Synthesis of ring-opened derivatives of triazole-containing quinolinones and their antidepressant and anticonvulsant activities.

Based on the potent antidepressant and anticonvulsant activities of the triazole-containing quinolinones reported in our previous work, a series of ring-opened derivatives of them were designed, synthesized in this work. Their antidepressant and anticonvulsant activities were screened using the forced swimming test (FST) and the maximal electroshock seizure test (MES), respectively. The results showed that compounds 4a, 5a, 6c-6e, 6g-6i, and 7 led to significant reductions in the accumulated immobility time in the FST at a dose of 50 mg/kg. Especially compound 7 exhibited higher levels of efficacy than the reference standard fluoxetine in the FST and the tail suspension test. The results of an open field test excluded the possibility of central nervous stimulation of 7, which further confirmed its antidepressant effect. Meanwhile, compounds 6a-6i and 7 showed different degrees of anticonvulsant activity in mice at the doses range from 300 to 30 mg/kg in the MES. Among them, compounds 6e and 7 displayed the ED50 of 38.5 and 32.7 mg/kg in the MES, and TD50 of 254.6 and 245.5 mg/kg, respectively. No one showed neurotoxicity at the dose of 100 mg/kg. The preliminary investigation forward to their mechanism indicated that regulation of GABAergic system might contribute to their anticonvulsive and anti-depressive action.

Design, synthesis, and evaluation of anticonvulsant activities of benzoxazole derivatives containing the 1,2,4-triazolone moiety.

A novel series of benzoxazole derivatives containing 1,2,4-triazolone (5a-m) was designed. These compounds were synthesized in order to screen their anticonvulsant activities by the maximal electroshock seizure (MES) model and the subcutaneous pentylenetetrazole (sc-PTZ) seizure model in mice. The rotarod test was used to evaluate their neurotoxicities. Most of the compounds showed anti-MES activities at 100 and 300 mg/kg. Compound 5f, which showed potential anticonvulsant activity in the MES model with ED50 values of 22.0 mg/kg, was considered as the most promising one in this study. It exhibited greater safety than that of carbamazepine and valproate regarding neurotoxicity. The efficacy of compound 5f in inhibiting the tonic seizures and death induced by the convulsants 3-mercaptopropionic acid and BIC was also verified. In an enzyme-linked immunosorbent assay, compound 5f and the positive drug phenytoin significantly increased the γ-aminobutyric acid (GABA) level in the mouse brain. Further, pretreatment with an inhibitor of the GABA synthesizing enzyme dramatically raised the ED50 value of 5f in the MES model. These results confirmed that the compound 5f plays its anticonvulsive action via regulating the GABA function in the brain. Also, a docking study of the compound 5f in the benzodiazepine (BZD) binding site of the GABAA receptor confirmed possible binding of the compound 5f with BZD receptors.

Synthesis and Evaluation of the Anticonvulsant Activities of 4-(2-(Alkylthio)benzo[d]oxazol-5-yl)-2,4-dihydro-3H-1,2,4-triazol-3-ones.

In this study, a novel series of 4-(2-(alkylthio)benzo[d]oxazol-5-yl)-2,4-dihydro-3H-1,2,4-triazol-3-ones (4a-m) was designed and synthesized. The anticonvulsant activities of these compounds were evaluated by using the maximal electroshock seizure (MES) and subcutaneous pentylenetetrazole (scPTZ) seizure models in mice. The neurotoxicity of these compounds was evaluated using the rotarod neurotoxicity test. The majority of compounds showed anti-MES activities at 100 or 300 mg/kg. Compound 4g was considered to be the most promising, based on its potency against MES- and PTZ-induced seizures with ED50 values of 23.7 and 18.9 mg/kg, respectively. The TD50 value of 4g was 284.0 mg/kg, which resulted in a higher protective index (PI = TD50/ED50) value than that of carbamazepine and valproate. In an ELISA test, compound 4g significantly increased the γ-aminobutyric acid (GABA) content in mouse brain. In addition, pretreatment with thiosemicarbazide (an inhibitor of the GABA synthesizing enzyme) significantly decreased the activity of 4g in the MES model, which suggests that the mechanism through which compound 4g elicits its anticonvulsive action is at least in part through increasing the GABA level in the brain.

Recent developments on triazole nucleus in anticonvulsant compounds: a review.

