Design,Synthesis, and Antitumor Activity of (E,Z)‐1‐(dihydrobenzofuran‐5‐yl)‐3‐phenyl‐2‐(1,2,4‐triazol‐1‐yl)‐2‐propen‐1‐ones

A series of (E,Z)‐1‐(dihydrobenzofuran‐5‐yl)‐3‐phenyl‐2‐(1,2,4‐triazol‐1‐yl)‐2‐propen‐1‐ones ( C1 – C35 ) were designed and synthesized, and the structures of compounds (Z)‐ C27 and (Z)‐ C29 were confirmed by single‐crystal X‐ray diffraction. The antitumor activities of these novel compounds against cervical cancer (HeLa), lung cancer (A549), and breast cancer (MCF‐7) cell lines were evaluated in vitro. Majority of the title compounds exhibited strong antitumor activities and were much more promising than the positive control Taxol, which were also accompanied by lower cytotoxicity to normal cells. In particular, compounds (E,Z)‐ C24 exhibited the most consistent potent activities against three neoplastic cells with IC₅₀ values ranging from 3.2 to 7.1 μm . Further researches demonstrated that compounds (E,Z)‐ C24 could induce cell apoptosis and arrest cell cycle at the G2/M and S phases. Meanwhile, the structure–activity relationship between the configurations and cytotoxicity of the compounds was also investigated.     

Synthesis and Antitubercular Screening of [(2‐Chloroquinolin‐3‐yl)methyl] Thiocarbamide Derivatives

A series of 1‐(substituted‐phenyl)‐1‐[(2‐chloroquinolin‐3‐yl)methyl]thiocarbamide and 1‐(substituted‐phenyl)‐1‐[(2‐chloroquinolin‐3‐yl)methyl]methylthiocarbamide derivatives was synthesized as antitubercular agent. The structure of quinolinyl amines and their thiocarbamide derivatives were established on the basis of IR, ¹H and ¹³C‐NMR and mass spectral data. All the compounds were tested in vitro for antimycobacterial activity against Mycobacterium tuberculosis (ATCC‐25177) in Lowenstein‐Jensen medium by well diffusion method and MIC by twofold serial dilution method. Results of the antitubercular screening revealed that compounds showed moderate to good antitubercular activity. Compound having two halogens in the phenyl rings viz. 3g , 3h , 4g, and 4h exhibited MIC of 50 μg/mL. The computational parameters relevant to absorption and permeation of target compounds were also calculated and found to be well correlated with antitubercular activity.     

Syntheses,calcium channel modulation effects,and nitric oxide release studies of O2‐alkyl‐1‐(pyrrolidin‐1‐yl) diazen‐1‐ium‐1,2‐diolate 4‐aryl(heteroaryl)‐1,4‐dihydro‐2,6‐dimethyl‐3‐nitropyridine‐5‐carboxylates

