INTRODUCTION:
The most commonly prescribed pharmaceuticals worldwide
for the management of pain and inflammation are non-steroidal anti-inflammatory
medicines (NSAIDs)1. Modifying popular non-selective NSAIDs is one
of the primary approaches used to create new medications2,3.
Derivatization of the carboxylate function of typical NSAIDs has been found in
several trials to offer the dual benefits of lowering gastrointestinal side
effects and increasing anti-inflammatory activity4–7.
The long-term use of completely selective COX-2
inhibitors is linked to an elevated risk of cardiovascular illnesses. Classic
NSAIDs inhibit COXs enzymes in a non-selective manner, encouraging unwanted
side effects owing to COX-1 inhibition, such as stomach irritation and ulcers.
Therefore, the current focus of research is on finding compounds that
preferentially selectively inhibit COX-2 rather than COX-1, inhibiting COX-2
more effectively than COX-1 and preventing the side effects on the stomach
caused by the strong inhibition of COX-1 and the cardiovascular effects caused
by the very marked inhibition of COX-2 8,9.
The first stage of converting arachidonic acid into
prostaglandins, leukotrienes, and thromboxanes is catalyzed by endogenous
enzymes called cyclooxygenases (COXs). The isoforms of COX (COX-1 and 2) share
almost all of the amino acid residues that make up their active sites and the
areas directly close to them. The only difference is that in COX-1, valine
replaces Ile434, Ile523, and His513; in COX-2, arginine replaces these same
amino acid residues. In general, COX-1 is a constitutive enzyme that maintains
the homeostasis of various tissues, such as the kidneys by maintaining renal
plasma flow and the filtration rate in the presence of systemic
vasoconstriction and platelet aggregation 8. The tissue-specific
COX-2 isoenzyme is extensively triggered by inflammatory agents and expressed
in various inflammatory conditions, including cancer, the hippocampus, and the
female reproductive tract 8.
The COX-2 is similar to COX-1 enzyme except for the
replacement of the three amino acids that mentioned above that made the polar
hydrophilic side pocket of COX-2 active site bigger than the COX-1 active site,
lead to large molecules could not fit into the COX-1 active site but still have
the ability to bind with COX-2 enzyme10,11.
The scope of this research, to design and synthesis of
derivatives of classic NSAIDS, aspirin and diflunisal to shift their effect
from nonselective COX inhibitor to preferential selective COX-2 inhibitor, such
as meloxicam and their in-silico properties12.
MATERIALS AND METHODS:
Materials:
Diclofenac crystalline powder, and Aspirin Sodium
crystalline powder were supplied by Modern Yemeni Pharma. Diflunisal
crystalline powder was gift from Ram Pharmaceutical Co. Jordan.
All anal reagents and anhydrous solvents were obtained
from Apollo Scientific Chemicals U.K. and were typically utilized in their
original form.
Melting points were determined by using a calibrated
STUART SMP11 (U.K.) melting apparatus.Thin layer chromatography was performed
on DC-Kartan SI alumina o.2mm plates to monitor the reaction's development and
purity.
An IR spectrum captured on FT-IR6100 Type A as KBr
disks was used to identify the target substances.
1H–NMR
spectra obtained with an internal reference of tetramethylsilane utilizing a
JEOL500 MHz spectrometer (USA).
Synthesis of Aspirin Anhydride Compound (1).
After dissolving 10 g of aspirin (55.5 mmol) in 150 ml
of dichlomethane, 5.72 g of dicyclohexylcarbodimide (DCC) (27.7 mmol) was
added. The reaction mixture was constantly stirred at room temperature for 3
hours. Filtration was used to remove the white precipitate of dicyclohexylurea
that had developed. Compound (1)was obtained by vacuum-evaporating the filtrate
and forming an oily product13.
Synthesis of Compound (2).
