Synthesis, biological evaluation and docking studies of methylene bearing cyanopyrimidine derivatives possessing a hydrazone moiety as potent Lysine specific demethylase-1 (LSD1) inhibitors: A promising anticancer agents.

A series of novel cyanopyrimidine-hydrazone hybrids were synthesized and characterized with various spectroscopic techniques. The synthesized compounds were tested at NCI, USA, on a 60-cell line panel and most of the compounds showed remarkable cytotoxic activity against different cancer cell lines. Compound 5a was found to be the most potent compound of the series and it was further selected for five dose assays wherein it exhibited GI50 value of 0.414 µM and 0.417 µM against HOP-62 and OVCAR-4 cell lines respectively. The in-silico mechanistic studies indicated that these compounds are acting through inhibition of lysine specific demethylase 1 (LSD1) as evident from in to vitro LSD1 inhibition activity of compounds. Among various synthesized derivatives, compound 5a was found to have IC50-value of 0.956 µM. In addition, absorption, distribution, metabolism, excretion and toxicity profile (ADMET) was assessed for these novel derivatives to get an insight on their pharmacokinetic/dynamic attributes which revealed that synthesized compounds showed acceptable metabolic stability in human liver microsomes with minimal inhibition of cytochrome P450s (CYPs). The results indicated that compound 5a could be a promising lead compound for further development as a therapeutic agent for anticancer activity.

Design and synthesis of pyrazole-pyrazoline hybrids as cancer-associated selective COX-2 inhibitors.

In continuation of our previous work on cancer and inflammation, 15 novel pyrazole-pyrazoline hybrids (WSPP1-15) were synthesized and fully characterized. The formation of the pyrazoline ring was confirmed by the appearance of three doublets of doublets in 1 H nuclear magnetic resonance spectra exhibiting an AMX pattern for three protons (HA , HM , and HX ) of the pyrazoline ring. All the synthesized compounds were screened for their in vitro anticancer activity against five cell lines, that is, MCF-7, A549, SiHa, COLO205, and HepG2 cells, using the MTT growth inhibition assay. 5-Fluorouracil was taken as the positive control in the study. It was observed that, among them, WSPP11 was found to be active against A549, SiHa, COLO205, and HepG2 cells, with IC50 values of 4.94, 4.54, 4.86, and 2.09 µM. All the derivatives were also evaluated for their cytotoxicity against HaCaT cells. WSPP11 was also found to be nontoxic against normal cells (cell line HaCaT), with an IC50 value of more than 50 µM. The derivatives were also evaluated for their in vitro anti-inflammatory activity by the protein (egg albumin) denaturation assay and the red blood cell membrane stabilizing assay, using diclofenac sodium and celecoxib as standard. Compounds that showed significant anticancer and anti-inflammatory activities were further studied for COX-2 inhibition. The manifestation of a higher COX-2 selectivity index of WSPP11 as compared with other derivatives and an in vitro anticancer activity against four cell lines further established that compounds that were more selective toward COX-2 also exhibited a better spectrum of activity against various cancer cell lines.

Methylene-bearing sulfur-containing cyanopyrimidine derivatives for treatment of cancer: Part-II.

In continuation of our previous work on anticancer and anti-inflammatory agents, a series of 22 novel methylene-bearing sulfur-containing cyanopyrimidine derivatives was synthesized by Biginelli condensation reaction, which was followed by nucleophilic substitution of the chloro group with secondary or tertiary amines. Structural confirmation of these derivatives was attained through different spectral techniques. Then, anticancer evaluation of these compounds was done at the National Cancer Institute. Compounds 4g, 4j, 4k, and 4v demonstrated appreciable results against different cell lines. Among the synthesized compounds, 4g (NSC: 795475) exhibited a growth inhibition (GI) of 81.34% against the NCI-H460 lung cancer cell line, 72.64% against the ACHN renal cancer cell line, and 112.17% against the OVCAR-4 ovarian cancer cell line. Compound 4j (NSC: 795746) was active against U-251 CNS cancer, OVCAR-4 ovarian cancer, and 786-0 and ACHN renal cancer cell lines, with GI of 78.84%, 150.38%, 75.64%, and 86.45%, respectively. The literature supporting the association between cancer and underlying inflammation prompted us to evaluate the four compounds, 4g, 4j, 4k, and 4v, with appreciable anticancer activity for their in vitro anti-inflammatory activity. Cyclooxygenase (COX)-2 inhibition studies were also performed to study the molecular target. To validate the target study, molecular docking studies in the ligand-binding domain of COX-2 (PDB ID: 1CX2) were also performed. Compounds 4g, 4j, and 4k did not show cytotoxicity on RAW 264.7 cells up to 10 µM concentration; however, compound 4v showed cytotoxic effects at 10 µM concentration.

