Deepak K. Lokwani

Design, synthesis and pharmacological screening of novel nitric oxide donors containing 1,5-diarylpyrazolin-3-one as nontoxic NSAIDs.

Various substituted 1,5-diarylpyrazol-3-one derivatives were synthesized and screened for analgesic, anti-inflammatory activities, ulcerogenic potential and for their ability to release nitric oxide. Most compounds exhibited significant analgesic and anti-inflammatory activities. It was interesting to note that out of ten compounds, 7j (59.64%) was found to have anti-inflammatory activity greater than the standard drug Indomethacin (57.89%), whereas compound 7b (57.89%) was found to be equipotent to that of standard, Indomethacin. The pharmacological studies suggested that the presence of 4-nitro and 2-methoxy on phenyl ring at C(5) of pyrazole has a significant anti-inflammatory activity and 4-chloro substitution on same phenyl ring was found to have decreased activity. However only a phenyl substituted derivative was found to have most potent activity. Compound 7j containing plane phenyl at C(5) of pyrazole was found to have significant analgesic activity (56.86%) in acetic acid induced writhing model. Compounds 7d and 7i having 4-chloro substituted phenyl ring showed least analgesic activity (10.78%) and (6.86%) respectively. The compounds also showed significantly reduced GI-ulcerogenicity and gastroprotective results in histopathological studies i.e. they were found to be causing no mucosal injury. All the synthesized compounds were found to exhibit significant nitric oxide releasing activity, in both in vitro and in vivo models. Molecular docking studies served to be an important tool for the study of binding of compounds with that of a COX-2 enzyme. The results of the docking studies were found to endorse the result of experimental work. Thus, the rationale used to design the NCEs was found to produce the promising results as anticipated. Therefore it can be said that the strategy employed can serve as an important tool in future for the design and development of novel therapeutic agents of various categories too.

Design of potential reverse transcriptase inhibitor containing Isatin nucleus using molecular modeling studies

Two Dimensional (2D) and Three Dimensional (3D) Quantitative Structure-Activity Relationship (QSAR) studies were performed for correlating the chemical composition of Isatin analogues and their anti-HIV activity using Multiple Linear Regression (MLR) Analysis and k Nearest Neighbor Molecular Field Analysis (kNN MFA), respectively. New Chemical Entities (NCEs) were designed using results of QSAR studies. Binding affinities of designed NCEs were studied on Reverse Transcriptase enzyme using docking studies and their ADME properties were also predicted. Finally most promising compounds were selected from molecular modeling studies. Five compounds containing Isatin nucleus were synthesized and tested for their anti-HIV activity by performing Reverse Transcriptase Assay. Three compounds showed significant Reverse Transcriptase inhibiting activity compared to standard Navirapine. Structure-Activity Relationships were also discussed bases on obtained molecular modeling and experimental data.

Design, synthesis, and evaluation of anti-inflammatory, analgesic, ulcerogenicity, and nitric oxide releasing studies of novel indomethacin analogs as non-ulcerogenic derivatives.

Most non-steroidal anti-inflammatory drugs (NSAIDs) suffer from the deadlier gastrointestinal (GI) toxicities. The free -COOH group is responsible for the GI toxicity associated with all traditional NSAIDs. In the present research work, the main objective was to develop new chemical entities as potential anti-inflammatory agents with no GI toxicities. The results of synthesis and pharmacological screening of a series of hybrid molecules having general formula 2-(5-(5-(substituted phenyl)-2-oxo-ethylthio)-1,3,4-oxadiazole-2-yl)-2-phenyl-1H-indol-1-yl)-2-oxoethyl nitrate are described. These compounds were tested in vivo for their anti-inflammatory, analgesic, and ulcerogenic properties, and subjected to histopathological studies. Compound 7c, 2-(5-(5-(3-hydroxyphenyl)-2-oxo-ethylthio)-1,3,4-oxadiazole-2-yl)-2-phenyl-1H-indol-1-yl)-2-oxoethyl nitrate, was the most potent in this series. The compounds that showed significantly reduced GI ulcerogenicity also showed promising results in histopathological studies, and they were found to cause no mucosal injury. All the synthesized compounds were found to exhibit significant nitric oxide releasing activity in an in vitro method. In conclusion, the designed hybrid molecules were found to be significantly promising.

