Synthesis, antimicrobial and antioxidant activities of pyridyl substituted thiazolyl triazole derivatives

In this present study, 63 different 5-[4-methyl-2-(pyridin-3/4-yl)thiazole-5-yl]-4-substituted-3-substituted benzylthio-4H-1,2,4-triazole derivatives were synthesized, and evaluated for their in vitro antimicrobial activity against various human pathogenic microorganisms and antioxidant activity. The derivatives were synthesized in a multi-step synthesis procedure including triazole and thiazole ring closure reactions, respectively. The synthesized derivatives (A1-24; B1-39) were screened for their antibacterial, antifungal, and antioxidant activities compared to standard agents. The derivatives possessing 3-pyridyl moiety particularly exhibited relatively high antibacterial activity (MIC= < 3.09-500 µg/mL) against Gram-positive bacteria, and compounds possessing 4-pyridyl moiety showed remarkable antioxidant activity

Synthesis of New Thiazole Derivatives Bearing Thiazolidin-4(5H)-One Structure and Evaluation of Their Antimicrobial Activity

The first report about antimicrobial resistance was published in the 1940s. And today, the antimicrobial resistance has become a worldwide problem. Because of this problem, there is a need to develop new drugs. That's why we synthesized some novel thiazolidine-4-one derivatives and evaluated their antimicrobial activity. The final compounds were obtained by reacting 2-[(4,5-diphenylthiazol-2-yl)imino]thiazolidin-4-one with some aryl aldehydes. The synthesized compounds were investigated for their antimicrobial activity against four Candida species, five gram-negative and four gram-positive bacterial species. The lead compounds (4a- h) were obtained with a yield of at least 70%. All compounds showed antimicrobial activity. Compound 4f (MIC: 31.25 µg/ml) exhibited more efficacy than the other compounds against C. glabrata (ATCC 24433). Compound 4b (MIC: 62.5 µg/ml) was the most active compound against all bacterial species, particularly K. pneumoniae (NCTC 9633). Whereas, compound 4c (MIC: <31.25 µg/ml) was observed as the most active compound against E. coli (ATCC 25922). In general, all compounds (4a-4h) showed antimicrobial activity against all fungi and bacterial species. Compounds 4b (2,6-dichlorobenzylidene), 4c (2,6-dihydroxybenzylidene), 4f (1H-pyrrol-2- yl)methylene), 4g (4-triflouromethylbenzylidene) and 4h (2,3,4-trimethoxybenzylidene) were determined as the most active compounds

Antimicrobial properties of heterocyclic compounds against clinical mastitis isolates

ABSTRACT: Mastitis causes significant economic losses to the dairy cattle industry. The present study aimed to evaluate the antibacterial properties of 39 heterocyclic derivatives (1,3-thiazoles and 4-thiazolidinones) against clinical mastitis isolates from dairy cows. Milk samples were collected from cows with clinical mastitis and the bacterial species were identified by PCR. Antibacterial activity was assessed using the broth microdilution method. First, 39 heterocyclic compounds were tested against four bacterial isolates (Staphylococcus aureus, Streptococcus agalactiae, Corynebacterium bovis and Escherichia coli) randomly chosen from those recovered from the milk samples (Study 1). Subsequently, the compounds with the strongest antibacterial activity were tested against all the bacterial isolates recovered from the milk samples (Study 2). 1,3-thiazoles showed the strongest antibacterial activity, specially compounds 30 and 38, which also showed bactericidal properties according to their minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) values. Corynebacterium spp. and Enterobacteriaceae isolates were the most susceptible to compounds 30 and 38. Compounds 30 and 38 are promising targets for new antimicrobial agents.