Identification of novel selective Mtb-DHFR inhibitors as antitubercular agents through structure-based computational techniques.

Inhibition of dihydrofolate reductase from Mycobacterium tuberculosis-dihydrofolate reductase (Mtb-DHFR) has emerged as a promising approach for the treatment of tuberculosis. To identify novel Mtb-DHFR inhibitors, structure-based virtual screening (SBVS) of the Molecular Diversity Preservation International (MolMall) database was performed using Glide against the Mtb-DHFR and h-DHFR enzymes. On the basis of SBVS, receptor fit, drug-like filters, and ADMET (absorption, distribution, metabolism, excretion, and toxicity) analysis, 16 hits were selected and tested for their antitubercular activity against the H37 RV strain of M. tuberculosis. Five compounds showed promising activity with compounds 11436 and 15275 as the most potent hits with IC50 values of 0.65 and 12.51 µM, respectively, against the H37 RV strain of M. tuberculosis. The two compounds were further tested in the Mtb-DHFR and h-DHFR enzymatic assay for selectivity and were found to be three- to eight-fold selective towards Mtb-DHFR over h-DHFR with minimum inhibitory concentration values of 5.50, 73.89 µM and 42.00, 263.00 µM, respectively. In silico simulation studies also supported the stability of the protein-ligand complex formation. The present study demonstrates the successful utilization of in silico SBVS tools for the identification of novel and potential Mtb-DHFR inhibitors and compound 11436 ((2,4-dihydroxyphenyl)(3,4,5-trihydroxyphenyl)methanone) as a potential lead for the development of novel Mtb-DHFR inhibitors.

Unveiling novel diphenyl-1H-pyrazole based acrylates tethered to 1,2,3-triazole as promising apoptosis inducing cytotoxic and anti-inflammatory agents.

Meagre and suboptimal therapeutic response along with the side effect profile associated with the existing anticancer therapy have necessitated the development of new therapeutic modalities to curb this disease. Bearing in mind the current scenario, a series of 1,2,3-triazole linked 3-(1,3-diphenyl-1H-pyrazol-4-yl)acrylates was synthesized following a multi-step reaction scheme. Initial screening for anticancer potential was done by in vitro sulforhodamine B assay against four human cancer cell lines- MCF-7 (breast), A549 (Lung) and HCT-116 and HT-29 (Colon). On evaluation, several compounds showed promising growth inhibition against all the cell lines, particularly compounds 6e, 6f and 6n. Among them, compound 6f displayed IC50 values of 1.962, 3.597, 1.764 and 4.496 µM against A549, HCT-116, MCF-7 and HT-29 cell lines respectively. Furthermore, the apoptosis inducing potential of the compounds was determined by Hoechst staining and DNA fragmentation assay. Colony formation inhibition assay was also carried out to determine the long term cytotoxic potential of the molecules. Moreover, compounds 6e, 6f and 6n were also evaluated for anti-inflammatory activity by protein albumin denaturation assay and red blood cell membrane stabilizing assay.

Targeting malaria and leishmaniasis: Synthesis and pharmacological evaluation of novel pyrazole-1,3,4-oxadiazole hybrids. Part II.

