studies on clinically important nitrogen and sulphur...

Studies on clinically important nitrogen and sulphur containing heterocyclic compounds

DECEMBER 2013 Page 131

SECTION-A

SPECTROSCOPIC ANALYSIS OF SYNTHESIZED COMPOUNDS

Newly synthesized compounds were characterized by IR, 1H NMR, 13C NMR and

mass spectral data as follows.

Part-I, Series-3

The structure of the final derivative GK3-7 was established on the basis of their

spectroscopic data. For example, the IR spectra of compound (GK3-7) showed

characteristic absorption band of carbonyl group at 1687 cm-1, while vibrations

appeared at 3071, 3029 and 2924 cm-1 corresponding to C-H stretching of

aromatic, -CH=CH- and –CH3 groups respectively. Absorption displayed at 745

cm-1 was due to C-Cl stretching vibrations, while C-O-C stretching vibration in

oxadiazole ring appeared at 1228 cm-1. Strong absorption band displayed at 3397

cm-1 was characteristic of secondary amine (N-H) stretching in benzimidazole

ring. 1H NMR spectrum of compound GK3-7 showed two doublets at δ 6.61 and

7.94 ppm due to the protons of alkene carbons attached to carbonyl group and 3-

chlorophenyl respectively. Secondary amine proton displayed chemical shift value

at δ 9.84 ppm as a singlet and remaining twelve protons revealed multiplet

between δ 7.22-7.84 ppm. Two singlets observed at δ 1.88 and 2.38 ppm

integrating for six protons of two methyl groups attached to oxadiazole ring and

phenyl ring respectively. 13C NMR spectrum of compound GK3-7, carbon atom of

carbonyl group and methine carbon (asymmetric carbon) appeared at δ 166.8

and 90.6 ppm respectively. Two signals displayed at δ 118.6 and 141.9 ppm were

characteristics of alkene carbons attached to carbonyl and 3-chlorophenyl groups

respectively. Two methyl carbons revealed chemical shifts at δ 21.4 and 27.8 ppm

whereas carbon of chlorine group showed chemical shift value at δ 134.1 ppm.

The mass spectrum of GK3-7 showed molecular ion peak at m/z = 457.44 (M+)

along with other fragment ion peaks, which is in agreement with its proposed

structure. All the synthesized compounds were fully characterized by

spectroscopic methods and gave satisfactory analytical and spectral data.

Structure of compound (GK3-7) is described in the following Figure A.



CHARACTERIZATION OF 1-(2-(1H-BENZO[d]IMIDAZOL-2-YL)-2-METHYL-5-(P-TOLYL)-1,3,4-OXADIAZOL-3(2H)-YL)-3-(3-CHLOROPHENYL)PROP-2-EN-1-

ONE (GK3-7)

The IR spectral assignments (Figure-1)

No. Wave number (cm-1) Assignment 1 3397 N-H Stretching (2º amine) 2 3071, 3029 C-H stretching, aromatic ring, -CH=CH- 3 2924 C-H stretching, -CH3 4 1687 >C=O stretching 5 1554, 1438 >C=N-, >C=C< stretching 6 1228 C-O-C stretching, oxadiazole ring 7 745 C-Cl stretching

Assignment of 1H NMR chemical shifts (δ ppm) to different protons (Figure-2)

No. Chemical shift (δ ppm) Multiplicity Proton assignment No. of

protons

1 1.88 Singlet -CH3 of oxadiazole ring 3 2 2.38 Singlet -CH3 of phenyl ring 3 3 6.61 Doublet =CH-CO- 1 4 7.22-7.80 Multiplet Ar-H 12 5 7.94 Doublet =CH-Ar 1 6 9.64 Singlet N-H of benzimidazole ring 1

Assignment of 13C NMR chemical shifts (δ ppm) to different carbons (Figure-3)

21.4, 27.8, 90.6, 115.1 (2), 118.6, 123.2 (2), 125.6 (2), 126.1, 126.7, 128.1,

129.2 (2), 129.7, 130.2, 134.1, 136.7, 138.8 (2), 140.8, 141.4, 141.9, 157.2,

166.8

Proposed fragmentation pattern (LCMS) (Figure-4)

No. m/z Relative intensity % Ion

1 457.44 42% (M+) C26H21ClN4O2



Figure 1

Figure 2



Figure 3

m/z60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 360 380 400 420 440 460 480 500 520 540 560 580 600

%

0

100GK5-VII P 2 (0.037) 1: TOF MS ES+

1.15e3479.40

139.20

83.12

70.08

135.12

119.1393.09

439.41

331.27

309.29

199.20

140.20

175.18141.11

274.41241.23

239.20

217.21 242.23

291.27381.33

365.32342.31

437.38

398.37421.38

457.44

458.43

571.54

571.36

549.51

531.49480.41

495.39

529.46

550.51

551.53

572.54

587.47591.54

597.54

Figure 4



CHARACTERIZATION OF 1-(2-(1H-BENZO[d]IMIDAZOL-2-YL)-5-(4-CHLORO- PHENYL)-2-METHYL-1,3,4-OXADIAZOL-3(2H)-YL)-3-PHENYLPROP-2-EN-1-

ONE (GK1-4)





protons

1 1.86 Singlet -CH3 of oxadiazole ring 3 2 6.58 Doublet =CH-CO- 1 3 7.18-7.81 Multiplet Ar-H 13 4 7.98 Doublet =CH-Ar 1 5 9.88 Singlet N-H of benzimidazole ring 1



Figure 5

Figure 6



CHARACTERIZATION OF 1-(2-(1H-BENZO[d]IMIDAZOL-2-YL)-5-(4-CHLORO- PHENYL)-2-METHYL-1,3,4-OXADIAZOL-3(2H)-YL)-3-(2-CHLOROPHENYL)-

PROP-2-EN-1-ONE (GK2-4)





protons




Figure 7

Figure 8



CHARACTERIZATION OF 1-(2-(1H-BENZO[d]IMIDAZOL-2-YL)-5-(4-CHLORO- PHENYL)-2-METHYL-1,3,4-OXADIAZOL-3(2H)-YL)-3-(4-CHLOROPHENYL)-






protons




Figure 9

Figure 10



CHARACTERIZATION OF 1-(2-(1H-BENZO[d]IMIDAZOL-2-YL)-5-(4-METHOXY- PHENYL)-2-METHYL-1,3,4-OXADIAZOL-3(2H)-YL)-3-(4-HYDROXYPHENYL)-



No. Wave number (cm-1) Assignment 1 3447 O-H Stretching 2 3398 N-H Stretching (2º amine) 3 3071, 3029 C-H stretching, aromatic ring, -CH=CH- 4 2923, 2854 C-H stretching, -CH3, -OCH3 5 1666 >C=O stretching 6 1523, 1492 >C=N-, >C=C< stretching 7 1229 C-O-C stretching, oxadiazole ring



protons

1 1.84 Singlet -CH3 of oxadiazole ring 3 2 3.86 Singlet -OCH3 of phenyl ring 3 3 6.46 Doublet =CH-CO- 1 4 7.20-7.81 Multiplet Ar-H 12 5 7.92 Doublet =CH-Ar 1 6 9.14 Singlet O-H of phenyl ring 1 7 9.82 Singlet N-H of benzimidazole ring 1