In a 100 ml round bottom flask with a reflux
condenser, boiling stones were added together with Compound (1) (2,5 g, 7.3
mmol), 4-(4-Fluorophenyl) isoxazol-5-amine (1.3005 g, 7.3 mmol), zinc dust
(0.0075 g), glacial acetic acid (0.7 ml, 12.241 mmol), and dioxane (30 ml).
With constant stirring, the reaction mixture was refluxed for approximately
three hours. After the solvent was vacuum-evaporated, the residue was dissolved
in ethyl acetate, and it was filtered over anhydrous sodium sulphate after
being washed three times with distilled water, three times with NaHCO3 (10%,
3X), and three times with HCL (IN, 3X). After the filtrate was evaporated, the
residue was redissolved in ethyl acetate to facilitate recrystallization, which
was then filtered and overnight stored in a cool place14. After
filtering the mixture, the precipitate was recovered to yield compound (2).
2-{[4-(4-fluorophenyl) isoxazol-5-yl] carbamoyl}
phenyl acetate, as white needle crystal (23% yield) M.p. 220-223°C, IR (KBr,
cm-1): 3327 (NH, amide), 3037 (CH, ArH), 1771(C= O, ester), (2928,2850 st.vib.
of C-H, ester) 1629 (C=O, amide), 1600,1576, 1436 (Ar.).
1H–NMR(DMSO.d6,
500MHz) δ pmm : 2.81 (s,3H,-CH3 of OC=O-CH3),8.05(s, 1H,
CONH,H exchangeable with D2O),7.78( s, 1H,CH=N,
Isoxazol),7.61(d,2H,2 -CH= at position 3` and 5`),7.61(d,2H,2 -CH= at position
2` and 6`),7.39-7.45 (m,4H, Ar.H Acetate).
Synthesis of Compound (3).
Compound (1) (2,5 g, 7.3 mmol), zinc dust (0.0075 g),
glacial acetic acid (0.7 ml, 12.241 mmol), compound (1) (1,35 g, 7.3 mmol), and
dioxane (30 ml) are all added to a 100 ml round-bottom flask, were prepared as
previously described in (2) to liberate compound(3),
2-[(6-chloro-1,3-benzothiazol-2-yl) carbamoyl] phenyl acetate, as white cotton
crystals (38% yield). Mp. 188-191° C, Rf = 0.42, IR (KBr, cm-1): 3376 (NH,
amide), 3086 (CH, ArH), 1761 (C= O, ester) 1672 (C=O, amide), 1610, 1527, 1461,
(Ar),(2928,2850st.vib. of C-H, ester). 1H–NMR (DMSO.d6, 500MHz)
δ pmm: 2.71(s,3H, -CH3 of OC=O-CH3),8.04(s,1H, CONH, H exchangeable with
D2O),7.11-7.59 (m,4H of Ar.H Acetate),7.62-7.63(m,2H, at position 4`,5` of
benzothiazole),7.71(s, 1H at position 7` of benzothiazole).
Synthesis of 5–(2,4–Difluorophenyl) acetylsalicylic
acid compound (4).
A 200 ml round conical flask containing 10 g of dried
Diflunisal (40 mmol) was used. After adding acetic anhydride (25 ml, 262 mmol)
and five drops of concentrated sulfuric acid dropwise, the contents were mixed
by rotating the conical flask for five minutes. The mixture was then heated in
a water bath to approximately 50-60 °C while being stirred for thirty minutes.
After allowing the reaction mixture to cool down and occasionally stirring it,
cold distilled water was added until a precipitate formed,then filtered using a
suction pump. The crude product was then collected after being repeatedly
cleaned with cold distilled water15. The process of recrystallization
used 95% ethanol. After collecting and drying the precipitation, compound (5)
was obtained as a white, fine crystal with a 91% yield.
Synthesis of 5–(2,4–Difluorophenyl)–acetyl salicylic
acid anhydride compound (5).:
After dissolving compound (4) (8 g, 27.376 mmol) in
150 ml of methylene chloride, (2.824 g, 13.688 mmol) of dicyclohexylcarbodimide
(D.C.C.) was added. For approximately three hours, the reaction mixture was
constantly agitated at room temperature. Dicyclohexylurea precipitated as a
white precipitate, which was filtered off. A solid product with an 85% yield of
the target compound (5) was obtained by vacuum-evaporating the solvent.