In continuance with earlier reported work, an extension has been carried out by the same research group. Mulling over the ongoing condition of resistance to existing antimalarial agents, we had reported synthesis and antimalarial activity of certain pyrazole-1,3,4-oxadiazole hybrid compounds. Bearing previous results in mind, our research group ideated to design and synthesize some more derivatives with varied substitutions of acetophenone and hydrazide. Following this, derivatives 5a-r were synthesized and tested for antimalarial efficacy by schizont maturation inhibition assay. Further, depending on the literature support and results of our previous series, certain potent compounds (5f, 5n and 5r) were subjected to Falcipain-2 inhibitory assay. Results obtained for these particular compounds further strengthened our hypothesis. Here, in this series, compound 5f having unsubstituted acetophenone part and a furan moiety linked to oxadiazole ring emerged as the most potent compound and results were found to be comparable to that of the most potent compound (indole bearing) of previous series. Additionally, depending on the available literature, compounds (5a-r) were tested for their antileishmanial potential. Compounds 5a, 5c and 5r demonstrated dose-dependent killing of the promastigotes. Their IC50 values were found to be 33.3 ±â€¯1.68, 40.1 ±â€¯1.0 and 19.0 ±â€¯1.47 µg/mL respectively. These compounds (5a, 5c and 5r) also had effects on amastigote infectivity with IC50 of 44.2 ±â€¯2.72, 66.8 ±â€¯2.05 and 73.1 ±â€¯1.69 µg/mL respectively. Further target validation was done using molecular docking studies. Acute oral toxicity studies for most active compounds were also performed.

Synthesis of pyrazole acrylic acid based oxadiazole and amide derivatives as antimalarial and anticancer agents.

Depravity of malaria in terms of morbidity and mortality in human beings makes it a major health issue in tropical and subtropical areas of the globe. Drug counterfeiting and non-adherence to the treatment regimen have significantly contributed to development and spread of multidrug resistance that has highlighted the need for development of novel and more efficient antimalarial drugs. Complexity associated with cancer disease and prevalence of diversified cell populations vindicates highly specific treatment options for treatment of cancer. Resistance to these anticancer agents has posed a great hindrance in successful treatment of cancer. Pondering this ongoing situation, it was speculated to develop novel compounds targeting malaria and cancer. Moving on the same aisle, we synthesized pyrazole acrylic acid based oxadiazole and amide derivatives using multi-step reaction pathways (6a-x; 6a'-h'). Schizont maturation inhibition assay was employed to determine antimalarial potential. Compound 6v emerged as the most potent antimalarial agent targeting falcipain-2 enzyme. Anticancer activity was done using sulforhodamine B assay. Compounds 6b' and 6g' demonstrated promising results against all the tested cell lines. Further, Microscopic view clearly indicated formation of apoptotic bodies, chromatin condensation, shrinkage of cells and bleb formation. Validation of the results was achieved using molecular docking studies. From the obtained results, it was observed that cyclization (oxadiazole) favored antimalarial activity while non-cyclized compounds (amides) emerged as better anticancer agents.

Synthesis, docking, in vitro and in vivo antidiabetic activity of pyrazole-based 2,4-thiazolidinedione derivatives as PPAR-γ modulators.

The design, synthesis, structure-activity relationship, and biological activity of 2,4-thiazolidinedione derivatives as peroxisome proliferator-activated receptor-γ (PPAR-γ) modulators for antidiabetic activity are reported. Fifteen 2,4-thiazolidinedione derivatives clubbed with pyrazole moiety were docked into the ligand binding domain of PPAR-γ by the Glide XP module of Schrodinger. Eight derivatives (5a, 5b, 5d, 5f, 5i, 5l, 5n, 5o) having Glide XP scores > -8 as compared to the standard drug, rosiglitazone (Glide XP score = -9.165), showed almost similar interaction with the amino acids such as HIS 449, TYR 473, TYR 327, HIS 323, and SER 289 in the molecular docking studies. These eight derivatives were further screened for PPAR-γ transactivation and in vivo blood glucose lowering activity in the streptozotocin-induced diabetic rat model. Compounds 5o, 5n, 5a, 5i, and 5b showed 52.06, 51.30, 48.65, 43.13, and 40.36% PPAR-γ transactivation as compared to the reference drugs rosiglitazone and pioglitazone with 85.30 and 65.22% transactivation, respectively. The data analysis showed significant blood glucose lowering effects (hypoglycemia) of compounds 5o, 5n, and 5a (140.1 ± 4.36, 141.4 ± 6.15, and 150.7 ± 4.15, respectively), along with reference drugs pioglitazone (135.2 ± 4.91) and rosiglitazone (141.1 ± 5.88) as compared to the diabetic control. Furthermore, the most potent compound 5o also elevated the PPAR-γ gene expression by 2.35-fold as compared to rosiglitazone (1.27-fold) and pioglitazone (1.6-fold). It also significantly lowered the AST, ALT, and ALP levels and caused no damage to the liver.