Epilepsy is one of the common diseases seriously threatening life and health of human. More than 50 million people are suffering from this condition and anticonvulsant agents are the main treatment. However, side effects and intolerance, and a lack of efficacy limit the application of the current anticonvulsant agents. The search for new anticonvulsant agents with higher efficacy and lower toxicity continues to be the focus and task in medicinal chemistry. Numbers of triazole derivatives as clinical drugs or candidates have been frequently employed for the treatment of various types of diseases, which have proved the importance of this heterocyclic nucleus in drug design and discovery. Recently many endeavours were made to involve the triazole into the anticonvulsants design, which have brought lots of active compounds. This work is an attempt to systematically review the research of triazole derivatives in the design and development of anticonvulsant agents during the past two decades.

Synthesis and Bioactivity Evaluation of N-Arylsulfonylindole Analogs Bearing a Rhodanine Moiety as Antibacterial Agents.

Due to the rapidly growing bacterial resistance to antibiotics and the scarcity of novel agents under development, bacterial infections are still a pressing global problem, making new types of antibacterial agents, which are effective both alone and in combination with traditional antibiotics, urgently needed. In this paper, seven series of N-arylsulfonylindole analogs 5-11 bearing rhodanine moieties were synthesized, characterized, and evaluated for antibacterial activity. According to the in vitro antimicrobial results, half of the synthesized compounds showed potent inhibition against four Gram-positive bacteria, with MIC values in the range of 0.5-8 µg/mL. For multidrug-resistant strains, compounds 6a and 6c were the most potent, with MIC values of 0.5 µg/mL, having comparable activity to gatifloxacin, moxiflocaxin and norfloxacin and being 128-fold more potent than oxacillin (MIC = 64 µg/mL) and 64-fold more active than penicillin (MIC = 32 µg/mL) against Staphylococcus aureusATCC 43300.

Design, Synthesis and Evaluation of the Antidepressant and Anticonvulsant Activities of Triazole-Containing Benzo[d]oxazoles.

BACKGROUND: Epilepsy and depression are two of the common diseases seriously threatening life and health of human. A shared neurobiological substrate led to the bidirectional relationship and high comorbid occurrence of the two disorders. Recently, an increasing number of patients with epilepsy (PWE) require some form of antidepressant medication. However, most of the available antidepressants are inadequate for PWE for some reasons. So, the search for novel and increasingly effective drugs with anticonvulsant and antidepressant activities is necessary. METHODS: A series of 2-substituted-6-(4H-1,2,4-triazol-4-yl)benzo[d]oxazoles (5a-p) were designed and synthesized. Their anticonvulsant activities were evaluated using maximal electroshock shock (MES) and subcutaneous pentylenetetrazole (scPTZ) seizure models in mice. Their antidepressant activities were screened with the forced swimming test (FST). RESULTS: All the compounds showed anti-MES activities in different degree, among which 5g and 5j were the most promising one with ED50 value of 31.7 and 12.7 mg/kg, respectively. What's more, 5g and 5j also exhibited nice anti-scPTZ activities and low neurotoxicity. Interestingly, these compounds also showed good antidepressant activities in FST. And the efficacy of 5g were also confirmed by a tail suspension test and a open field test. The pretreatment of thiosemicarbazide (an inhibitor of γ- aminobutyric acid synthesis enzyme) significantly increased the ED50 of 5g in MES and reversed the reductions in the immobility time of 5g in FST. CONCLUSION: Triazole-containing benzo[d]oxazole is a good skeleton to develop compounds with both anticonvulsant and antidepressant activities. We have got the compound 5g, which display remarkable antidepressant and anticonvulsant activities, and the GABAergic system was involved in the action mechanism of 5g.

Synthesis and Antibacterial Evaluation of (S,Z)-4-methyl-2-(4-oxo-5-((5-substituted phenylfuran-2-yl) methylene)-2-thioxothiazolidin-3-yl)Pentanoic Acids.

The microbial resistance has become a global hazard with the irrational use of antibiotics. Infection of drug-resistant bacteria seriously threatens human health. Currently, there is an urgent need for the development of novel antimicrobial agents with new mechanisms and lower levels of toxicity. In this paper, a series of (S ,Z)-4-methyl-2-(4-oxo-5-((5-substitutedphenylfuran-2-yl) methylene)-2-thioxothiazolidin-3-yl)pentanoic acids via a Knoevenagel condensation were synthesized and evaluated for their antibacterial activity in - vitro. The synthesized compounds were characterized by IR, (1)H NMR and MS. The antibacterial test in - vitro showed that all of the synthesized compounds had good antibacterial activity against several Gram-positive bacteria (including multidrug-resistant clinical isolates) with minimum inhibitory concentration (MIC) values in the range of 2-4 µg/mL. Especially compounds 4c, 4d, 4e and 4f were the most potent, with MIC values of 2 µg/mL against four multidrug-resistant Gram-positive bacterial strains.

