Administration in December 2012 and delamanid received approval from the European Medicines Agency and Japan’s Pharmaceuticals Medical Devices Agency in 2014 (4). All these mentioned drugs that have been already approved for TB theraphy are composed of diverse chemical entities and mechanisms of actions. Since last decade, the researchers have developed several compound series originated from target-based screening efforts as nitroimidazopyrans (PA- 824), oxazolidinones (linezolid, sutezolid, posizolid), 1,2-ethylenediamine-based compound-SQ109, benzothiazinones (BTZ038, PBTZ169), Imidazopyridine amides (Q203) (5, 6). In addition to the mentioned chemical entities, compounds with 1,3,4-thiadiazole structure are also the subjects of efforts to identify new anti TB drugs and they are being investigated in significant number of works (7-9). Some representatives of 1,3,4-thiadiazole compounds with promising antituberculosis activity were shown in Figure 1.
This research article is aimed to synthesize and evaluate antimicrobial activity of a series of newly synthesized (5Z)-5-(E)-3-(1H-indoly-3- yl)-1-phenylallylideneamino)-2, 5-dihydro-1, 3, 4-thiadiazole-2-thiol 1(a-h). First of all N-substituted indole-3-carboxaldehyde derivatives are prepared from a mixture of Indole-3-carboxaldehyde (10 mmol), the appropriate alkylating reagent, anhydrous K 2 CO 3 and DMF was
Objective: Thiadiazolederivatives were reported to have wide range of biological activities. Hence present work was planned to synthesize thiadiazolederivatives and screen for their analgesic, antipyretic and anti-inflammatory. Methods: Thiosemicarbazide was made to react with aryl carboxylic acid in presence of concentrated sulphuric acid to form 5-(substituted phenyl)-2-amino -1, 3, 4-thiadiazole. To aromatic amines, chloroacetyl chloride was added drop wise in presence of glacial acetic acid and saturated solution of sodium acetate to form 2- chloro-N-substituted-phenyl-acetamide. This acetamide compound was reacted with 5-(substituted phenyl)-2-amino -1, 3, 4-thiadiazole in 1, 4- dioxane and triethylamine (TEA), refluxed for 3 hrs to form N- (substuted-phenyl)-2-[5-(3-substituted-phenyl)-1, 3, 4-thiadiazol-2-yl amino]-acetamide. Characterization of all the compounds was performed by IR, 1 HNMR, Mass spectroscopic and elemental analysis. Results: The compounds IIIA10, VA17, 2b and 3b have showed significant analgesic, antipyretic and anti-inflammatory activity. Conclusion: The compounds bearing p-chlorophenyl and 2-nitrophenyl group at C5 position of the thiadiazole moiety have shown profound activity when compared to compounds which were lacking of these groups.
phenyl substituted, 2-amino1, 3, 4thiadiazole derivates. These derivatives on further treatment with various aldehydes to form Schiff base. The structures of the compounds were confirmed by IR, 1 HNMR and elemental analysis. The physicochemical properties involve determination of drug-like property of the synthesized compounds. It is based on the Lipinski’s rule of 5 and can be determined by using molinspiration cheminformatics software. All the synthesized compounds showed zero violation of Lipinski’s rule of five, which indicates good bioactivity and bioavailabilty.The anthelmintic activity of those compounds was investigated by method described in details by Kuppast and Nayak.Parameters under study were mean paralysis and mean lethal time in Pheretima posthuma. All the compounds having significant activity than standard drug except compounds 3b, 3c and 3d.
KI (0.166 g, 1 mmol) was dissolved in 10 ml water and the solution was cooled to 0 °C. Then, it was added dropwise under continuous stirring into a diazonium salt solution of com- pound 1, which had been prepared in accordance with the general procedure. The pH was ad- justed to 3–4 and after standing for 12 h at room temperature, the resulting colored precipitate was filtered under vacuum and purified by crystallization from an ethanol–water mixture (8:2).
, analgesic 19 , cytotoxic 20 - 21 , pesticide 22 and pesticidal and fungicidal activities 23 . Pyrimidine derivatives exhibited various biological activities such as anti-proliferative 24 , anticancer 25, 26 , anti- hypertensive 27 , antioxidant 28, 29 , antiviral 30 , anti- inflammatory and analgesic activities 31, 32 . Certain pyrimidine derivatives play a significant role in several biological processes and show, anti- leishmanial activities 33 and CNS depressant properties 34 . On the basis of above mentioned importance of pyrazolines and pyrimidines efforts have been made to design and synthesize mutual prodrugs containing these nuclei to produce synergistic antimicrobial activity. The synthesized compounds have been subjected for in vitro antimicrobial activity against some selected bacterial and fungal strains.