1 455.47 82% (M+) C26H22N4O4


DECEMBER 2013 3

Figure 11

Figure 12



m/z60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 360 380 400 420 440 460 480 500 520 540 560 580 600

%

0

100GK5-VII N 3 (0.056) 1: TOF MS ES-

7.93e3307.31

215.23

173.22111.0687.0762.03 121.12137.13

214.83

216.25

251.24217.26 283.30

455.47

357.38

308.34

311.33

340.36339.40

358.40437.48

413.46393.39 435.45

547.56

456.50

505.54473.51

529.56

548.58

573.60572.52 589.61 597.63

Figure 13



Part-II, Series-1

The structure of the final derivative GK6-1 was established on the basis of their

spectroscopic data. For example, the IR spectra of compound GK6-1 showed

characteristic absorption band of carbonyl group at 1693 cm-1. Absorption bands

at 1517 and 1582 cm-1 were due to stretching vibrations corresponding to C=C

and C=N groups respectively. Strong absorption band displayed at 1222 cm-1 was

characteristic of C-O-C stretching in oxadiazole ring. Compound endowed with

chloro group appeared vibration at 756 cm-1, while absorption bands appeared at

3158 and 3017 cm-1 corresponding to C-H stretching of aromatic and -CH=CH-

groups respectively. 1H NMR spectrum of compound GK6-1 showed two doublets

at δ 6.52 and 7.96 ppm due to the protons of alkene carbons attached to

carbonyl group and phenyl ring respectively. Two singlets observed at δ 6.84 and

8.23 ppm integrating for one proton attached to asymmetric carbon and one

pyrazole ring proton (C5-H) respectively. Two doublets appeared at δ 8.14 and

8.78 ppm for four protons of pyridine ring (C3-H & C5-H; C2-H & C6-H) and

remaining fourteen protons displayed multiplet between δ 7.34-7.86 ppm. 13C

NMR spectrum of compound GK6-1, carbon atom of carbonyl group and methine

carbon (asymmetric carbon) appeared at δ 167.2 and 78.8 ppm respectively. Two

carbons of alkene group appeared chemical shifts at δ 141.8 and 118.9 ppm due

to carbon attached to phenyl ring and carbonyl group respectively whereas

carbon of chlorine group showed chemical shift value at δ 134.4 ppm. The mass

spectrum of GK6-1 showed molecular ion peak at m/z = 531.12 (M+), along with

other fragment ion peaks, which is in agreement with its proposed structure. All

synthesized compounds were fully characterized by spectroscopic methods and

gave satisfactory analytical and spectral data. Structure of compound (GK6-1) is

described in the following Figure B.



CHARACTERIZATION OF 1-(2-(3-(4-CHLOROPHENYL)-1-PHENYL-1H-PYRA- ZOL-4-YL)-5-(PYRIDIN-4-YL)-1,3,4-OXADIAZOL-3(2H)-YL)-3-PHENYLPROP-2-

EN-1-ONE (GK6-1)


No. Wave number (cm-1) Assignment 1 3158, 3017 C-H stretching, aromatic ring, -CH=CH- 2 1693 >C=O stretching 3 1582, 1517 >C=N-, >C=C< stretching 4 1222 C-O-C stretching, oxadiazole ring 5 756 C-Cl stretching



protons 1 6.40 Doublet =CH-CO- 1 2 6.84 Singlet C2-H oxadiazole ring 1 3 7.14-7.78 Multiplet Ar-H 14 4 7.96 Doublet =CH-Ar 1 5 8.14 Doublet C3-H & C5-H pyridine ring 2 6 8.23 Singlet C5-H pyrazole ring 1 7 8.78 Doublet C2-H & C6-H pyridine ring 2


78.8, 117.2, 118.9, 119.8 (2), 123.2, 124.2 (2), 126.2, 127.8, 128.0 (2), 128.5

(2), 128.9 (2), 129.2 (2), 129.8 (2), 131.2, 134.4, 135.1, 138.5, 139.8, 141.8,

149.3 (2), 149.8, 157.1, 167.2


No. m/z Relative intensity % Ion 1 531.12 100% (M+) C31H22ClN5O2



Figure 14

Figure 15



Figure 16

Figure 17



CHARACTERIZATION OF 1-(2-(3-(4-FLUOROPHENYL)-1-PHENYL-1H-PYRA- ZOL-4-YL)-5-(PYRIDIN-4-YL)-1,3,4-OXADIAZOL-3(2H)-YL)-3-PHENYLPROP

-2-EN-1-ONE (GK7-1)


No. Wave number (cm-1) Assignment

1 3166 C-H stretching, aromatic ring, -CH=CH- 2 3028 C-H stretching, -CH=CH- 3 1694 >C=O stretching 4 1592, 1528 >C=N-, >C=C< stretching 5 1232 C-O-C stretching, oxadiazole ring 6 1152 C-F stretching



protons

1 6.51 Doublet =CH-CO- 1 2 6.84 Singlet C2-H oxadiazole ring 1 3 7.20-7.82 Multiplet Ar-H 14 4 8.03 Doublet =CH-Ar 1 5 8.20 Doublet C3-H & C5-H pyridine ring 2 6 8.34 Singlet C5-H pyrazole ring 1 7 8.86 Doublet C2-H & C6-H pyridine ring 2



Figure 18

Figure 19



CHARACTERIZATION OF 1-(2-(3-(4-METHOXYPHENYL)-1-PHENYL-1H-PYRA- ZOL-4-YL)-5-(PYRIDIN-4-YL)-1,3,4-OXADIAZOL-3(2H)-YL)-3-PHENYLPROP-2-

EN-1-ONE (GK8-1)



1 3142 C-H stretching, aromatic ring, -CH=CH- 2 3016 C-H stretching, -CH=CH- 3 2832 C-H stretching, -OCH3 4 1682 >C=O stretching 5 1572, 1512 >C=N-, >C=C< stretching 6 1212 C-O-C stretching, oxadiazole ring



protons

3.81 Singlet -OCH3 3 1 6.40 Doublet =CH-CO- 1 2 6.80 Singlet C2-H oxadiazole ring 1 3 7.15-7.80 Multiplet Ar-H 14 4 7.88 Doublet =CH-Ar 1 5 8.06 Doublet C3-H & C5-H pyridine ring 2 6 8.21 Singlet C5-H pyrazole ring 1 7 8.75 Doublet C2-H & C6-H pyridine ring 2



Figure 20

Figure 21



CHARACTERIZATION OF 1-(2-(3-(4-NITROPHENYL)-1-PHENYL-1H-PYRAZOL-4-YL)-5-(PYRIDIN-4-YL)-1,3,4-OXADIAZOL-3(2H)-YL)-3-PHENYLPROP-2-EN-1-

ONE (GK9-1)



