Thiazolidinedione or Rhodanine: A Study on Synthesis and Anticancer Activity Comparison of Novel Thiazole Derivatives.

PURPOSE: A new series of thiazolyl-2,4-thiazolidinedione / rhodanine compounds T1-T23 was synthesized and tested for their anticancer activities. Hepatocellular carcinoma cell lines were chosen due to their strong drug resistance to test the new compounds. METHODS: All compounds were synthesized via Knoevenagel Condensation reaction and thiazolidinedione ester compounds (T3,T9,T15,T20) were hydrolyzed for obtaining the acidic compounds (T6,T12,T17,T23). All compounds were firstly screened for their anticancer activity against two hepatocellular carcinoma (HCC) cell lines, Huh7 and Plc/Prf/5 (Plc) cell lines by sulforhodamine B assay. Further IC50 values were calculated for three candidates (T4, T15, T21) in five different HCC (Huh7, Plc, Snu449, HepG2, Hep3B) and one breast cancer (Mcf7) cell line. RESULTS: Compounds T4, T15, T21 had very strong anticancer effects even though their 10 µM concentration in Huh7 cell line. According to IC50 values, T21 was the most effective compound with IC50 values in a range from 2 to 16 µM in 6 cancer cell lines. In terms of cytotoxicity T21 mostly affected Huh7 and interestingly it was less effective against Plc. CONCLUSIONS: Considering these results it can be suggested that compounds T4, T15 and T21 may lead to the development of more potent anticancer drugs in the future. This article is open to POST-PUBLICATION REVIEW. Registered readers (see "For Readers") may comment by clicking on ABSTRACT on the issue's contents page.

Studies on the antioxidant activity of some chromonylrhodanine derivatives.

Fifteen chromonylrhodamine derivatives (CRs) were synthesized and the antioxidant activity levels were evaluated for the first time. The antioxidant activity potencies of these chromone derivatives were evaluated towards superoxide anion radicals, hydroxyl radicals and 2,2-diphenyl-1-picrylhydrazyl radicals. Also, the total antioxidant capacity of the tested compounds was measured using the ferric-ferrozine assay. The antioxidant activities were investigated using a chemiluminescence (CL) assay, spectrophotometry measurements, direct electron paramagnetic resonance (EPR) and the EPR spin-trapping technique. The 5,5-dimethyl- 1-pyrroline-1-oxide (DMPO) was applied as spin trap. Eleven of the 15 chromone compounds exhibited a decrease in the CL accompanying the superoxide anion radical produced in anhydrous dimethylsulfoxide (DMSO), ranging from 71-94% at concentration of 1 mmol /L; four of these compounds enhanced light emission in the range 231-672%. Similarly, these compounds caused 28-58% inhibition in the intensity of the DMPO-OOH radical EPR signal and the DMPO-OH radical (from 12-48%). Furthermore, three of these compounds showed very good antioxidant response towards the DPPH radical (EC50 : 0.51-0.56 µmol/L) and the high reduction potentials. These findings demonstrate that the chromone compounds tested may be considered as effective free radicals scavengers, a finding that is of great pharmacological importance.

Studies on the antioxidant activity of some thiazolidinedione, imidazolidinedione and rhodanine derivatives having a flavone core.

A series of flavonyl-2,4-thiazolidinedione, imidazolidinedione and rhodanine derivatives were tested for their antioxidant activity as scavengers of oxygen free radicals. Free radical scavenging activities, including superoxide anion radical O2•, hydroxyl radical (HO(•)) and 2,2'-diphenyl-1-picrylhydrazyl free radical have been evaluated using chemiluminescence, electron paramagnetic resonance and spin trapping with 5,5-dimethyl-1-pyrroline-1-oxide as a spin trap. Potassium superoxide in dimethylsulfoxide and 18-crown-6 ether were used for the production of O2•. Hydroxyl radical was generated using the Fenton reaction. Ten of the eleven examined compounds exhibited decrease in chemiluminescence, but there were large differences in the decrease, ranging from 16% to 89%; also, two of these compounds increased light emission by about 200%. On the contrary, all compounds tested exhibited 30-68% scavenging HO(•) and 25-96% scavenging the DPPH(•) radical respectively. Possible mechanisms are proposed to explain the results.

Studies on the antioxidant activities of some new chromone compounds.