Microwave-Assisted Facile Synthesis, Anticancer Evaluation and Docking Study of N-((5-(Substituted methylene amino)-1,3,4-thiadiazol-2-yl)methyl) Benzamide Derivatives

In the present work, 12 novel Schiff’s bases containing a thiadiazole scaffold and benzamide groups coupled through appropriate pharmacophore were synthesized. These moieties are associated with important biological properties. A facile, solvent-free synthesis of a series of novel 7(a–l) N-((5-(substituted methylene amino)-1,3,4-thiadiazol-2-yl)methyl) benzamide was carried out under microwave irradiation. Structures of the synthesized compounds were confirmed by IR, NMR, mass spectral study and elemental analysis. All the synthesized hybrids were evaluated for their in vitro anticancer activity against a panel of four human cancer cell lines, viz. SK-MEL-2 (melanoma), HL-60 (leukemia), HeLa (cervical cancer), MCF-7 (breast cancer) and normal breast epithelial cell (MCF-10A) using 3-(4,5-dimethythiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay method. Most of the synthesized compounds exhibited promising anticancer activity, showed comparable GI50 values comparable to that of the standard drug Adriamycin. The compounds 7k, 7l, 7b, and 7a were found to be the most promising anticancer agents in this study. A molecular docking study was performed to predict the probable mechanism of action and computational study of the synthesized compounds 7(a–l) was performed to predict absorption, distribution, metabolism, excretion and toxicity (ADMET) properties, by using QikProp v3.5 (Schrödinger LLC). The results showed the good oral drug-like behavior of the synthesized compounds 7(a–l).

Ultrasound Mediated One-Pot, Three Component Synthesis, Docking and ADME Prediction of Novel 5-Amino-2-(4-chlorophenyl)-7-Substituted Phenyl-8,8a-dihydro-7H-(1,3,4)thiadiazolo(3,2-α)pyrimidine-6-carbonitrile Derivatives as Anticancer Agents

Herein, we report an environmentally friendly, rapid, and convenient one-pot ultrasound-promoted synthesis of 5-amino-2-(4-chlorophenyl)-7-substituted phenyl-8,8a-dihydro-7H-(1,3,4)thiadiazolo(3,2-α)pyrimidine-6-carbonitrile derivatives. The in-vitro anticancer activities of these compounds were evaluated against four human tumor cell lines. Among all the synthesized derivatives, compound 4i, which has substituent 3-hydroxy-4-methoxyphenyl is found to have the highest GI50 value of 32.7 μM, 55.3 μM, 34.3 μM, 28.9 μM for MCF-7, K562, HeLa and PC-3 cancer cell lines respectively. A docking study of the newly synthesized compounds were performed, and the results showed good binding mode in the active site of thymidylate synthase enzyme. ADME properties of synthesized compounds were also studied and showed good drug like properties.

Synthesis and evaluation of anti-inflammatory, analgesic, ulcerogenicity and nitric oxide-releasing studies of novel ibuprofen analogs as nonulcerogenic derivatives

Since the last 41xa0years, Ibuprofen has been one of the most widely used Non-Steroidal Anti-Inflammatory Drug (NSAID) due to its anti-inflammatory actions. As all the NSAIDs are suffering from the deadlier GI toxicities, Ibuprofen also is no exception to these toxicities. The free –COOH group is thought to be responsible for the Gastrointestinal (GI) tract toxicity associated with all the traditional NSAIDs. Therefore, the main aim of this study was to develop new chemical entities as potential anti-inflammatory agents with less GI toxicities. In this article, synthesis of a series of Hybrid molecules containing important pharmacophore of Ibuprofen and substituted diaryl rings on 5-membered heterocycle similar to coxibs and Nitric oxide-releasing moiety are described. All the synthesized compounds were tested in vivo for their anti-inflammatory, analgesic, ulcerogenic properties, and histopathological studies and in vitro for their nitric oxide-releasing properties. Out of the six synthesized compounds, four compounds showed significant anti-inflammatory and analgesic activity which was compared with standard. All the synthesized compounds exhibited significant nitric oxide-releasing and reduced GI ulcerogenic activity.

Design, docking study and ADME prediction of Isatin derivatives as anti-HIV agents

Non-nucleoside reverse transcriptase inhibitors (NNRTI) has a definitive role and most commonly used in treatment of HIV infection. NNRTI act by binding to specific binding site (non-nucleoside binding pocket-NNBP) in reverse transcriptase (RT) enzyme. With the objective of developing efficient NNRTI, we have designed various Isatin analogs for effective treatment of AIDS and were subjected to molecular docking studies on five different crystal structures of RT complexed with five different ligands Nevirapine, Delaviridine, Efavirenz, Etravirine, and Rilpivirine. Combined dock-score of compound N21, N11, N23 was found to be comparable with standards indicated that Isatin analogs have good binding affinity for NNBP. Docking results suggested that these types of compounds could be binding in the NNRTI binding site in a similar mode to a known non-nucleoside inhibitors. ADME properties of Isatin analogs were also analyzed using Qikprop 2.5 tool of Schrodinger software.

