Synthesis, anti-Candida activity, and cytotoxicity of new (4-(4-iodophenyl)thiazol-2-yl)hydrazine derivatives

Synthesis and Antimicrobial Activity of Novel Hydrazone and 1,2,4-Triazole-3-thione Derivatives

Abstract

Novel hydrazone and 1,2,4-triazole-3-thione derivatives were obtained via the reaction of N1,N3,2-triaryl-6-hydroxy-6-methyl-4-oxocyclohexane-1,3-dicarboxamides with acid hydrazides and thiosemicarbazide, respectively. Structure of the products was proved using IR and 1H NMR spectroscopy methods. Some of the synthesized compounds were tested for antimicrobial activity

Synthesis, electrochemical, optical and biological properties of new carbazole derivatives

Carbazole skeleton is the key structural motif of many biologically active compounds including synthetic and natural products. Based on the (E)-2-(2-(4-9H-carbazol-9-yl)benzylidene) hydrazinyl)thiazole as skeleton, three novel carbazole dyes were synthesized. The scientific analysis includes the effect of changing the strength of the activating substituents and their exchange for the deactivating substituent on the chemical and biological properties. The presented research showed a significant influence of the CH₃, OCH₃ and CH₂COOC₂H₅ groups on the spectral properties of the tested derivatives. Their significant influence is also visible in electrochemical, nonlinear-optic and biological properties. The study also included the analysis of the use of the presented derivatives as potential fluorescent probes for in vivo and in vitro tests. Quantum-chemical calculations complement the conducted experiments.

Synthetic Derivatives against Wild-Type and Non-Wild-Type Sporothrix brasiliensis: In Vitro and In Silico Analyses

Recently, the well-known geographically wide distribution of sporotrichosis in Brazil, combined with the difficulties of effective domestic feline treatment, has emphasized the pressing need for new therapeutic alternatives. This work considers a range of synthetic derivatives as potential antifungals against Sporothrix brasiliensis isolated from cats from the hyperendemic Brazilian region. Six S. brasiliensis isolates from the sporotrichotic lesions of itraconazole responsive or non-responsive domestic cats were studied. The minimum inhibitory concentrations (MICs) of three novel hydrazone derivatives and eleven novel quinone derivatives were determined using the broth microdilution method (M38-A2). In silico tests were also used to predict the pharmacological profile and toxicity parameters of these synthetic derivatives. MICs and MFCs ranged from 1 to >128 µg/mL. The ADMET computational analysis failed to detect toxicity while a good pharmacological predictive profile, with parameters similar to itraconazole, was obtained. Three hydrazone derivatives were particularly promising candidates as antifungal agents against itraconazole-resistant S. brasiliensis from the Brazilian hyperendemic region. Since sporotrichosis is a neglected zoonosis currently spreading in Latin America, particularly in Brazil, the present data can contribute to its future control by alternative antifungal drug design against S. brasiliensis, the most virulent and prevalent species of the hyperendemic context.

Synthesis and Physicochemical Characterization of Novel Dicyclopropyl-Thiazole Compounds as Nontoxic and Promising Antifungals

There is a need to search for new antifungals, especially for the treatment of the invasive Candida infections, caused mainly by C. albicans. These infections are steadily increasing at an alarming rate, mostly among immunocompromised patients. The newly synthesized compounds (3a-3k) were characterized by physicochemical parameters and investigated for antimicrobial activity using the microdilution broth method to estimate minimal inhibitory concentration (MIC). Additionally, their antibiofilm activity and mode of action together with the effect on the membrane permeability in C. albicans were investigated. Biofilm biomass and its metabolic activity were quantitatively measured using crystal violet (CV) staining and tetrazolium salt (XTT) reduction assay. The cytotoxic effect on normal human lung fibroblasts and haemolytic effect were also evaluated. The results showed differential activity of the compounds against yeasts (MIC = 0.24-500 µg/mL) and bacteria (MIC = 125-1000 µg/mL). Most compounds possessed strong antifungal activity (MIC = 0.24-7.81 µg/mL). The compounds 3b, 3c and 3e, showed no inhibitory (at 1/2 × MIC) and eradication (at 8 × MIC) effect on C. albicans biofilm. Only slight decrease in the biofilm metabolic activity was observed for compound 3b. Moreover, the studied compounds increased the permeability of the membrane/cell wall of C. albicans and their mode of action may be related to action within the fungal cell wall structure and/or within the cell membrane. It is worth noting that the compounds had no cytotoxicity effect on pulmonary fibroblasts and erythrocytes at concentrations showing anticandidal activity. The present studies in vitro confirm that these derivatives appear to be a very promising group of antifungals for further preclinical studies.