RESUMO: A mastite causa significativas perdas econômicas à indústria leiteira bovina. O presente estudo teve como objetivo avaliar as propriedades antibacterianas de 39 derivados heterocíclicos (1,3-tiazóis e 4-tiazolidinonas) contra isolados clínicos de mastite em vacas leiteiras. Amostras de leite foram coletadas de vacas com mastite clínica e as espécies bacterianas isoladas foram identificadas por PCR. A atividade antibacteriana foi avaliada pelo método de microdiluição em caldo. Primeiramente, os 39 compostos heterocíclicos foram testados contra quatro isolados bacterianos (Staphylococcus aureus, Streptococcus agalactiae, Corynebacterium bovis e Escherichia coli) escolhidos aleatoriamente dentre os recuperados das amostras de leite (Estudo 1). Posteriormente, compostos com atividade antibacteriana mais forte foram testados contra todos os isolados bacterianos recuperados das amostras de leite (Estudo 2). Os compostos 1,3-tiazóis apresentaram a maior atividade antibacteriana, principalmente os compostos 30 e 38, que também apresentaram propriedades bactericidas de acordo com seus valores de concentração inibitória mínima (CIM) e concentração bactericida mínima (CBM). Os isolados Corynebacterium spp. e Enterobacteriaceae foram os mais suscetíveis aos compostos 30 e 38. Os compostos 30 e 38 mostraram-se promissores como novos agentes antimicrobianos.

Antimicrobial properties of heterocyclic compounds against clinical mastitis isolates / Propriedades antimicrobianas de compostos heterocíclicos contra isolados de mastite clínica

Mastitis causes significant economic losses to the dairy cattle industry. The present study aimed to evaluate the antibacterial properties of 39 heterocyclic derivatives (1,3-thiazoles and 4-thiazolidinones) against clinical mastitis isolates from dairy cows. Milk samples were collected from cows with clinical mastitis and the bacterial species were identified by PCR. Antibacterial activity was assessed using the broth microdilution method. First, 39 heterocyclic compounds were tested against four bacterial isolates (Staphylococcus aureus, Streptococcus agalactiae, Corynebacterium bovis and Escherichia coli) randomly chosen from those recovered from the milk samples (Study 1). Subsequently, the compounds with the strongest antibacterial activity were tested against all the bacterial isolates recovered from the milk samples (Study 2). 1,3-thiazoles showed the strongest antibacterial activity, specially compounds 30 and 38, which also showed bactericidal properties according to their minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) values. Corynebacterium spp. and Enterobacteriaceae isolates were the most susceptible to compounds 30 and 38. Compounds 30 and 38 are promising targets for new antimicrobial agents.(AU)

A mastite causa significativas perdas econômicas à indústria leiteira bovina. O presente estudo teve como objetivo avaliar as propriedades antibacterianas de 39 derivados heterocíclicos (1,3-tiazóis e 4-tiazolidinonas) contra isolados clínicos de mastite em vacas leiteiras. Amostras de leite foram coletadas de vacas com mastite clínica e as espécies bacterianas isoladas foram identificadas por PCR. A atividade antibacteriana foi avaliada pelo método de microdiluição em caldo. Primeiramente, os 39 compostos heterocíclicos foram testados contra quatro isolados bacterianos (Staphylococcus aureus, Streptococcus agalactiae, Corynebacterium bovis e Escherichia coli) escolhidos aleatoriamente dentre os recuperados das amostras de leite (Estudo 1). Posteriormente, compostos com atividade antibacteriana mais forte foram testados contra todos os isolados bacterianos recuperados das amostras de leite (Estudo 2). Os compostos 1,3-tiazóis apresentaram a maior atividade antibacteriana, principalmente os compostos 30 e 38, que também apresentaram propriedades bactericidas de acordo com seus valores de concentração inibitória mínima (CIM) e concentração bactericida mínima (CBM). Os isolados Corynebacterium spp. e Enterobacteriaceae foram os mais suscetíveis aos compostos 30 e 38. Os compostos 30 e 38 mostraram-se promissores como novos agentes antimicrobianos.(AU)

Synthesis and Antitumor Activity of C-3 Arylidene Thiazolotriazolone of Ofloxacin Derivatives / 中国药学杂志

OBJECTIVE: To discover an efficient strategy for a conversion of the antibacterial activity into an antitumor activity. METHODS: Pharmacophore and scaffold hopping-based rational drug design principles, the title fluoroquinolone C-3 thiazolotriazole unsaturated ketones (6a-6l) were designed and synthesized with a S-triazole ring and α,β-unsaturated ketone, respectively, as an isostere and fused modified group from ofloxacin (1), and their structures were characterized by elemental analysis and spectral data, and the in vitro antitumor activity against the tested tumor cell lines was evaluated by a MTT assay. RESULTS: Twelve new title compounds were synthesized, and exhibited more significant potency than parent 1. The title compounds with fluorophenyl or O-methoxyphenyl displayed comparable activity to comparasion doxorubicin. CONCLUSION: A fused heterocyclic unsaturated ketone skeleton as an isostere of the C-3 carboxylic acid group are shown to be an alternative route for further design of lead antitumor fluoroquinolone.

