Synthesis and evaluation of some novel benzothiazole derivatives as potential anticancer and antimicrobial agents

Intensive efforts are underway worldwide to develop anticancer and antimicrobial agents. Therefore, a novel series of pyrido[2,1-b]benzo [d]thiazole and 2-(benzo [d] thiazol-2-ylamino)pyrimidine derivatives was synthesized. The synthesized compounds were evaluated for their anticancer activity. Among the tested compounds, compounds 3a, 3b, and 7 exhibited more cytotoxic action than the control drug doxorubicin (CAS 23214-92-8; IC50: 52 microg/ml). Compound 7 was the most potent cytotoxic, with an IC50 of 42.55 pg/ ml, while compounds 3a and 3b induced high cytotoxic action with IC50 values of 50.15 pg/ml and 50.45 pg/ml, respectively. Moreover, the synthesized compounds were screened for their antibacterial and antifungal activities. Compound 6 exhibited moderate antifungal activity against C. albicans with a minimum inhibitory concentration of 125 pg/ml.     

Synthesis of some novel substituted purine derivatives as potential anticancer, anti-HIV-1 and antimicrobial agents

In search of novel purine antimetabolites, a series of 8-substituted methylxanthine derivatives was prepared in order to explore their in vitro anticancer, anti-HIV-1 and antimicrobial activities. The target compounds include: 8-[(3-substituted-4-oxo-thiazolidin-2-ylidene)hydrazino]-1,3-dimethyl (or 1,3,7-trimethyl)-3,7-dihydropurine-2,6-diones 5a-e, 8-[(3,4-disubstituted 2,3-dihydrothiazol-2-ylidene)hydrazino]-1,3,7-trimethyl-3,7-dihydropurine-2,6-diones 6a-d and 8-(5-amino-3-arylpyrazol-1-yl)-1,3-dimethyl- (or 1,3,7-trimethyl)-3,7-dihydropurine-2,6-diones 7a-g. The in vitro anticancer results revealed that compound 5d exhibited a super sensitivity profile towards leukemia K-562 with a GI(50) value of <0.01 microM. Compound 7c showed significant activity against colon cancer HCT-15 and renal cancer CAKI-1 (GI(50) values of 0.47 and 0.78 microM, respectively). Compound 7a displayed high activity against colon cancer HCT-15 (GI(50 )= 0.8 microM). The anti-HIV-1 results indicated that compound 6b displayed a good reduction of viral cytopathic effect (56.69%). The antimicrobial results showed that compound 5a was four times more active than ampicillin against P. aerugenosa (MIC =or< 25 microg/mL), compound 5b had twice the activity of ampicillin, while compounds 5d, 7c and 7f were equipotent to ampicillin. On the other hand, compound 7a was equipotent to ampicillin against P. vulgaris (MIC = 50 microg/mL).     

Synthesis and biological evaluation of some novel fused pyrazolopyrimidines as potential anticancer and antimicrobial agents

Synthesis and evaluation of anticancer and antimicrobial activity of some novel pyrazolopyrimidines and fused pyrazolopyrimidines are reported. Twelve analogs were selected to be evaluated for their in vitro anticancer potential against a panel of three human tumor cell lines: hepatocellular carcinoma HepG2, cervical carcinoma HelaS3 and colon carcinoma CaCo. The obtained data revealed that eight compounds namely; 6b, 6d, 7c, 8c, 10b, 12b, 13a and 13b were able to exhibit variable degrees of anticancer activities against the three used cell lines, of which compound 6d proved to be the most active. On the other hand, all the newly synthesized compounds were subjected to in vitro antibacterial and antifungal screening. Almost all the tested compounds were found to possess variable degrees of antimicrobial activities. Collectively, compounds 7c, 8c, 12b, 13a and 13b could be considered as possible agents with dual anticancer and antimicrobial activities.     