Effect of the Chloro-Substitution on Electrochemical and Optical Properties of New Carbazole Dyes

Carbazole derivatives are the structural key of many biologically active substances, including naturally occurring and synthetic ones. Three novel (E)-2-(2-(4-9H-carbazol-9-yl)benzylidene)hydrazinyl)triazole dyes were synthesized with different numbers of chlorine substituents attached at different locations. The presented research has shown the influence of the number and position of attachment of chlorine substituents on electrochemical, optical, nonlinear, and biological properties. The study also included the analysis of the use of the presented derivatives as potential fluorescent probes for in vivo and in vitro tests. Quantum-chemical calculations complement the conducted experiments.

Design and Efficient Synthesis of Novel 4,5-Dimethylthiazole-Hydrazone Derivatives and their Anticancer Activity

Background::

Recently, researchers have been warning about the increased mortality of the various cancer types. Also, the lung adenocarcinoma and the glioma types are burning issues for world's health due to late or wrong diagnosis and/or insufficient treatment methods. For this purpose, our research group designed and synthesized novel 4,5-dimethyl thiazole-hydrazone derivatives which were tested against cancer and normal cell lines to understand the structureactivity relationship (SAR).

Method::

The lead compounds were obtained by reacting 2-(substituted aryl-2-ylmethylene) hydrazin-1-carbothioamide with 3-chloro-2-butanone derivatives. The structural elucidation of the compounds was performed by 1H-NMR, 13C-NMR, and LC/MS-IT-TOF spectral and elemental analyses. The synthesized compounds were tested in vitro for the anticancer activity against A549 human lung adenocarcinoma and C6 rat glioma cells and investigated for which pathway to induce cell death. Also, the docking study of the active compounds was achieved to understand the SAR.

Result and Discussion::

The targeted compounds (2a-2l) were synthesized successfully above 70% yields, and the analysis findings proved their purity. In general, the results of activity studies displayed significant effects against at least one cell line, except compounds 2e (indol-3-yl) and 2h (4-dimethylaminophenyl). Furthermore, compounds 2b and 2f displayed potential anticancer activity. With the help of molecular docking study, a potential selectivity of compound 2f was observed for type II protein kinase. On the other hand, compound 2b interacted with the active site nearly the same as Dasatinib. Therefore, these two compounds could be used as a base on developing selective anticancer drugs.

Conclusion::

Pyridin-2-yl (2b) derivative was found to be a favorable molecule with high anticancer potency against C6 and A549 cell lines. Additionally, 1-naphthyl (2f) derivative was a worthy compound for potential selectivity. In future studies, it will be our priority to focus on developing derivatives of these two compounds (2b and 2f) and elucidate their mechanisms.