A group of racemic 4‐aryl(heteroary)‐1,4‐dihydro‐2,6‐dimethyl‐3‐nitropyridine‐5‐carboxy‐lates possessing a potential nitric oxide donor C‐5 O²‐alkyl‐1‐(pyrrolidin‐1‐yl)diazen‐1‐ium‐1,2‐diolate ester [alkyl=(CH₂)_n, n=1–4] substituent were synthesized using a modified Hantzsch reaction. Compounds having a C‐4 2‐trifluoromethylphenyl ( 16 ), 2‐pyridyl ( 17 ), or benzofurazan‐4‐yl ( 20 ) substituent generally exhibited more potent smooth‐muscle calcium channel antagonist activity (IC₅₀ values in the 0.55 to 38.6 μM range) than related analogs having a C‐4 3‐pyridyl ( 18 ), or 4‐pyridyl ( 19 ) substituent with IC₅₀ values > 29.91 μM, relative to the reference drug nifedipine (IC₅₀=0.0143 μM). The point of attachment of C‐4 isomeric pyridyl substituents was a determinant of antagonist activity where the relative potency profile was 2‐pyridyl > 3‐pyridyl and 4‐pyridyl. Subgroups of compounds 16a–d , 17a–d , and 20a–d having alkyl spacer groups of variable chain length [–CO₂(CH₂)_nO–, n=1–4] exhibited small differences in calcium channel antagonist potency. Replacement of the ester “methyl” moiety of Bay K 8644 by an O²‐alkyl‐1‐(pyrrolidin‐1‐yl)diazen‐1‐ium‐1,2‐diolate group provided the Bay K 8644 group of analogs 16a‐d that retained the desired cardiac positive inotropic effect. The most potent compound in this group, O²‐ethyl‐1‐(pyrrolidin‐1‐yl)diazen‐1‐ium‐1,2‐diolate 1,4‐dihydro‐2,6‐dimethyl‐3‐nitro‐4‐(2‐trifluoromethylphenyl)pyridine‐5‐carboxylate ( 16b , EC₅₀=0.096 μM) is about eightfold more potent positive inotrope (cardiac calcium channel agonist) than the reference compound Bay K 8644 (EC₅₀=0.77 μM). A similar replacement of the ester “isopropyl” group in the C‐4 benzofurazan‐4‐yl group of compounds by an O²‐alkyl‐1‐(pyrrolidin‐1‐yl)diazen‐1‐ium‐1,2‐diolate ester substituent provided compounds 20 (n=1 and 4) that were approximately equipotent cardiac positive inotropes with the parent reference compound PN 202‐791 ( 3 , EC₅₀=9.40 μM). The O²‐alkyl‐1‐(pyrrolidin‐1‐yl)diazen‐1‐ium‐1,2‐diolate ester moiety present in 1,4‐dihydropyridine calcium channel modulating compounds 16–20 is not a suitable ?NO donor moiety because the percent nitric oxide released upon in vitro incubation with either l ‐cysteine, rat serum, or pig liver esterase was less than 1%. Drug Dev. Res. 60:204–216, 2003. © 2003 Wiley‐Liss, Inc.     

Synthesis of Novel 2,5‐Disubstituted 1,3,4‐Thiadiazoles for Their Potential Anticonvulsant Activity: Pharmacophoric Model Studies

A series of novel N¹‐[5‐(4‐substituted phenyl)‐1,3,4‐thiadiazol‐2‐yl]‐N⁴‐(4‐substituted benzaldehyde)‐semicarbazone 1 – 12 , N¹‐[5‐(4‐substituted phenyl)‐1,3,4‐thiadiazol‐2‐yl]‐N⁴‐[1‐(4‐substituted phenyl)ethanone]‐semicarbazone 13 ‐ 16 , and N¹‐[5‐(4‐substituted phenyl)‐1,3,4‐thiadiazol‐2‐yl]‐N⁴‐[1‐(4‐substituted phenyl) (phenyl) methanone]‐semicarbazone 17 – 20 were synthesized for their anticonvulsant activity. The chemical structures of the compounds were proved by elemental and spectral (IR, ¹H‐NMR, ¹³C‐NMR, and MS) analysis. The anticonvulsant potential of the compounds was investigated using maximal electroshock seizure (MES) and subcutaneous pentylenetrtrazole (scPTZ) models. Compound 19 was found to possess significant anticonvulsant activity in both the models employed for anticonvulsant evaluation. Compounds 8 , 13 , 15 , and 16 also demonstrated a marked anticonvulsant property. The results of the present study validated that the pharmacophore model with four binding sites is essential for anticonvulsant activity. The efforts were also made to establish structure‐activity relationships among the synthesized compounds.     