1 3167 C-H stretching, aromatic ring, -CH=CH- 2 3036 C-H stretching, -CH=CH- 3 1693 >C=O stretching 4 1588, 1532 >C=N-, >C=C< stretching 5 1512 N=O stretching, -NO2 6 1232 C-O-C stretching, oxadiazole ring



protons

1 6.44 Doublet =CH-CO- 1 2 6.80 Singlet C2-H oxadiazole ring 1 3 7.18-7.82 Multiplet Ar-H 14 4 7.98 Doublet =CH-Ar 1 5 8.24 Doublet C3-H & C5-H pyridine ring 2 6 8.31 Singlet C5-H pyrazole ring 1 7 8.81 Doublet C2-H & C6-H pyridine ring 2



Figure 22

Figure 23



Part-III, Series-1 Structure of compound (GK10-1) was confirmed on the basis of spectral data. For

example, the IR spectra of compound (GK10-1) showed absorption bands at 3163

and 2931 cm-1 characteristic of C-H stretching of aromatic ring and alkyl chain

respectively. Absorption reported at 752 cm-1 was due to C-Cl stretching

vibrations, while cyanide group stretching vibration appeared at 2281 cm-1.

Strong absorption band displayed at 3393 cm-1 was characteristic of secondary

amine (N-H) stretching in pyrimidine ring. Absorption bands at 1541 and 1496

cm-1 were due to stretching vibrations corresponding of C=N and C=C groups

respectively. 1H NMR spectrum of compound (GK10-1) displayed two triplets at δ

3.11 and 3.42 ppm due to protons of two methylene groups attached to cyanide

group and sulphur atom respectively. Two doublets appeared at δ 5.11 and 6.32

ppm corresponding to protons attached to asymmetric carbon and methine

carbon of pyrimidine ring respectively. Secondary amine proton displayed

chemical shift value at δ 9.61 ppm as a singlet and remaining nine protons

appeared multiplet between δ 7.42-8.26 ppm. 13C NMR spectrum of compound

(GK10-1) revealed twenty nonequivalent carbons. Two different methylene carbons

appeared at δ 47.9 and 54.6 ppm, while cyanide group carbon displayed

chemical shift value at δ 119.2 ppm. The appearance of signal around at δ 166.6

ppm was assignable to carbon of pyrimidine ring attached to two nitrogen and a

sulphur atoms. Two signals displayed at δ 132.7 and 152.2 ppm were

characteristics of carbons of quinoline ring attached to chlorine atom whereas

assymetric carbon of pyrimidine revealed chemical shift at δ 48.4 ppm. The mass

spectrum of GK10-1 showed molecular ion peak at m/z = 439.42 (M+) along with

other fragment ion peaks, which is in agreement with its proposed structure. All

synthesized compounds were fully characterized by spectroscopic methods and

gave satisfactory analytical and spectral data. Structure of compound (GK10-1) is

described in the following Figure C.



CHARACTERIZATION OF 3-((6-(2,6-DICHLOROQUINOLIN-3-YL)-4-PHENYL-1,6-DIHYDROPYRIMIDIN-2-YL)THIO)PROPANENITRILE (GK10-1)



1 3393 N-H stretching, pyrimidine ring 2 3163 C-H stretching, aromatic ring, alkyl chain 3 2931 C-H stretching, alkyl chain 4 2281 -C≡N stretching, nitrile group 5 1541 >C=N-stretching 6 1496 >C=C< stretching 7 752 C-Cl stretching


No. Chemical

shift (δ ppm)

Multiplicity Proton assignment No. of protons

1 3.11 Triplet -CH2-CN 2 2 3.42 Triplet -CH2-S- 2 3 5.11 Doublet H-C-NH- (asymmetric carbon) 1 4 6.32 Doublet H-C=C-N (olefinic carbon) 1 5 7.20-8.20 Multiplet Ar-H 9 6 9.61 Singlet H-N< (2º amine) 1


47.9, 48.4, 54.6, 114.1, 119.2, 123.5, 126.4 (2), 127.2, 127.8, 128.4 (2), 128.9,

131.6, 132.1, 132.7, 135.2, 136.8, 142.2, 143.7, 152.2, 166.6



1 439.42 100% (M+) C22H16Cl2N4S



Figure 24

Figure 25



Figure 26

Figure 27



CHARACTERIZATION OF 3-((6-(2-CHLORO-6-FLUOROQUINOLIN-3-YL)-4-(4-CHLOROPHENYL)-1,6-DIHYDROPYRIMIDIN-2-YL)THIO)PROPANENITRILE

(GK11-4)


No. Wave number (cm-1) Assignment 1 3381 N-H stretching, pyrimidine ring 2 3144 C-H stretching, aromatic ring 3 2920 C-H stretching, alkyl chain 4 2266 -C≡N stretching, nitrile group 5 1566 >C=N-stretching 6 1515 >C=C< stretching 7 1113 C-F stretching 8 766 C-Cl stretching



protons

1 3.15 Triplet -CH2-CN 2 2 3.51 Triplet -CH2-S- 2 3 5.18 Doublet H-C-NH- (asymmetric carbon) 1 4 6.12 Doublet H-C=C-N (olefinic carbon) 1 5 7.18-8.21 Multiplet Ar-H 8 6 9.72 Singlet H-N< (2º amine) 1



Figure 28

Figure 29



CHARACTERIZATION OF 3-((6-(2-CHLORO-6-METHOXYQUINOLIN-3-YL)-4-(4- CHLORO-PHENYL)-1,6-DIHYDROPYRIMIDIN-2-YL)THIO)PROPANENITRILE

(GK12-4)


No. Wave number (cm-1) Assignment 1 3413 N-H stretching, pyrimidine ring 2 3192 C-H stretching, aromatic ring 3 2947 C-H stretching, alkyl chain 4 2829 C-H stretching, -OCH3 5 2314 -C≡N stretching, nitrile group 6 1528 >C=N-stretching 7 1481 >C=C< stretching 8 734 C-Cl stretching



protons

1 3.12 Triplet -CH2-CN 2 2 3.46 Triplet -CH2-S- 2 3 3.87 Singlet -OCH3 3 4 5.17 Doublet H-C-NH- (asymmetric carbon) 1 5 6.11 Doublet H-C=C-N (olefinic carbon) 1 6 7.21-8.18 Multiplet Ar-H 8 7 9.62 Singlet H-N< (2º amine) 1



Figure 30

Figure 31



SECTION-B

BIOLOGICAL EVALUATION OF SYNTHESIZED COMPOUNDS

Introduction

Antimicrobial agents are among the most commonly used and misused of all

drugs. The inevitable consequence of the widespread use of antimicrobial agents

has been the emergence of antibiotic-resistant pathogens, fueling an ever-

increasing need for new drugs. However, the pace of antimicrobial drug

development has slowed dramatically, with only a handful of new agents, few of

which are novel, being introduced into clinical practice each year. Reducing

inappropriate antibiotic use is thought to be the best way to control resistance.

