. Procedure:-
the zone of inhibition were measured.6 Screening of Antifungal activity of synthesized compounds:Compound Concentration Zone of inhibition (mm) No. (µg/ml) C.albicans 250 00 500 06 6a 750 08 1000 09 250 08 500 13 6b 750 18 1000 22 250 00 500 06 6c 750 07 1000 10 250 00 500 05 6d 750 06 1000 08 250 09 500 14 6e 750 17 1000 23 250 00 500 00 6f 750 07 1000 09 250 04 500 06 6g 750 07 1000 10 250 00 500 00 6h 750 04 1000 06 50 25 Fluconazole 100 28 150 31
Table-5: Zone of Inhibition (Antifungal)
All the synthesized compounds were dissolved separately to prepare a stock solution containing 1000µg/ml and 800µg/ml in water. 1 ml of this solution were aseptically transferred to the sterile nutrient broth medium and made up to 10 ml with sterile nutrient media, thus 1 ml of the resulted solution gives 1000µg/ml. 5ml of the above solution were transferred to 5ml of water to give half the concentration of first. Thus, from 1000µg/ml stock solution, a successive concentration like 500, 250, 125, 62.5 and so will prepared in a similar manner up to 6 dilutions from sixth 5 ml of the solution were discarded. Thus, from 800µg/ml stock solution, a successive concentration like 400, 200, 100, 50 and so were prepared in a similar manner up to 6 dilutions from sixth 5ml of the solution were discarded. The tubes were mixed well after each addition. All the tubes were inoculated with 0.5ml of the test organism culture. The process was repeated with different test organism. A positive control and a negative control were also prepared to confirm the nutritive property and sterility, respectively of the prepared to confirm nutritive property and sterility, respectively of the prepared medium. The tubes were incubated at 27°C for 48 hours. The presence or absence of growth of organisms were observed after incubation.7
102
Internationale Pharmaceutica Sciencia Apr-June 2013 Vol 3 Issue 2
Dhaval K. Patel, et al: Synthesis and SAR of some Novel N-(3-Chloro-2-Oxo-4-substituted (Aryl) Azetidin-1-yl)
Substitutions with the electron withdrawing groups MIC of Antifungal Screening:-
on phenyl ring C-2 and C-4 position influences the antimicrobial activity. Earlier Sushil Kumar et al, has
Minimum Inhibitory Concentrations (µg\ml)
reported 2-Cl, 4-NO2 substitution on phenyl ring
Compound No.
C.albicans (MTCC 227)
6a
400
enhances the antimicrobial activity. Present study
6b
150
indicates that electron withdrawing groups improves
6c
400
the antimicrobial activity compared to electron
6d
500
releasing groups phenyl ring. In congeneric series
6e
150
6f
600
6g
250
6h
750
Fluconazole
25
compounds 6b and 6e with 4-Cl and 2-NO2 on phenyl ring
exhibited
maximum
activity
among
all
synthesized compounds. Increasing in the activity observed in the following order: 2-NO2-C6H4->4-Cl-C6H4->2-Furyl>4-N
Table-6: MIC (Antifungal)
(CH3)2C6H4->4-OCH3-C6H4->4-OH-C6H4->1Naphthyl>-C6H5 CONCLUSION:Among all the synthesized moieties, compounds 6b and 6e have shown higher antimicrobial activity due to electron withdrawing groups substituted on phenyl ring which is attached at 2nd position of azetidinones ring. Study concludes that electron withdrawing
Figure-4: Histogram of MIC (Antifungal Screening)
groups substituted on phenyl ring like 4-Cl, 2-NO2 and furyl can be favourable for antimicrobial activity. Study also concludes that electron releasing groups
DISCUSSION: All
synthesized
like –H, -OH, -OCH3, -N,N(CH3)2 and naphthyl has compounds
were
screened
for
antifungal activity by disc diffusion method at different
concentration
ranges
from
250
to
1000µg/ml. Compounds 6b and 6e have shown
shown poor activity. If a compound with electron withdrawing groups like 2-F, 3-Cl, 4-Br, 4-F etc on phenyl ring used in future, it may exhibit better antimicrobial activity.
highest zone of inhibition against C.albicans having MIC 150 and 150µg/ml respectively. All synthesized compounds were found to be less potent compared to the standard drug Fluconazole. STRUCTURE
ACTIVITY
ACKNOWLEDGEMENT: I am very thankful to my guide Mr. Chirag S. Rami and also thankful to Dr. D.J. Sen sir for constant
RELATIONSHIP
STUDY:
support throughout the project. I am especially thankful to department of Microbiology, SSPC,
O Cl
O
Mehsana as well as my classmates during entire project work.
N NH Aryl
N
REFERENCES:
Ar= -C6H5, 2-Cl-C6H4-, 4-Cl-C6H4-, 3-OH-C6H4-, 4-
1)
Kumar S., Kumar P., Sati N., “Synthesis and
OH-C6H4-, 4-OCH3-C6H4-, 4-NO2-C6H4-, 2-NO2-C6H4,
Biological
1-Naphthyl, 2-Furyl, 4-N(CH3)2C6H4-, 3-OH, 4-OCH3-
Azetidinones of 1-Naphthol.” J. Pharm. & Bioallied.
C6H4-
Sci., 2012, 4(3), 246-249.
Internationale Pharmaceutica Sciencia Apr-June 2013 Vol 3 Issue 2
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