Synthesis andin vitro evaluation of some novel benzofuran derivatives as potential anti-HIV-1, anticancer, and antimicrobial agents

A novel series of 1-(1-benzofuran-2-yl-ethylidene)-4-substituted thiosemicarbazides (2a-d) along with some derived ring systems: substituted-2,3-dihydro-thiazoles (3a-c, 4a-f) and thiazolidin-4-ones (5a-d and 6a-d), were synthesized. In addition, cyanoacetic acid-(1-benzofuran-2-yl-ethylidene) hydrazide (7) was used to prepare another new series of compounds consisting of substituted pyridin-2(1H)-ones (8a-c); 2-thioxo-2,3-dihydro-thiazoles (9a-d) and 2-thioxo-2,3-dihydro-6H-thiazolo[4,5-d]pyrimidin-7-ones (10a-c, 11a-c). The absolute configuration of compound 5c was determined by X-ray crystallography. The compounds prepared were evaluated for their in vitro anti-HIV, anticancer, antibacterial, and antifungal activities. Among the tested compounds, compounds 5c and 9a produced a significant reduction [symbols, see text] the viral cytopathic effect (93.19% and 59.55%) at concentrations > 2.0 x 10(-4) M and 2.5 x 10(-5) M respectively. Compound 9a was confirmed to have moderate anti-HIV activity. Compounds 2a, 2d, and 5c showed mild antifungal activity. However, none of the tested compounds showed any significant anticancer activity.     

Synthesis of some novel 4-arylidene pyrazoles as potential antimicrobial agents

Background

Pyrazole and pyrazolone motifs are well known for their wide range of biological activities such as antimicrobial, anti-inflammatory, and antitumor activities. The incorporation of more than one pharmacophore in a single scaffold is a well known approach for the development of more potent drugs. In the present investigation, a series of differently substituted 4-arylidene pyrazole derivatives bearing pyrazole and pyrazolone pharmacophores in a single scaffold was synthesized.

Results

The synthesis of novel 4-arylidene pyrazole compounds is achieved through Knovenagel condensation between 1,3-diaryl-4-formylpyrazoles and 3-methyl-1-phenyl-1H-pyrazol-5-(4H)-ones in good yields. All compounds were evaluated for their in vitro antimicrobial activity.

Conclusions

A series of 4-arylidene pyrazole derivatives was evaluated for their in vitro antimicrobial activity against two Gram-positive (Bacillus subtilis and Staphylococcus aureus) and two Gram-negative bacteria (Pseudomonas fluorescens and Escherichia coli), as well as two pathogenic fungal strains (Candida albicans and Saccharomyces cerevisiae). The majority of the compounds displayed excellent antimicrobial profile against the Gram-positive (B. subtilis and S. aureus), and some of them are even more potent than the reference drug ciprofloxacin.

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Synthesis of some pyrazolines and pyrimidines derived from polymethoxy chalcones as anticancer and antimicrobial agents

The synthesis of a series of certain polymethoxy chalcones and some derived pyrazole, pyrimidine, and thiazolopyrimidine ring structures is reported. Eleven compounds 4 , 6 , 9 , 11 , 14–17 , 22 , 24 , and 25 were selected by the National Cancer Institute (NCI) to be screened for their in‐vitro anticancer activity, whereas all the synthesized compounds were evaluated for their in‐vitro antimicrobial activity. Compounds 4 , 6 , and 11 were found to possess a significant broad spectrum antitumor potential against most of the tested subpanel tumor cell lines. The pyrazolines 4 and 6 displayed remarkable growth inhibitory activities (GI₅₀ MG‐MID values of 2.10 and 1.38 µM, respectively), together with moderate cytostatic effects (TGI MG‐MID values of 47.9 and 42.7 µM, respectively). Meanwhile, the pyrimidin‐2‐one 11 showed a noticeable overall tumor growth inhibitory activity, together with high cytostatic and cytotoxic efficacies (GI₅₀, TGI and LC₅₀ MG‐MID values of 3.39, 17.4, and 61.7 µM, respectively). On the other hand, compounds 3 , 4 , 13 , 15 , 19 , 20 , and 23 were found to be the most active antimicrobial members in this investigation with a broad spectrum of activity. Compound 23 was four times superior to ampicillin against Pseudomonas aeruginosa. The best antifungal activity was demonstrated by compounds 4 , 5 , and 11 which possessed almost half the activity of clotrimazole against Candida albicans. Collectively, the obtained biological results suggest that compound 4 could be considered as a possible dual antimicrobial‐anticancer agent.     

