Metal chelators can be potentially employed in the treatment of various diseases, ranging from metal overload to neoplastic conditions. Some xanthene derivatives were previously reported to complex metals. Thus, in a search for a novel iron or copper chelator, a series of 9-(substituted phenyl)-2,6,7-trihydroxy-xanthene-3-ones was tested using a competitive spectrophotometric approach. The most promising compound was evaluated in biological models (breast adenocarcinoma cell lines and erythrocytes). In general, substitution of the benzene ring in position 9 had a relatively low effect on the chelation. Only the trifluoromethyl substitution resulted in stronger chelation, probably via a positive effect on solvation. All compounds chelated iron, but their copper-chelating effect was only minimal, since it was no longer observed under highly competitive conditions. Interestingly, all compounds reduced both iron and copper. Additional experiments showed that the trifluoromethyl derivative protected erythrocytes and even cancer cells against excess copper. In summary, the tested compounds are iron chelators, which are also capable of reducing iron/copper, but the copper-reducing effect is not associated with increased copper toxicity.

Arylmethylenebis(3-hydroxy-5,5-dimethyl-2-cyclohexen-1-one) derivatives (aryl=2-hydroxynaphthyl ( 1 ) and 3,4-dihydroxyphenyl ( 2 ) have been synthesized and their structures have been elucidated. Both compounds were examined for their antioxidant, antimicrobial and cytotoxic activity. Antioxidative activities of synthesized compounds were evaluated by 2,2-diphenyl-1-picryl-hydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) methods. The microbial screening was performed by diffusion method on bacterial strains Staphylococcus aureus , Enterococcus faecalis , Bacillus subtilis and Candida albicans . Cytotoxic activity was tested on liver hepatocellular carcinoma cell line (Hep G2) by Neutral red assay. Compared to compound 2 , compound 1 showed better antimicrobial and antifungal activity, while compound 2 showed better antioxidant activity with IC 50 of 0.0156 mM and FRAP value 50469.44 µmol/l Fe 2+ . Both compounds showed cytotoxic activity. Obtained results implicate the importance of arylmethylenebis(3-hydroxy-5,5-dimethyl-2-cyclohexen-1-on) derivatives as a potential antioxidant, antimicrobial and cytotoxic agents.

Introduction: Hyperuricemia is an independent risk factor for the development of many diseases. Aim: The aim of this paper is to compare the effects of allopurinol and febuxostat on the values of triglycerides and uric acid in hyperuricemic patients. Methods: This was a pharmacological-clinical retrospective-prospective study. The research sample comprised 50 examinees of both genders and different ages who were undergoing allopurinol (100 mg/day) or febuxostat (80 mg/day) therapy. Statistical Product and Service Solutions (SPSS) Software and Microsoft Excel were used for statistical analysis. Results: Examinees who were treated with allopurinol had a statistically significant decrease in uric acid concentrations (by 126.28 ± 20.36 μmol/l) at the end of the observation compared to the initial values (p = 0.006). Examinees who were treated with febuxostat had a statistically significant decrease in uric acid concentrations (by 252.80 ± 94.17 μmol/l) at the end of the observation compared to the initial values (p = 0.001). The initial value of triglycerides was 1.58 ± 0.64 mmol/l in allopurinol-treated examinees, and 1.60 ± 0.52 mmol/l in febuxostat-treated examinees. After three and six months of allopurinol use, there was a statistically significant increase in triglyceride values (p = 0.046 and p = 0.042, respectively). A statistically significant decrease in triglyceride values (by 0.16 ± 0.10 mmol/l) was noted after three months of febuxostat use (p = 0.012). Conclusion: The results of this research confirmed the previous findings and pointed out the positive pharmacological effects of allopurinol and febuxostat.