Synthesis of compound (6).:
Compound (5) (2,5g, 4.414 mmol),
4-(4-Fluorophenyl)isoxazol-5-amine (0.786 g.,.4.414 mmol), zinc dust (0.004 g),
glacial acetic acid (0.7 ml, 12.241 mmol) and dioxane (30 ml) were all placed
in 100 ml round bottom flask were prepared as previously described in (2) to
liberate afforded compound (6), 2',4'-difluoro-3-{[4-(4-fluorophenyl)
isoxazol-5-yl] carbamoyl}biphenyl-4-yl acetate, as white needle crystal. 24%
yield, Mp. 219-222 °C, Rf= 0.32, IR (KBr, cm-1) 3326 (NH, amide), 3036 (CH,
Ar-H), 1711 (C=O, ester) (2928,2850 st.vib. of C-H ester),1640 (C=O, amide)
1626, 1537, 1436 (Ar). 1H–NMR(DMSO.d6, 500MHz)
δ pmm: 2.12 (s,3H,-CH3 of OC=O-CH3), 8.06(s, 1H, CONH,H exchangeable with
D2O),7.89 (s, 1H at position 3`of di-F Ar-H), 7.014-7.016 (m, 2H at position 5`
and 6` of di-F Ar-H), 7.52( s, 1H at position 2), 6.96-6.99 (m,2H, at position
5, 6), 7.44 (d, 2H of 2",6"),7.50(d, 2H of 3",5"), 7.66 (s,
1H,CH=N, Isoxazole).
Synthesis of compound (7).
Compound (5) (2,5g, 4.414 mmol),
3-methyl-4-[3-(trifluoromethyl)phenyl]-5-isoxazolamine (1.096 g.,.4.414 mmol),
zinc dust (0.004 g), glacial acetic acid (0.7 ml, 12.241 mmol) and dioxane (30
ml) were placed in 100 ml round bottom flask, were mixed in 100 ml round bottom
flask, were prepared as previously described in (2) to generate compound (7),
2',4'-difluoro-3-{[4-(3-trifluoromethyl-phenyl)3-methyl-isoxazol-5-yl]
carbamoyl} biphenyl-4-yl acetate, as a white long needle crystal (27 % yield).
Mp. 217- 220°C, Rf = 0.37.IR (KBr,cm-1 ): 3327 (NH, amide), 1626 (C=O, amide),
3036(CH -ArH), 1713 (C=O, ester), (2930,2853 st.vib. of C-H ester) 1610, 1536,
1460 (Ar). 1H–NMR(DMSO.d6, 500MHz) δ
pmm:2.05 (s,3H,-CH3 of OC=O-CH3), 2.47 ( s, 3H,-CH3, Isoxazole), 8.06(s, 1H,
CONH,H exchangeable with D2O),8.16 (s, 1H at position 3`of di-F Ar-H), 7.012
-7,014 ( m,2H at position 5`and 6` of di-F Ar-H),7.52( s, 1H at position 2),
6.98-6.99 (m, 2H, at position 5, 6), 7.03 ( s, 1H,CH at position 2"),
7.12-7.17 (m, 3H at position 4",5" and 6").
PHARMACOLOGY:
In the current study, adult male albino rats weighing
200 ± 20 were employed. For a period of five days, the animals were housed in
controlled environments with a 12-hour light and 12-hour dark cycle. They had
access to food and water. Rats were brought into the lab three hours prior to
the experiment, and they were split up into 6 groups(for anti-inflammatory
activity test) and 7 groups (for ulcerogenic index test) each group of 5 rat,
All the animal experiments were performed by following the approval of study
protocols by the Research Animals Ethics Committee, UST(MECA No. 2016/1), the
doses of standards and prepared compounds have to be calculated16 .