Design

According to one pot microwave assisted synthesis, the versatile precursor 2- aminothiazole was prepared and utilized for the construction of new thiazole hybrids targeting MCF7 cell lines. 2‐amino thiazole was condensed with corresponding aldehydes to yield Schiff’sbase (2) intermediates followed by the diazo coupling reaction furnished the designed hybrids(3) contains azo-methine and diazo linkages in its structures. The newly synthesizedcompounds were confirmed on the basis of IR and H1NMR spectral analytical data. All thesynthesized compounds were evaluated for their in-vitro cytotoxicity activity against MCF-7celllines using MTT assay method. The obtained results revealed the more promising compoundsof the synthesised series, 3B and 3H with CTC50 value of 17.77±0.31μg/ml, 17.83±1.14 μg/ml.

Synthesis and antitumor activity of fluoroquinolone C-3 arylidene thiazolone derivatives from ciprofloxacin / 药学学报

To expand an efficient strategy for the conversion of antibacterial activity of fluoroquinolones into an antitumor activity, sixteen new compounds, 1-cyclopropyl-6- fluoro-7-(4-methyl-piperazin-1-yl)-3-(5-arylidene-thiazol-4(5H)-one-2-yl)-quinolon-4(1H)-ones (7a-7p), were designed and synthesized with a thiazolone ring and an arylidene moiety as an isostere and modified group, respectively, from ciprofloxacin. Their structures were characterized by elemental analysis and spectral data. The in vitro antitumor activity of the synthesized compounds were measured using Hep-3B, Capan-1 and HL60 cell lines and were found to be more potent than ciprofloxacin. Meanwhile, the SAR revealed that the halogenated phenyl compounds such as fluorophenyl (7h, 7i), chlorophenyl (7j, 7k) or bromophenyl compounds (7l, 7m), and aromatic heterocyclic substitution such as furyl (6n) or pyridyl compounds (6o, 6p) displayed better activity than the control compounds, especially the IC50 values of pyridyl compounds 6o and 6p against Capan-1 cell growth was comparable to doxorubicin. Thus, an arylidene-modified thiazolone scaffold as the replacement of the C-3 carboxylic acid group appears to be an alternative route for an improved antitumor activity of fluoroquinolones.

Assessment of anti-diabetic activity of a novel hydrazine-thiazole derivative: in vitro and in vivo method

Diabetes mellitus is a chronic disease resulting in oxidative stress that promotes tissue damage. The appearance of this disease is highly related to lifestyle and food of the population, being of great interest to search for a dietary supplement that can also act by reducing oxidative alterations. Based on the broad range of biological activity of thiazole derivatives, this work aimed to evaluate the in vitro antioxidant activity of a novel hydrazine-thiazole derivative and studies in vivo. In in vivo experiments, the liver extracts of healthy and diabetic Wistar rats were used, with analysis to determine the enzymatic activity of SOD, CAT, GPx, and GR, and determination of lipid peroxidation. Finally, in the blood of these animals, biochemical parameters were evaluated. Statistical evidence of changes caused in liver enzymes and liquid peroxidation was not detected; however, these parameters were also not changed between control groups with and without diabetes. On the other hand, concerning biochemical parameters, significant differences were detected in uric acid, alkaline phosphatase, ALT, and urea, indicating a possible antioxidant protective role of such substances in the liver and kidney of diabetic animals that could be acting by means other than that commonly reported in the literature.