Synthesis and Anticonvulsant Evaluation of some New 6-(Substituted-phenyl)thiazolo[3,2-b][1,2,4]triazole Derivatives in Mice.

Epilepsy is the most frequent nearological affiction and afflicts 1% about of the world's population. Currently there is an urgent need for the development of novel anticonvulsants with higher levels of potency and lower levels of toxicity. In this paper, a series of new 6-(substituted-phenyl)thiazolo[3,2-b][1,2,4]triazole derivatives were synthesized and tested for their anticonvulsant activities using the maximal electroshock (MES) and subcutaneous pentylenetetrazole (PTZ) screens, which are the most widely employed seizure models for early identification of candidate anticonvulsants. Their neurotoxicity was determined applying the rotarod test. In these compounds, 6-(4-fluorophenyl)thiazolo[3,2-b][1,2,4]triazole (3c) showed selective protection against the MES seizures with an ED50 value of 49.1 mg/Kg and a TD50 value of 94.1 mg/Kg, which provided compound 3c a protective index (PI = TD50/ED50) of 1.9 in the MES test. 6-(4-Propoxyphenyl)thiazolo[3,2-b][1,2,4]triazole (5b) was found to be active in both models, i.e. MES test and PTZ test. In the PTZ screen, compound 5b gave an ED50 of 63.4 mg/Kg and a TD50 of 105.6 mg/Kg, resulting in a PI value of 1.7 which is higher than carbamazepine.

Design, synthesis and evaluation of the antidepressant and anticonvulsant activities of triazole-containing quinolinones.

A series of 1-substituted-6-(4H-1,2,4-triazol-4-yl)-3,4-dihydroquinolin-2(1H)-ones were designed, synthesized, and screened for their antidepressant and anticonvulsant activities. Interestingly, compounds 5i, 5j, 5m, and 5n led to significant reductions in the immobility time in the forced swimming test at a dose of 50 mg/kg, and exhibited higher levels of efficacy than the reference standard fluoxetine. In addition, compound 5i exhibited greater efficacy than fluoxetine in the tail suspension test. The results of an open field test further confirmed that compound 5i provided a good antidepressant effect. In the maximal electroshock seizure screen, compounds 5c and 5d showed moderate levels of anticonvulsant activity and protected 100% of the animals at a dose of 100 mg/kg. None of the synthesized compounds showed any neurotoxicity in the rotarod test at a dose of 100 mg/kg.

Synthesis and anticonvulsant activity evaluation of 7-alkoxy[1,2,4]triazolo[3,4-b]benzothiazol-3(2H)-ones.

A new series of 7-alkoxy[1,2,4]triazolo[3,4-b]benzothiazol-3(2H)-ones were synthesized and evaluated for their anticonvulsant activities. Among these compounds, 7-propoxy[1,2,4]triazolo[3,4-b]benzothiazol-3(2H)-one (4c) and 7-butoxy[1,2,4]triazolo[3,4-b]benzothiazol-3(2H)-one (4d) showed the highest activity against maximal electroshock (MES)-induced tonic extension [effective dose (ED)50 : 11.4 and 13.6 mg/kg, respectively]. It is worth mentioning that compound 4d showed especially low neurotoxicity, which led to a high protective index (PI >51). The orally anticonvulsant activity data of compound 4d further confirmed its efficacy, in an MES test, and its high safety with a PI value of 50.2. In addition, the potency of compound 4h against seizures induced by pentylenetetrazole, 3-mercaptopropionic acid, and bicuculline in the chemical-induced seizure tests suggested that compound 4d may exert its anticonvulsant activity through affecting the GABAergic system.

Synthesis and evaluation of the anticonvulsant activity of 8-alkoxy-4,5-dihydrobenzo[b][1,2,4]triazolo[4,3-d][1,4]thiazepine derivatives.

Two series of 8-alkoxy-4,5-dihydrobenzo[b][1,2,4]triazolo[4,3-d][1,4]thiazepine derivatives (6a-q and 7a-q) were synthesized and evaluated for their anticonvulsant activity using the maximal electroshock (MES) method. All of the compounds prepared were effective in the MES screens. Among which, compound 7j was considered as the most promising one with an ED50 value of 26.3 mg/kg and a superior protective index value of 12.6. The potency of compound 7j against seizures induced by pentylenetetrazole, 3-mercaptopropionic acid and bicuculline suggested that two different mechanisms of action might potentially be involved in its anticonvulsant activity, including the inhibition of voltage-gated ion channels and the modulation of GABAergic activity. A computational study was also conducted to predict the pharmacokinetic properties of the compounds prepared, with the results supporting the use of these compounds as a group of promising antiepileptic agents.