Synthesis,In Vitro Protoporphyrinogen Oxidase Inhibition,and Herbicidal Activity of N‐(Benzothiazol‐5‐yl)hexahydro‐1H‐isoindole‐1,3‐diones and N‐(Benzothiazol‐5‐yl)hexahydro‐1H‐isoindol‐1‐ones

Protoporphyrinogen oxidase ( EC 1.3.3.4 ) is one of the most significant targets for a large family of herbicides. As part of our continuous efforts to search for novel protoporphyrinogen oxidase‐inhibiting herbicides, N‐(benzothiazol‐5‐yl)tetrahydroisoindole‐1,3‐dione was selected as a lead compound for structural optimization, leading to the syntheses of a series of novel N‐(benzothiazol‐5‐yl)hexahydro‐1H‐isoindole‐1,3‐diones ( 1a – o ) and N‐(benzothiazol‐5‐yl)hexahydro‐1H‐isoindol‐1‐ones ( 2a – i ). These newly prepared compounds were characterized by elemental analyses, ¹H NMR, and ESI‐MS, and the structures of 1h and 2h were further confirmed by X‐ray diffraction analyses. The bioassays indicated that some compounds displayed comparable or higher protoporphyrinogen oxidase inhibition activities in comparison with the commercial control. Very promising, compound 2a , ethyl 2‐((6‐fluoro‐5‐(4,5,6,7‐tetrahydro‐1‐oxo‐1H‐isoindol‐2(3H)‐yl)benzo[d]thiazol‐2‐yl)‐sulfanyl)acetate, was recognized as the most potent candidate with K_i value of 0.0091 μm . Further greenhouse screening results demonstrated that some compounds exhibited good herbicidal activity against Chenopodium album at the dosage of 150 g/ha.     

Design,Synthesis and Evaluation of Antidepressant Activity of Novel 2‐Methoxy 1, 8 Naphthyridine 3‐Carboxamides as 5‐HT3 Receptor Antagonists

A series of novel 1,8‐naphthyridine‐3‐carboxamides as 5‐HT₃ receptor antagonists were synthesized with an intention to explore the antidepressant activity of these compounds. The title carboxamides were designed using ligand‐based approach keeping in consideration the structural requirement of the pharmacophore of 5‐HT₃ receptor antagonists. The compounds were synthesized using appropriate synthetic route from the starting material nicotinamide. 5‐HT₃ receptor antagonism of all the compounds, which was denoted in the form of pA₂ value, was determined in longitudinal muscle myenteric plexus preparation from guinea‐pig ileum against 5‐HT₃ agonist, 2‐methyl‐5‐HT. Compound 8g (2‐methoxy‐1, 8‐naphthyridin‐3‐yl) (2‐methoxy phenyl piperazine‐1‐yl) methanone was identified as the most active compound, which expressed a pA₂ value of 7.67. The antidepressant activity of all the compounds was examined in mice model of forced swim test (FST); importantly, none of the compounds was found to cause any significant changes in the locomotor activity of mice at the tested dose levels. In FST, the compounds with considerably higher pA₂ value exhibited promising antidepressant‐like activity, whereas compounds with lower pA₂ value did not show antidepressant‐like activity as compared to the control group.     

Novel 3,6‐Disubstituted 7H‐1,2,4‐Triazolo[3,4‐b][1,3,4]thiadiazines: Synthesis,Characterization, and Evaluation of Analgesic / Anti‐inflammatory,Antioxidant Activities

In this study, the synthesis of a new series of 3,6‐disubstituted‐7H‐1,2,4‐triazolo[3,4‐b][1,3,4]thiadiazine 1a – 4c compounds derived from 4‐amino‐3‐substituted‐1,2,4‐triazole‐5‐thiones 1 – 4 is described. All of the synthesized compounds were screened for their possible analgesic / anti‐inflammatory, antioxidant activities and gastric toxicity. The compound 2c was found to have both significant analgesic and consistent anti‐inflammatory activity without inducing any gastric lesions along with minimal lipid peroxidation. A deep insight into the structures of the active compounds revealed that the compounds carrying an electron withdrawing group (a chloride or fluoride) on the phenyl ring at 6‐position of the condensed heterocyclic derivatives exhibited noticeable higher activity.     