Although awareness of the consequences of antibiotic misuse is increasing,

overprescribing remains widespread, driven largely by patient demand, time

pressure on clinicians, and diagnostic uncertainty. If the gains in the treatment

of infectious diseases are to be preserved, clinicians must be wiser and more

selective in the use of antimicrobial agents.

The history of chemotherapeutic agents1

Bacteria were first identified in the 1670s by van Leeuwenhoek, following his

invention of the microscope. However, it was not until the nineteenth century

that their link with disease was appreciated. This appreciation followed the

elegant experiments carried out by the French scientist Pasteur, who

demonstrated that specific bacterial strains were crucial to fermentation and that

these and other microorganisms were far more widespread than was previously

thought. The possibility that these microorganisms might be responsible for

disease began to take hold.

An early advocate of a 'germ theory of disease' was the Edinburgh surgeon Lister.

Despite the protests of several colleagues who took offence at the suggestion that

they might be infecting their own patients, Lister introduced carbolic acid as an

antiseptic and sterilizing agent for operating theatres and wards. The

improvement in surgical survival rates was significant.

During that latter half of the nineteenth century, scientists such as Koch were

able to identify the microorganisms responsible for diseases such as tuberculosis,



cholera, and typhoid. Methods such as vaccination for fighting infections were

studied. Research was also carried out to try and find effective antibacterial

agents or antibiotics. However, the scientist who can lay claim to be the father of

chemotherapy-the use of chemicals against infection—was Paul Ehrlich. Ehrlich

spent much of his career studying histology, then immunochemistry, and won a

Nobel prize for his contributions to immunology. However, in 1904 he switched

direction and entered a field which he defined as chemotherapy. Ehrlich's

'Principle of Chemotherapy' was that a chemical could directly interfere with the

proliferation of microorganisms, at concentrations tolerated by the host. This

concept was popularly known as the 'magic bullet', where the chemical was seen

as a bullet which could search out and destroy the invading microorganism

without adversely affecting the host. The process is one of selective toxicity,

where the chemical shows greater toxicity to the target microorganism than to

the host cells. Such selectivity can be represented by a 'chemotherapeutic index',

which compares the minimum effective dose of a drug with the maximum dose

which can be tolerated by the host. This measure of selectivity was eventually

replaced by the currently used therapeutic index.

By 1910, Ehrlich had successfully developed the first example of a purely

synthetic antimicrobial drug. This was the arsenic-containing compound

‘salvarsan’ (Figure 1). Although it was not effective against a wide range of

bacterial infections, it did prove effective against the protozoal disease sleeping

sickness (trypanosomiasis) and the spirochaete disease of syphilis. The drug was

used until 1945 when it was replaced by penicillin.

Over the next twenty years, progress was made against a variety of protozoal

diseases, but little progress was made in finding antibacterial agents, until the

introduction of ‘proflavine’ (Figure 1) in 1934. It is an interesting drug since it

targets bacterial DNA rather than protein. Despite the success of this drug, it was

not effective against bacterial infections in the bloodstream and there was still an

urgent need for agents which would fight these infections.

This need was answered in 1935 with the discovery that a red dye called

‘prontosil’ (Figure 1) was effective against streptococci infections in vivo. As

discussed later, prontosil was eventually recognized as being a prodrug for a new

class of antibacterial agents-the sulfa drugs (sulfonamides). The discovery of



these drugs was a real breakthrough, since they represented the first drugs to be

effective against bacterial infections carried in the bloodstream. They were the

only effective drugs until penicillin became available in the early 1940s.

Although penicillin was discovered in 1928, it was not until 1940 that effective

means of isolating it were developed by Florey and Chain. Society was then

rewarded with a drug which revolutionized the fight against bacterial infection

and proved even more effective than the sulfonamides. Many antibacterial agents

are now available and the vast majority of bacterial diseases such as syphilis,

tuberculosis, typhoid, bubonic plague, leprosy, diphtheria, gas gangrene,

tetanus, gonorrhea have been brought under control. This represents a great

achievement for medicinal chemistry and it is perhaps sobering to consider the

hazards which society faced in the days before penicillin.

Bacteria are unicellular microorganisms. They are typically a few micrometers

long and have many shapes including spheres, rods and spirals. Microorganisms

have played profound roles in warfare, religion and the migration of populations.

Control of microbial population is necessary to prevent transmission of diseases,

infection, decomposition, contamination and spoilage caused by them.2 Man’s

personal comforts and convenience depend to a large extent on the control of

microbial population.



Bacteria

Bacteria are a successful and ancient form of life, quite different from the

eukaryotes (which include the fungi, plants and animals). They are small cells,

found in the environment as either individual cells or aggregated together as

clumps, and their intracellular structure is far simpler than eukaryotes.

Bacteria have a single circular DNA chromosome that is found within the

cytoplasm of the cell as they do not have a nucleus. Indeed they lack any of the

intracellular organelles so characteristic of eukaryotic cells, such that they do not

have the golgi apparatus, endoplasmic reticulum, lysosomes nor mitochondria.

However they are generally capable of ‘free-living’ and therefore they possess all

the biosynthetic machinery that is needed for this, including 70S ribosomes (as

opposed to the larger 80S forms found in eukaryotes) distributed throughout the

cytoplasm.

The most complex region of the cell is often the cell surface. The cell wall/outer

membrane is described below, but in addition some bacteria may secrete a

polysaccharide capsule onto their outer surface, some may have flagella which

they require for mobility and some may have external projections such as

fimbriae and pili which are useful for adherence in their chosen habitat.

Although bacteria are generally far simpler than eukaryotic cells, they are

extremely efficient within their own little niche - and this may include the ability

to cause human infections. Bacteria multiply by binary fission and there is no

sexual interaction.3



Unlike animals and other eukaryotes, bacterial cells do not contain a nucleus or

other membrane-bound organelles. Although the term bacteria traditionally

included all prokaryotes, the scientific nomenclature changed after the discovery

that prokaryotic life consists of two very different groups of organisms that

evolved independently from an ancient common ancestor. These evolutionary

domains are called Bacteria and Archaea.4

The study of the biology of bacteria requires some knowledge of the Gram-stain

reaction. This technique is essential in the identification and classification of

bacteria. In 1884, Hans Christian Gram found that bacteria could be divided into

two groups.

The study of the biology of bacteria requires some knowledge of the Gram-stain

reaction. This technique is essential in the identification and classification of

bacteria. In 1884, Hans Christian Gram found that bacteria could be divided into

two groups. In this process, purple dyes are poured over bacteria that have been

spread out thinly on a microscope slide and the cell walls of the bacteria (made

out of peptidoglycan) take up the colour. If a solvent is then applied to the slide,

bacteria which have only got a cell wall still keep their purple colour, but bacteria

which have got an extra cell membrane (made out of phospholipid) outside their

cell wall quickly lose the purple stain and become colourless; in order to be able

to see these bacteria under the microscope a second red stain is then used.

� Bacteria that manage to keep the original purple dye have only got a cell

wall - they are called Gram-positive.