Design, synthesis, fungicidal activities and structure-activity relationship studies of (-)-borneol derivatives containing 2-aryl-thiazole scaffold

A series of (-)-borneol derivatives containing 2-aryl-thiazole scaffold were designed, synthesized, and characterized by ¹H NMR, ¹³C NMR, and HRMS. The fungicidal activities of these novel compounds against Fusarium oxysporum, Magnaporthe grisea, Botrytis cinerea, and Penicillium digitatum were evaluated. The results indicated that (1S,2R,4S)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-yl(Z)-4-oxo-4-(((2-phenylthiazol-4-yl)methyl)amino)but-2-enoate (6a) displayed potential fungicidal activities with broad spectrum. Especially, 6a exhibited an IC₅₀ value of 48.5 mg/L against P. digitatum, which has higher fungicidal activity than commercial products hymexazol and amicarthiazol. Moreover, (1S,2R,4S)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-yl-4-oxo-4-(((2-phenylthiazol-4-yl)methyl)amino)butanoate (5a) possesses an IC₅₀ value of 24.3 mg/L against B. cinerea, comparable to hymexazol and far superior to amicarthiazol. Furthermore, the superficial structure-activity relationship was discussed, which might be helpful for discovering novel fungicides.

Synthesis, antimicrobial activity, and determination of the lipophilicity of ((cyclohex-3-enylmethylene)hydrazinyl)thiazole derivatives

Synthesis and investigation of antimicrobial activity of fifteen novel thiazoles containing cyclohexene moiety are presented. Among the derivatives, compounds 3a–3d, 3f, 3n, and 3o showed very strong activity against the reference Candida spp. strains with MIC = 0.015–3.91 µg/ml. The activity of these compounds is similar and even higher than the activity of nystatin used as positive control. Compounds 3d, 3f, 3n, 3o showed the highest activity with very strong effect towards most of yeasts isolated from clinical materials with MIC = 0.015–7.81 µg/ml. The cytotoxicity studies for the most active compounds showed that Candida spp. growth was inhibited at noncytotoxic concentrations for the mammalian L929 fibroblast. In addition, a good correlation was obtained between lipophilicity of compounds determined using reversed phase thin-layer chromatography and their antifungal activity.

A Novel Series of Acylhydrazones as Potential Anti-Candida Agents: Design, Synthesis, Biological Evaluation and In Silico Studies

In the context of an increased incidence of invasive fungal diseases, there is an imperative need of new antifungal drugs with improved activity and safety profiles. A novel series of acylhydrazones bearing a 1,4-phenylene-bisthiazole scaffold was designed based on an analysis of structures known to possess anti-Candida activity obtained from a literature review. Nine final compounds were synthesized and evaluated in vitro for their inhibitory activity against various strains of Candida spp. The anti-Candida activity assay revealed that some of the new compounds are as active as fluconazole against most of the tested strains. A molecular docking study was conducted in order to evaluate the binding poses towards lanosterol 14α-demethylase. An in silico ADMET analysis showed that the compounds possess drug-like properties and represent a biologically active framework that should be further optimized as potential hits.

Analysis of imidazoles and triazoles in biological samples after MicroExtraction by packed sorbent

This paper reports the MEPS-HPLC-DAD method for the simultaneous determination of 12 azole drugs (bifonazole, butoconazole, clotrimazole, econazole, itraconazole, ketoconazole, miconazole, posaconazole, ravuconazole, terconazole, tioconazole and voriconazole) administered to treat different systemic and topical fungal infections, in biological samples. Azole drugs separation was performed in 36 min. The analytical method was validated in the ranges as follows: 0.02–5 μg mL⁻¹ for ravuconazole; 0.2–5 μg mL⁻¹ for terconazole; 0.05–5 μg mL⁻¹ for the other compounds. Human plasma and urine were used as biological samples during the analysis, while benzyl-4-hydroxybenzoate was used as an internal standard. The precision (RSD%) and trueness (Bias%) values fulfill with International Guidelines requirements. To the best of our knowledge, this is the first HPLC-DAD procedure coupled to MEPS, which provides the simultaneous analysis of 12 azole drugs, available in the market, in human plasma and urine. Moreover, the method was successfully applied for the quantitative determination of two model drugs (itraconazole and miconazole) after oral administration in real samples.