Anti-inflammatory activity Tested compounds:
Ovalbumin paw edema method:
Prior to the experiment day, the adult male albino
rats, weighing 200 ± 20, were randomly divided into 6 distinct groups (n = 5),
and they were deprived overnight with unlimited access to water. A single
intraperitoneal injection of 0.2 ml of DMSO was administered to the control
group, other six animals’ groups were treated I.P with tested agents (2,3,6 and
7) with (2.31, 2.35, 3.07, and 3.50 mg. / 0.4 kg.) respectively, and the
other 6th animals’ group were injected I.P with standard Diclofenac sodium in
dose (2.16 mg /0.4 kg.)Next, the animals get a subcutaneous injection of 0.1 ml
of Ovalbumin into the sub-plantar side of the left hind paw, one hour after the
last dose17.The animals were anaesthetized with Chloroform, at 2
hours after challenge then paw is cute, its weight is measured compared with
right one. The weight difference value between two paws was obtained by
subtracting right paw from left paw and the average weight (mean) are
calculated and evaluated statistically. The percentage of inhibition of edema
comparative with the treated compounds were calculated and for control,
Diclofenac, and tested compounds 2,3,6, and 7 respectively.
Calculations (Paw edema and % edema inhibition):
% Edema inhibition = [1- (WT / WC)] X 100
WT = weight difference of edema of tested animals WC=
weight difference of edema of control animals 18.
Ulcerogenic Index screening:
Animals were divided into seven groups (n = 5).
Animals were fasted 20 hr. before drug administration. The synthesized agents
(2,3,6,7 and compounds), Celecoxib and Indomethacin. were given orally in a
dose of (2.31, 2.35, 3.07, 3.50, 2.59 and 2.55 mg. / ml. respectively )
dissolved in propylene glycol 50%v/v for six groups, while 7th group received
vehicle( propylene glycol50%v/v) only, animals were given two dosages on the
second and third days after fasting for two hours, being allowed to eat for two
hours, and then fasting for an additional twenty hours. On the fourth day, the
animals underwent chloroform anesthesia, were sacrificed, had their stomachs
extracted, their greater curvature opened, and then washed with 0.9% saline.
Sargent Welch Microscopic Anatomy (40X) was used to count the number of red
spots representing mucosal injury, and its degree (ulcerogenicity severity) was
evaluated by mean from 0 (no lesion) to 4 (exceptionally severe lesion)19.
Percentage incidence/10= (number of animals exhibiting
ulcers divided by the total number of animals in the group *100) / 1020.
Statistical Method:
Statistical processing of the result by using the test
of analysis of variance (ANOVA test) to show the differences among all groups
if it is present, the highly significance is considerable, in which (p <
0.01). To conform that the result obtained by ANOVA test using T-test, in which
highly significance if (p < 0.01).
ADME procedure for synthesized compounds (2,3,6,7):
All ligands (2,3,6 and 7) had been drown by using
ChemDraw (V. 19.1), transformed by the Swiss ADME to SMILE by process that
prediction the physicochemical descriptors and pharmacokinetic properties.The
permeability through GIT and blood brain barrier of the small molecule have
been measured using BOILED-EGG,and utilized to compute the lipophilicity and
polarity of target compounds21.
Ligands and Protein Receptor Preparation:
Chem3D (v. 19.1) was utilized to apply the MM2 force
field to decrease the energy for our synthesized Ligands. The crystal
structures of COX-1 and COX-2 (PDB: 4O1Z and1PXX) respectively and then setting
up the protein by eliminating all water molecules that are not involved in
binding interaction with the reference drug, as well as adding hydrogen atoms
to amino acid residues to produce correct ionization and tautomeric states,
which were downloaded from the Protein Data Bank (PDB).