In this study, various 3-β-[(N-benzenesulphonyl/tosyl)-4-(un) substituted anilino]ethyl-4-amino-5-mercapto-4(H)- 1,2,4-triazoles (5a–f), with biologically active 'sulphonamide' moiety as the side chain have been prepared. The structures of the newly synthesised compounds have been established on the basis of their spectral data and elemental analysis. All the compounds were evaluated for antimicrobial activities against Escherichia coli, Bacillus cirroflagellosus, Aspergillus niger and Colletotrichum capsici. Most of the compounds investigated exhibited significant antifungal activity against Colletotrichum capsici, even greater than fluconazole, the standard used. Only two compounds 3f (59%) and 5e (67%), have shown moderate antituberculosis activity. All the triazoles exhibited moderate degree of antiinflammatory activity and least ulcerogenecity. Most of the compounds have shown significant analgesic activity (81.02–120.72%) in comparison with aspirin (49.39%). In the MES method, only compound 3e exhibited a protection of 66.66%, whereas others exhibited minimum protection of (33.33%).
ACKNOWLEDGEMENT: The authors are thankful to the Director, SAIF, Punjab University, Chandigarh, for providing the IR, 1 H NMR, MASS spectral data and are also thankful to Mr. Dhansukh Rajani (Microbiologist), Micro care Laboratory, Surat, for antimicrobial screening. We are also thankful to Trusty, Shri Shankarsinh Vaghela Bapu, Jayendrakumariba, Shri c. J. Josh and my principal Shri Milan Satia, Shankarsinh Vaghela Bapu Institute of Pharmacy, Gandhinagar, Gujarat, India.
Heterocyclic systems are one of the most important classes of organic compounds present in nature or synthesized in laboratory. These compounds posses an array of biological activities and are employed in the treatment of commonly occurring diseases. Keeping this in view, some new 2-amino-4,6- diarylpyrimidine from chalcones were synthesized. Eight novel 2-amino-4,6- diarylpyrimidine derivatives have been prepared by condensation of chalcone derivatives with guanidine hydrochloride. The structures of the synthesized compounds were assigned on the basis of elemental analysis, IR spectra, 1 H NMR and Mass spectral data. These compounds were screened for their antibacterial activity. The recorded zone of inhibition showed significant antibacterial activity when compared with reference standard Sparfloxacin.
for substituted Cinnoline thiophene derivatives exhibits potent anti-inflammatory activity. All derivatives failed to produce significant anti-inflammatory activity, while somederivatives mainly 6-Bromo, 6-Chloro, 7-Chloro, 8-Fluoro, 7,8-Dichloro substitutedderivatives not only demonstrated approximately same anti-inflammatory activity as standard drug but also show potent activity. Especially Chloro Substituted Compounds Showed more potent antimicrobial activity and anti-inflammatory activity among all the substituted cinnoline thiophene compounds. This might be due to the reason that cinnoline ring system is identical to ring system found in Phenylbutazone. Inflammation is a normal response to infection and injury and involves the recruitment of immune systems to neutralize invading pathogens, repair injured tissues and promote wound healing. Chronic or excessive activation of the immune system is associated with an increase reactive oxygen species (ROS), prolonged activation of inducible NO synthase (iNOS) and of the release of proinflammatory cytokines. This may increase susceptibility to infections and cause inflammation. Drugs that block the action of the cytokine, tumor necrosis factor-α (TNF-α) have proved to be very effective in the treatment of inflammation 17 . The findings of study revealed that the Cinnoline thiophene derivatives inhibit the action of cytokine and TNF-α. 5 Conclusions
All the synthesized compounds 4(a-n) and 5(a-n) have been screened in vitro for their antibacterial activity against B. subtilis (Bs), E. coli (Ec), S. aureus (Sa) and K. pneumoniae (Kp) at two concentrations (50 and 100 ppm) and antifungal activity against A. niger (An), A. flavus (Af), F. oxisporium (Fo) and T. viride (Tv) at two concentrations (50 and 100 ppm). Standard antibacterial Streptomycin and fungicide Griseofulvin were also screened under the similar conditions for comparison. The following compounds were found active against the tested becteria: 4d(Ec, Sa), 4f(Bs, Kp), 4g(Ec), 4h(Bs, Ec, Sa), 4i, 4j(Kp), 5b, 5c, 5d, 5e, 5f, 5g(Bs, Ec, Kp, Sa), 5i(Ec, Kp, Sa), 5h(Kp), 5k (Ec), 5n(Kp, Sa) and fungi: 5f(Af, Tv), 5g(An), 4n(Fo), 5b(Tv), 5c(Af, Fo), 5d(An), 5e, 5f, 5g(An, Af, Fo, Tv), 5i(Af, Fo), 5j(An, Af), 5h(Fo, Tv), 5k(An, Af), 5l, 3m, 5n(An). On the basis of structural activity relationship it has been observed that among the substituents present on the phenyl ring, halo derivatives were found to be highly active against in the series. Further study reveals that bromo derivatives are highly active.