Synthesis, biological evaluation and quantitative structure-active relationships of 1,3-thiazolidin-4-one derivatives. A promising chemical scaffold endowed with high antifungal potency and low cytotoxicity

With reference to recent studies reporting on the various biological properties of the thiazolidinone scaffold, we synthesized more than a hundred compounds characterized by a 1,3-thiazolidin-4-one nucleus derivatised at the C2 with a hydrazine bridge linked to (cyclo)aliphatic or hetero(aryl) moieties, and their N-benzylated derivatives. These molecules were assayed as potential anti-Candida agents and they were shown to possess comparable, and in some cases higher biological activity than well-established topical and systemic antimycotic drugs (i.e. clotrimazole, fluconazole, ketoconazole, miconazole, tioconazole, amphotericin B). Compounds endowed with the lowest MICs underwent further testing in order to assess their cytotoxic effect (CC₅₀) on Hep2 cells, which demonstrated their relative safety. Finally, QSAR and 3-D QSAR models were used to predict putative chemical modifications of the 1,3-thiazolidin-4-one scaffold in order to design new and potential more active compounds against Candida spp.

Synthesis, antimicrobial and anticonvulsant screening of small library of tetrahydro-2H-thiopyran-4-yl based thiazoles and selenazoles

Synthesis and investigation of antimicrobial activity of 22 novel thiazoles and selenazoles derived from dihydro-2H-thiopyran-4(3H)-one are presented. Additionally, anticonvulsant activity of six derivatives is examinated. Among the derivatives, compounds 4a-f, 4i, 4k, 4 l, 4n, 4o-s and 4v have very strong activity against Candida spp. with MIC = 1.95-15.62 μg/ml. In the case of compounds 4a-f, 4i, 4k, 4 l, 4n, 4o, 4r and 4s, the activity is very strong against some strains of Candida spp. isolated from clinical materials, with MIC = 0.98 to 15.62 μg/ml. Additionally, compounds 4n-v are found to be active against Gram-positive bacteria with MIC = 7.81-62.5 μg/ml. The results of anticonvulsant screening reveal that compounds 4a, 4b, 4m and 4n demonstrate a statistically significant anticonvulsant activity in the pentylenetetrazole model, whereas compounds 4a and 4n showed protection in 6-Hz psychomotor seizure model. Noteworthy, none of these compounds impaired animals' motor skills in the rotarod test. We also performed quantum chemical calculation of interaction and binding energies in complex of 4a with cyclodextrin.

Antimicrobial activity, synergism and inhibition of germ tube formation by Crocus sativus-derived compounds against Candida spp

The limited arsenal of synthetic antifungal agents and the emergence of resistant Candida strains have prompted the researchers towards the investigation of naturally occurring compounds or their semisynthetic derivatives in order to propose new innovative hit compounds or new antifungal combinations endowed with reduced toxicity. We explored the anti-Candida effects, for the first time, of two bioactive compounds from Crocus sativus stigmas, namely crocin 1 and safranal, and some semisynthetic derivatives of safranal obtaining promising biological results in terms of minimum inhibitory concentration/minimum fungicidal concentration (MIC/MFC) values, synergism and reduction in the germ tube formation. Safranal and its thiosemicarbazone derivative 5 were shown to display good activity against Candida spp.

Novel 1,3-thiazolidin-4-one derivatives as promising anti-Candida agents endowed with anti-oxidant and chelating properties

Pursuing our recent outcomes regarding the antifungal activity of N-substituted 1,3-thiazolidin-4-ones, we synthesized thirty-six new derivatives introducing aliphatic, cycloaliphatic and heteroaromatic moieties at N1-hydrazine connected with C2 position of the thiazolidinone nucleus and functionalizing the lactam nitrogen with differently substituted (NO2, NH2, Cl and F) benzyl groups. These compounds were tested to evaluate their minimum inhibitory concentration (MIC) against several clinical Candida spp. with respect to topical and systemic reference drugs (clotrimazole, fluconazole, ketoconazole, miconazole, tioconazole, amphotericin B). Moreover, anti-oxidant properties were also evaluated by using different protocols including free radical scavenging (DPPH and ABTS), reducing power (CUPRAC and FRAP), metal chelating and phosphomolybdenum assays. Moreover, for the most active derivatives we assessed the toxicity (CC50) against Hep2 human cells in order to characterize them as multi-target agents for fungal infections.