Synthesis and Antimicrobial Activity of Some Novel 2‐[4‐(Substituted Piperazin‐/Piperidin‐1‐ylcarbonyl)phenyl]‐1H‐benzimidazole Derivatives

In this study, we report the synthesis and antimicrobial evaluation of several new 4‐(1H‐benzimidazol‐2‐yl)benzamides ( 11 – 30 ) and 5‐chloro‐1‐(p‐fluorobenzyl)‐2‐{4‐[(4‐methylpiperazin‐1‐yl)carbonyl]phenyl}‐1H‐benzimidazole ( 33 ). Compound 20 exhibited the best antibacterial activity with MIC value of 6.25 μg/mL against Staphylococcus aureus and methicillin‐resistant Staphylococcus aureus (MRSA). Significant antifungal activities were obtained with the compounds 13 , 14, 18 , 19, and 33 with MIC values of 3.12 μg/mL which are close to fluconazole.     

Discovery of Novel 2‐(piperidin‐4‐yl)‐1H‐benzo[d]imidazole Derivatives as Potential Anti‐Inflammatory Agents

A novel 2‐(piperidin‐4‐yl)‐1H‐benzo[d]imidazole derivative 5 with good anti‐inflammatory activity was identified from our in‐house library. Based on hit compound 5 , two series of 2‐(piperidin‐4‐yl)‐1H‐benzo[d]imidazole derivative 6a – g and 7a – h were designed and synthesized as novel anti‐inflammatory agents. Most of synthesized compounds exhibited good inhibitory activity on NO and TNF‐α production in LPS‐stimulated RAW 264.7 macrophages, in which the compound 6e showed most potent inhibitory activity on NO (IC₅₀ = 0.86 μm ) and TNF‐α (IC₅₀ = 1.87 μm ) production. Further evaluation revealed that compound 6e displayed more potent in vivo anti‐inflammatory activity than ibuprofen did on xylene‐induced ear oedema in mice. Additionally, Western blot analysis revealed that compound 6e could restore phosphorylation level of IκBα and protein expression of p65 NF‐κB in LPS‐stimulated RAW 264.7 macrophages.     

Development of 2‐(Substituted Benzylamino)‐4‐Methyl‐1, 3‐Thiazole‐5‐Carboxylic Acid Derivatives as Xanthine Oxidase Inhibitors and Free Radical Scavengers

A series of 2‐(substituted benzylamino)‐4‐methylthiazole‐5‐carboxylic acid was designed and synthesized as structural analogue of febuxostat. A methylene amine spacer was incorporated between the phenyl ring and thiazole ring in contrast to febuxostat in which the phenyl ring was directly linked with the thiazole moiety. The purpose of incorporating methylene amine was to provide a heteroatom which is expected to favour hydrogen bonding within the active site residues of the enzyme xanthine oxidase. The structure of all the compounds was established by the combined use of FT‐IR, NMR and MS spectral data. All the compounds were screened in vitro for their ability to inhibit the enzyme xanthine oxidase as per the reported procedure along with DPPH free radical scavenging assay. Compounds 5j, 5k and 5l demonstrated satisfactory potent xanthine oxidase inhibitory activities with IC₅₀ values, 3.6, 8.1 and 9.9 μm , respectively, whereas compounds 5k , 5n and 5p demonstrated moderate antioxidant activities having IC₅₀ 15.3, 17.6 and 19.6 μm , respectively, along with xanthine oxidase inhibitory activity. Compound 5k showed moderate xanthine oxidase inhibitory activity as compared with febuxostat along with antioxidant activity. All the compounds were also studied for their binding affinity in active site of enzyme (PDB ID‐1N5X).     