Recent reviews evidence that the naturally occurring compounds containing the chromone skeleton exhibit antiradical activities, providing protection against oxidative stress. The antioxidant activities of 13 new synthesized chromonyl-2,4-thiazolidinediones, chromonyl-2,4-imidazolidinediones and chromonyl-2-thioxoimidzolidine-4-ones were evaluated using in vitro antioxidant assays, including superoxide anion radical (O2(-•)), hydroxyl radical (HO(•)), 2,2-diphenyl-1-picryl-hydrazyl free radical (DPPH(•)) scavenging capacity and total antioxidant capacity ferric ion reducing activity. Superoxide anion radical was produced using potassium superoxide/18-crown-6-ether dissolved in dimethylsulfoxide, and the Fenton-like reaction (Fe(II) + H2O2) was a generator of hydroxyl radicals. Chemiluminescence, spectrophotometry, electron paramagnetic resonance (EPR) and 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) as the spin trap were the measurement techniques. The results showed that the majority of the chromone derivatives tested showed a strong scavenging effect towards free radicals, similar to the chemiluminescence reaction with superoxide anion radical with a high activity, inhibition of the DMPO-OOH radical EPR signal (24-58%), the DMPO-OH radical EPR signal (4-75%) and DPPH radical EPR signal (6-100%) at 1 mmol/L. Several of the examined compounds exhibited the high reduction potentials. The results obtained show that the new synthesized chromone derivatives may directly scavenger reactive oxygen species and thus may play a protective role against oxidative damage.

6-Methyl 3-chromonyl 2,4-thiazolidinedione/2,4-imidazolidinedione/2-thioxo-imidazolidine-4-one compounds: novel scavengers of reactive oxygen species.

The benefits of antioxidants on human health are usually ascribed to their potential ability to remove reactive oxygen species providing protection against oxidative stress. In this paper the free radicals scavenging activities of nine 6-methyl 3-chromonyl derivatives (CMs) were evaluated for the first time by the chemiluminescence, electron paramagnetic resonance, spin trapping and 2,2-diphenyl-1-picrylhydrazyl (DPPH(•)) methods. The total antioxidant capacity was also measured using a ferric-ferrozine reagent. Compounds having a hydrogen atom at the N3-position of the ß-ring were effective in quenching CL resulted from the KO2 /18-crown-6-ether system (a source of superoxide anion radical, O2•¯) in a dose-dependent manner over the range of 0.05-1 mmol/L [IC50 ranged from 0.353 (0.04) to 0.668 (0.05) mmol/L]. The examined compounds exhibited a significant scavenging effect towards hydroxyl radicals (HO(•) HO(•)), produced by the Fenton reaction, and this ranged from 24.0% to 61.0%, at the concentration of 2.5 mmol/L. Furthermore, the compounds examined were also found to inhibit DPPH(•) and this ranged from 51.9% to 97.4% at the same concentration. In addition, the use of the total antioxidant capacity assay confirmed that CM compounds are able to act as reductants. According to the present study, CM compounds showed effective in vitro free radical scavenging activity and may be considered as potential therapeutics to control diseases of oxidative stress-related etiology.

Antioxidant activities of some new chromonyl-2,4-thiazolidinediones and chromonyl-2,4-imidazolidinediones having chromone cores.

The antioxidant properties of 11 new synthesized chromonyl-2,4-thiazolidinediones and chromonyl-2,4-imidazolidinediones (CBs) were investigated. The antioxidant activities and mechanisms of the CBs interaction with reactive oxygen species (ROS) were clarified using various in vitro antioxidant assay methods including superoxide anion radical (O2(•-)), hydroxyl radical (HO(•)), 1,1-diphenyl-2-picryl-hydrazyl free radical (DPPH(•)) scavenging activity and the iron (II)-ferrozine complex formation. The potassium superoxide/18-crown-6 ether dissolved in dimethylsulfoxide (DMSO) was applied as a source of superoxide anion radical. Hydroxyl radicals were produced in the Fenton-like reaction Fe(II)+H2O2. Chemiluminescence, spectrophotometry, and electron paramagnetic resonance (EPR) spectroscopy using 5,5-dimethyl-1-pyrroline-1-oxide (DMPO) as spin trap were applied as the measurement techniques. The CBs examined that exhibited good free radical scavenging activity also showed strong total antioxidant power capacity. Possible mechanisms of antioxidation are proposed to explain the differences in the experimental results between the chromone derivatives with imidazolidine-2,4-dione ring and those with thiazolidine-2,4-dione ring. In conclusion, some of the new CBs are promising to be applied as inhibitors of free radicals.

Free radical scavenging activity of novel thiazolidine-2,4-dione derivatives.

Free radical activity towards superoxide anion radical (O2•¯), hydroxyl radical (HO(•)) and 2,2-diphenyl-1-picrylhydrazyl (DPPH(•)) of a series of novel thiazolidine-2,4-dione derivatives (TSs) was examined using chemiluminescence, electron paramagnetic resonance (EPR) and EPR spin trapping techniques. 5,5-Dimethyl-1-pyrroline-N-oxide (DMPO) was applied as the spin trap. Superoxide radical was produced in the potassium superoxide/18-crown-6 ether dissolved in dimethyl sulfoxide. Hydroxyl radical was generated in the Fenton reaction (Fe(II) + H2O2. It was found that TSs showed a slight scavenging effect (15-38% reduction at 2.5 mmol/L concentration) of the DPPH radical and a high scavenging effect of O2•¯ (41-88%). The tested compounds showed inhibition of HO(•)-dependent DMPO-OH spin adduct formation (the amplitude of EPR signal decrease ranged from 20 to 76% at 2.5 mmol/L concentration. Our findings present new group compounds of relatively high reactivity towards free radicals.