Abstract Twelve previously synthesized, biologically active 2,6,7-trihydroxyxanthen-3-one derivatives were evaluated in vitro for antiproliferative activity. Compounds were screened against HeLa, SW620, HepG2 and A549 tumor cell lines. Compound with the trifluormethyl group on C-4’ position of the phenyl ring showed the best inhibitory activity towards HeLa and A549 tumor cells with IC50 of 0.7 and 4.1 µmol L−1, resp. Compound with chlorine and fluorine substituents on aryl ring showed the best antiproliferative activity against SW620 with IC50 of 4.1 µmol L–1 and against HepG2 tumor cell line with IC50 of 4.2 µmol L–1. Analyses of cytotoxic and genotoxic potential of the trifluormethyl derivative were performed with cytokinesis-block micronucleus cytome assay in human lymphocyte culture and revealed no genotoxic and cytotoxic effects. The most potent compounds were subjected to molecular docking simulations in order to analyse bindings to molecular targets and, at the same time, further support the results of experimental cytotoxic tests. Docking studies showed sites of importance in forming hydrogen bonds of the most potent compounds with targets of interest.

In the present study, we investigated the antiproliferative activity of essential oil from leaves of Melissa officinalis L. grown in Southern Bosnia and Herzegovina. In vitro evaluation of antiproliferative activity of the M. officinalis essential oil was carried out on three human tumor cell lines: MCF-7, NCI-H460 and MOLT-4 by MTT assay. M. officinalis essential oil was characterized by high percentage of monoterpenes (77,5%), followed by the sesquiterpene fraction (14,5%) and aliphatic compounds (2,2%). The main constituents of the essential oil of M. officinalis are citral (47,2%), caryophyllene oxide (10,2%), citronellal (5,4%), geraniol (6,6%), geranyl acetate (4,1%) and βcaryophyllene (3,8%). The essential oil showed significant antiproliferative activity against three cancer cell lines, MOLT-4, MCF-7, and NCI-H460 cells, with GI50 values of <5, 6±2 and 31±17 μg/mL, respectively. The results revealed that M. officinalis L. essential oil has a potential as anticancer therapeutic agent.

Ten biologically active 2,2,5,5-tetramethyl-9-aryl-3,4,5,6,7,9-hexahydro-1H-xanthene-1,8(2H)-dione derivatives were synthesized and their structures were confirmed by IR, 1H and 13C NMR spectroscopy and mass spectrometry. Synthesized compounds were scanned for their antioxidant, antimicrobial and antiproliferative activity. Antibacterial activity was tested by the diffusion and dilution method against Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa, while antifungal activity was tested against Candida albicans and Saccharomyces cerevisiae. Antiproliferative activity was tested against HeLa (cervical carcinoma), SW620 (colorectal adenocarcinoma, metastatic), hepatocellular carcinoma (HEpG2), lung carcinoma cells (A549) and mouse embryo fibroblast cell line (3T3). The best antioxidant activity showed compound 2 with two hydroxy groups substituted on phenyl ring in positions 2' and 3'. The best antimicrobial activity of all synthesized compounds showed compound 8, while the best antiproliferative activity showed compound 6. Results signify the importance of xanthene-1,8-dione derivatives as potential antioxidant and antiproliferative agents.

BACKGROUND Currently, used oral antiplatelet drugs are both limited and associated with the risk of treatment failure/resistance. Research in this area is hence highly desired. A series of xanthene-3-ones derivatives, we had synthesized, showed us that these derivatives had antiplatelet activity. As far as we know, no research on the effects of xanthen-3-ones in this area has been done. OBJECTIVE The aim was to study the antiplatelet potential of a series of synthesised 9-phenylxanthene- 3-ones and to find the ideal structural feature(s) for antiplatelet potential and determine the mechanism of action. METHODS The compounds were synthesized from 1,2,4-triacetoxybenzene and various benzaldehydes. The reaction proceeded smoothly under acidic alcoholic conditions, furnishing the desired products in good yields. The compounds were first screened in whole human blood where platelet aggregation was induced by arachidonic acid. Further analysis was targeted at search of the mechanism of action. RESULTS Initial screening showed that a majority of the synthesized derivatives had substantial antiplatelet potential. None of the compounds were able to block cyclooxygenase 1 or thromboxane synthase. The mechanism appeared to be based on antagonism of thromboxane effects. The most potent compound 9-(4'-dimethylaminophenyl)-2,6,7-trihydroxy-xanthene-3-one had better potential to block collagen induced platelet aggregation than clinically used acetylsalicylic acid. CONCLUSION The last mentioned derivative is promising for further in vivo testing.