Cytotoxicity Test of Cervical Collar in Aids / 中国康复理论与实践

Objective To study the cytotoxicity of cervical collar in rehabilitation technical aids and to investigate the cytotoxicity of domestic marketed products. Methods According to the experimental principle of GB/T 16886.5-2003 and GB/T 16175-2008,microscopic observa-tion and Thiazole Blue Colorimetric methods were used to observe the toxicity of extract from four different cer-vical collars on the cells(L929). Results When the concentration of the extract was 0.1 g/ml,the cytotoxicity was grade three and grade two in the cervi-cal collars D and A,respectively;and it was grade one both in cervical collars B and C.When the concentration of the extract was 0.2 g/ml,the cytotoxicity was grade four in cervical collars A and D,and was grade two in cer-vical collars B and C. Conclusion The cervical collars varied in the cytotoxicity,especially in cervical collars A and D.

Synthesis and antitumor activity of 3-(5-benzylidenethuzolo-triazlone)fluoroquinolones / 中国药科大学学报

@#To discover an efficient approach for the conversion of antibacterial fluoroquinolones into an antitumor activity, a fused heterocycle ring core, thiazolo［3, 2-b］［1, 2, 4］triazol-5-one was used as an isostere and further modified with an arylidene group. Then, 12 novel C-3 fused heterocyclic unsaturated ketones, 1- ethyl-6-fluoro-7-(4-methyl-piperazin-1-yl)-3-［6-arylidene-thiazolo［3, 2-b］［1, 2, 4］triazol-5(6H)-one-3-yl］- quinolon-4(1H)-ones(6a-6l), were designed and synthesized from pefloxacin(1). The structures were characterized by elemental analysis and spectral data, and the in vitro antitumor activity of the title compounds against SMMC-7721, Capan-1 and HL60 cell lines was evaluated. The preliminary pharmacological results demonstrated that the title compounds exhibited more significantly antiproliferative activity than the parent 1. The compounds with fluorophenyl or o-methoxyphenyl showed comparable activity to the comparasion doxorubicin. Thus, it appears to be an alternative route for a fused heterocyclic unsaturated ketone as an isostere of the C-3 carboxylic group to improve the antitumor activity.

Design, synthesis and anti-tumor activity of novel 5-amino-2-(benzylthio) thia-zole-4-carboxamide derivatives / 中国药科大学学报

A series of 5-amino-2-( benzylthio ) thiazole-4-carboxamide derivatives were designed and synthesized to discover novel compounds with anti-tumor activity. Compounds DDO-5401-DDO-5416 were synthesized using 2-amino-2-cyanoacetamide as the start material. The structures of the synthesized compounds were confirmed by IR, 1 H NMR and ESI-MS. The in vitro anti-tumor activities of the synthesized compounds were determined by MTT assay in HCT116 , HepG2 , A549 , MDA-MB-231 and MCF-7 cell lines. Target compounds showed good anti-tumor activity especially in A549 cell line. SAR study showed that electron donating groups were more favorable than electron absorption ones. Compound DDO-5413 exhibited noteworthy activity in MDA-MB-231 and MCF-7 cell lines with IC50 value lower than the positive reference dasatinib. It suggested that DDO-5413 might be the candidate for further investigation.

Characterizing drug-metabolizing enzymes and transporters that areCAR-target genes in mouse intestine

Intestine is responsible for the biotransformation of many orally-exposed chemicals. The constitutive androstane receptor (CAR/Nr1i3) is known to up-regulate many genes encoding drug-metabolizing enzymes and transporters (drug-processing genes/DPGs) in liver, but less is known regarding its effect in intestine. Sixty-day-old wild-type andmice were administered the CAR-ligand TCPOBOP or vehicle once daily for 4 days. In wild-type mice,mRNA was down-regulated by TCPOBOP in liver and duodenum.mice had altered basal intestinal expression of many DPGs in a section-specific manner. Consistent with the liver data (Aleksunes and Klaassen, 2012), TCPOBOP up-regulated many DPGs (, and) in specific sections of small intestine in a CAR-dependent manner. However, the mRNAs ofandwere previously known to be up-regulated by TCPOBOP in liver but were not altered in intestine. Interestingly, many known CAR-target genes were highest expressed in colon where CAR is minimally expressed, suggesting that additional regulators are involved in regulating their expression. In conclusion, CAR regulates the basal expression of many DPGs in intestine, and although many hepatic CAR-targeted DPGs wereCAR-targets in intestine, pharmacological activation of CAR in liver and intestine are not identical.