Molecular interactions of bisphenols and analogs with glucocorticoid biosynthetic pathway enzymes: an in silico approach.

Glucocorticoids are known to have vital effects on metabolism, behavior and immunity. Any sort of impairment in their synthesis may lead to the generation of numerous ill health effects. Different environmental toxicants, including bisphenols and their analogs pose deleterious effect on the biosynthesis of glucocorticoids, thereby leading to endocrine disruption. In order to assess the effect of these environmental toxicants on gluocorticoid biosynthetic pathway, an in silico study was performed. This involved molecular docking studies of 18 ligands with the selected participating enzymes of the pathway. These enzymes were CYP11A1, CYP11B2, CYP19A1, CYP17A1, 3α/20ß-HSD, 3ß/17ß-HSD and CYP21A2. Comparison of their binding affinity was made with the known inhibitors of these enzymes. In case of CYP11A1, Bisphenol M (BP M) had the lowest docking score (D score) of -8.699 kCal/mol, and was better than that of the standard, Metyrapone. Bisphenol PH (BP PH) was found to have significant affinity with CYP11B2. In case CYP19A1, results were found to be comparable with the standards, Exemestane and Letrozole. BP PH elicited better results than the standard Abiraterone acetate against CYP17A1. BP M had a D score of -7.759 against 3α/20ß-HSD, again better results than the standard, Trilostane. Upon molecular docking of BP PH against CYP21A2, it was seen that amongst all the analogs, it had maximum interactions along with the lowest D score. From all the above instances mentioned, it is quite evident that certain BPA analogs have more potential to modulate the enzymes involved in comparison to the known inhibitors.

Molecular interactions of dioxins and DLCs with the xenosensors (PXR and CAR): An in silico risk assessment approach.

Dioxins and dioxin-like compounds (DLCs) are known to cause endocrine disruption in humans and animals. Being lipophilic xenobiotic chemicals, they can be easily absorbed into the biological system from the surrounding environments, thereby causing various health dysfunctions. In the present study, a total of 100 dioxins and DLCs were taken, and their binding pattern was assessed with the xenosensors pregnane X receptor (PXR) and constitutive androstane receptor (CAR) in comparison with the corresponding known inhibitors and a well-studied endocrine disrupting xenobiotic, bisphenol A (BPA). The nuclear receptors CAR and PXR are known to play a significant role in handling potential toxins by coordinating cellular transport and metabolic functions of the same. Among different endocrine-disrupting chemicals used in the present study, DLCs (PCDFs and PCBs) elicited better interactions in comparison with the parent dioxin (polychlorinated dibenzodioxins) compounds. On comparing D scores of all the compounds against both the receptors, PCDF 8-hydroxy-3,4-dichlorodibenzofuran (8-OH-DCDF) and PCB tetrachlorobenzyltoluene (TCBT) exhibited significant molecular interactions against PXR (-7.633 kcal mol-1 ) and CAR (-8.389 kcal mol-1 ), respectively. Predominant interactions were found to be H-bonding, π-π stacking, hydrophobic, polar, and van der Waals. By contrast, BPA and some natural ligands tested in this study showed lower binding affinities with these receptors than certain DLCs reported herein, ie, certain DLCs might be more toxic than the proven toxic agent, BPA. Such studies play a pivotal role in the risk assessment of exposure to dioxins and DLCs on human health.

Molecular interactions of dioxins and DLCs with the ketosteroid receptors: an in silico risk assessment approach.