� Bacteria that lose the original purple dye and can therefore take up the

second red dye have got both a cell wall and a cell membrane - they are

called Gram-negative.

Gram-positive Gram-negative



Gram-positive bacteria have a cell wall composed of a single thick layer of

peptidoglycan. Gram-negative bacteria have a cell wall with several thinner layers

composed of peptidoglycan, lipopolysaccharide and protein. The Gram-stain

reaction can identify bacteria as Gram-positive or Gram-negative, but potentially

messy stains and expensive microscopes are needed. The KOH test is a faster and

simpler method to determine the same reaction. When Gram-negative bacterial

cells are placed in an alkaline solution (3% KOH), the cells walls are destroyed,

and the cell contents, including the DNA, are released. Because their cell wall

structure is different, Gram-positive bacteria will not lyse in 3% KOH. The KOH

method was originally developed by a Japanese scientist named Ryu in 1938.

The Gram-stain is an important diagnostic tool in human medicine because some

antibiotics are effective against only Gram-negative bacteria (e.g., erythromycin)

and some against only Gram-positive ones (e.g., penicillin, actinomycin). Bacteria

also cause plant diseases. Most plant pathogenic bacteria are Gram negative

(Agrobacterium, Erwinia, Pseudomonas, Ralstonia, and Xanthomonas). A few

bacterial genera found in association with plants are Gram-positive (Bacillus,

Clavibacter, and Streptomyces).5 For evaluation of antibacterial activity in our

case, we have used Staphylococcus aureus and Streptococcus pyogenes from

Gram-positive group of bacteria and Escherichia coli and Pseudomonas

aeruginosa from Gram-negative group of bacteria.

Classification and Mechanism of Action of Antimicrobial agents6

Antimicrobial agents are classified based on chemical structure and proposed

mechanism of action, as follows:

1. Agents that inhibit synthesis of bacterial cell walls, including the β-lactam

class (e.g., penicillins, cephalosporins and carbapenems) and dissimilar

agents such as cycloserine, vancomycin and bacitracin;

2. Agents that act directly on the cell membrane of the microorganism,

increasing permeability and leading to leakage of intracellular compounds,

including detergents such as polymyxin, polyene antifungal agents (e.g.,

nystatin and amphotericin B) which bind to cell-wall sterols and the

lipopeptide daptomycin;7



3. Agents that disrupt function of 30S or 50S ribosomal subunits to reversibly

inhibit protein synthesis, which generally are bacteriostatic (e.g.,

chloramphenicol, tetracyclines, erythromycin, clindamycin, streptogramins and

linezolid);

4. Agents that bind to the 30S ribosomal subunit and alter protein synthesis,

which generally are bactericidal (e.g., aminoglycosides);

5. Agents that affect bacterial nucleic acid metabolism, such as the rifamycins

(e.g., rifampin and rifabutin), which inhibit RNA polymerase and the

quinolones which inhibit topoisomerases;

6. The antimetabolites, including trimethoprim and the sulfonamides which

block essential enzymes of folate metabolism.

There are several classes of antiviral agents, including:

1. Nucleic acid analogs such as acyclovir or ganciclovir which selectively inhibit

viral DNA polymerase, and zidovudine or lamivudine, which inhibit HIV

reverse transcriptase;

2. Non-nucleoside HIV reverse transcriptase inhibitors, such as nevirapine or

efavirenz;

3. Inhibitors of other essential viral enzymes, e.g., inhibitors of HIV protease or

influenza neuraminidase;

4. Fusion inhibitors such as enfuvirtide.

Additional categories likely will emerge as more complex mechanisms are

elucidated. The precise mechanism of action of some antimicrobial agents still is

unknown.

Antimicrobial activity of the synthesized compounds

It has been estimated that the life span of humans has increased by almost a

decade since the discovery of antimicrobial agents against microbial infections. A

consequence of our success with antibacterial agents and improved medical care

is the increase in the number of fungal infections. The incidence of fungal

infection has increased dramatically in the past 20 years partly due to increase



in the number of people whose immune systems are compromised by AIDS,

aging, organ transplantation or cancer therapy. Accordingly, the increase in rates

of morbidity and mortality of infections has been now recognized as a major

problem. In response, pharmaceutical industry has developed a number of novel

less toxic antifungal for clinical use. Its increased use often for prolonged period,

has led to the increased incidence of infections with less common species, with

intrinsic resistance to one or more of the available antifungal agents.

Fungi are non-photosynthetic eukaryotes growing either as a colony of single

cells (yeasts) or as filamentous multicellular aggregates (molds). Most fungi live

as saprobes in soil or dead plant material and are important in the mineralization

of organic matter. Some are pathogens of humans and animals. The in vitro

methods used for detection of antifungal potency are similar to those used in

antibacterial screening. As with bacteria, it is easy to discover several synthetic

and natural compounds that, in minute quantities, can retard or prevent growth

of fungi.

Screening methods for antimicrobial activity

The following conditions must be follow for the screening of antimicrobial

activity:8-10 � There should be intimate contact between the test organisms and

substance to be evaluated.

� Required conditions should be provided for the growth of microorganisms.

� Conditions should be same through the study.

� Aseptic / sterile environment should be maintained.

Various methods have been used from time to time by several workers to evaluate

the antimicrobial activity. The evaluation can be done by the following methods.

� Turbidometric method

� Agar streak dilution method

� Serial dilution method

� Agar diffusion method

� Following Techniques are used as agar diffusion method

� Agar Cup method



� Agar Ditch method

� Paper Disc method

We have used the Broth Dilution Method to screen the antimicrobial activity.

It is one of the non-automated in vitro microbial susceptibility tests. This classic

method yields a quantitative result for the amount of antimicrobial agents that is

needed to inhibit growth of specific microorganisms. It is carried out in tubes.

� Macrodillution Method in Tubes

� Microdillution format using plastic trays

In the present protocol we have used the Micro dilution format.

Materials and method

1. All the synthesized drugs were used for antimicrobial test procedures 2. All necessary controls like:

� Drug control;

� Vehicle control;

� Agar control;

� Organism control;

� Known antimicrobial drugs control;

� All MTCC cultures were tested against above mentioned known and

unknown drugs;

� Mueller hinton broth was used as nutrient medium to grow and dilute the

drug suspension for the test microorganism;

� Inoculum size for test strain was adjust to 106 CFU [Colony Forming Unit]

per milliliter by comparing the turbidity;

� Serial dilution technique was followed by micro method as per NCCLS-

1992 manual.11

Following common standard strains were used for screening of antibacterial and

antifungal activities. The strains were procured from Institute of Microbial

Technology, Chandigarh.



� Escherichia coli (Gram-negative) MTCC-443

� Pseudomonas aeruginosa (Gram-negative) MTCC-1688

� Staphylococcus aureus (Gram-positive) MTCC-96

� Streptococcus pyogenes (Gram-positive) MTCC-442

� Candida albicans MTCC-227

� Aspergillus niger MTCC-282

� Aspergillus clavatus MTCC-1323

2% DMSO was used as diluent/vehicle to get desired concentration of drugs to

test upon standard bacterial strains.

