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.

Introduction: We studied the chemical composition and antimicrobial, antioxidant, and antiproliferative activities of essential oils from flowers of Lavandula angustifolia grown in Southern Bosnia and Herzegovina. Methods: The chemical profile of essential oil was evaluated by means of gas chromatography-mass spectrometry. Antimicrobial activity was tested against six bacterial strains. The antioxidant activity by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) test and the antiproliferative activity against three human cancer cell lines, MCF-7, NCI-H460, and MOLT-4, were investigated using 3-(4,5-dimethylthiazol-2-Yl)-2,5-diphenyltetrazolium bromide tests. Results: In L. angustifolia essential oil, monoterpene alcohols were the most represented class of volatiles (51.8%), including linalool, lavandulol, and terpinen-4-ol, α-terpineol as the major components, followed by monoterpene esters (22.6%). The most important antibacterial activity of essential oil was expressed on Gram-negative strains. Investigated essential oil was able to reduce DPPH radicals into the neutral DPPH-H form (inhibitory concentration 50% [IC50] = 0.421 mg/ml), and this activity was dose dependent. The essential oil showed significant antiproliferative activity against three cancer cell lines, MOLT-4, MCF-7, and NCI-H460 cells, with IC50 values of 17, 94, and 97 µg/ml, respectively. The result of the antiproliferative assay indicates that MOLT-4 cell line was the most sensitive to investigated essential oil. Conclusion: The results revealed that L. angustifolia essential oil may be important growth inhibitor against the microbes studied. It also possesses significant antioxidant activity and demonstrated excellent antiproliferative activity against MOLT-4 cells.

Ten 9-aryl substituted hydroxylated xanthen-3-ones, including three new compounds (III) are synthesized using a reliable one-pot synthesis.

Oxidative stress is directly related to several diseases and symptoms, where antioxidant compounds, such as xanthenes, may become important in prevention and/or treatmant. Ten biologically active 9-aryl substituted 2, 6, 7-trihydroxyxanthen-3-one derivatives were synthesized using reliable one-pot synthesis and their structures were confirmed by IR, 1H and 13C NMR spectroscopy and mass spectrometry. Some of the synthesized compounds were scanned for their antioxidant potency using electrochemical method cyclic voltammetry of immobilized microparticles. Substitution of hydrogen at the phenyl ring of 2, 6, 7-trihydroxy-9-phenylxanthen-3-one with an electron-donating group affected the reducing power of the compounds by lowering the biological oxidation potential. These results signify the importance of xanthen-3-one derivatives as antioxidant agents and their further biological evaluation.

Platelet hyperactivity and platelet interaction with endothelial cells contribute to the development and progression of many cardiovascular diseases such as atherosclerosis and thrombosis. The impact of platelet activity with different pharmacological agents, such as acetylsalicylic acid and coumarin derivatives, has been shown to be effective in the prevention of cardiovascular disease. Artemisia dracunculus, L. Asteraceae (Tarragon) is used for centuries in the daily diet in many Middle Eastern countries, and it is well known for its anticoagulant activity. The present study investigates the presence of coumarins in tarragon leaves and subsequently determines the extract with a major amount of coumarin derivatives. The solvents of different polarities and different pH values were used for the purpose of purifying the primary extract in order to obtain fractions with the highest coumarin content. Those extracts and fractions were investigated for their anticoagulant activity by determining prothrombin time (PT) and the international normalized ratio (INR), expressed in relation to the coagulation time of the healthy person. Purified extracts and fractions obtained from plant residue after essential oil distillation, concentrated in coumarin derivatives, showed the best anticoagulant activity, using samples of human blood. INR maximum value (2.34) and consequently the best anticoagulant activity showed the methanol extract at concentration of 5%.  The INR value of normal plasma in testing this extract was 1.05.