Synthesis and antidiabetic activity of some new chromonyl-2,4-thiazolidinediones.

A series of chromonyl-2,4-thiazolidinediones/imidazolidinediones/2-thioxo-imidazolidine-4-ones (IIIa-i, IVa-i) was prepared by Knoevenagel reaction of 2,4-thiazolidinedione/2,4-imidazolidinedione/2-thioxo-imidazolidine-4-one (IIa-c) with 2/3-formyl chromone (Ia-b) and then alkylation with methyl/ethyl iodide. The prepared compounds were tested for their insulinotropic activities in INS-1 cells. Compounds iVb and iVc (at lower concentration, 1 µg/mL) were able to increase insulin release in the presence of 5.6 mmol/L glucose." should be written as "Compounds IVb and IVc (at lower concentration, 1 µg/mL) and also IIId and IIIg (at higher concentration) were able to increase insulin release in the presence of 5.6 mmol/L glucose. Compounds iVb and iVc (at lower concentration, 1 µg/mL) were able to increase insulin release in the presence of 5.6 mmol/L glucose.

Scavenging capacities of some thiazolyl thiazolidine-2,4-dione compounds on superoxide radical, hydroxyl radical, and DPPH radical.

The scavenging effects of eighteen thiazolyl thiazolidine-2,4-dione compounds (TTCs) on superoxide radical ( (-) (*) ) (2), hydroxyl radical HO(*), and 1,1-diphenyl-2-picrylhydrazyl (DPPH(*)) radical were evaluated by the chemiluminescence technique, electron spin resonance spectrometry (ESR) and visible spectrophotometry, respectively. The examined compounds were shown to have 27-59% ( (-) (*) ) (2) scavenging ability, 19-69% HO(*) scavenging activity and 2-32% DPPH(*) scavenging ability. This property of the tested compound seems to be important in the prevention of various diseases of free radicals etiology.

Synthesis and antimicrobial activity of some novel thiazolidine-2,4-dione derivatives.

In this study, a series of phenylethylsulfanyl-1,3-thiazolo-thiazolidine-2,4-dione derivatives (VII a-f, VIII a-f) and 5-methyl-[1,2,4]triazolyl-sulfanyl-1,3-thiazolo-thiazolidine-2,4-dione derivatives (IX a-f, X a-f) were synthesized and evaluated for their antibacterial and antifungal activities against S. aureus (ATCC 25923), methicillin resistant S. aureus (MRSA ATCC 43300), B. subtilis (ATCC 6633), E. coli (ATCC 23556) and C. albicans (ATCC10145). All the compounds were found active against used bacteria.

Synthesis and antidiabetic activity of some new chromonyl-2,4-thiazolidinediones.

A series of chromonyl-2,4-thiazolidinediones (VIa-f) and chromonyl-2,4-imidazolidinediones (VIIa-f) was prepared by Knoevenagel reaction of substituted benzyl-2,4-thiazolidinediones (IVa-f) and substituted benzyl-2,4-imidazolidinediones (Va-f) with chromone-3-carboxaldehyde (I). The prepared compounds were tested for their insulinotropic activities in INS-1 cells. Compounds VIa, VIb, VId and VIIe (at lower concentration; 1 microg/ml) were able to increase insulin release in the presence of 5.6 mmol/l glucose; their effects were lower than that of glibenclamide (CAS 10238-21-8). The activity of the most potent compound (VId) was still 9% less than that of glibenclamide.

Synthesis and antidiabetic activity of novel 2,4-thiazolidinedione derivatives containing a thiazole ring.

A series of thiazolyl-2,4-thiazolidinediones (Ia-f, IIa-f and IIIa-f) was prepared by Knoevenagel reaction of substituted benzyl-2,4-thiazolidinediones (4a-f) with chlorothiazolecarbaldehydes (2, 3a-b). The prepared compounds were tested for their insulinotropic activities in INS-1 cells. A significant insulinotropic effect was seen with compounds If and IIa.

Synthesis and biological activity of some new flavone derivatives.

In this study, a new series of 2-(4-[substituted benzylamino-methyl)-phenyl]-4H-benzopyrane-4-one (IVa-e) and N-substituted benzyl-N-[4-(4-oxo-4H-benzopyrane-2-yl)benzyl]-3-phenyl-acrylamide (Va-e) derivatives was synthesized and the results of their biological activity are reported. The synthesized compounds were tested for their in vitro antifungal and antibacterial activities. Compound IVa showed the best antifungal activity compared with miconazole (CAS 22916-47-8). Compound IVe indicated the same antibacterial activity compared with the control drug ampicillin (CAS 69-53-4).