Synthesis and biological evaluation of novel 4,5-dihydropyrazole derivatives as potent anticancer and antimicrobial agents

A focused library of 4,5-dihydropyrazole dervivatives (4, 5, 6, 7a–h, 8, 9a–g, and 10a–g) were synthesized from novel 5-(2,6-difluorophenyl)-3-phenyl-4,5-dihydropyrazole-1-carbothioamide 4. The synthesized compounds were characterized using elemental analysis and spectral data (IR, mass spectra, ¹H and ¹³C NMR) and evaluated for antimicrobial activity by broth dilution method and in vitro anticancer activity. Among the synthesized compounds 7a, 9c, 9g, and 10d exhibit broad spectrum antimicrobial activity against tested microbial strains. The in vitro cancer results ascertain 7a, 9c, and 10d are most potent molecules in comparison to reference standard cisplatin.     

Synthesis and biological evaluation of novel hydroquinone dimethyl ethers as potential anticancer and antimicrobial agents

The synthesis of two novel series of quinol dimethyl ethers linked to either various functionalities or to some biologically active nitrogenous heterocycles is described. Nine of the newly synthesized quinol dimethyl ethers 5a, b, 9b, 10a, d, 12a, b, and 13a, b were selected by the NCI and were tested initially at a single high dose (10 μM) in the full NCI 60 cell panel. Four of the screened quinol dimethyl ethers bearing unsubstituted phenylhydrazone 5a, 4-chlorophenylhydrazone 5b, 4-chlorophenyl-3-sulfanyl-1,2,4-triazole 9b, as well as 4-chloroanilino-1,3,4-oxadiazole 12b moieties satisfied the threshold antitumor screen. 4-Chlorophenylhydrazone 5b showed very promising results and accordingly was chosen for in vivo antitumor screening. Thus, compound 5b of the series could be considered as the potential lead for development of novel anticancer agents. In addition, compounds 5a–c, 6a–c, 9a–c, 10a, b, d, e, g, h, 11a–c, 12a–c, and 13a–c were screened for their in vitro antimicrobial activity. Some of the tested compounds exhibited special high activity comparable to the reference ampicillin against Pseudomonas aeruginosa and Escherichia coli.     

Synthesis and QSAR studies of some novel disubstituted 1,2,4-triazoles as antimicrobial agents

Disubstituted 1,2,4-triazoles 3a–k, 4a–k, and 6a–k have been synthesized from anthranilic acid and nicotinic acid, respectively, through a multi-step reaction sequence via their hydrazides. Synthesized compounds were evaluated for their in vitro antimicrobial activity against two gram-positive bacteria (S. aureus and B. subtilis), three gram-negative bacteria (E. coli, S. typhi, and K. pneumonia) as well as four fungi (A. niger, A. fumigatus, A. flavus, and C. albicans). To explore computational approach, structure–activity relationships were generated statistically using the synthesized compounds and their respective quantitative values of biological activities. These models can be used in future for predicting antimicrobial activity on similar class of compounds.     