Synthesis,Hypoglycaemic, Hypolipidemic and PPARγ Agonist Activities of 5‐(2‐Alkyl/aryl‐6‐Arylimidazo[2,1‐b][1,3,4]thiadiazol‐5‐yl)methylene‐1,3‐Thiazolidinediones

A novel series of 5‐(2‐alkyl/aryl‐6‐arylimidazo[2,1‐b][1,3,4]thiadiazol‐5‐yl)methylene‐1,3‐thiazolidinediones were synthesized as possible PPARγ agonists. The structures of these target molecules were established by spectral and analytical data. All the newly synthesized compounds were screened for their in vivo hypoglycaemic and hypolipidemic activity in male Wistar rats. Further, compounds with good activity were screened for PPARγ agonist activity. Among the screened compounds, 5‐{[2‐Cyclohexyl‐6‐(4‐methoxyphenyl)imidazo[2,1‐b] [1,3,4]thiadiazol‐5‐yl]methylene}‐1,3‐thiazolidine‐2,4‐dione (3i) exhibits promising hypoglycaemic and hypolipidemic activity via potential PPARγ agonist activity.     

Synthesis and kinetics studies of N′‐(2‐(3,5‐disubstituted‐4H‐1,2,4‐triazol‐4‐yl)acetyl)‐6/7/8‐substituted‐2‐oxo‐2H‐chromen‐3‐carbohydrazide derivatives as potent antidiabetic agents

A novel series of N′‐(2‐(3,5‐disubstituted‐4H‐1,2,4‐triazol‐4‐yl)acetyl)‐6/7/8‐substituted‐2‐oxo‐2H‐chromen‐3‐carbohydrazides were synthesized and studied for their α‐glucosidase inhibition activity. Most of the synthesized compounds exhibited potential α‐glucosidase inhibition activity with IC₅₀ values ranging from 0.96 ± 0.02 to 32.86 ± 0.73 µg/ml. Among them, compounds 3e and 4e , having a methoxy group on the coumarin ring, proved to be the most potent ones, showing an enzyme inhibition activity with IC₅₀ = 0.96 ± 0.02 and 1.44 ± 0.06 µg/ml, respectively. The kinetic study through Lineweaver–Burk plots revealed that the inhibition mechanism of the most active compounds 3d, 3e, 4d , and 4e , on the α‐glucosidase activity, was found to be in the competitive mode.     

A Novel Antifungal Agent with Broad Spectrum: 1‐(4‐Biphenylyl)‐3‐(1H‐imidazol‐1‐yl)‐1‐propanone

A series of (1‐substituted aryl)‐3‐(1H‐imidazol‐1‐yl)‐1‐propanones was synthesized through the N‐alkylation of imidazole with 3‐dimethylamino‐1‐(substituted aryl)‐1‐propanone hydrochlorides (ketonic Mannich bases). A second series of N¹‐substituted imidazoles was obtained by the reduction of the carbonyl function of the imidazole–ketones in the previous series by means of NaBH₄. All of the compounds were evaluated for antifungal activity against 16 strains of Candida, and 3‐(1H‐imidazol‐1‐yl)‐1‐(4‐biphenylyl)‐1‐propanone emerged as a broad‐spectrum antifungal agent. Several 3‐(1H‐imidazol‐1‐yl)‐1‐(2′‐(substituted benzyl)oxyphenyl)‐1‐propanones were also active towards Candida kefyr.     

Design,Synthesis, Biological Evaluation,and Docking Study of Acetylcholinesterase Inhibitors: New Acridone‐1,2,4‐oxadiazole‐1,2,3‐triazole Hybrids

In this study, novel acridone‐1,2,4‐oxadiazole‐1,2,3‐triazole hybrids were designed, synthesized, and evaluated for their acetylcholinesterase and butyrylcholinesterase inhibitory activity. Among various synthesized compounds, 10‐((1‐((3‐(4‐methoxyphenyl)‐1,2,4‐oxadiazol‐5‐yl)methyl)‐1H‐1,2,3‐triazol‐4‐yl)methyl)acridin‐9(10H)‐one 10b showed the most potent anti‐acetylcholinesterase activity (IC₅₀ = 11.55 μm ) being as potent as rivastigmine. Also docking outcomes were in good agreement with in vitro results confirming the dual binding inhibitory activity of compound 10b .     

