9-(4'-dimethylaminophenyl)-2,6,7-trihydroxy-xanthene-3-one is a potentially novel antiplatelet drug which antagonizes the effect of thromboxane A2

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

SYNTHESIS OF BISCOUMARIN DERIVATIVES AS ANTIMICROBIAL AGENTS

Objective: As a further part of our chemical and biological studies in this field, we describe the preparations of the properly substituted benzylidene-bis-(4-hydroxycoumarin) derivatives 5a-h and 3-(6-oxo-(1H)-benzopyrano[4,3-b]benzopyran-7-yl)-4-hydroxycoumarin derivatives 6a-e. Methods: The synthesized compounds were screened for their in vitro antimicrobial activity against five strains of bacteria and two fungal strains using disk diffusion assay and dilution method. The way in which the substituent group's physicochemical properties influence the antimicrobial activity is discussed in the paper. Results: The in vitro evaluation of their inhibitory properties towards five strains of Gram-positive and Gram-negative bacteria and two fungal strains indicated that the                                       4-trifluoromethylbenzylidene derivative of bis-(4-hydroxycoumarin) (compound 5c) and                    3-(6-oxo-(1H)-18-bromobenzopyrano[4,3-b]benzopyran-7-yl)-4-hydroxycoumarin derivative (compound 6b) possess the most potent antibacterial activities, with MIC of 3.9 μg/mL - 7.8 μg/mL against Gram-positive bacteria. Conclusion: The compound 6b has greater antibacterial activity than the standard chloramfenicol (inhibition zone 26 mm and MIC 1.9 μg/mL) against Staphyloccocus aureus and could be considered as leading compound in the future antimicrobial drug development.   Key words: Benzylidene-bis-(4-hydroxycoumarin), benzopyranocoumarin derivatives, antibacterial assays, antifungal activity

Anti-inflammatory potential of polyphenols: Combining in silico prediction and in vivo data

Introduction: Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by joint inflammation and destruction, leading to significant pain and disability. Adenosine deaminase (ADA) is identified as a biomarker for RA’s inflammatory process. This study aims to investigate the potential of flavonoids and phenolic acids to inhibit ADA activity (in silico) and evaluate their anti-inflammatory effects in a RA model (in vivo). Methods: The molecular docking study was conducted using YASARA Structure 19.12.14. software following the Auto Dock 4.2 protocol. A rat model with pristane-induced arthritis was used to test the anti-inflammatory effect of selected polyphenols. The consistency of the development of the rat model was evaluated through the following indicators artistic score, paw volume, and body weight. Quercetin was administered intragastrically at doses of 150 and 400 mg/kg over 15 days. The C-reactive protein (CRP) level in serum was measured with an automatic biochemical analyzer. Statistical analyses were performed using SPSS 29.0.2.0. Results: Molecular docking simulations showed flavonoids inhibited ADA activity with inhibition constants ranging from 0.012 mM to 0.190 mM. In the in vivo RA model, quercetin significantly reduced joint inflammation and serum CRP levels at a higher dose of 400 mg/kg. Conclusion: Quercetin shows promise as an anti-inflammatory agent for RA by targeting ADA, suggesting that flavonoid-rich plant extracts could enhance RA treatment

Interaction of 2,6,7-Trihydroxy-Xanthene-3-Ones with Iron and Copper, and Biological Effect of the Most Active Derivative on Breast Cancer Cells and Erythrocytes

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

Thin layer chromatography-application in qualitative analysis on presence of coumarins and flavonoids in plant material