Synthesis and biological evaluation of some 2,4,5-trisubstituted thiazole derivatives as potential antimicrobial and anticancer agents

We report on the synthesis and biological evaluation of two series of 2,4,5-polysubstituted thiazoles comprising the acid hydrazide functionality and some derived pharmacophores known to contribute to various chemotherapeutic activities. All newly synthesized compounds were subjected to in-vitro antibacterial and antifungal screening. Of the compounds tested, 13 derivatives displayed inhibitory effect on the growth of three Gram-positive strains while they lack activity against Gram-negative bacteria. Moreover, four compounds were able to exert antifungal activity against C. albicans. Potential antibacterial and antifungal activities were linked to the thiosemicarbazide function 6a-f and those substituted with both the thioureido and thiosemicarbazide moieties 12a-f. Compounds 6f and 12f (R = 4-F-C(6)H(4)) could be considered as the most active members in this investigation with a broad spectrum of antibacterial activity against three types of Gram-positive bacteria, together with an appreciable antifungal activity against C. albicans. Compounds 6d, 6f, and 12f were twice as active as ampicillin against B. subtilis. The best antifungal activity was shown by compound 6d 50% less active than clotrimazole. 17 compounds were selected and tested for their preliminary in-vitro anticancer activity according to the current one-dose protocol of the NCI. Three cell lines, non-small cell lung cancer Hop-92, ovarian cancer IGROV1, and melanoma SK-MEL-2, exhibited some sensitivity against most of the tested compounds. Compound 12f proved to be the most active anticancer member with a broad spectrum of activity against most of the tested subpanel tumor cell lines. Consequently, 12f was carried over to be tested in the five-dose assay.     

Synthesis of some new bis-thiazoles as possible anticancer agents

Several new 5-(2,3-dihydrothiazol-2-yledinyl)rhodanines 3a-c and 5-(4-oxothiazolidinon-2-ylidenyl)rhodanine 4 were synthesized through the reaction of 5-thiocarbamoyl rhodanines 2 with phenacyl bromides or chloroacetic acid, respectively. The synthesis of the arylidene derivatives 5a-c were also described. The 5-(4-amino-5-cyano-2,3-dihydrothiazol-2-yledinyl)rhodanines 10a, b were obtained through reaction of rhodanines 1a, b with thiazolium salt 9. All the prepared compounds were screened for their anticancer activity using the NCI in vitro anticancer screening program. Three compounds showed promising anticancer activity against particular human cell lines used in the assay.     

Synthesis of 4-substituted aminoquinoline-3-carboxylates as potential antimicrobial agents

A series of 4-substituted aminoquinoline-3-carboxylates was prepared and evaluated for antimicrobial activity. Four of the compounds (VIII, XIII, XV, and XXIII) exhibited low activity against Staphylococcus aureus.     

Synthesis and bioevaluation of diphyllin glycosides as novel anticancer agents

A series of diphyllin glycosides were synthesized from diphyllin by phase transfer catalysis glycosylation, deprotection, and etherification, and the structures were established by (1) H NMR, (13) C NMR, and HRMS. These glycosides were evaluated for their in vitro cytotoxicity against HCT-116, A549, and A549T cancer cell lines by MTT assay, and most of them were cytotoxic at submicromolar concentrations. They were also effective against the paclitaxel-resistant cell line A549T. The kDNA decatenation assay indicated that most of these compounds inhibited topoisomerase IIα-mediated kDNA decatenation. In addition, the in vitro tubulin polymerization study showed that compounds 5 and 6 had antimicrotubule activity with a paclitaxel-like mode of action. Taken together, these results suggest that these diphyllin glycosides act on both TopoII and tubulin.     

Synthesis and bioevaluation of novel arylnaphthalene lignans as anticancer agents

Novel arylnaphthalene lignans were synthesized and their structures were established by ¹H NMR, ¹³C NMR, and HRMS. These compounds were evaluated for their in vitro cytotoxicity against cancer cell lines by MTT assay. Compound 5d possessed the highest cytotoxicity against KB cells. Apoptosis of KB cells treated with 5d was observed by acridine orange and ethidium bromide double staining assay. Western blot analysis disclosed that 5d induced apoptosis via mitochondrial pathway accompanied by an increased expression of Bax and a decreased expression of Bcl-2.     