A series of N-(5-amino-2-methylphenyl)-4-(3-pyridyl)-2-pyrimidinamine derivatives 4a-k were synthesized by the reaction of N-(5-amino-2-methylphenyl)-4-(3-pyridyl)-2-pyrimidinamine with various aldehydes. The newly synthesized compounds were characterized by elemental analyses, UV-visible, FT-IR and 1 H NMR spectral studies. All compounds were evaluated their in vitro antimicrobial activity against clinically isolated strains i.e., Bacillus subtilis, Staphylococcus aureus, Xanthomonas campestris, Escherichia coli, Fusarium oxysporum. Compounds 4f, 4g, 4h and 4i exhibited good antimicrobial activity when compared with other compounds in the series against tested pathogenic bacterial and fungal strains.
The quinoline nucleus is an important class of heterocyclic compounds found in many synthetic and natural products with a wide range of pharmacological activities, such as antiviral , anticancer , antibacterial [3, 4], analgesic , antifungal , antiobesity , anti- inflammatory , and antiplasmodial  activity, which can be well illustrated by the large number of drugs in the market containing this heterocyclic class. The 1,2,3-triazole ring system has been the subject of considerable research interest mainly due to its usefulness in synthetic organic chemistry and also because of the pharmacological properties associated with some of its derivatives. Hence the synthesis of 1,2,3-triazoles incorporated with quinoline moiety is of very importance and they possess many biological activities . Prompted by these observations and in search of new antimicrobial agents, herein we reported the synthesis of novel series of 1,2,3- triazolyl quinolines.
The nonsteroidal anti-inflammatory drugs like Aspirin, Ibuprofen, Mefenamic acid inhibit Cyclooxygenase(COX) enzyme and control release of inflammatory mediators responsible for inflammation. COX exist as isoenzymes COX-1 and COX-2.Treatment with NSAID has some side effects in different patients such as gastric irritation, ulceration due to inhibition of protective COX-1 enzyme. Larger active site of COX-2 than COX-1 is basis for selectivity in design of selective COX-2 inhibitors. 5-alkyl/ aryl 2-amino 1,3,4-thiadiazolederivatives were designed and which can interact with binding site of the COX-2 enzyme more selectively. These synthesized compounds were confirmed by TLC, MP and spectral analysis. The docking studies were performed using Vlife MDS4.3 software using COX-2 receptor. It has been observed that, phenyl substitution on 1,3,4 Thiadiazole ring shows higher dock score than aliphatic substitution. Further substitution on ortho, meta & para position of phenyl ring with hydroxy group shows remarkable binding affinity for receptor but substitution on ortho, meta & para position of phenyl ring with chloro or nitro group shows reduction in dock score indicating less binding affinity for receptor. The in-vitro anti-inflammatory activity binding was performed using carrageenan induced paw edema method in rats for the compounds which has shown significant dock score .Among the synthesized compounds, 5(2,5 dihydroxy phenyl) 2amino 1,3,4 thiadiazole has shown significant anti-inflammatory activity.