Synthesis and biological evaluation of (E)-1-(substituted)-3-phenylprop-2-en-1-ones bearing rhodanines as potent anti-microbial agents.

Herein, we report the design, syntheses and in vitro anti-microbial activity of two series of rhodanines with chalcone moiety. Anti-microbial tests showed that some of the synthesized compounds exhibited good inhibition (MIC = 1-8 µg/mL) against multi-drug-resistant Gram-positive organisms, including methicillin resistant and quinolone-resistant Staphylococcus aureus, in which the compound 4g was found to be the most potent with minimum inhibitory concentration (MIC) value of 1 µg/mL against two methicillin-resistant S. aureus.

Synthesis and antibacterial evaluation of rhodanine-based 5-aryloxy pyrazoles against selected methicillin resistant and quinolone-resistant Staphylococcus aureus (MRSA and QRSA).

With an intention to synergize the anti-bacterial activity of 5-aryloxy pyrazole and rhodanine derivatives, eight series of hybrid compounds have been synthesized and evaluated for their antibacterial activity. The majority of the synthesized compounds showed good inhibitory activity against selected methicillin resistant and quinolone-resistant Staphylococcus aureus (MRSA, QRSA) with minimum inhibitory concentration (MIC) values in the range of 1-32 µg/mL. The cytotoxicity test suggests that these compounds exhibited in vitro antibacterial activity at non-cytotoxic concentrations. These studies therefore suggest that rhodanine-based 5-aryloxy pyrazoles are interesting scaffolds for the development of novel Gram-positive antibacterial agents.

Synthesis and anticonvulsant activity evaluation of 8-alkoxy-5-(4H-1,2,4-triazol-4-yl)quinoline derivatives.

Two series of 8-alkoxy-5-(4H-1,2,4-triazol-4-yl)quinolines and 8-alkoxy-5-(2H-1,2,4-triazol-3-one-4-yl)quinolines were synthesized. The anticonvulsant activity of these compounds was evaluated with maximal electroshock seizure test and rotarod test. Among the synthesized compounds, 8-octoxy-5-(4H-1,2,4-triazol-4-yl)quinoline (4g) was the most active compound with ED(50) of 8.80 mg/kg, TD(50) of 176.03 mg/kg and protective index of 20.0. Its neurotoxicity was lower than all other synthesized compounds and also markedly lower than that of the reference drug carbamazepine. In addition, the potency of compound 4g against seizures induced by pentylenetetrazole, 3-mercaptopropionic acid, and bicuculline suggested its broad spectrum activity, and the mechanisms of action including inhibition of voltage-gated ion channels and modulation of GABAergic activity might involve in its anticonvulsant activity.

Synthesis and anticonvulsant activity evaluation of 6-substituted-[1,2,4]triazolo[3,4-a](tetrazolo[5,1-a])phthalazine derivatives.

With the aim of finding new anticonvulsant drugs, new 6-substituted-[1,2,4]triazolo[3,4-a] (tetrazolo[5,1-a]) phthalazine derivatives (1-34) have been designed and synthesized. All the compounds were evaluated for their anticonvulsant activities using the maximal electroshock test (MES). Most of the synthesized compounds exhibited potent anticonvulsant activities in the MES. The most promising compound 14 showed significant anticonvulsant activity in MES test with ED50 value of 9.3 mg/kg. It displayed a wide margin of safety with protective index much higher than the standard drug Carbamazepine. And the potency of compound 14 against seizures induced by Pentylenetetrazole, Isoniazid, Thiosemicarbazide and 3-Mercaptopropionic acid in the chemical-induced seizure tests suggested that compound 14 displayed wide spectrum of activity in several models.

Design, synthesis, and anticonvulsant activity evaluation of 4-(3-alkoxy-phenyl)-2,4-dihydro-[1,2,4]triazol-3-ones.