Docking procedures:
For molecular docking, a completely licensed version
for tools of Genetic Optimization for Ligand Docking (GOLD) (v. 5.6.2) was used
22,23. The GOLD Suite's Hermes visualizer tool was utilized to
further configure the receptors for the docking process. All of the protein
residues within (10 Aᵒ) of the standard ligands that occur in the
downloaded protein structure complexes were used as the binding location for
GOLD docking. Both of proteins 4O1Z and 1PXX was chosen for the docking
investigation to compare COX-2 with small molecule antagonists. The cavity and
active site were identified using CCDC Superstar. Using the protein's reference
ligand, the radius (10 Aᵒ) of the active site was estimated. CHEMPLP was
utilized to calculate the steric complementarity between ligand and direct
amino acid interaction with specific protein, considering length and
angle-dependent hydrogen. The interaction of the EGFR tyrosine kinase amino
acid residues with our produced ligands was analyzed using docking data, which
comprised binding mode, docked location, and binding free energy 24.
RESULT AND DISCUSSION:
Chemistry:
Anhydride intermediates (1 and 5) are
created by utilizing two moles of initial Acylated substances of aspirin and
diflunisal, were linked together with 1 mole of DCC as a coupling agent11.
The mechanism of action entails adding a class of starting medications that
include carboxylic acid to DCC to create extremely reactive intermediates (1
and 5). employing amino groups from heterocyclic compounds to acylate
anhydrides (1 and 5) was faster than employing a really unpleasant acyl
chloride25. The catalyst zinc dust enabled the reactions to
accelerate. These reactions are additional forms of nucleophilic reactions in
which zinc dust is used as a catalyst and the nucleophile (-NH2) is added to
the carbonyl carbon of anhydride in mildly acidic environment (by adding
glacial acetic acid). as scheme 1 illustrates.
Anti-inflammatory:
The anti-inflammatory effects of synthesized agents
that are compared with the reference agent were studied on adult albino rats
because they are sensitive to the induction of inflammation, well-responded to
anti-inflammatory agents, easily handled, and available 26.
The average of weight differences of hind paw edema in
control animals was 0.43758 g.
It is significantly decreased in both reference and
tested animal groups, the results are shown in table 1. the result indicates
that such compounds have a significant anti-inflammatory effect.
The synthesized compounds; compounds (2, 3, 6, and 7)
have a potent anti-inflammatory effect in comparing to diclofenac sodium as
reference agent.
The anti-inflammatory effect of tested compounds
compared to that of the reference drugs which is compatible with many
comparative studies involves selective COX-2 inhibitors and classic NSAIDS in
the treatment of inflammatory conditions in which selective COX-2 inhibitors
such as Rofecoxib and Meloxicam showed promised equivalent efficacy 27.
Ulcerogenicity:
Acute ulcerogenicity of tested compounds results shown
in table 2, in which compounds (2) and (6) showed the least ulcerogenic in
comparing to Celecoxib standared compound of known high selective COX-2
profile, followed by compounds (3, 7) they showed ulcer index above Celecoxib.
The ulcer index for tested compounds (2,3,6,7), Indomethacin, and Celecoxib as
reference are shown in table 2. Indomethacin are non-selective (COX-1 and COX-2
inhibitors) 28. So that it showed highest ulcer index.
Compound (2) showed a highest anti-inflammatory
activity with low gastric effects, while compound (6) showed a good
anti-inflammatory activity with lowest ulcer index in comparing to reference.
This anti-inflammatory activity might due to bulky structure of (2 and 6)
derivatives which have similar heterocyclic nucleus (4-[4-Fluorophenyl]
isoxazol-5-amine) might enhance a good liability to occupy the side pocket of
COX-2 enzyme with maintenance of the anti-inflammatory activity.
Scheme 1. Synthesis of target compounds (2,3,6 7).
All the synthesized compounds having promising docking
result with COXs enzymes, fitted in the cox -2 active site except compound 3,
as shown in figs. 1-4. COX-1 result a lower binding energy because COX-2 active
site is bigger than COX-1 active site, and the synthesized compound especially
compound 2 and 6 have a hetero cyclic nucleus with sufficient size,aryl
and amido arylring attached ortho tocentral isoxazol-5-amine ring, which required for cox-2 selectivity,
and makes difficulty in insertion of COX-1 pocket.