Synthesis and Antibacterial Activity of a New Series of 3‐[3‐(Substituted Phenyl)‐1‐Isonicotinoyl‐1H‐Pyrazol‐5‐yl]‐2H‐Chromen‐2‐one Derivatives

A novel series of 3‐[3‐(substituted phenyl)‐1‐isonicotinoyl‐1H‐pyrazol‐5‐yl]‐2H‐chromen‐2‐one derivatives 4a – k have been synthesized by the reaction of 3‐[2,3‐dibromo‐3‐(substituted phenyl) propanoyl]‐2H‐chromen‐2‐one 3a – k and isonicotinic acid hydrazide in the presence of triethylamine in absolute ethanol, characterized by spectral data and screened for their in‐vitro antibacterial activity against Gram‐positive and Gram‐negative bacteria. Among the series, compounds 4e , 4i , and 4k displayed an encouraging antibacterial activity profile as compared to the reference drug ampicillin against tested bacterial strains.     

Synthesis of Novel Oxazolo[4,5‐b]pyridine‐2‐one based 1,2,3‐triazoles as Glycogen Synthase Kinase‐3β Inhibitors with Anti‐inflammatory Potential

A novel series of oxazolo[4,5‐b]pyridine‐2‐one based 1,2,3‐triazoles has been synthesized by click chemistry approach and evaluated for in vitro GSK‐3β inhibitory activity. Compound 4g showed maximum inhibition with IC₅₀ value of 0.19 μ m . Keeping in view the effect of GSK‐3β inhibition on inflammation, compounds 4g , 4d , 4f , 4i , 4n and 4q exhibiting significant GSK‐3β inhibition were examined for in vivo anti‐inflammatory activity in rat paw edema model. The compounds 4g , 4d , 4f and 4i showed pronounced in vivo anti‐inflammatory activity (76.36, 74.54, 72.72 and 70.90%, respectively, after 5h post‐carrageenan administration) and were further found to inhibit the pro‐inflammatory mediators, viz. NO, TNF‐ α , IL‐1 β , and IL‐6 substantially in comparison with indomethacin, an anti‐inflammatory drug as well as SB216763, a GSK‐3 β inhibitor, reported to exert a similar effect. Histopathology studies confirmed the tolerance of gastric mucosa to these compounds.     

Design and syntheses of methyl 2‐methyl‐2‐[2‐(4‐benzoyl‐5‐phenyl‐7‐halo‐2‐azabicyclo[4.1.0]hept‐3‐ene)]acetates: novel inhibitors of cyclooxygenase‐2 (COX‐2) with analgesic‐antiinflammatory activity

A group of methyl 2‐methyl‐2‐[2‐(4‐benzoyl‐5‐phenyl‐7‐halo‐2‐azabicyclo[4.1.0]hept‐3‐ene)]acetates ( 10–15 ), and the related acetamide derivative ( 16 ), that possess a variety of C‐7 substituents (Br, Cl, F, H), were designed for evaluation as analgesic‐antiinflammatory agents. The effect of the C‐7 substituent(s) and the nature of the acetic acid ester (R¹ = Ome) or acetamide (R¹ = NH₂) moiety on analgesic activity was determined using a 4% NaCl‐induced abdominal constriction assay. Compounds 10–16 inhibited writhing by 36–82%, relative to the reference drugs aspirin (58% inhibition) and celecoxib (62% inhibition). The nature of the C‐7 substituents was a determinant of analgesic activity in the 7,7‐dihalo group of compounds where the relative activity profile was 7‐Cl₂ > 7‐Br₂ > 7‐F₂ > 7‐Cl,7‐F, and for 7‐monohalo compounds where the potency order was 7‐Br > 7‐Cl. Elaboration of the 7,7‐dibromo methyl acetate ester ( 10 ) to the corresponding acetamide derivative ( 16 ) enhanced analgesic activity. The nature of the 7‐halo substituent(s) in the 7,7‐dihalo group of compounds was a determinant of antiinflammatory activity, determined using the carrageenan‐induced rat paw edema assay, where the relative potency order was 7‐Br₂ > 7‐Cl₂ > 7‐F₂ > 7‐Cl,7‐F. The most potent 7,7‐dibromo compound ( 10 ) inhibited inflammation by 62%, relative to the reference drug ibuprofen (44%), and 10 inhibited COX‐2 (IC₅₀ = 26.4 μM) and COX‐1 (IC₅₀ = 227 μM) for a COX‐2 selectivity index of 8.6. Docking 10 in the active site of human COX‐2 showed it binds in the center of the COX‐2 binding site with the C‐5 phenyl ring oriented toward the acetylation site (Ser⁵³⁰), and the phenyl group of the C‐4 benzoyl moiety oriented in the vicinity of the COX‐2 secondary binding pocket near Val⁵²³. Drug Dev. Res. 49:75–84, 2000. © 2000 Wiley‐Liss, Inc.     