Dioxins and dioxin-like compounds (DLCs) are the ones with poor water solubility and low volatility, resistant to physical, chemical and biological processes, persistent in the environment even under extreme conditions. Due to lipophilic nature, they get adhered to the fatty material and concentrate through biomagnification and bioaccumulation, thereby easily getting incorporated into food chains, paving the way to endocrine disruption via modulation of various human receptors. This in turn leads to certain adverse health effects. In the present study, a total of 100 dioxins and DLCs were taken and their binding pattern was assessed with the ketosteroid receptors, i.e. androgen (hAR), glucocorticoid (hGR), progesterone (hPR) and mineralocorticoid (hMR) in comparison to the corresponding natural steroids and a known endocrine disrupting xenobiotic, Bisphenol A (BPA). Most of the DLCs, particularly those bearing hydroxyl (-OH) group showed considerable affinities with ketosteroid receptors. On comparing D scores of all the dioxins and DLCs against all four receptors, compound 8-hydroxy-3,4-dichlorodibenzofuran(8-OH-DCDF) exhibited least D score of -9.549 kcal mol-1 against hAR. 3,8-Dihydroxy-2-chlorodibenzofuran(3,8-DiOH-CDF), 4'-hydroxy-2,3,4,5-tetrachlorobiphenyl (4'-OH-TCB) and 4-hydroxy-2,2',5'-trichlorobiphenyl(4-OH-TCB) also showed comparable molecular interactions with the ketosteroid receptors. These interactions mainly include H-bonding, π-π stacking, hydrophobic, polar and van der Waals' interactions. In contrast, BPA and some natural ligands tested in this study showed lower binding affinities with these receptors than certain DLCs reported herein, i.e. certain DLCs might be more toxic than the proven toxic agent, BPA. Such studies play a pivotal role in the risk assessment of exposure to dioxins and DLCs on human health.

Novel pyrazole-pyrazoline hybrids endowed with thioamide as antimalarial agents: their synthesis and 3D-QSAR studies.

One of the most viable options to tackle the growing resistance to the antimalarial drugs is hybrid molecules. It involves combination of different scaffolds in one frame that may lead to compounds with diverse biological profiles. In this context, new hybrids of three different scaffolds viz pyrazole, pyrazoline and thiosemicarbazone moiety were incorporated into one single compound and evaluated for their in vitro schizontocidal activity against the CQ-sensitive 3D7 strain of Plasmodium falciparum. Compounds with significant in vitro antimalarial activity were further evaluated for cytotoxicity against VERO cell lines. The best active compound 48 exhibited an IC50 of 1.13 µM. The in vitro results were further validated by quantitative structure-activity relationship (QSAR).

Osteogenic effect of alogliptin in chemical-induced bone loss: a tri-modal in silico, in vitro, and in vivo analysis.

OBJECTIVE: To investigate the effects of Alogliptin in chemical-induced post-menopausal osteoporosis. METHODOLOGY: The binding affinity of alogliptin with osteogenic proteins was analysed in silico. The effect of alogliptin on osteogenic proteins and mineralization of osteoblastic cells was evaluated in UMR-106 cells. Further, in vivo anti-osteoporotic activity of alogliptin was evaluated in postmenopausal osteoporosis. Various bone turnover markers were assayed in serum. This followed the analysis of microarchitecture of bone, histology, and immunohistochemistry (IHC) of bone tissue. RESULTS: Docking scores showed that alogliptin has binding affinity for bone alkaline phosphatase (BALP), osteocalcin, and bone morphogenic protein (BMP-2). Alogliptin also enhanced mineralization of osteoblast cells, evidenced with increased ALP, osteocalcin, and BMP-2. Animal studies revealed significant elevation of bone formation markers, bone ALP, osteocalcin and BMP-2, and decreased bone resorption markers, receptor activator of NF-κß (RANKL), cathepsin K (CTSK), tartrate resistant acid phosphatase (TRAcP5b) in VCD-induced post-menopausal osteoporosis. Micro computed tomography (µCT) analysis and histology of femur bone and lumbar vertebrae demonstrated decrease in trabecular separation and improved bone density. IHC of femur showed reduced DPP4 enzyme. CONCLUSIONS: Alogliptin increased mineralization in osteoblast cells. It had beneficial effects also altered bone turnover markers, repaired the trabecular microstructure, improved bone mineral density, and exhibited bone forming capacity targeting DPP-4 enzyme in postmenopausal osteoporosis.

