Synthesis, antifungal and cytotoxic activities of 2-aryl-3-((piperidin-1-yl)ethyl)thiazolidinones

Catalytic One-pot Solvent Free Synthesis, Biological Activity, and Docking Study of New Series of 1, 3-thiazolidine-4-one Derivatives Derived from 2- (P-tolyl) Benzoxazol-5-amine

OBJECTIVE

In this study, a simple triethylammonium salt of phosphoric acid (triethylammonium dihydrogen phosphate) (4) in the liquid state was utilized as an inexpensive, efficient one-pot three components, solvent-free synthesis of thiazolidine-4-one derivatives, with good to excellent yields. Techniques such as FT-IR, 1H-NMR, 13C-NMR, 13C-NMR-DEPT-135, and MS. were used for the structural elucidation. The high biotic efficiency of the newly obtained compounds was confirmed by in vitro antimicrobial action against Gram-positive (S. Aureus), Gram-negative bacteria (P. Aeruginosa and E. Coli) and antifungal activity (C. Albicans) via microplate titer dilution technique. Finally, a molecular docking study was performed with a resolved crystal structure of S. Aureus D-alanine alanyl carrier protein ligase (PDB ID: 7VHV). This investigation aimed to synthesize a new series of thiazolidine-4-one derivatives combined with benzoxazole moiety.

MATERIAL AND METHODS

Ionic liquid assistance one-pot solvent-free synthesis method used to synthesize a new series of thiazolidine-4-one derivative 10(a-e).

RESULTS

Structural identification of new synthesis and biological evaluation via techniques of (IR, 1H-NMR, 13C-NMR, 13C-NMR-DEPT-135, and MS).

CONCLUSION

Ionic liquid is utilized as an inexpensive, efficient one-pot three-component solvent-free synthesis of thiazolidine-4-one derivatives with good to excellent yields. Most of the synthesized compounds showed high biological and anti-fungal activity, in line with the docking study against mentioned microorganism and crystal structure of PDB (ID: 7VHV), respectively.

Cytotoxic effect, enzyme inhibition, and in silico studies of some novel N-substituted sulfonyl amides incorporating 1,3,4-oxadiazol structural motif

Abstract

The acetylcholinesterase and carbonic anhydrase inhibitors (AChEIs and hCAIs) remain key therapeutic agents for many bioactivities such as anti-Alzheimer and antiobesity antiepileptic, anticancer, antiinfective, antiglaucoma, and diuretic effects. Here, it has been attempted to discover novel multi-target AChEIs and hCAIs that are highly potent, orally bioavailable, may be brain penetrant, and have higher effectiveness at lower doses than tacrine and acetazolamide. After detailed investigations both in vitro and in silico, novel N-substituted sulfonyl amide derivatives (6a–j) were determined to be highly potent inhibitors for AChE and hCAs (K_Is are in the range of 23.11–52.49 nM, 18.66–59.62 nM, and 9.33–120.80 nM for AChE, hCA I, and hCA II, respectively). Moreover, according to the cytotoxic effect studies, such as the ADME-Tox, cortex neuron cells, and neuroblastoma SH-SY5Y cell line, compounds 6a, 6d, and 6h, which are the most potent representative versus the target enzymes, were identified as orally bioavailable, highly selective, and brain preferentially distributed AChEIs and hCAIs. The docking studies revealed precise binding modes between 6a, 6d, and 6h and hCA II, hCA I, and AChE, respectively. The results presented here might provide a solid basis for further investigation into more potent AChEIs and hCAIs.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s11030-022-10422-8.

Novel Thiazole-Based Thiazolidinones as Potent Anti-infective Agents: In silico PASS and Toxicity Prediction, Synthesis, Biological Evaluation and Molecular Modelling

AIMS AND OBJECTIVE

The infectious disease treatment remains a challenging concern owing to the increasing number of pathogenic microorganisms associated with resistance to multiple drugs. A promising approach for combating microbial infection is to combine two or more known bioactive heterocyclic pharmacophores in one molecular platform. Herein, the synthesis and biological evaluation of novel thiazole-thiazolidinone hybrids as potential antimicrobial agents were dissimilated.