Minimal inhibition concentration (MIC)

The main advantage of the ‘Broth Dilution Method’ for MIC determination lies

in the fact that it can readily be converted to determine the MIC as well.

1. Serial dilutions were prepared in primary and secondary screening.

2. The control tube containing no antibiotic is immediately sub cultured [before

inoculation] by spreading a loopful evenly over a quarter of [plate of medium

suitable for the growth of the test organism and put for incubation at 37 0C

overnight. The tubes are then incubated overnight.

3. The MIC of the control organism is read to check the accuracy of the drug

concentrations.

4. The lowest concentration inhibiting growth of the organism is recorded as

MIC.

5. The amount of growth from the control tube before incubation [which

represents the original inoculum] is compared.

Methods used for primary and secondary screening

Each synthesized drug was diluted obtaining 2000 μg/mL concentration, as a

stock solution.

Primary screen: In primary screening 1000 μg/mL, 500 μg/mL,

and 250 μg/mL concentrations of the synthesized drugs were

taken. The active synthesized drugs found in this primary screening

were further tested in a second set of dilution against all

microorganisms.



Secondary screen: The drugs found active in primary screening

were similarly diluted to obtain 200 μg/mL, 100 μg/mL, 50 μg/mL,

25 μg/mL and 12.5 μg/mL concentrations.

Reading result

The highest dilution showing at least 99 % inhibition zone is taken as MIC. The

result of this is much affected by the size of the inoculum. The test mixture

should contain 106 organism/mL.

The standard drugs

The standard drugs used in the present study is “Ciprofloxacin” which showed

25, 25, 50 and 50 μg/mL and “Chloramphenicol” which displayed 50 μg/mL

MIC in six sets against E. coli, P. aeruginosa, S. aureus & S. pyogenes

respectively, for evaluating antibacterial activity. “Griseofulvin” is used as the

standard drug for antifungal activity which showed 500, 100 & 100 μg/mL MIC

in six sets against C. albicans, A. niger and A. clavatus respectively, used for the

antifungal activity.

Photographs of the strains used for antibacterial and antifungal activities

E. coli P. aeruginosa S. aureus

S. pyogenes C. albicans A. niger

A. clavatus



Currently used antibacterial and antifungal drugs



TABLE-1: ANTIMICROBIAL ACTIVITY OF 1-(2-(1H-BENZO[d]IMIDAZOL-2-YL)-2-METHYL-5-(ARYL)-1,3,4-OXADIAZOL-3(2H)-YL)-3-PHENYLPROP-2-EN-1-

ONES

Sr. No. -R

Minimum inhibitory concentration (MIC)

For bacteria (μg/mL) For fungi (μg/mL) E.c. P.a. S.a. S.p. C.a. A.n. A.c.

GK1-1 -H 500 1000 500 1000 500 1000 500 GK1-2 -2-Cl 100 100 200 125 100 100 50 GK1-3 -3-Cl 100 200 250 100 100 200 250 GK1-4 -4-Cl 25 12.5 50 25 50 100 12.5 GK1-5 -4-F 50 50 125 25 100 25 25 GK1-6 -2-CH3 500 500 250 500 1000 500 1000 GK1-7 -4-CH3 500 250 1000 500 500 250 250 GK1-8 -3-NO2 100 50 125 125 100 50 100 GK1-9 -4-NO2 25 50 25 12.5 50 25 12.5 GK1-10 -4-OH 500 200 100 250 250 1000 500 GK1-11 -3-OCH3 1000 500 500 500 500 500 1000 GK1-12 -4-OCH3 500 1000 500 250 250 500 1000 GK1-13 -4-Br 250 100 100 50 100 100 100 Ciprofloxacin 25 25 50 50 - - - Chloramphenicol 50 50 50 50 - - - Griseofulvin - - - - 500 100 100

TABLE-2: ANTIMICROBIAL ACTIVITY OF 1-(2-(1H-BENZO[d]IMIDAZOL-2-YL)-2-METHYL-5-(ARYL)-1,3,4-OXADIAZOL-3(2H)-YL)-3-(2-CHLOROPHENYL)

PROP-2-EN-1-ONES

Sr. No. -R



GK2-1 -H 1000 500 500 500 500 500 1000 GK2-2 -2-Cl 125 100 100 200 100 250 100 GK2-3 -3-Cl 200 100 200 100 200 100 250 GK2-4 -4-Cl 50 25 50 25 100 50 25 GK2-5 -4-F 25 50 50 12.5 25 50 25 GK2-6 -2-CH3 1000 500 500 200 1000 500 500 GK2-7 -4-CH3 500 500 1000 500 1000 500 500 GK2-8 -3-NO2 125 100 25 125 100 50 50 GK2-9 -4-NO2 50 50 12.5 25 100 250 25 GK2-10 -4-OH 500 250 200 500 250 500 250 GK2-11 -3-OCH3 1000 500 1000 500 500 1000 1000 GK2-12 -4-OCH3 1000 1000 500 500 250 1000 500 GK2-13 -4-Br 200 50 100 100 100 250 100 Ciprofloxacin 25 25 50 50 - - - Chloramphenicol 50 50 50 50 - - - Griseofulvin - - - - 500 100 100



TABLE-3: ANTIMICROBIAL ACTIVITY OF 1-(2-(1H-BENZO[d]IMIDAZOL-2-YL)-2-METHYL-5-(ARYL)-1,3,4-OXADIAZOL-3(2H)-YL)-3-(3-CHLOROPHENYL)

PROP-2-EN-1-ONES

Sr. No. -R



GK3-1 -H 500 500 1000 1000 1000 500 1000 GK3-2 -2-Cl 100 100 125 100 50 100 100 GK3-3 -3-Cl 250 100 100 250 100 100 200 GK3-4 -4-Cl 50 50 50 25 50 12.5 25 GK3-5 -4-F 25 12.5 50 25 50 25 50 GK3-6 -2-CH3 500 500 250 500 500 250 500 GK3-7 -4-CH3 1000 500 500 200 500 1000 1000 GK3-8 -3-NO2 100 100 125 100 50 100 100 GK3-9 -4-NO2 50 25 12.5 25 25 25 50 GK3-10 -4-OH 1000 250 500 500 500 1000 250 GK3-11 -3-OCH3 500 500 1000 1000 1000 1000 1000 GK3-12 -4-OCH3 1000 500 500 1000 500 1000 1000 GK3-13 -4-Br 125 25 100 125 200 100 100 Ciprofloxacin 25 25 50 50 - - - Chloramphenicol 50 50 50 50 - - - Griseofulvin - - - - 500 100 100