A series of 2-(p-substituted benzylidene)-3-(5-propyl-1, 3, 4-thiadiazol-2-yl) thiazolidin-4-ones were synthesized by the reaction of Schiff’s bases of N-(p-substituted benzylidene)-5 propyl -1, 3, 4-thiadiazole-2-amines with thioglycolic acid in 1, 4-dioxane as solvent and studied for their in vitro antibacterial activity. Reaction of thiosemicarbazide with butanoic acid in presence of concentrated sulphuric acid led to the formation of 5-propyl-1, 3, 4-thiadiazole-2-amines which on further reaction with different p-substituted benzaldehydes yielded the compounds Schiff’s bases of N-(p-substituted benzylidene)-5- propyl -1,3, 4-thiadiazole-2-amines which is further reaction with thioglycollic acid in presence of small amount of zinc chloride in 1,4 dioxane as solvent gave title compounds. These compounds were characterized by spectral analysis. All the synthesized compounds were evaluated for their in vitro for their antibacterial activity against two Gram positive bacterial strains (Bacillus subtilis and Staphylococcus aureus) and two Gram negative bacterial strains (Escherichia coli and Pseudomonas aeruginosa) and their minimum inhibitory concentration (MIC) were determined.
Another group of researchers reported the synthesis of 1,3,4-oxadiazole 2a, under microwave irradiation of the mixture of hydrazide 1a and triethyl orthoester on the surface of Nafi on-NR50 (P 4 S 10 /Al 2 O 3 ), however yield didn’t exceed 85% . A higher yield was observed (up to 90%) for target products 2d, 2e in presence of substituents (OMe and F) in the 4-position of the aromatic ring in the initial acyl hydrazides 1d, 1e.
Melting points were determined using open capillary tube method and the values are presented uncorrected. IR spectra were recorded on FTIR(Shimadzu, IR-Affinity-1) spectrometer using KBr pellets technique. 1 HNMR were recorded using Bruker, Avance Ⅲ HD NMR spectrometer using CDCl 3 as solvent and TMS as internal standard. The chemical
1000 mg/kg. Anticancer activity of these compounds was performed In vitro by cell proliferation assay using 3- (4,5-dimethylthiazol-2yl)-2, 5-diphenyltetrazolium bromide (MTT) staining method. Cell lines (A-549), Adeno carcinomic human alveolar basal epithelial cell line is used for screening. The compds, (6.h), (6.i), (6.k), (6.l) and (6.m), showed significant anticancer activity as percent cell lysis <75 to 100. Other compounds also exhibited promising anticancer activity.
In recent years research is concern on nitrogen containing heterocyclic compounds and their pharmaceutical importance [1,2]. Piperidine is a six membered heterocyclic compound containing five carbon and one nitrogen atom. The chemical nature of Piperidine is basic. The piperidine ring exhibits excellent structural attribute of many alkaloid, natural products and drug product . Watson et al. reported that there were thousands of piperidine compounds mentioned in clinical and preclinical studies during a recent 10 year period . Many of drugs having piperidine nucleus used as different therapeutic agents in recent scenario. Peroxitine (1) as antidepressant [5,6], methylphenidate (2), ethylphenidate (3) , pipradrol (4), desoxypipradrol (5)  as analeptics/nootropics (Stimulants) raloxifene (6) as SERM (selective estrogen receptor modulators) , minoxidil (7) as vasodilators , risperidone (8), thioridazine (9), mesoridazine (10), haloperidol (11), pimozide (12), droperidol (13), and melperone (14) as Neuroleptics (antipsychotics) , pethidine (meperidine) (15), loperamide (16) as anti-opioids [11,12], tiagabine (17) as anticonvulsant , solifenacin (18) used in the treatment of an overactive bladder , carmegliptine (19) used as an anti-diabetes drug , aplaviroc (20) as anti-HIV drug . Piperidine derivatives are also active as local anesthetics, such as mepivacaine (21), ropivacaine (22), and bupivacaine (23) . Piperidine derivatives are also potent as antimicrobial agents [18,19], anesthetic agents  and Aryl hydrocarbon receptor  (Figure 1).
Synthesis of compound (4a-4j): A slurry consisting of 1-(5-methoxy-2-oxoindolin-3-ylidene)-4- (substituted pyridin-2-yl) thiosemicarbazide (0.002 mol), THF (3ml) and 37% formalin (1ml) was made. To this secondary amine (0.003mol) was added drop wise with cooling and shaking. The reaction mixture was allowed to stand at room temperature for 1hour with occasional shaking after, which it was warmed on a steam bath for 15minutes. At the end of the period the contents were cooled and the product obtained was recrystallized from chloroform and petroleum ether.