Synthesis, molecular docking and QSAR studies of 2, 4-disubstituted thiazoles as antimicrobial agents.

In present study a series of 2,4-disubstituted thiazole derivatives was synthesized and evaluated for their in vitro antibacterial and antifungal activities against B. subtilis, E. coli, S. aureus, C. albicans and A. niger by tube dilution method. The analysis of antimicrobial activity results indicated that the presence of NO2 and OCH3 groups at para position of phenyl group improved the antimicrobial activity significantly. Molecular docking studies also supported in vitro activity results and showed that NO2 and OCH3 groups containing compounds have greater affinity towards the target glucosamine-6-phosphate synthase. QSAR studies indicated that molecular connectivity index (2χv) and Kier’s shape index (α3) are the key parameters for antimicrobial activity of synthesized thiazole derivatives and can be cosidered as important factors for interaction with target site of different microorganisms. It is pertinent to note that multi-target QSAR models were more effectual in demonstrating the antimicrobial activity than one-target QSAR models.

Synthesis and antitumor activity of C-3 thiazolo 3 2-b 1 2 4 triazole-substituted pefloxacin derivatives / 中国药科大学学报

To search for fluoroquinolones(FQs)with antitumor activity;the C-3 carboxylic acid group of peflox-acin (1)was replaced by fused heterocyclic core;and twelve novel thiazolo[3;2-b][1;2;4]triazole heterocycles(6a-6l)were designed and synthesized.The structures of target compounds were characterized by elemental anal-ysis and spectral data.The results of the in vitro antiproliferative effect on SMMC-7721;L1210 and HL60 cell lines showed that the title compounds exhibited more significant antitumor activity than both of the pefloxacin and the corresponding opening-ring intermediates(5 a-5 l).Among them;the target compounds which possess a ben-zene ring bearing a hydroxyl group (6e)or a fluorine atom (6j)exhibited more potent antiproliferative effect on SMMC-7721 cells than other compounds.Therefore;the antitumor fluoroquinolones can be designed by replacing the C-3 carboxylic acid group of fluoroquinolones with the thiazolo[3;2-b][1;2;4]triazole moiety.

α-Glucosidase Inhibitory Activity of 4-Aryl-N-(2,4-Thiazolidinedione-5-Acetyl)-1,3-Thiazol-2-Amines.

A series of N-(4-aryl-1,3-thiazol-2-yl)-2-(2,4-dioxo-1,3-thiazolidin-5-yl)acetamides 3a-k and N- (1,3-benzothiazol-2-yl)-2-(2,4-dioxo-1,3-thiazolidin-5-yl)acetamides 3l-n are synthesized and evaluated for their α-glucosidase inhibitory activity. N-[4-(m-Chlorophenyl)-1,3-thiazol-2yl]-2-(2,4-dioxo-1,3-thiazolidin-5- yl)acetamide (3g) and N-[4-(o-fluorophenyl)-1,3-thiazol-2-yl]-2-(2,4-dioxo-1,3-thiazolidin-5-yl)acetamide (3j) have shown very good inhibition. The remaining compounds have exhibited moderate to good activity ranging from 37- 63 % of α-glucosidase enzyme inhibition.

Synthesis, Characterization and Antimicrobial Activities of Schiff bases of 2-amino-4-(O-chloroanilino)-1, 3-thiazole.

A novel series of schiff bases of 2-amino-4-(o-chloro anilino)-1, 3-thiazole (3a-3j) were synthesized and screened for their antibacterial and antifungal activities. The structures of these compounds were ascertained by UV, IR, 1H NMR, mass spectra and elemental analysis. The antibacterial activity of the synthesized schiff bases were evaluated against Gram positive bacteria such as Staphylococcus aureus, Bacillus subtilis and Gram negative bacteria like Escherichia coli and Klebsiella pneumonia. All the compounds had shown moderate to significant antibacterial activity amongst them; compound 3e exhibited more significant activity against the tested bacteria. The antifungal activity was screened against two strains of fungi such as Candida albicans and Aspergillus niger. Similar to antibacterial activity compound 3e exhibited significant antifungal activity. The standard drugs Amoxycillin and Amphotericin B were used to screen antibacterial and antifungal activity at 10μg/ml respectively. Interestingly compound 3e had shown more prominent inhibitory activity against the tested bacteria and fungi.