TABLE-4: ANTIMICROBIAL ACTIVITY OF 1-(2-(1H-BENZO[d]IMIDAZOL-2-YL)-

2-METHYL-5-(ARYL)-1,3,4-OXADIAZOL-3(2H)-YL)-3-(4-CHLOROPHENYL) PROP-2-EN-1-ONES

Sr. No. -R



GK4-1 -H 1000 1000 500 500 500 1000 500 GK4-2 -2-Cl 125 100 100 50 100 50 100 GK4-3 -3-Cl 200 100 100 100 100 100 250 GK4-4 -4-Cl 125 50 25 50 25 100 50 GK4-5 -4-F 50 12.5 50 12.5 12.5 25 50 GK4-6 -2-CH3 1000 500 500 1000 1000 500 500 GK4-7 -4-CH3 500 1000 1000 250 1000 1000 1000 GK4-8 -3-NO2 200 100 125 100 100 100 100 GK4-9 -4-NO2 25 50 25 50 50 100 50 GK4-10 -4-OH 500 500 200 250 200 500 250 GK4-11 -3-OCH3 500 1000 1000 500 1000 500 1000 GK4-12 -4-OCH3 1000 1000 500 1000 1000 500 500 GK4-13 -4-Br 100 50 200 100 100 200 100 Ciprofloxacin 25 25 50 50 - - - Chloramphenicol 50 50 50 50 - - - Griseofulvin - - - - 500 100 100



TABLE-5: ANTIMICROBIAL ACTIVITY OF 1-(2-(1H-BENZO[d]IMIDAZOL-2-YL)-2-METHYL-5-(ARYL)-1,3,4-OXADIAZOL-3(2H)-YL)-3-(4-HYDROXYPHENYL)

PROP-2-EN-1-ONES

Sr. No. -R



GK5-1 -H 500 500 1000 1000 1000 500 500 GK5-2 -2-Cl 100 100 125 100 200 100 100 GK5-3 -3-Cl 250 200 100 200 100 100 500 GK5-4 -4-Cl 25 50 50 25 50 25 50 GK5-5 -4-F 50 25 50 25 25 25 25 GK5-6 -2-CH3 1000 500 1000 500 500 1000 1000 GK5-7 -4-CH3 1000 500 1000 500 1000 1000 500 GK5-8 -3-NO2 100 100 100 125 100 100 100 GK5-9 -4-NO2 12.5 50 50 25 25 12.5 25 GK5-10 -4-OH 500 200 250 500 1000 500 500 GK5-11 -3-OCH3 1000 1000 500 1000 500 250 200 GK5-12 -4-OCH3 1000 1000 1000 1000 1000 500 1000 GK5-13 -4-Br 200 100 100 125 100 100 100 Ciprofloxacin 25 25 50 50 - - - Chloramphenicol 50 50 50 50 - - - Griseofulvin - - - - 500 100 100

TABLE-6: ANTIMICROBIAL ACTIVITY OF 1-(2-(3-(4-CHLOROPHENYL)-1-PHE-

NYL-1H-PYRAZOL-4-YL)-5-(PYRIDIN-4-YL)-1,3,4-OXADIAZOL-3(2H)-YL)-3-(ARYL)PROP-2-EN-1-ONES

Sr. No. -R



GK6-1 -H 1000 1000 500 1000 1000 500 1000 GK6-2 -2-Cl 500 1000 500 250 500 1000 1000 GK6-3 -3-Cl 1000 500 250 100 1000 500 500 GK6-4 -4-Cl 250 500 100 250 250 500 250 GK6-5 -4-F 500 500 200 250 500 200 250 GK6-6 -2-CH3 100 100 125 125 100 100 100 GK6-7 -4-CH3 50 25 25 25 50 50 25 GK6-8 -3-NO2 1000 500 250 500 1000 1000 1000 GK6-9 -4-NO2 500 500 250 250 1000 500 500 GK6-10 -4-OH 100 200 100 125 250 100 50 GK6-11 -3-OCH3 100 62.5 50 50 50 25 25 GK6-12 -4-OCH3 50 50 12.5 125 25 100 12.5 GK6-13 -4-Br 250 500 200 250 500 250 500 Ciprofloxacin 25 25 50 50 - - - Chloramphenicol 50 50 50 50 - - - Griseofulvin - - - - 500 100 100



TABLE-7: ANTIMICROBIAL ACTIVITY OF 1-(2-(3-(4-FLUOROPHENYL)-1-PHE- NYL-1H-PYRAZOL-4-YL)-5-(PYRIDIN-4-YL)-1,3,4-OXADIAZOL-3(2H)-YL)-3-

(ARYL)PROP-2-EN-1-ONES

Sr. No. -R



GK7-1 -H 1000 500 500 1000 1000 1000 1000 GK7-2 -2-Cl 500 1000 500 500 1000 500 500 GK7-3 -3-Cl 1000 500 100 250 500 500 500 GK7-4 -4-Cl 250 500 100 250 250 500 250 GK7-5 -4-F 500 1000 250 200 1000 500 250 GK7-6 -2-CH3 100 125 100 200 100 50 250 GK7-7 -4-CH3 125 50 12.5 25 50 12.5 25 GK7-8 -3-NO2 500 500 250 500 1000 500 1000 GK7-9 -4-NO2 1000 500 200 250 1000 500 1000 GK7-10 -4-OH 200 100 125 62.5 100 100 500 GK7-11 -3-OCH3 50 125 50 125 100 25 100 GK7-12 -4-OCH3 25 50 25 50 25 50 25 GK7-13 -4-Br 500 250 200 200 1000 500 200 Ciprofloxacin 25 25 50 50 - - - Chloramphenicol 50 50 50 50 - - - Griseofulvin - - - - 500 100 100

TABLE-8: ANTIMICROBIAL ACTIVITY OF 1-(2-(3-(4-METHOXYPHENYL)-1-PH-

ENYL-1H-PYRAZOL-4-YL)-5-(PYRIDIN-4-YL)-1,3,4-OXADIAZOL-3(2H)-YL)-3-(ARYL)PROP-2-EN-1-ONES

Sr. No. -R



GK8-1 -H 500 1000 500 1000 1000 500 500 GK8-2 -2-Cl 500 1000 500 1000 1000 1000 500 GK8-3 -3-Cl 500 500 250 250 1000 1000 500 GK8-4 -4-Cl 100 500 250 250 500 500 250 GK8-5 -4-F 1000 1000 500 200 1000 500 500 GK8-6 -2-CH3 100 100 125 50 100 100 50 GK8-7 -4-CH3 50 12.5 25 12.5 12.5 12.5 12.5 GK8-8 -3-NO2 1000 500 500 250 1000 500 500 GK8-9 -4-NO2 500 500 250 500 1000 500 500 GK8-10 -4-OH 100 200 100 62.5 100 100 250 GK8-11 -3-OCH3 50 50 25 25 25 100 25 GK8-12 -4-OCH3 12.5 50 12.5 25 12.5 50 12.5 GK8-13 -4-Br 250 250 200 200 1000 500 500 Ciprofloxacin 25 25 50 50 - - - Chloramphenicol 50 50 50 50 - - - Griseofulvin - - - - 500 100 100



TABLE-9: ANTIMICROBIAL ACTIVITY OF 1-(2-(3-(4-NITROPHENYL)-1-PHE- NYL-1H-PYRAZOL-4-YL)-5-(PYRIDIN-4-YL)-1,3,4-OXADIAZOL-3(2H)-YL)-3-