Microwave assisted one pot synthesis of some pyrazole derivatives as a safer anti-inflammatory and analgesic agents.

A series of pyrazolo[3,4-b]quinolines have been synthesized using one-pot water mediated synthetic route under microwave irradiation involving the condensation of 2-chloroquinoline-3-carbaldehydes with semicarbazide or 2,4-dinitrophenyl hydrazine. The compounds were evaluated for their anti-inflammatory, analgesic, ulcerogenic and lipid peroxidation actions. The pharmacological evaluation showed that the compounds are good at inhibiting edema induced by carrageenan and also showed prominent analgesic activity with lesser GI toxicity as indicated by severity index and LPO values.

Quinoline: A versatile heterocyclic.

Quinoline or 1-aza-naphthalene is a weak tertiary base. Quinoline ring has been found to possess antimalarial, anti-bacterial, antifungal, anthelmintic, cardiotonic, anticonvulsant, anti-inflammatory, and analgesic activity. Quinoline not only has a wide range of biological and pharmacological activities but there are several established protocols for the synthesis of this ring. The article aims at highlighting these very diversities of the ring.

A Review on the Synthesis and Anticancer Potentials of Imidazothiazole Derivatives.

Cancer is one of the severe diseases in which abnormal cells divide and proliferate in an uncontrolled manner without any regulation. Globally cancer is among the leading causes of death; according to a recent report of by the WHO, around 10 million people died in 2018 due to cancer. It has also been reported that by 2040, approximately 30 million new cases will be reported every year. The increase in the incidences of cancer is taking a toll on the health care system worldwide. Considerable scientific literature is available on anticancer agents but newer therapeutic strategies are still required in this field to address novel approaches to drug design and discovery to counter this problem. Imidazothiazole represents a privileged scaffold in medicinal chemistry and provides the medicinal chemist the possibility to modulate the physiochemical properties of the lead compound. In recent times, imidazothiazole scaffold is broadly explored for its anticancer activity, which acts through various mechanisms such as EGFR, B-RAF, DHFR kinase inhibition and tubulin polymerization inhibition and other molecular mechanisms of action. Due to their feasible synthetic accessibility and promising pharmacological profile, it has attracted various medicinal chemists to explore and develop imidazothiazole derivatives as potent and safe anticancer agents. In the present article, we have reviewed various potent imidazothiazole scaffold-based derivatives reported as anticancer agents, their synthetic strategies, Structure Activity Relationship (SAR), mechanism of action, and molecular docking along with their future perspective. This review will be very useful for medicinal chemists for drug design and development of imidazothiazole-based potent antiproliferative agents.

Synthesis and HDAC1 inhibitory activity of a novel series of coumarin-based amide derivatives for treatment of cancer.

Background: Histone deacetylases (HDACs) play a vital role in the epigenetic regulation of transcription and expression. HDAC1 overexpression is seen in many cancers. Methodology: The authors synthesized and evaluated 27 novel coumarin-based amide derivatives for HDAC1 inhibitory activity. The compounds were screened at the US National Cancer Institute, and 5k and 5u were selected for five-dose assays. Compound 5k showed GI50 values of 0.294 and 0.264 µM against MOLT-4 and LOX-IMVI, respectively; whereas 5u had GI50 values of 0.189 and 0.263 µM, respectively. Both derivatives showed better activity than entinostat and suberoylanilide hydroxamic acid. Compound 5k exhibited an IC50 value of 1.00 µM on ACHN cells. Conclusion: Coumarin derivatives exhibited promising HDAC1 inhibitory potential and warrant future development as anticancer agents.

SAR based Review on Diverse Heterocyclic Compounds with Various Potential Molecular Targets in the Fight against COVID-19: A Medicinal Chemist Perspective.