Drugs, natural medicinal plant, animals and mineral materials, have a large and various application in official pharmacy and medicine. Carriers of multilateral pharmacological effects that those drugs shown, are chemically define as active components that are present in them. Methods of qualitative and quantitative analysis are used for the chemical investigation of components that drugs contain. Method of thin layer chromatography has been shown as very reliable. According to the chemical investigation of single drugs, it is possible to define a group of compound or single compound comparing them with standards. Relating to the usage of method of thin layer chromatography, it has been carried out investigation on presence of coumarinsand flavonoids in domestic plant material that have wide everyday usage. Coumarins and flavonoids from the point of view of chemical belonging are phenol derivatives with important pharmacological effects. Applying method of thin layerchromatography, it is detected presence of coumarins and flavonoids substances in plant material that has been tested. Anethi graveolens fructus et folium (fruit and leaf of dill), Anethum graveolens L., Apiaceae, Avenae sativae fructus (fruit of oats), Avena sativa L., Poaceae and Asperulae odoratae herba (sweet woodruff), Asperula odorata L., Rubiaceae. Chromatograms are developed in systems cyclohexane-ethylacetat (13:7) and toluene-ether (1:1) saturated with 10% acetic acid, and visualisation by observing on UV lamp (254 and 366 nm), spraying with reagents KOH (10% ethanol solution) and diphenylboryloxyethylamine (1% methanol solution)

Chemical composition, antimicrobial and antioxidant properties of Mentha longifolia (L.) Huds. essential oil

<strong>Introduction:</strong> Present study describes the antimicrobial activity and free radical scavenging capacity (RSC) of essential oil from Mentha longifolia (L.) Huds. Aim of this study to investigate the quality, antimicrobial and<br />antioxidant activity of wild species Mentha longifolia essential oil from Bosnia and Herzegovina.<br /><strong>Methods: </strong>The chemical profi le of essential oil was evaluated by the means of gas chromatography-mass spectrometry (GC-MS) and thin-layer chromatography (TLC). Antimicrobial activity was tested against 6<br />bacterial strains. RSC was assessed by measuring the scavenging activity of essential oils on 2,2- diphenyl-1-picrylhydrazil (DPPH).<br /><strong>Results:</strong> The main constituents of the essential oil of M. longifoliae folium were oxygenated monoterpenes,piperitone oxide (63.58%) and 1,8-cineole (12.03%). Essential oil exhibited very strong antibacterial activity.The most important antibacterial activity essential oil was expressed on Gram negative strains: Escherichia coli, Pseudomonas aerginosa and Salmonella enterica. subsp.enterica serotype ABONY. Antioxidant activity was evaluated as a RSC. Investigated essential oil was able to reduce DPPH radicals into the neutral DPPHH form (IC50=10.5 μg/ml) and this activity was dose –dependent.<br /><strong>Conclusion:</strong> The study revealed signifi cant antimicrobial activity of the investigated essential oil. The examined oil exhibited high RSC, which was found to be in correlation to the content of mainly monoterpene<br />ketones and aldehydes. These results indicate that essential oils could serve as safe antioxidant and antiseptic supplements in pharmaceuticals

Comparison of ARCHITECT chemiluminiscent microparticle immunoassay for determination of Troponin I in serum with AXYM MEIA technology

Introduction: The aim of this study was determination of troponin I at serum using Architect (Abbott) and AxSYM System (Abbott). Troponin is regulatory subunit of the troponin complex associate with actin filament within muscle cells and it is a marker for diagnosis of myocardial damage. Methods: We used Architect STAT chemiluminescent microparticle immunoassay (CMIA) and AxSYM microparticle Enzyme Immunoassay (MEIA), techniques for quantitative determination of cardiac TnI in human serum or plasma. At our study we have proved precision, reproducibility and accuracy from both methods. The investigation included patients (n=119) who have myocardial infarction or ischemic heart damage and were treated at cardiology, emergency, internal medicine and neurology unit in Clinical Center University in Sarajevo. Results: The precision for three controls using Architect STAT TnI asssay technology were 3.6 – 5.2 % and reproducibility was 3.7 to 5.6 %. The AxSYM STAT TnI has precision for three controls 4.3–6.6 % and reproducibility was from 4.8 to 7.8 %. We have got very good correlation between Architect and AxSYM technology r = 0.999 in the investigation of troponin I in serum. Conclusions: We can conclude that chemiluminescent troponin assay I (Architect) showed good analytical performance and gave new possibility at troponin I determination