Figure 1. 3D structural image of H-bond and brief
contact interaction profiles for compound (2) binding with COX-2 (code of PDB:
1PXX).
It is administered in a ball-and-stick format, whereas
amino acids are administered as capped sticks.
Figure 2. 3D structural image of H-bond and brief contact interaction profiles
for compound (2) binding with COX-2 (code of PDB: 1PXX).
It is administered in a ball-and-stick format, whereas
amino acids are administered as capped sticks.
Figure 3. 3D structural image of H-bond and brief contact
interaction profiles for compound (6) binding with COX-2 (code of PDB: 1PXX).
It is administered in a ball-and-stick format, whereas amino acids are
administered as capped sticks.
Figure4. 3D structural image of H-bond and brief
contact interaction profiles for compound (7) binding with COX-2 (code of PDB:
1PXX).
It is administered in a ball-and-stick format, whereas
amino acids are administered as capped sticks.
CONCLUSION:
Novel non-steroidal anti-inflammatory agents were
chemically synthesized and spectroscopically identified by I.R and 1 HNMR.
The results of preliminary pharmacological evaluation indicate that compound
(2) has highest anti-inflammatory activity and with less ulcerogenicity,
followed by compound (6), which showed a good anti-inflammatory activity with
lesser ulcerogenic index, so that, these compounds suspected as preferential
selectivity toward COX-2 enzyme. The chemical responsible for COX-2 selectivity
may be attributed to the similarity bearing of sufficient size of heterocyclic
nucleus [4-(4-Fluorophenyl) isoxazol-5-amine] in compounds (2, 6) which makes
compounds 2 and 6 with higher bulky forms and increases the rigidity of
chemical structure (binding side chain) and enable them to bind to the extra
pocket in COX-2 specific binding site, and decrease their affinity toward to
COX-1 binding site. ADME showed all of synthesized compounds had TPSA values
less than 140, and the bioavailability result showed good orally passive
absorption, suggesting that all compound pass the rule of five upon
bioavailability so, they could be orally absorbable except compound (7) fail
due to its high molecular weight (M.wt
. Molecular docking showed PLP fitness of
the docked compounds on COX-2 show preferentially selective cox-2 inhibitors.
Compound (6) showed highest cox-2 affinity even celecoxib but tended to
inhibits COX-1 more than celecoxib, while compounds (3 and 7) produced lowest
COX-2 affinity might due to the nature of heterocyclic ring.The all of studies, anti-inflammatory,
ulcer index, ADME and molecular docking results showed good correlation in
respect to compounds (6 and2).
REFERENCES:
1.
Da Costa BR. Reichenbach
S. Keller N.Nartey L. Wandel S. Jüni P. Trelle S. Effectiveness of
non-steroidal anti-inflammatory drugs for the treatment of pain in knee and hip
osteoarthritis: a network meta-analysis. Lancet. 2017; 390(10090): e21-e33.
doi: 10.1016/S0140-6736(17)31744-0.
2.
Marnett LJ. Kalgutkar
AS. Design of selective inhibitors of cyclooxygenase-2 as nonulcerogenic
anti-inflammatory agents. Curr Opin Chem Biol. 1998; 2(4): 482-490. doi:
10.1016/s1367-5931(98)80124-5.
3.
Takahashi M. Ogawa T.
Kashiwagi H. Fukushima F. Yoshitsugu M. HabaTakahashi M, Ogawa T, Kashiwagi H.
Fukushima F. YoshitsuguM.Haba M. Hosokawa M. Chemical synthesis of an
indomethacin ester prodrug and its metabolic activation by human
carboxylesterase 1. Bioorg Med Chem Lett. 2018; 28(6): 997-1000.doi:
10.1016/j.bmcl.2018.02.035.
4.
Mahdi MF. Mohammed MH.