A series of 4-(3-alkoxy-phenyl)-2,4-dihydro-[1,2,4]triazol-3-ones were synthesized using the appropriate synthetic route and evaluated experimentally in the maximal electroshock test; their neurotoxicities were evaluated by the rotarod neurotoxicity test. The structures of these compounds were confirmed by IR, MS, (1) H-NMR, and elementary analysis. All target compounds exhibited anticonvulsant activity to varying degrees in the maximal electroshock test. 4-(3-Benzyloxy-phenyl)-2,4-dihydro-[1,2,4]triazol-3-one (4i) was the most promising compound with an ED(50) value of 30.5 mg/kg and a protective index (PI) of 18.63, showing a higher safety than the standard carbamazepine (PI=6.45). In addition, the potency of compound 4i against seizures induced by pentylenetetrazole and 3-mercaptopropionic acid suggested its broad-spectrum activity, and the mechanisms of action including inhibition of voltage-gated ion channels and modulation of GABAergic activity might be involved in its anticonvulsant activity.

Synthesis and anticonvulsant activity evaluation of 5-phenyl-[1,2,4]triazolo[4,3-c]quinazolin-3-amines.

In the present study we describe the syntheses and anticonvulsant activity evaluation of 5-phenyl-[1,2,4]triazolo[4,3-c]quinazolin-3-amine derivatives. Their anticonvulsant activity and neurotoxicity were evaluated by the maximal electroshock seizure test (MES) and the rotarod test, respectively. The majority of the compounds prepared were effective in the MES screens at a dose level of 100 mg/kg. Of these compounds, the most promising was compound 8h, which showed an ED(50) value of 27.4 mg/kg and a protective index (PI) value of 5.8. These values were superior to those provided by valproate (ED(50) and PI values of 272 and 1.6, respectively) in the MES test in mice. As well as its anti-MES efficacy, the potencies of compound 8h against seizures induced by pentylenetetrazole and thiosemicarbazide were also established, with the results suggesting that the GABAergic system-mediated mechanisms might be involved in its anticonvulsant activity.

Synthesis and evaluation of anticonvulsant and antidepressant activities of 5-alkoxytetrazolo[1,5-c]thieno[2,3-e]pyrimidine derivatives.

A series of 5-alkoxytetrazolo[1,5-c]thieno[2,3-e]pyrimidine derivatives were synthesized and their anticonvulsant and antidepressant activities were evaluated. Pharmacological tests showed that four of the synthesized compounds had weak anticonvulsant activity, while most of the compounds had excellent antidepressant activity. The most active compound was 5-(2,4-dichlorobenzyloxy)tetrazolo[1,5-c] thieno[2,3-e]pyrimidine, which decreased the immobility time by 51.62% at a dose of 100 mg/kg. The results of open-field tests of this compound indicated that it had no significant effects on the locomotor activity compared with the control group at the doses assayed in the forced swimming tests test. This means that the antidepressant activity detected in the FST for the compound is not the result of central nervous system stimulant properties, and further confirms its antidepressant-like effect.

Synthesis and bioactivity evaluation of rhodanine derivatives as potential anti-bacterial agents.

Five series of (Z)-5-(4-(2-oxo-2-phenylethoxy)benzylidene)-2-thioxothiazolidin-4-one derivatives (I-V) were synthesized, characterized, and evaluated for their anti-bacterial activity. Most of the synthesized compounds showed potent inhibition against several Gram-positive bacteria (including multidrug-resistant clinical isolates) with MIC values in the range of 1-32 µg/mL. Compounds IIIi, Vb and Vc presented the most potent activity, showing four-fold more potency than norfloxacin (MIC = 8 µg/mL and 4 µg/mL) and 64-fold more activity than oxacillin (MIC > 64 µg/mL) against MRSA CCARM 3167 and 3506 strains with MIC values of 1 µg/mL, and 64-fold more potency than norfloxacin (MIC > 64 µg/mL) and comparable activity to oxacillin (MIC = 1 µg/mL) against the QRSA CCARM 3505 and 3519 strains. None of the compounds exhibited any activity against the Gram-negative bacteria Escherichia coli 1356 at 64 µg/mL.

Synthesis and anticonvulsant activities of some triazolothiadiazole derivatives.

The present study describes the synthesis and anticonvulsant activity evaluation of 6-substituted-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazole derivatives (4a-4x) and their partially dehydrogenated products 5,6-dihydro-6-substituted-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazole derivatives (5a-5n). The bioevaluation demonstrated that most compounds in the series of 4a-4x exhibited potent anticonvulsant activity in the maximal electroshock test. Among which, 6-(4-chlorophenyl)-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazole (4h) emerged as the most promising candidate on the basis of its favorable ED(50) value of 23.7 mg/kg and PI value of 10.8. In addition, the potency of compound 4h against seizures induced by pentylenetetrazole, 3-mercaptopropionic acid, and bicuculline in the chemical-induced seizure tests suggested that compound 4h displayed broad-spectrum activity in several models, and it may exert its anticonvulsant activity through affecting the GABAergic system.