Quantitation of the Percentage of Reticulated Platelets to Diagnose the Cause of Thrombocytopenia / 대한진단검사의학회지

BACKGROUND: Since reticulated platelets (RP), known to be newly released from megakaryocytes in the bone marrow into the blood, contain RNA in their cytoplasm, we can detect them by staining RNA remnants with fluorescent dyes and performing flow cytometric analysis. We attempted to search for the best conditions in quantitating the percentage of RP (RP%) to identify causes of thrombocytopenia. METHODS: The RP% were measured on venous blood samples collected in EDTA from 63 normal controls and 48 thrombocytopenic patients. The thrombocytopenic patients were divided into two groups according to the causes: hypoplastic and destructive. The RP% was determined by a flow cytometric analysis with anti-CD41a and thiazole orange (TO) as a fluorochrome. RESULTS: In patients with their platelet count less than 50 x 10(9)/L, the RP% of two patient groups showed a significant difference. The RP% and platelet count were correlated directly in the hypoplastic group, but inversely in the destructive group. According to the results of ROC curve, the best conditions in quantitating RP% to identify the cause of thrombocytopenia was to apply a 2% threshold of TO positivity among gated platelets; its sensitivity and specificity were 93.3% and 83.3%, respectively. w CONCLUSIONS: The RP% is considered to be a good marker for differentiating destructive from hypoplastic thrombocytopenia and monitoring of the destructive thrombocytopenic patient having normal bone marrow such as idiopathic thrombocytopenic purpura. For the accurate measurement of the RP%, the condition of 2% TO threshold is considered to be appropriate.

Synthesis and investigation and antifungal and antibacterial properties of some 2-amino thiazole derivatives

Condensing 2-amino-4-methyl-5-carbe thoxythiazole obtained from the cyclization process between thioure and ethylacetoacetate and oidine with some acylating agents to yield 9 new compounds of thiazole. All of them were screened for their invitro antibacterial and antifungal activities with respect to clotrimazol and cloramphenicol. The results showed that [2-(3,5-substuted salicylamido)-4-methyl-5-car-bethoxythiazole] compounds are active against gram-positive bacteria.

Synthesis of some thiazole derivatives with anti fungal and anti microbial potential

The synthesis, structure elucidation and bio-activity of certain new 2-subtituted thiazole derivatives were reported. The newly prepared compounds were screened for their in vitro antibacterial and antifungal activities. The result revealed that almost compounds were active against fungi, 5 compounds were active against gram-positive bacteria. Meanwhile, 3 compounds had a remarkable both antibacterial and antifungal activities.

Diagnostic Value of Reticulated Platelet in Thrombocytopenia

PURPOSE: We performed this study to determine the diagnostic significance and useful cut-off value of reticulated platelet, which can be used for discriminating the destructive thrombocytopenia from underproductive thrombocytopenia. METHODS: We evaluated 37 patients with thrombocytopenia who were admitted to the Wonju christian hospital from March to July, 1995. All patients were evaluated with bone marrow megakaryocyte count. We divided them into two groups, group 1 was consisted of underproductive thrombocytopenic patients and group 2 was consisted of destructive thrombocytopenic patients. We measured the peripheral blood reticulated platelet count by FACScan flowcytometry after thiazole orange staining. RESULTS: 1) Among 37 patients, underproductive group consisted of 21 patients and destructive group consisted of 16 patients. 2) There was no significant difference in platelet count between two groups (41.7 31.8x109/L vs. 41.0 29.1x109/L). 3) Destructive group showed higher reticulated platelet count than underproductive group (7.7 3.7% vs. 19.1 11.1% : p<0.01). 4) Ideal cut-off value of reticulated platelet count for the discrimination of two groups was 11%. Its sensitivity and specificity were 88% and 95%, respectively. CONCLUSIONS: We suggest that reticulated platelet count is closely correlated with thrombopoiesis of bone marrow. The measurement of reticulated platelet can be a simple and useful diagnostic tool to discriminate destructive thrombocytopenia from underproductive thrombocytopenia.