Jassim AA. Design, synthesis and preliminarypharmacological evaluation of new
non-steroidal anti-inflammatory agents having a 4-(methylsulfonyl) aniline
pharmacophore. Molecules. 2012; 17(2): 1751–1763. doi:
10.3390/molecules17021751
5.
Kalgutkar AS. Rowlinson
SW.Crews BC. Marnett LJ. Amide derivatives ofmeclofenamic acid as selective
cyclooxygenase-2 inhibitors. Bioorg Med Chem Lett. 2002; 12(4): 521-524. doi:
10.1016/s0960-894x(01)00792-2.
6.
Kalgutkar AS. Crews BC.
Saleh S. Prudhomme D. Marnett LJ. Indolyl esters and amides related to
indomethacin are selective COX-2 inhibitors. Bioorg Med Chem. 2005; 13(24):
6810–6822. doi: 10.1016/j.bmc.2005.07.073.
7.
Khanna S. Madan M.
Vangoori A. Banerjee R. ThaimattamR.Jafar Sadik Basha SK. Ramesh
M.CasturiSR.Pal M. Evaluation of glycolamide esters of indomethacin as
potential cyclooxygenase-2 (COX-2) inhibitors. Bioorg Med Chem. 2006; 14(14):
4820–4833. doi: 10.1016/j.bmc.2006.03.023
8.
D.S. Mohale. A. S.
Tripathi. J. B. Wahane, A. V. Chandewar. A paramacological review on
cyclooxygenase enzyme.Indiangournal of pharmacy and pharmacology enzyme. .
2014; 1(1): 46-58
9.
F. Buttgereit. G. R.
Burmester Simon LS. Am. J. Med. 2001; 110; Suppl 3A:13S-9S. doi:
10.1016/s0002-9343(00)00728-2
10.
Chakraborti AK. Garg SK.
Kumar R. Motiwala HF. Jadhavar PS. Progress in COX-2 inhibitors: a journey so
far. Curr Med Chem. 2010; 17(15): 1563–1593. doi: 10.2174/092986710790979980
11.
Llorens O. Perez JJ.
Palomer A. Mauleon D. Structural basis of the dynamic mechanism of ligand
binding to cyclooxygenase. Bioorg Med Chem Lett. 1999; 19(9): 2779–2784.
https://doi.org/10.1016/S0960-894X(99)00481-3
12.
Howard S. Smith, Witney
Baird.Meloxicam and selective COX-2 inhibitorsn in the manegment of pain in the
palliative care population. Amreican Journal of Hspital and palliative Medicin.
2003; 20(4): 297-306. DOI: 10.1177/104990910302000413
13.
Banerjee P. K; Amidon,
G. L.Physicochemical Property Modification Strategies Based on Enzyme Substrate
Specificities I: Rationale, Synthesis, and Pharmaceutical Properties of Aspirin
Derivatives. Journal of Pharmaceutical Science. 1981; 12 (70); 1299-1303. DOI:
10.1002/jps.2600701202.
14.
AlMekhlafi S. Alkadi H.
El-Sayed M.K. synthesis and anti-inflammatory activity of novel aspirin and
ibuprofen amide derivatives. Journal of Chemical and Pharmaceutical Research.
2015; 7(2): 503-510.
15.
Furniss BS. and
Hannaford A J. Vogel’s textbook of practical organic chemistry. Longman,
London.1978.
16.
Paget GE. and Barnes J
M. Toxicity Test. In Evaluation of Drug Activities, edited by Laurence D R. and
Bacharach A L. Eds. Academic Press, Massachusetts. 1964; Eds: 135-166.
https://doi.org/10.1016/B978-1-4832-2845-7.50012-8
17.
Randall LO. and Baruth
H.Analgesic and anti-inflammatory activity of
6-chloro-alpha-methyl-carbazole-2-acetic acid (C-5720). Arch Int Pharmacodyn
Ther. 1976; 220(1): 94-114.
18.
Winter C A. Risley EA.
