Ming-Xia Song

Synthesis and antimicrobial evaluation of l-phenylalanine-derived C5-substituted rhodanine and chalcone derivatives containing thiobarbituric acid or 2-thioxo-4-thiazolidinone

Four novel series of compounds, including the l-phenylalanine-derived C5-substituted rhodanine (6a-q, 7a-j) and chalcone derivatives containing thiobarbituric acid or 2-thioxo-4-thiazolidinone (9a-e, 11a-e) have been designed, synthesized, characterized, and evaluated for their antibacterial activity. Some of these compounds showed significant antibacterial activity against Gram-positive bacterias, especially against the strains of multidrug-resistant clinical isolates, among which compounds 6c-e, 6g, 6i, 6j and 6q exhibiting high levels of antimicrobial activity against Staphylococcus aureus RN4220 with minimum inhibitory concentration (MIC) values of 2 μg/mL. Compound 6q showed the most potent activity of all of the compounds against all of the test multidrug-resistant clinical isolates tested. Unfortunately, however, none of the compounds were active against Gram-negative bacteria at 64 μg/mL.

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 biological evaluation of rhodanine derivatives bearing a quinoline moiety as potent antimicrobial agents

Three series of rhodanine derivatives bearing a quinoline moiety (6a-h, 7a-g, and 8a-e) have been synthesized, characterized, and evaluated as antibacterial agents. The majority of these compounds showed potent antibacterial activities against several different strains of Gram-positive bacteria, including multidrug-resistant clinical isolates. Of the compounds tested, 6g and 8c were identified as the most effective with minimum inhibitory concentration (MIC) values of 1 μg/mL against multidrug-resistant Gram-positive organisms, including methicillin-resistant and quinolone-resistant Staphylococcus aureus (MRSA and QRSA, respectively). None of the compounds exhibited any activity against the Gram-negative bacteria Escherichia coli 1356 at 64 μg/mL. The cytotoxic activity assay showed that compounds 6g, 7g and 8e exhibited in vitro antibacterial activity at non-cytotoxic concentrations. Thus, these studies suggest that rhodanine derivatives bearing a quinoline moiety are interesting scaffolds for the development of novel Gram-positive antibacterial agents.

Synthesis and anticonvulsant activity of 7-phenyl-6,7-dihydro-[1,2,4]triazolo[1,5-a]pyrimidin-5(4H)-ones and their derivatives.

Herein, we described the syntheses and anticonvulsant activities of 7-(substituted-phenyl)-6,7-dihydro-[1,2,4]triazolo[1,5-a]pyrimidin-5(4H)-ones (1a-1o) and their derivatives. Most of the synthesized compounds exhibited potent anticonvulsant activities in the maximal electroshock test (MES). The most promising compound 1i showed significant anticonvulsant activity in MES test with ED(50) value of 19.7 mg/kg. It displayed a wide margin of safety with protective index much higher than the standard drugs. In addition, the potence of compound 1i against seizures induced by Pentylenetetrazole, Isoniazid, Thiosemicarbazide, 3-Mercaptopropionic acid, and Bicuculline in the chemical-induced seizure tests suggested that compound 1i displayed broad spectrum activity in several models, and it is likely to have several mechanisms of action including inhibiting voltage-gated ion channels and modulating GABAergic activity.

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 ED50 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.

Synthesis and anticonvulsant activity of 7-alkoxy-triazolo-[3, 4-b]benzo[d]thiazoles.

The present study describes the chemical synthesis and anticonvulsant activity evaluation of a series of 7-alkoxy-triazolo-[3, 4-b]benzo[d]thiazoles. Most compounds exhibited good anticonvulsant activity in the Maximal electroshock (MES) test. And the structure-activity relationships (SAR) were analyzed. Among the compounds studied, 7-octyloxy-triazolo-[3, 4-b]benzo[d]thiazole (5g) was found to be the most potent compound with a median effective dose (ED(50)) value of 8.0 mg/kg and a protective index (PI) value of 15.0, possessing better anticonvulsant activity and higher safety than marketed drugs carbamazepine and phenytoin. The mechanism study of compound 5g showed that it displayed broad spectrum activity in several models, and it is likely to have several mechanisms of action (including inhibiting voltage-gated ion channels and GABAergic activity).

Synthesis and Biological Evaluation of [1,2,4]Triazolo[3,4-a]phthalazine and Tetrazolo[5,1-a]phthalazine Derivatives Bearing Substituted Benzylpiperazine Moieties as Positive Inotropic Agents

Two series of [1,2,4]triazolo[3,4‐a]phthalazine and tetrazolo[5,1‐a]phthalazine derivatives bearing substituted benzylpiperazine moieties have been synthesized and evaluated for their positive inotropic activity by measuring left atrium stroke volume on isolated rabbit heart preparations. The majority of the derivatives exhibited better in vitro activity than the existing drug, milrinone, and 6‐((4‐(4‐methoxyphenyl)piperazin‐1‐yl)methyl)tetrazolo[5,1‐a]phthalazine. 8 m in particular was identified as the most potent with an increased stroke volume of 12.02 ± 0.20% (milrinone: 2.46 ± 0.07%) at a concentration of 3 × 10–5 m. The chronotropic effects of the compounds that exhibited good potency were also evaluated.

The Synthesis and Anti-Bacterial Activities of N-carboxymethylRhodanines

A large number of reports have been published in recent years regarding the use of N-carboxymethyl rhodanines as antimicrobial agents. Molecules belonging to this structural class have been reported to exhibit good inhibitory activities towards various Gram-positive bacteria, including several multidrug-resistant strains such as methicillinresistant Staphylococcus aureus and quinolone-resistant Staphylococcus aureus. In this mini-review, we have provided a summary of recent research directed towards the synthesis of N-carboxymethyl rhodanines, and their pharmacological evaluation as antimicrobial agents.

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

Abstract 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.

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. Whats 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.