Synthesis and in‐vitro Cytotoxicity of Poly‐functionalized 4‐(2‐Arylthiazol‐4‐yl)‐4H‐chromenes

A new series of 4‐aryl‐4H‐chromenes bearing a 2‐arylthiazol‐4‐yl moiety at the 4‐position were prepared as potential cytotoxic agents. The in‐vitro cytotoxic activity of the synthesized 4‐aryl‐4H‐chromenes was investigated in comparison with etoposide, a well‐known anticancer drug, using MTT colorimetric assay. Among them, the 2‐(2‐chlorophenyl)thiazol‐4‐yl analog 4b showed the most potent activity against nasopharyngeal epidermoid carcinoma KB, medulloblastoma DAOY, and astrocytoma 1321N1, and compound 4d bearing a 2‐(4‐chlorophenyl)thiazol‐4‐yl moiety at the 4‐position of the chromene ring exhibited the best inhibitory activity against breast cancer cells MCF‐7, lung cancer cells A549, and colon adenocarcinoma cells SW480 with IC₅₀ values less than 5 μM. The ability of compound 4b to induce apoptosis was confirmed in a nuclear morphological assay by DAPI staining in the KB and MCF‐7 cells.     

Synthesis and in‐vitro Antimycobacterial Evaluation of 1‐(Cyclopropyl/2,4‐difluorophenyl/tert‐butyl)‐1,4‐dihydro‐ 8‐methyl‐6‐nitro‐4‐oxo‐7‐(substituted secondary amino)quinoline‐3‐carboxylic acids

Fifty one newer 1‐(cyclopropyl/2,4‐difluorophenyl/tert‐butyl)‐1,4‐dihydro‐8‐methyl‐6‐nitro‐4‐oxo‐7‐(substituted secondary amino)quinoline‐3‐carboxylic acids were synthesized from 1,3‐dichloro‐2‐methylbenzene and evaluated for in‐vitro antimycobacterial activities against Mycobacterium tuberculosis H37Rv (MTB), multi‐drug resistant Mycobacterium tuberculosis (MDR‐TB), and Mycobacterium smegmatis (MC²). Among the synthesized compounds, 1‐cyclopropyl‐1,4‐dihydro‐7‐(3,4‐dihydro‐6,7‐dimethoxyisoquinolin‐2(1H)‐yl)‐8‐methyl‐6‐nitro‐4‐oxoquinoline‐3‐carboxylic acid 9p was found to be the most active compound in vitro with a MIC value of 0.39 μM against MTB. Against MDR‐TB, compound 7‐(2‐carboxy‐5,6‐dihydroimidazo[1,2‐a]pyrazin‐7(8H)‐yl)‐1‐cyclopropyl‐1,4‐dihydro‐8‐methyl‐6‐nitro‐4‐oxoquinoline‐3‐carboxylic acid 9n was found to be the most active with a MIC value of 0.09 μM.