MATERIALS AND METHODS

The preparation of the substituted 5-benzylidene-2-thiazolyimino-4- thiazolidinones was achieved in three steps from 2-amino-5-methylthiazoline. All the compounds have been screened in PASS antibacterial activity prediction and in a panel of bacteria and fungi strains. Minimum inhibitory concentration and minimum bacterial concentration were both determined by microdilution assays. Molecular modeling was conducted using Accelrys Discovery Studio 4.0 client. ToxPredict (OPEN TOX) and ProTox were used to estimate the toxicity of the title compounds.

RESULTS

PASS prediction revealed the potentiality antibacterial property of the designed thiazolethiazolidinone hybrids. All tested compounds were found to kill and to inhibit the growth of a vast variety of bacteria and fungi, and were more potent than the commercial drugs, streptomycin, ampicillin, bifomazole and ketoconazole. Further, in silico study was carried out for prospective molecular target identification and revealed favorable interaction with the target enzymes E. coli MurB and CYP51B of Aspergillus fumigatus. Toxicity prediction revealed that none of the active compounds was found toxic.

CONCLUSION

Substituted 5-benzylidene-2-thiazolyimino-4-thiazolidinones, endowing remarkable antibacterial and antifungal properties, were identified as a novel class of antimicrobial agents and may find a potential therapeutic use to eradicate infectious diseases.

Design and synthesis of novel 4-thiazolidinone derivatives with promising anti-breast cancer activity: Synthesis, characterization, in vitro and in vivo results

Novel lead compounds as anticancer agents with the ability to circumvent emerging drug resistance have recently gained a great deal of interest. Thiazolidinones are among such compounds with well-established biological activity in the field of oncology. Here, we designed, synthesized and characterized a series of thiazolidinone structures (8a-8k). The results of anti-proliferative assay led to the discovery of compound 8j with a high potent cytotoxic effect using colon, liver and breast cancer cells. Furthermore, MDA-MB-231 and 4T1 cell lines were used to represent triple negative breast cancer (TNBC). Next, a number of in vitro and in vivo evaluations were carried out to demonstrate the potential activity against TNBC and also elucidate the possible mechanism of cell death induction. Our in vitro outcomes exhibited an impressive anticancer activity for compound 8j toward MDA-MB-231 cells through inducing apoptosis and a remarkable anti-metastatic feature via suppressing MMP-9 expression as well. Consistently, the in vivo and immunohistopathologic evaluations demonstrated that this compound significantly inhibited the 4T1 induced tumor growth and its metastasis to the lung. Altogether, among numerous thiazolidinone derivatives, compound 8j might represent a promising anticancer agent for TNBC, which is a major concern in the developed and developing countries.

Saturated Five-Membered Thiazolidines and Their Derivatives: From Synthesis to Biological Applications

In past decades, interdisciplinary research has been of great interest for scholars. Thiazolidine motifs behave as a bridge between organic synthesis and medicinal chemistry and compel researchers to explore new drug candidates. Thiazolidine motifs are very intriguing heterocyclic five-membered moieties present in diverse natural and bioactive compounds having sulfur at the first position and nitrogen at the third position. The presence of sulfur enhances their pharmacological properties, and, therefore, they are used as vehicles in the synthesis of valuable organic combinations. They show varied biological properties viz. anticancer, anticonvulsant, antimicrobial, anti-inflammatory, neuroprotective, antioxidant activity and so on. This diversity in the biological response makes it a highly prized moiety. Based on literature studies, various synthetic approaches like multicomponent reaction, click reaction, nano-catalysis and green chemistry have been employed to improve their selectivity, purity, product yield and pharmacokinetic activity. In this review article, we have summarized systematic approaches for the synthesis of thiazolidine and its derivatives, along with their pharmacological activity, including advantages of green synthesis, atom economy, cleaner reaction profile and catalyst recovery which will help scientists to probe and stimulate the study of these scaffolds.