Nuss GW. Carrageenin-Induced Edema in Hind Paw of the Rat as an Assay for
Anti-Inflammatory Drug. Proceedings of the Society for Experimental Biology and
Medicine. 1962; 111: 544-547. http://dx.doi.org/10.3181/00379727-111-27849
19.
V. Alagarsamy. S Meena.
KV Ramaseshu. V. Raja Solomon. T Durai Ananda Kumar. K. Thirumurugan. Synthesis
of Novel 3-Butyl-2-Substituted Amino-3H-Quinazolin-4-ones as Analgesic and
Anti-inflammatory Agents. Chem Biol Drug Des. 2007; 70(3): 254-60. doi:
10.1111/j.1747-0285.2007.00548.x.
20.
Robert A. James E.
Nezamis JE. LancesterC . Alexander J. Hanchar.Cytoprotection by prostaglandins
in rats: Prevention of gastric necrosis produced by alcohol, HCl, NaOH,
hypertonic NaCl, and thermal injury. Gastroenterol. 1979; 3(77): 433-443. http//doi.org/10.1016/0016-5085(79)90002-7
21.
Daina A. Zoete V. A
boiled‐egg to predict gastrointestinal absorption and brain penetration
of small molecules. ChemMedChem. 2016; 11(11): 1117-1121. doi:
10.1002/cmdc.201600182
22.
Jones G. Willett P. Glen
RC. Leach AR. Taylor R. Development and validation of a genetic algorithm for
flexible docking. Journal of Molecular Biology. 1997; 267(3): 727-48. doi:
10.1006/jmbi.1996.0897
23.
Jones G. Willett P. Glen
RC. Molecular recognition of receptor sites using a genetic algorithm with a
description of desolvation. Journal of Molecular Biology. 1995; 245(1): 43-53.doi:
10.1016/s0022-2836(95)80037-9.
24.
Ng HW. Zhang W.Shu M.
Luo H. Ge W. Perkins R. Tong W. Hong H. Competitive molecular docking approach
for predicting estrogen receptor subtype α agonists and antagonists. BMC
bioinformatics. 2014; 11 (15): 1-15. doi: 10.1186/1471-2105-15-S11-S4.
25.
Kalgutkar, A, S., Crews,
B. C., Rowlinson, S. W., and Garner, C. Aspirin-like Molecules that Covalently
Inactivate Cyclooxygenase-2. Science. 1998; 5367 (280): 1268–70. DOI.10.1126/science.286.5367.1268
26.
Dale M and Forman J.
Text of immunopharmacology. Blackwell Scientific Publication,Oxford London.
253 -61.1989
27.
Deeks J J. Smith L A.
Bradley M D.Efficacy, tolerability, and upper gastrointestinal safety of
celecoxib for treatment of osteoarthritis and rheumatoid arthritis: systematic
review of randomized controlled trials.BMJ. 2002; 325(619). doi:
https://doi.org/10.1136/bmj.325.7365.619
28.
Lanza FL. Chan KL.
Quigley MM. Guidelines for prevention of NSAID-related ulcer complications. The
American Journal of Gastroenterology. 2009; 104(3): 728–738. doi:
10.1038/ajg.2009.115.
29.
Pajouhesh H. Lenz GR.
Medicinal chemical properties of successful central nervous system drugs.
NeuroRx. 2005; 2(4): 541-53. DOI: 10.1602/neurorx.2.4.541
30.
Verdonk ML. Cole JC.
Hartshorn MJ. Murray CW. Taylor RD. Improved protein–ligand docking using GOLD.
Proteins: Structure, Function, and Bioinformatics. 2003; 52(4): 609-23.
https://doi.org/10.1002/prot.10465
31.
Adeniyi AA. Ajibade PA.
Comparing the suitability of autodock, gold and glide for the docking and
predicting the possible targets of Ru (II)-based complexes as anticancer
agents. Molecules. 2013; 18(4): 3760-78. doi: 10.3390/molecules18043760
32.
Alvarez J. Shoichet B.
Virtual screening in drug discovery. CRC press. 2005