Identification and Isolation of Pharmacologically Active Triterpenes in Betuale Cortex, Betula Pendula Roth., Betulaceae

Betulae cortex, Betulapendula Roth., Betulaceae, comprise triterpene substances which are confirmed to posses very important pharmacological activities such as anti-inflammatory, anticancer and antiviral. In this study, extraction of triterpene substances from both, inner and external birch bark was carried out and after that qualitative analysis on betulin, betulinic acid, oleanolic acid and lupeol was performed by method of thin layer chromatography. By this separation method, applying system for development benzene-ethyl acetate-formic acid (36:12:5), is gained a good separation of examined triterpene substances from methanol extracts of inner and external birch bark as well as used standards. From obtained row triterpene mixtures, certain triterpene substances are isolated using method of dry column chromatography. To those substances infrared (IR) spectra were recorded and compared with IR spectra of adequate standards. The study encloses all obtained IR spectra and interpretations on the basis of which can be concluded that triterpene substances, betulin, betulin acid and lupeol isolated from external birch bark give identical characteristic signals and absorbance as referent standards. Method of dry column chromatography has resulted as simple, efficient, repeatable and economical for laboratory conditions. Beside this, a sufficient quantity of examined triterpene substances is also obtained for continuation of their further analytical analysis

Identification and Isolation of Pharmacologically Active Triterpenes in Betuale Cortex, Betula Pendula Roth., Betulaceae

Betulae cortex, Betulapendula Roth., Betulaceae, comprise triterpene substances which are confirmed to posses very important pharmacological activities such as anti-inflammatory, anticancer and antiviral. In this study, extraction of triterpene substances from both, inner and external birch bark was carried out and after that qualitative analysis on betulin, betulinic acid, oleanolic acid and lupeol was performed by method of thin layer chromatography. By this separation method, applying system for development benzene-ethyl acetate-formic acid (36:12:5), is gained a good separation of examined triterpene substances from methanol extracts of inner and external birch bark as well as used standards. From obtained row triterpene mixtures, certain triterpene substances are isolated using method of dry column chromatography. To those substances infrared (IR) spectra were recorded and compared with IR spectra of adequate standards. The study encloses all obtained IR spectra and interpretations on the basis of which can be concluded that triterpene substances, betulin, betulin acid and lupeol isolated from external birch bark give identical characteristic signals and absorbance as referent standards. Method of dry column chromatography has resulted as simple, efficient, repeatable and economical for laboratory conditions. Beside this, a sufficient quantity of examined triterpene substances is also obtained for continuation of their further analytical analysis

The capacity of Lamiaceae essential oils, extracts and hydrolats against pathogenic biofilms

The study aimed to analyse the potential of Lamiaceae essential oils, extracts, and hydrolats against bacterial biofilms. Bacterial cells Pseudomonas aeruginosa, Staphylococcus aureus, and Bacillus cereus were exposed to Thymus vulgaris L. (thyme), Salvia officinalis L. (sage), Mentha × piperita L. (mint) essential oils, extracts, and hydrolats. The result of the minimal inhibitory concentration assessment shows the highest antibacterial potential for essential oils, followed by extracts and hydrolats respectively. The anti-biofouling capacity revealed that thyme essential oil has the highest potential for biofilm prevention for all tested bacteria, reducing up to 91% of biofilm, followed by mint (88%) and sage (87%) essential oil. While the thyme extract (84%), sage extract (83%) and hydrolat (77%) we less effective. The chemical composition of thyme essential oil showed a high percentage of monoterpene hydrocarbons and oxygenated monoterpenes, among which p-cymene and thymol were the most predominant. The bacterial cell membrane integrity assessment shows a significant increase in dead cells by increasing the concentration of thyme essential oil. The findings of our research indicate that the choice of herbal preparation significantly affects the active components, thereby influencing both antibacterial and anti-biofouling capabilities. Lamiaceae essential oils show great potential for biofilm management and represent a good candidate for antibacterial application in pharmacy, medicine, and industry