2-(2-Methoxyphenyl)-3-((Piperidin-1-yl)ethyl)thiazolidin-4-One-Loaded Polymeric Nanocapsules: In Vitro Antiglioma Activity and In Vivo Toxicity Evaluation

Among gliomas types, glioblastoma is considered the most malignant and the worst form of primary brain tumor. It is characterized by high infiltration rate and great angiogenic capacity. The presence of an inflammatory microenvironment contributes to chemo/radioresistance, resulting in poor prognosis for patients. Recent data show that thiazolidinones have a wide range of pharmacological properties, including anti-inflammatory and antiglioma activities. Nanocapsules of biodegradable polymers become an alternative to cancer treatment since they provide targeted drug delivery and could overcome blood-brain barrier. Therefore, here we investigated the in vitro antiglioma activity and the potential in vivo toxicity of 2- (2-methoxyphenyl) -3- ((piperidin-1-yl) ethyl) thiazolidin-4-one-loaded polymeric nanocapsules (4L-N). Nanocapsules were prepared and characterized in terms of particle size, polydispersity index, zeta potential, pH, molecule content and encapsulation efficiency. Treatment with 4L-N selectively decreased human U138MG and rat C6 cell lines viability and proliferation, being even more efficient than the free-form molecule (4L). In addition, 4L-N did not promote toxicity to primary astrocytes. We further demonstrated that the treatment with sub-therapeutic dose of 4L-N did not alter weight, neither resulted in mortality, toxicity or peripheral damage to Wistar rats. Finally, 4L as well as 4L-N did not alter makers of oxidative damage, such as TBARS levels and total sulfhydryl content, and did not change antioxidant enzymes SOD and CAT activity in liver and brain of treated rats. Taken together, these data indicate that the nanoencapsulation of 4L has potentiated its antiglioma effect and does not cause in vivo toxicity.

Synthesis and evaluation of steroidal thiazoline conjugates as potential antiviral agents

Aim: Many heterocyclic compounds derived from natural steroids exhibited broad activities, so this work focused on the investigations on a series of steroidal thiazoline conjugates as antiviral agents. Materials & methods: A series of steroid derivatives containing thiazoline heterocycles were designed and synthesized via a convenient condensation procedure. The compounds were screened for their potential antivirus activities against Enterovirus 71 (EV71) and Coxsackie Virus Type B (CVB3). Results and Conclusion: The in vitro bioassay indicated that compounds 5b, 5g and 5i exhibited excellent antiviral effects on EV71, and compounds 5b, 5e, 6c and 6g presented better antiviral activities against CVB3 compared with the controls ribavirin or pirodavir. These results indicate that these steroidal thiazoline conjugates might be feasible therapeutic candidates against EV71 infection, which might also be considered as promising compounds for optimization of potential antivirus agents.

Novel thiazolidinone-containing compounds, without the well-known sulphonamide zinc-binding group acting as human carbonic anhydrase IX inhibitors

A small collection of 26 structurally novel thiazolidinone-containing compounds, without the well-known sulphonamide zinc-binding group, were synthesised and tested in enzyme inhibition assays against the tumour-associated hCA IX enzyme. Inhibition constants in the lower micromolar region (K_I < 25 μM) have been measured for 17 of the 26 compounds. Even though the K_I values are relatively weak, the fact that they do not contain a sulphonamide moiety suggests that these compounds do not interact with the active site zinc ion. Therefore, docking studies and molecular dynamics simulations have been performed to suggest binding poses for these structurally novel inhibitors.

Thiazoles and Thiazolidinones as COX/LOX Inhibitors

Inflammation is a natural process that is connected to various conditions and disorders such as arthritis, psoriasis, cancer, infections, asthma, etc. Based on the fact that cyclooxygenase isoenzymes (COX-1, COX-2) are responsible for the production of prostaglandins that play an important role in inflammation, traditional treatment approaches include administration of non-steroidal anti-inflammatory drugs (NSAIDs), which act as selective or non-selective COX inhibitors. Almost all of them present a number of unwanted, often serious, side effects as a consequence of interference with the arachidonic acid cascade. In search for new drugs to avoid side effects, while maintaining high potency over inflammation, scientists turned their interest to the synthesis of dual COX/LOX inhibitors, which could provide numerous therapeutic advantages in terms of anti-inflammatory activity, improved gastric protection and safer cardiovascular profile compared to conventional NSAIDs. Τhiazole and thiazolidinone moieties can be found in numerous biologically active compounds of natural origin, as well as synthetic molecules that possess a wide range of pharmacological activities. This review focuses on the biological activity of several thiazole and thiazolidinone derivatives as COX-1/COX-2 and LOX inhibitors.