Synthesis, evaluation and docking studies on steroidal pyrazolones as anticancer and antimicrobial agents

A series of new steroidal pyrazolones have been synthesized, characterised and evaluated for their in vitro anticancer activity. They were tested against five cancer (SW480, HepG2, A549, HeLa and HL-60) cell lines. The synthesized compounds showed high selectivity and compound 4 showed the strongest inhibitory activity against human SW480 (IC₅₀ = 11.67 μmol L^?1). In addition, the synthesized compounds were tested for their antimicrobial activity by disc diffusion assay and MIC by broth micro dilution method against Gram-positive, Gram-negative strains of bacteria as well as fungus strains and we found a correlation between the observed and predicted antimicrobial activities. Docking studies were performed to investigate the hypothetical binding mode of the target compounds. This study provided a new molecular scaffold for the further development of anticancer as well as antimicrobial agents.     

新型三唑类化合物的合成及抗真菌活性

目的寻找广谱、高效、低毒的新一代三唑类抗真菌药物。方法根据靶酶活性位点的空间特征、各种力场和关键残基分布，设计并合成了21个1-(1,2,4-三唑-1H -1-基)-2-(2,4-二氟苯基)-3-(4-取代-1-哌嗪基)-2-丙醇类化合物，并测定了体外抑菌活性。结果体外抑菌测试结果表明，所有化合物对8种致病真菌均有一定程度的抗真菌活性，对深部真菌的活性明显优于浅部真菌。在哌嗪的各种取代基中，苯基和杂环取代的抗真菌活性明显优于苯甲酰基取代。结论有多个化合物的体外抗真菌活性明显高于氟康唑和特比萘芬，其中化合物VIII-1,4,5和IX-3具有广谱、高活性的优点，值得进一步研究。     

Synthesis of some novel quinoline-3-carboxylic acids and pyrimidoquinoline derivatives as potential antimicrobial agents

The synthesis and in vitro antimicrobial evaluation of several quinoline and pyrimidoquinoline derivatives are described. Treatment of 7-substituted quinolin-2(1H)-one-3-carboxylic acids 2a-c with phosphoryl chloride or thionyl chloride gave rise to the 7-substituted 2-chloroquinoline-3-carboxylic acids 3a-c and 7-substituted 2-chloro-3-chlorocarbonylquinolines 5a-c respectively. The 2-chloro function in compounds 3a-c was replaced by 2-aminothiazole or 2-aminopyridine to give 2-(thiazol-2-yl)aminoquinoline-3-carboxylic acids 4a-c or 2-(pyrid-2-yl)aminoquinoline-3-carboxylic acids 4d-f. Treatment of 5a-c with the same heterocyclic amines at room temperature furnished the corresponding 7-substituted 2-chloro-3-heteryl-aminocarbonylquinolines 6a-f. The tetracyclic 9-substituted thiazolo[3', 2':1, 2]-pyrimido[4, 5-b]quinolin-5-ones 7a-c and 10-substituted pyrido[1', 2':1, 2]-pyrimido[4, 5-b]quinolin-6-ones 7d-f were synthesized by heating 5a-c with the heterocyclic amines in toluene or by heating 6a-f under reflux in dimethylformamide. The products were evaluated in vitro for potential antimicrobial activity.     

Synthesis and characterization of flurbiprofen hydrazide derivatives as potential anti-HCV, anticancer and antimicrobial agents