Use of Quantitative Structure–Activity Relationship (QSAR) and ADMET prediction studies as screening methods for design of benzyl urea derivatives for anti-cancer activity

2D and 3D quantitative structure–activity relationship studies have been carried out for establishing a correlation between the structural properties of benzyl urea derivatives and their anti-tumour activities. From this correlation, the new chemical entities were designed, and their activity and absorption, distribution, metabolism, excretion, and toxicity properties were also predicted. Finally, the most promising compounds from these screening were synthesized and biologically evaluated for their anti-cancer properties. Compound 1-(2, 4-dimethylphenyl)-3, 3-dimethyl-1-(2-nitrobenzyl) urea (7d) showed significant anti-proliferative activity (at 100 µg/mL) in human cancer cell lines-T-cell leukemia (Jurkat J6), myelogenous leukemia (K562), and breast cancer (MCF-7) compared to reference standard 5-flurouracil.

DIPEAc promoted one-pot synthesis of dihydropyrido[2,3-d:6,5-d']dipyrimidinetetraone and pyrimido[4,5 d]pyrimidine derivatives as potent tyrosinase inhibitors and anticancer agents: in vitro screening, Molecular docking and ADMET predictions

The present method provides a wide scope and quick access to dihydropyrido[2,3-d:6,5-d′]dipyrimidinetetraone and pyrimido[4,5-d]pyrimidine derivatives in good to excellent isolated yields from a one-pot three-component reaction of aldehydes, barbituric acid and ammonium acetate/urea in DIPEAc at room temperature. Major advantages of the present methodology are: use of green solvent, short reaction time, catalyst free, compatibility with a wide range of substrates, ease of recovery, reusability of the reaction medium, and DIPEAc as an alternative solvent and catalyst. All the synthesized compounds (3a–k) and (4a–g) were evaluated for their in vitro anticancer and tyrosinase inhibitory activity. In vitro anticancer screening of the synthesized compounds was performed against MCF-7, HeLa and A-549 cancer cell lines and 3f, 3h and 3i showed good activity. The compounds 3a, 3c, 3f and 3i showed good in vitro anticancer activity against SK-MEL-2. The synthesized compounds were also tested on non-tumorigenic MCF-10A cell lines and were found to be selective towards their cancer cell lines. At the IC50 concentration of compound 3f there were typical morphological changes such as cell wall deformation, cell detachment, cell shrinkage and a reduced number of viable cells in MCF-7 cancer cell lines in comparison to control cells. Among the series, compounds 3f, 3h and 3i excellently inhibited the tyrosinase enzyme. A molecular docking study of the compounds was also performed and compounds showed overall very effective binding modes and good agglomeration in the active site by forming various interactions with active site residues. The in silico ADMET properties of the synthesized compounds showed that they possess worthy oral drug like properties.

Novel 2-(nitrooxy)ethyl 2-(4-(substituted phenyl)-2-((substituted phenyl)amino)thiazol-5-yl)acetate as Anti-inflammatory, Analgesic and Nitric Oxide Releasing Agents: Synthesis and Molecular Docking Studies

BACKGROUNDnDue to the need and adverse effects associated with the available anti-inflammatory agents, an attempt was made to develop the new anti-inflammatory agents with better activity and lesser adverse effects.nnnOBJECTIVEnSynthetic approaches based on chemical modification of NSAIDs have been undertaken with the aim of improving NSAIDs safety profile.nnnMETHODnIn the present study, a series of thiazole derivatives (3a-3x) was synthesized and tested for its anti-inflammatory with analgesic and nitric oxide releasing properties. In this work, synthesis of molecules containing substituted diaryl ring on 5-membered thiazole ring with nitric oxide releasing moiety is described.nnnRESULTSnOut of the twenty four synthesized compounds, five compounds showed considerable anti-inflammatory and analgesic activity in comparison with the standard. Most of the synthesized compounds showed considerable nitric oxide-releasing property. The molecular docking study was used to rationalize binding interaction at the active site and the result showed good binding interaction.nnnCONCLUSIONnFrom the results of pharmacological studies, we conclude that the synthesized compounds have not only retained, but showed enhanced anti-inflammatory and analgesic profile.