Primaquine-thiazolidinones block malaria transmission and development of the liver exoerythrocytic forms

Background

Primaquine is an anti-malarial used to prevent Plasmodium vivax relapses and malaria transmission. However, PQ metabolites cause haemolysis in patients deficient in the enzyme glucose-6-phosphate dehydrogenase (G6PD). Fifteen PQ-thiazolidinone derivatives, synthesized through one-post reactions from primaquine, arenealdehydes and mercaptoacetic acid, were evaluated in parallel in several biological assays, including ability to block malaria transmission to mosquitoes.

Results

All primaquine derivatives (PQ-TZs) exhibited lower cell toxicity than primaquine; none caused haemolysis to normal or G6PD-deficient human erythrocytes in vitro. Sera from mice pretreated with the test compounds thus assumed to have drug metabolites, caused no in vitro haemolysis of human erythrocytes, whereas sera from mice pretreated with primaquine did cause haemolysis. The ability of the PQ-TZs to block malaria transmission was evaluated based on the oocyst production and percentage of mosquitoes infected after a blood meal in drug pre-treated animals with experimental malaria caused by either Plasmodium gallinaceum or Plasmodium berghei; four and five PQ-TZs significantly inhibited sporogony in avian and in rodent malaria, respectively. Selected PQ-TZs were tested for their inhibitory activity on P. berghei liver stage development, in mice and in vitro, one compound (4m) caused a 3-day delay in the malaria pre-patent period.

Conclusions

The compound 4m was the most promising, blocking malaria transmissions and reducing the number of exoerythrocytic forms of P. berghei (EEFs) in hepatoma cells in vitro and in mice in vivo. The same compound also caused a 3-day delay in the malaria pre-patent period.

Electronic supplementary material

The online version of this article (doi:10.1186/s12936-017-1755-6) contains supplementary material, which is available to authorized users.

Synthetic 2-aryl-3-((piperidin-1-yl)ethyl)thiazolidin-4-ones exhibit selective in vitro antitumoral activity and inhibit cancer cell growth in a preclinical model of glioblastoma multiforme

Glioblastoma multiforme (GBM) is the worst form of primary brain tumor, which has a high rate of infiltration and resistance to radiation and chemotherapy, resulting in poor prognosis for patients. Recent studies show that thiazolidinones have a wide range of pharmacological properties including antimicrobial, anti-inflammatory, anti-oxidant and anti-tumor. Here, we investigate the effect antiglioma in vitro of a panel of sixteen synthetic 2-aryl-3-((piperidin-1-yl)ethyl)thiazolidin-4-ones where 13 of these decreased the viability of glioma cells 30-65% (100 μM) compared with controls. The most promising compounds such as 4d, 4l, 4m and 4p promoted glioma reduction of viability greater than 50%, were further tested at lower concentrations (12.5, 25, 50 and 100 μM). Also, the data showed that the compounds 4d, 4l, 4m and 4p induced cell death primarily through necrosis and late apoptosis mechanisms. Interestingly, none of these 2-aryl-3-((piperidin-1-yl)ethyl)thiazolidin-4-ones were cytotoxic for primary astrocytes, which were used as a non-transformed cell model, indicating selectivity. Our results also show that the treatment with sub-therapeutic doses of 2-aryl-3-((piperidin-1-yl)ethyl)thiazolidin-4-ones (4d, 4l and 4p) reduced in vivo glioma growth as well as malignant characteristics of implanted tumors such as intratumoral hemorrhage and peripheral pseudopalisading. Importantly, 2-aryl-3-((piperidin-1-yl)ethyl)thiazolidin-4-ones treatment did not induce mortality or peripheral damage to animals. Finally, 2-aryl-3-((piperidin-1-yl)ethyl)thiazolidin-4-ones also changed the nitric oxide metabolism which may be associated with reduced growth and malignity characteristics of gliomas. These data indicates for the first time the therapeutic potential of synthetic 2-aryl-3-((piperidin-1-yl)ethyl)thiazolidin-4-ones to GBM treatment.