A novel series of new flurbiprofen hydrazide derivatives 2-(2-fluorobiphenyl-4-yl)-N′-[(substituted phenyl/5-nitro-2-furyl)methylene]propanehydrazide (3a–k), 2-(2-fluorobiphenyl-4-yl)-N-(2-substituted-4-oxo-1,3-thiazolidine-3-yl)propanamide (4a–b, 4d–k), 2-[2-(2-fluorobiphenyl-4-yl) propanoyl]-N-substituted hydrazinecarbothioamide (5a–h) and 2-(2-fluorobiphenyl-4-yl)-N′-[(3-methyl-4-oxo-1,3-thiazolidin-2-ylidene]propanehydrazide (6a–b, 6e and 6g) has been synthesized in this study. All synthesized compounds were screened for antimicrobial activity against various bacterial and fungal strains. Additionally, compounds were evaluated for the ability to inhibit Hepatitis C virus NS5B polymerase. The most active 4-thiazolidinone compound was 4k (SGK119) with 67.0 % and thiosemicarbazide compound was 5d (SGK123) with 69.50 % inhibition at 200 μM against hepatitis C virus NS5B RNA polymerase. Anticancer activity of the selected compounds (3i, 3j, 3h, 4d, 4i and 6b) was determined at a single dose towards the full panel of 60 human cancer cell lines by the National Cancer Institute (NCI). 2-(2-Fluoro-4-biphenylyl)-N-[2-[4-(trifluoromethyl)phenyl]-4-oxo-1,3-thiazolidine-3-yl]propanamide 4d, containing thiazolidinone ring, demonstrated the most marked effect with 20.80 % growth percent on leukaemia cancer cell line SR at 10^?5 M. The results demonstrated that none of the compounds tested have anticandidal and antifungal activities, but two of them (4a and 4i) showed antibacterial inhibition against Micrococcus luteus, and Staphylococcus cohnii and Staphylococcus aureus, respectively.     

Synthesis and biological screening of some novel 6-substituted 2-alkylpyridazin-3(2H)-ones as anti-inflammatory and analgesic agents

Some novel derivatives of 2-alkyl 6-substituted pyridazin-3(2H)-ones were synthesized by condensation of 3,6-dichloropyridazine with the sodium salt of benzyl cyanide, followed by hydrolysis and coupling with alkyl halides. The synthesized compounds were screened as cyclooxygenase (COX)-1/COX-2 inhibitors and as analgesic and anti-inflammatory agents. Among the synthesized compounds, 6-benzyl-2-methylpyridazin-3(2H)-one ( 4a ), 6-benzoyl-2-propylpyridazin-3(2H)-one ( 8b ), and 6-(hydroxy(phenyl)methyl)-2-methylpyridazin-3(2H)-one ( 9a ) displayed the highest COX-2 selectivity indices of 96, 99, and 98, respectively, and analgesic efficacies of 47%, 46%, and 45% protection, respectively. Also, compounds 4a , 8b , and 9a showed anti-inflammatory activities of 65%, 60%, and 62% inhibition of edema, respectively, at a dose of 10 mg/kg, which is higher than that of diclofenac (58% inhibition of edema).     

Design,synthesis, and evaluation of novel 2-substituted 1,4-benzenediol library as antimicrobial agents against clinically relevant pathogens

Development of new antimicrobial agents, capable of combating resistant and multidrug-resistant fungal and bacterial clinical strains, is necessary. This study presents the synthesis and antimicrobial screening of 42 2-substituted-1,4-benzenediols, being 10 novel compounds. In total, 23 compounds showed activity against fungi and/or bacteria. Benzenediol compounds 2, 5, 6, 8, 11, and 12 demonstrated broad spectrum antimicrobial actions, including resistant and multidrug-resistant species of dermatophytes (Trichophyton mentagrophytes), Candida spp. and the ESKAPE panel of bacteria. Minimum inhibitory concentrations of these compounds for fungi and bacterial strains ranged from 25 to 50 µg/ml and 8–128 µg/ml, respectively. The antifungal mechanism of action is related to the fungal cell wall of dermatophytes and membrane disruption to dermatophytes and yeasts, in the presence of compound 8. Specific structural changes, such as widespread thinning along the hyphae and yeast lysis, were observed by scanning electron microscopy. The effects of compound 8 on cell viability are dose-dependent; however they did not cause genotoxicity and mutagenicity in human leukocyte cells nor haemolysis. Moreover, the compounds were identified as nonirritant by the ex-vivo Hen’s egg test-chorioallantoic membrane (HET-CAM). The furan-1,4-benzenediol compound 5 showed in vivo efficacy to combat S. aureus infection using embryonated chicken eggs. Therefore, the compounds 8, and 5 are promising as hits for the development of new antimicrobial drugs with reduced toxicity.