Anti-Candida activity and cytotoxicity of a large library of new N-substituted-1,3-thiazolidin-4-one derivatives

On the basis of the recent findings about the biological properties of thiazolidinones and taking into account the encouraging results about the antifungal activity of some (thiazol-2-yl)hydrazines, new N-substituted heterocyclic derivatives were designed combining the thiazolidinone nucleus with the hydrazonic portion. In details, 1,3-thiazolidin-4-ones bearing (cyclo)aliphatic or (hetero)aromatic moieties linked to the N1-hydrazine at C2 were synthesized and classified into three series according to the aromatic or bicyclic rings connected to the lactam nitrogen of the thiazolidinone. These molecules were assayed for their anti-Candida effects in reference to the biological activity of the conventional topic (clotrimazole, miconazole, tioconazole) and systemic drugs (fluconazole, ketoconazole, amphotericin B). Finally, we investigated the selectivity against fungal cells by testing the compounds endowed with the best MICs on Hep2 cells in order to assess their cell toxicity (CC50) and we noticed that two derivatives were less cytotoxic than the reference drug clotrimazole. Moreover, a preliminary molecular modelling approach has been performed against lanosterol 14-α demethylase (CYP51A1) to rationalize the activity of the tested compounds and to specify the target protein or enzyme.

New Hydrazones Bearing Thiazole Scaffold: Synthesis, Characterization, Antimicrobial, and Antioxidant Investigation

New series of hydrazones 5–18 were synthesized, in good yields, by reacting 4-methyl-2-(4-(trifluoromethyl)phenyl)thiazole-5-carbohydrazide with differently substituted benzaldehyde. The resulting compounds were characterized via elemental analysis, physico-chemical and spectral data. An antimicrobial screening was done, using Gram (+), Gram (−) bacteria and one fungal strain. Tested molecules displayed moderate-to-good growth inhibition activity. 2,2-Diphenyl-1-picrylhydrazide assay was used to test the antioxidant properties of the compounds. Monohydroxy (14–16), para-fluorine (13) and 2,4-dichlorine (17) derivatives exhibited better free-radical scavenging ability than the other investigated molecules.

Identification of a New Class of Antifungals Targeting the Synthesis of Fungal Sphingolipids

Recent estimates suggest that >300 million people are afflicted by serious fungal infections worldwide. Current antifungal drugs are static and toxic and/or have a narrow spectrum of activity. Thus, there is an urgent need for the development of new antifungal drugs. The fungal sphingolipid glucosylceramide (GlcCer) is critical in promoting virulence of a variety of human-pathogenic fungi. In this study, we screened a synthetic drug library for compounds that target the synthesis of fungal, but not mammalian, GlcCer and found two compounds [N'-(3-bromo-4-hydroxybenzylidene)-2-methylbenzohydrazide (BHBM) and its derivative, 3-bromo-N'-(3-bromo-4-hydroxybenzylidene) benzohydrazide (D0)] that were highly effective in vitro and in vivo against several pathogenic fungi. BHBM and D0 were well tolerated in animals and are highly synergistic or additive to current antifungals. BHBM and D0 significantly affected fungal cell morphology and resulted in the accumulation of intracellular vesicles. Deep-sequencing analysis of drug-resistant mutants revealed that four protein products, encoded by genes APL5, COS111, MKK1, and STE2, which are involved in vesicular transport and cell cycle progression, are targeted by BHBM.