Thiazolidin-4-ones from 4-(methylthio)benzaldehyde and 4-(methylsulfonyl)benzaldehyde: Synthesis, antiglioma activity and cytotoxicity

The present study assessed the biological potential of fourteen 1,3-thiazolidin-4-ones evaluating the antiglioma effect through decreasing of cell viability of glioblastoma multiform cells. The new compounds were efficient synthesized through multicomponent or multicomponent one-pot procedures in moderate to good yields (22-86%) from two arenealdehydes (4-(methylthio)benzaldehyde and 4-(methylsulfonyl)benzaldehyde), seven amines (aromatic and aliphatic) and mercaptoacetic acid. The compounds were identified and characterized by GC/MS and NMR, five of them by HRMS. Six thiazolidinones showed significant effect of decreasing cell viability compared to standard drug TMZ at 100 μM in 72 h in C6 cell line by MTT assay. The compounds 5b, 5e, 5g and 6e showed the best results in the screening at 100 μM and were analyzed at different concentrations (5, 25, 50, 100 and 250 μM). Compounds 5b and 5e showed statistical difference at 5 μM, 6e at 25 μM and 5g at 50 μM in 72 h of treatment. The cytotoxicity study in primary astrocytes cells was evaluated and none of fourteen compounds showed toxicity at 100 μM, eight of them were not cytotoxic at 250 μM, both in 72 h. In addition, the propidium iodide assay demonstrated that the compounds might induce cell death by necrosis. In conclusion, this work reports at least four compounds (5b, 5e, 5g and 6e) with potential anti-tumor effect against glioblastoma multiform cell presenting activity at low concentrations and safe profile of cytotoxicity.

Synthesis and antifungal activity of dehydroabietic acid-based 1,3,4-thiadiazole-thiazolidinone compounds

In an attempt to search for new natural products-based antifungal agents, a series of novel dehydroabietic acid derivatives bearing a 1,3,4-thiadiazole-thiazolidinone moiety were designed and synthesized. The primary bioassay used showed that at a concentration of [Formula: see text], the target compounds 3c, 3f, and 3n exhibited excellent antifungal activity (91.3 % inhibition) against Gibberella zeae, which was equivalent to the commercial antifungal drug azoxystrobin (positive control).

2-Aryl-3-(2-morpholinoethyl)thiazolidin-4-ones: Synthesis, anti-inflammatory in vivo, cytotoxicity in vitro and molecular docking studies

Seven new 4-thiazolidinones bearing the morpholino moiety were easily synthesized by one-pot reactions of 4-(2-aminoethyl)morpholine (2-morpholinoethylamine), arenealdehydes and mercaptoacetic acid refluxing toluene for 19 h with moderate to good yields (45-97%). These novel compounds were fully identified and characterized by NMR spectroscopy and mass spectrometry. Thiazolidin-4-ones in vivo anti-inflammatory activities were determined using a croton oil-induced ear edema model of inflammation in BALB C mice. The best results were found for compounds 4c (49.20 mmol/kg), 4d (49.20 mmol/kg) and 4f (52.48 mmol/kg), which showed the ability to decrease the ear edema in mice by 50%, 48% and 54%, respectively, when compared to the standard drug indomethacin. In addition, the in vitro cytotoxicity activity of thiazolidin-4-ones against Vero cells was also performed and four compounds (4a, 4c, 4d and 4f) showed no toxic effect at 500 μg/mL. A docking simulation of compounds into the 1Q4G (COX-1) and 4PH9 (COX-2) enzymes binding site was conducted. This preliminary result will guide us in for further studies to improve the anti-inflammatory activity.

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.

Facile synthesis of new N-sulfonamidyl-4-thiazolidinone derivatives and their biological evaluation

A one-pot three-component facile synthesis of N-sulfonamidyl-4-thiazolidinone derivatives using a [HDBU][HSO₄] reusable ionic liquid was carried out, together with an investigation into their antifungal and antioxidant properties and a molecular docking study.

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.