(ARYL)PROP-2-EN-1-ONES

Sr. No. -R



GK9-1 -H 1000 1000 500 500 500 500 1000 GK9-2 -2-Cl 1000 500 500 500 1000 1000 500 GK9-3 -3-Cl 500 200 250 500 500 1000 500 GK9-4 -4-Cl 200 500 250 250 1000 200 250 GK9-5 -4-F 500 1000 500 250 500 100 200 GK9-6 -2-CH3 125 100 125 50 50 100 100 GK9-7 -4-CH3 50 12.5 25 12.5 12.5 50 25 GK9-8 -3-NO2 500 1000 500 500 1000 500 200 GK9-9 -4-NO2 500 1000 500 500 500 500 1000 GK9-10 -4-OH 100 100 125 100 100 200 100 GK9-11 -3-OCH3 100 50 25 50 25 100 50 GK9-12 -4-OCH3 25 25 12.5 12.5 25 25 12.5 GK9-13 -4-Br 500 1000 500 500 500 200 250 Ciprofloxacin 25 25 50 50 - - - Chloramphenicol 50 50 50 50 - - - Griseofulvin - - - - 500 100 100

TABLE-10: ANTIMICROBIAL ACTIVITY OF 3-(6-(2,6-DICHLOROQUINOLIN-3-

YL)-4-(ARYL)-1,6-DIHYDROPYRIMIDIN-2-YLTHIO)PROPANENITRILES

Sr. No. -R



GK10-1 -H 1000 500 500 250 500 500 1000 GK10-2 -2-Cl 125 250 100 100 100 100 100 GK10-3 -3-Cl 100 200 250 100 500 200 250 GK10-4 -4-Cl 50 100 25 50 50 250 100 GK10-5 -4-F 50 100 25 12.5 12.5 50 25 GK10-6 -2-CH3 1000 500 200 500 1000 500 500 GK10-7 -4-CH3 500 500 1000 250 1000 500 1000 GK10-8 -3-NO2 125 12.5 100 25 100 12.5 100 GK10-9 -4-NO2 25 50 50 125 25 25 50 GK10-10 -3-OH 500 250 200 500 250 500 500 GK10-11 -4-OH 500 200 200 1000 200 500 250 GK10-12 -3-OCH3 500 500 1000 500 500 1000 500 GK10-13 -4-OCH3 500 250 500 1000 1000 1000 1000 GK10-14 -4-Br 100 250 100 250 100 250 100 Ciprofloxacin 25 25 50 50 - - - Chloramphenicol 50 50 50 50 - - - Griseofulvin - - - - 500 100 100



TABLE-11: ANTIMICROBIAL ACTIVITY OF 3-(6-(2-CHLORO-6-FLUORO QUINOLIN-3-YL)-4-(ARYL)-1,6-DIHYDROPYRIMIDIN-2-YLTHIO)

PROPANENITRILES

Sr. No. -R



GK11-1 -H 500 500 250 500 1000 500 500 GK11-2 -2-Cl 125 25 100 125 100 200 250 GK11-3 -3-Cl 200 500 250 100 250 500 250 GK11-4 -4-Cl 25 100 25 50 100 100 50 GK11-5 -4-F 100 50 25 12.5 25 100 12.5 GK11-6 -2-CH3 500 500 250 250 1000 1000 500 GK11-7 -4-CH3 1000 500 1000 500 1000 1000 1000 GK11-8 -3-NO2 100 100 100 200 100 250 100 GK11-9 -4-NO2 25 12.5 50 25 12.5 25 50 GK11-10 -3-OH 500 250 250 250 250 500 1000 GK11-11 -4-OH 500 500 200 500 500 500 250 GK11-12 -3-OCH3 1000 250 500 1000 1000 500 500 GK11-13 -4-OCH3 500 500 1000 1000 1000 500 500 GK11-14 -4-Br 125 250 100 100 100 250 50 Ciprofloxacin 25 25 50 50 - - - Chloramphenicol 50 50 50 50 - - - Griseofulvin - - - - 500 100 100

TABLE-12: ANTIMICROBIAL ACTIVITY OF 3-(6-(2-CHLORO-6-METHOXY

QUINOLIN-3-YL)-4-(ARYL)-1,6-DIHYDROPYRIMIDIN-2-YLTHIO) PROPANENITRILES

Sr. No. -R



GK12-1 -H 250 500 1000 500 500 1000 500 GK12-2 -2-Cl 125 100 125 200 100 100 100 GK12-3 -3-Cl 100 250 250 100 250 250 250 GK12-4 -4-Cl 25 100 25 125 100 250 50 GK12-5 -4-F 12.5 25 50 25 12.5 50 25 GK12-6 -2-CH3 1000 500 250 500 1000 500 500 GK12-7 -4-CH3 500 500 500 1000 1000 500 500 GK12-8 -3-NO2 50 100 125 100 100 25 50 GK12-9 -4-NO2 12.5 12.5 50 50 25 25 12.5 GK12-10 -3-OH 1000 500 500 500 500 500 500 GK12-11 -4-OH 1000 500 500 250 1000 250 250 GK12-12 -3-OCH3 1000 500 500 1000 1000 500 1000 GK12-13 -4-OCH3 500 500 500 500 500 250 500 GK12-14 -4-Br 100 250 100 200 100 250 250 Ciprofloxacin 25 25 50 50 - - - Chloramphenicol 50 50 50 50 - - - Griseofulvin - - - - 500 100 100



References

1. Patrick GL; ‘An Introduction to Medicinal Chemistry’, Oxford University

Press, New York, 1995.

2. Barrows W; ’Text Book of Microbiology’, W B Saunders Co., Philadelphia,

17th ed, 1959.

3. http://www.microbiologybytes.com/iandi/3a.html

4. Woese CR, Kandler O, Wheelis ML; ‘Towards a natural system of

organisms: proposal for the domains Archaea, Bacteria, and Eucarya’; Proc

Natl Acad Sci U.S.A., 87, 4576, 1990.

5. http://www.apsnet.org/education/K-12PlantPathways/TeachersGuide/

Activities/DNA_Easy/exercisepg1.htm

6. Brunton LL, Lazo JS, Parker KL; ‘Goodman & Gilman's the Pharmacological

basis of Therapeutics’, Mcgraw-Hill Medical Publishing Division, 2006.

7. Carpenter CF, Chambers HF; Clin Infect Dis, 38, 994, 2004.

8. Robert C; “Medical Microbiology”, ELBS and E & S; Livingstone, Briton,

11th ed., 895, 1970.

9. Sujatha GD; Ind J Expt Biol, 13, 286, 1975.

10. Walksman SA; “Microbial Antagonism and Antibiotic Substances”, Common

Wealth Fund, New York, 2nd ed, 72, 1947.

11. National Committee for Clinical Laboratory Standard., Reference method

for broth dilution antifungal susceptibility testing of yeasts Approved

standard M27A. NCCLS, Wayne, PA, 1997.

studies on clinically important nitrogen and sulphur...

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