IMPORTANCE

Fungal infections are a significant cause of morbidity and mortality worldwide. Current antifungal drugs suffer from various drawbacks, including toxicity, drug resistance, and narrow spectrum of activity. In this study, we have demonstrated that pharmaceutical inhibition of fungal glucosylceramide presents a new opportunity to treat cryptococcosis and various other fungal infections. In addition to being effective against pathogenic fungi, the compounds discovered in this study were well tolerated by animals and additive to current antifungals. These findings suggest that these drugs might pave the way for the development of a new class of antifungals.

Design, synthesis and antibacterial potential of 5-(benzo[d][1,3]dioxol-5-yl)-3-tert-butyl-1-substituted-4,5-dihydropyrazoles

A series of 5-(benzo[d][1,3]dioxol-5-yl)-3-tert-butyl-1-substituted-4,5-dihydropyrazole derivatives 4a-e and 6a-g have been synthesized and spectrally characterized. The antibacterial activity of the novel candidates has been screened using the agar diffusion test. These compounds were endowed with high antibacterial activity against different Gram +ve and Gram -ve bacteria when compared with standard antibacterial drugs. In the light of zone of inhibition and MIC results, Sarcina and Staphylococcus aureus are the most sensitive bacteria where pyrrolidinomethanone derivative 4e showed MICs at 80 and 110 nM, respectively. While hydroxypiperidinoethanone derivative 6c showed MIC at 90 nM for Sarcina.

A review exploring biological activities of hydrazones

The development of novel compounds, hydrazones has shown that they possess a wide variety of biological activities viz. antimicrobial, anticonvulsant, antidepressant, anti-inflammatory, analgesic, antiplatelet, antimalarial, anticancer, antifungal, antitubercular, antiviral, cardio protective etc., Hydrazones/azomethines/imines possess-NHN = CH- and constitute an important class of compounds for new drug development. A number of researchers have synthesized and evaluated the biological activities of hydrazones. This review aims at highlighting the diverse biological activities of hydrazones.

Synthesis of New [1,2,4]Triazolo[3,4-b][1,3,4]thiadiazines and Study of Their Anti-Candidaland Cytotoxic Activities

New triazolothiadiazine derivatives5a–hwere synthesized from 4-amino-3-(4-pyridyl)-5-mercapto-4H-1,2,4-triazole (3) with substituted aryl hydrazonoyl chlorides4a–h. The compounds were testedin vitroagainst elevenCandidaspecies and compared with standard drug ketoconazole. Among these compounds, the compounds bearingp-chlorophenyl5e,p-methoxyphenyl5c, phenyl5a,andp-sulphonamidophenyl5gsubstituents on triazolothiadiazine system were found to be the most effective derivatives againstCandidaspecies. Compound5ewas the most effective compound againstC. parapsilosis(ATCC 22019),C. albicans(ATCC 66027),C.specie [blood] 12810, andC.specie [urine] 300 with MIC value of 6.25 μg/mL, whereas ketoconazole exhibits the inhibitory activity with MIC value of 3–30 μg/mL against all tested strains. It was clear that there is a positive correlation between anti-Candidalactivity andp-chlorophenyl substitution on triazolothiadiazine ring. All the synthesized compounds were also investigated for their potential cytotoxicity on noncancer cell line (MCF-12) using WST-1 assay. Three compounds5d,5a,and5hwere found to have the same IC50value as that of standard drug ketoconazole against noncancer cell line MCF-12 (IC50≥ 1.0 × 105 μg/mL).

Synthesis and anti-Candida activity of novel 2-hydrazino-1,3-thiazole derivatives

Eighteen new hydrazino-1,3-thiazole derivatives were evaluated against 8 strains of multi-resistant Candida spp. Introduction of an indolyl moiety linked to the hydrazone function enhanced the in vitro anti-Candida activity, with an activity spectrum towards Candida albicans strains. Introduction of a (S)-2-aminoethyl chain on the thiazole nucleus largely enhanced the in vitro antifungal activity, with a selectivity oriented towards non-C. albicans species.