Synthesis, X-ray, DFT and photophysical properties of some new ferrocenyl hydrazono thiazolidin-4-ones and their derivatives

Cyclocondensation of thiosemicarbazone of 2-acetylferrocene with α-haloacids and α-haloketones afford new ferrocenyl hydrazono thiazolidin-4-ones and ferrocenyl hydrazono thiazoles respectively. Ferrocenyl hydrazono thiazolidin-4-one is easily converted into enamino ketone with N,N-dimethylformamide dimethyl acetal (DMF-DMA). The compounds were characterized by spectroscopic means and the structure of the new ferrocenyl hydrazono thiazolidin-4-one (3a) was determined by means of X-ray crystallography. The photophysical properties of these compounds were studied by means of UV/visible absorption spectroscopy and fluorescence spectroscopy. Density functional theory (DFT) calculations have been carried out with Gaussian 09W using B3LYP density functional method and 6-31G (d) basis set. (1)H and (13)C Nuclear Magnetic Resonance (NMR) have been calculated and correlated with experimental results. Antimicrobial activity studies of some new compounds have been reported.

Crystal structure of (±)-3-[(benzo[d][1,3]dioxol-5-yl)meth-yl]-2-(3,4,5-tri-meth-oxy-phen-yl)-1,3-thia-zolidin-4-one

In the title thia-zolidine-4-one derivative, C20H21NO6S, the central thia-zolidine ring is essentially planar (r.m.s. deviation for all non-H atoms = 0.0287 Å) and forms a dihedral angle of 88.25 (5)° with the meth-oxy-substituted benzene ring and 74.21 (4)° with the 1,3-benzodioxole ring. The heterocyclic ring (with two O atoms) fused to benzene ring adopts an envelope conformation with the non-ring-junction C atom as the flap. In the crystal, the mol-ecules are linked into chains along [001] through weak C-H⋯O inter-actions, forming R (4) 4(28) edge-fused rings.

Design, synthesis, and biological activities of novel azole-bonded β-hydroxypropyl oxime O-ethers

The synthesis and biological effects of 15 novel azole-bonded β-hydroxypropyl oxime O-ethers have been described. In this synthesis, the oximation of aromatic ketones followed by an O-alkylation reaction with epichlorohydrin and/or epibromohydrin led to the corresponding O-oxime ether adducts. Subsequently, the attained O-oxime ether adducts were used to synthesize the target molecules after treating them with the appropriate azole derivatives. The in vitro antifungal and antibacterial activities of title compounds were obtained against several pathogenic fungi, Gram-positive and/or Gram-negative bacteria. Benzophenone O-2-hydroxy-3-(2-phenyl-1 H-imidazol-1-yl) propyl oxime and 9H-fluoren-9-one O-2-hydroxy-3-(2-phenyl-1 H-imidazol-1-yl)propyl oxime proved to have considerable antifungal activity against Candida albicans, Candida krusei, Aspergillus niger, and Trichophyton rubrum. These two compounds demonstrated comparable antifungal activity to clotrimazole and fluconazole (standard drugs). All compounds were also tested against Escherichia coli and Staphylococcus aureus as Gram-negative and Gram-positive bacteria, respectively, and their activities were compared to gentamycin and ampicillin (reference drugs). In general, marginal antibacterial activity against tested bacteria was observed for the title compounds. A molecular docking study is also discussed for the two most potent compounds against fungi. The docking study reveals a considerable interaction between the two most potent compounds and the active site of Mycobacterium P450DM. Moreover, these two compounds are much strongly bound to the active site of Mycobacterium P450DM compared to fluconazole.

Synthesis and antioxidant activity of 3-(Pyridin-2-ylmethyl)-1,3-thiazinan(thiazolidin)-4-ones

The antioxidant properties of two series of thiazolidinones and thiazinanones were reported. The novel six-membered thiazinanones were synthesized from the efficient multicomponent reaction of 2-picolylamine (2-aminomethylpyridine), arenaldehydes, and the 3-mercaptopropionic acid in moderate to excellent yields. These novel compounds were fully identified and characterized by NMR and GC-MS techniques. In vitro antioxidant activities of all compounds were evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) tests. The antioxidant assays of thiobarbituric acid reactive species and total thiol content levels in the cerebral cortex and liver of rats were also performed. Thiazinanone 5a showed the best radical scavenging activity in DPPH and ABTS tests, as well as reduced lipid peroxidation and increased total thiol group in biological systems. Altogether, the results may be considered a good starting point for the discovery of a new radical scavenger.