Coronavirus disease (COVID-19) was reported to be transmitted from bats to humans and, became a pandemic in 2020. COVID-19 is responsible for millions of deaths worldwide and still, the numbers are increasing. Further, despite the availability of vaccines, mutation in the virus continuously poses a threat of re-emergence of the more lethal form of the virus. So far, the repurposing of drugs has been exercised heavily for the identification of therapeutic agents against COVID-19, which led FDA to approve many drugs for the same e.g., remdesivir, favipiravir, ribavirin, etc. The anti-COVID drugs explored via other approaches include nirmatrelvir (used in combination with ritonavir as Paxlovid), tixagevimab and cilgavimab (both used in combination with each other) and others. However, these approved drugs failed to achieve a significant clinical outcome. Globally, natural bioactive have also been explored for anti-COVID-19 effects, based on their traditional medicinal values. Although the clinical findings suggest that FDA-approved drugs and natural bioactives can help reducing the overall mortality rate but the significant clinical outcome was not achieved. Therefore, the focus has been shifted towards new drug development. In line with that, a lot of work has been done and still going on to explore heterocyclic compounds as potent anti- COVID-19 drugs. Several heterocyclic scaffolds have been previously reported with potent antiinflammatory, anticancer, anti-viral, antimicrobial and anti-tubercular effects. Few of them are under consideration for clinical trials whereas others are under preclinical investigation. Hence, this review discusses the evidence of rationally designed and tested heterocyclic compounds acting on different targets against COVID-19. The present article will help the researches and will serve as a pivotal resource in the design and development of novel anti-COVID-19 drugs.

Synthesis and anticonvulsant activity of some 2-(2-{1-[substituted phenyl]ethylidene}hydrazinyl)-4-(4-methoxy-phenyl)-6-oxo-1,6-dihydro-pyrimidine-5-carbonitrile.

A series of dihydro-pyrimidine-5-carbonitrile derivatives (3-16) were synthesized and evaluated for their anticonvulsant activity against MES and scPTZ models. Motor impairment screening was carried out by rotarod test method and CNS depressant effect was determined by Porsolt's force swim pool method. Compounds 4 and 9 having p-substituted bromo and m-substituted nitro groups, respectively, were found to be most active showing activity both in MES and scPTZ screen at lower doses of 30 mgkg(-1) at 0.5 h and 100 mgkg(-1) at 4 h. In the rotarod motor impairment screen, compound 4 did not show any motor impairment even at the maximum dose of 300 mgkg(-1); however, compound 9 showed motor impairment at 300 mgkg(-1) dose after 4.0 h. The compounds were also tested for their CNS depression effect. The compounds 4 and 9 showed 41.38 and 43.44% increase in immobility time with respect to control. The pharmacophore hypothesis also fits best for compounds 4 and 9.

Anti-inflammatory and antimicrobial activity of 4,5-dihydropyrimidine-5-carbonitrile derivatives: their synthesis and spectral elucidation.

Thirteen new 6-(1-H-indole-2-yl)-4-oxo-2-[2-(substituted-benzylidene)-hydrazinyl]-4,5-dihydropy-rimidine-5-carbonitrile derivatives were synthesized. The title compounds, hydrazones, were synthesized by reaction of hydrazine group of 2-hydrazinyl-4-(1-H-indole-2-yl)-6-oxo-1,6-dihydropyrimidine-5-carbonitrile (2) with different substituted aromatic aldehydes using a mixture (2:8, v/v) of glacial acetic acid and alcohol. The required intermediate compound 2 was synthesized from 2-mercapto-4-(1-H-indole-2-yl)-6-oxo-1,6-dihy-dropyrimidine-5-carbonitrile 1 upon nucleophilic attack by the hydrazine hydrate. Compound 1 was synthesized by modified Biginelli condensation method using indole-3-carbaldehyde, ethyl cyanoacetate and thiourea. The compounds were evaluated for their anti-inflammatory, analgesic, ulcerogenic and antimicrobial actions. Among the newer derivatives, one compound i.e., 6-(1-H-indole-2-yl)-4-oxo-2-[2-(2,6-dichlorobenzylidene)-hydrazinyl]-4,5-dihydropyrimidine-5-carbonitrile (7) emerged as lead compound having 71.14% inhibition of edema and 12.5 microg/mL MIC against both bacterial and fungal strains.