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The purposes of this study are the polymerization of temperature-sensitive copolymers based on N-isopropyl acrylamide and 10 mol % of 2-hydroxypropylmethacrylate, characterisations of their thermal, morphological and swelling properties, as well as the analysis of potential application in drug-delivery systems. Acetaminophen, the representative of non-steroidal anti-inflammatory drugs, was used as a model drug in this study. It is a common pain relief drug, which is also used for fever treatment. However, oral administration comes with certain health risks, mainly the overdose and frequent administration of up to four times a day. The goal of applying temperature-sensitive hydrogel is to enable extended administration once a day, depending on the body temperature. The swelling behavior of the obtained poly( N -isopropyl acrylamide- co -2-hydroxypropylmethacrylate) (p(NIPA/HPMA)) hydrogels and their temperature-sensitivity, kinetics and order of swelling processes at 18 and 38 °C were analyzed. The thermal properties of these hydrogels were observed by the DSC method, and the obtained thermograms showed both melting and glass transitions. The drug delivery system of p(NIPA/HPMA) hydrogels with loaded acetaminophen was analyzed using scanning electron microscopy and Fourier transform infrared spectroscopy methods. Structural analysis of FTIR spectra indicates that non-covalent intermolecular interactions of the type of hydrogen bonds were formed among functional groups of acetaminophen and side-chains of p(NIPA/HPMA) hydrogels. The surface structure of p(NIPA/HPMA) hydrogels after drug loading indicates the acetaminophen presence into the pores of the hydrogel network, and their loading efficiency was higher than 92%. Qualitative and quantitative analysis of acetaminophen, determined by the high-pressure liquid chromatography method, showed that about 90-99% of the loaded amount was released from p(NIPA/HPMA) hydrogels within 24 h. Kinetic parameters of the acetaminophen release under simulated gastrointestinal conditions were determined. Based on obtained results, the drug delivery system of temperature-sensitive p(NIPA/HPMA) hydrogels with loaded acetaminophen could be suitable for additional investigation for modulated drug administration, e.g., for extended drug administration.

The objectives of this study are the synthesis of thermosensitive poly( N -isopropylacrylamide- co -2-hydroxypropyl methacrylate), p(NiPAm-HPMet), hydrogels and the analysis of a drug-delivery system based on piroxicam, as a model drug, and synthesized hydrogels. A high pressure liquid chromatography method has been used in order to determine both qualitative and quantitative amounts of unreacted monomers and crosslinkers from polymerized hydrogels. Swelling kinetics and the order of a swelling process of the hydrogels have been analyzed at 10 and 40 °C. The copolymers' thermal properties have been monitored by the differential scanning calorimetry (DSC) method. DSC termograms have shown that melting occurs in two temperature intervals (142.36-150.72 °C and 153.14-156.49 °C). A matrix system with incorporated piroxicam has been analyzed by using FTIR and SEM methods. Structural analysis has demonstrated that intermolecular non-covalent interactions have been built between side-groups of copolymer and loaded piroxicam. Morphology of p(NiPAm-HPMet) after drug incorporation indicates the piroxicam presence into the copolymer pores. Kinetic parameters of the piroxicam release from hydrogels at 37 °C and pH 7.4 indicate that the fluid transport mechanism corresponds to Fickian diffusion. As a result, formulation of thermosensitive p(NiPAm-HPMet) hydrogels with incorporated piroxicam could be of interest for further testing as a drug carrier for modulated and prolonged release, especially for topical administration., Competing Interests: The authors declare no conflict of interest.

Antimicrobial and cytotoxic activities were tested for dried MeOH extracts of Hieracium calophyllum (CAL), H. coloriscapum (COL), H. pseudoschenkii (PSE), H. valdepilosum (VAL) and H. glabratum (GLA) herbs (flowering aerial parts), their 2 sesquiterpene lactones (SLs) 8-epiixerisamine A and crepiside E, and dried CH 2 Cl 2 extract of H. scheppigianum (SCH) herb. In microdilution test, extracts showed activity on all tested microorganisms (8 bacteria, 10 fungi). The best effect was exhibited by SCH and CAL on Salmonella Typhimurium (MIC=1.7-2.5 mg/mL MBC=3.4-5.0 mg/mL), and SCH and VAL on Candida albicans (MIC=2.5 mg/mL MFC=5.0 mg/mL). SLs showed notable effect on all tested fungi Aspergillus ochraceus, Penicillium funiculosum, C. albicans and C. krusei (MIC=0.15-0.4 mg/mL MFC=0.3-0.8 mg/mL). In MTT test, extracts inhibited growth of all tested cancer cells (HeLa, LS174 and A549), with the best effect on HeLa (IC 50 =148.1 μg/mL for SCH, and 152.3-303.2 μg/mL for MeOH extracts); both SLs were active against HeLa cells (IC 50 =46.2 μg/mL for crepiside E and 103.8 μg/mL for 8-epiixerisamine A). Extracts and SLs showed good safety profile on normal MRC-5 cells., (© 2022 Wiley-VHCA AG, Zurich, Switzerland.)

Dry MeOH extracts of the twig barks of Pyrus communis subsp. pyraster, P. spinosa and their hybrid P.×jordanovii nothosubsp. velenovskyi, collected in wild in Serbia, were analyzed. By LC/MS, the contents of arbutin (99.9-131.0 mg/g), chlorogenic acid (2.2-6.3 mg/g), catechin (1.0-5.3 mg/g) and total dimeric and trimeric procyanidins (42.2-61.3 mg/g), including procyanidin B2 (8.9-17.2 mg/g), were determined. Colorimetrically, high contents of total phenolics (436.2-533.4 mg GAE/g) and tannins (339.4-425.7 mg GAE/g), as well as strong total antioxidant activities (FRAP values 4.5-5.9 mmol Fe 2+ /g), and DPPH (SC 50 =6.6-7.1 μg/ml) and hydroxyl radical (SC 50 =447.1-727.7 μg/ml) scavenging abilities were revealed. In vitro, all extracts exhibited notable inhibition of α-amylase (IC 50 =310.8-617.7 μg/ml) and particularly strong inhibition of α-glucosidase (IC 50 =2.1-3.7 μg/ml). Molecular docking predicted that among identified compounds procyanidin B2 is the best inhibitor of these carbohydrate-digesting enzymes. Obtained results showed that the barks of investigated Pyrus hybrid and its parent taxa have similar composition and bioactivity., (© 2021 Wiley-VHCA AG, Zurich, Switzerland.)

The composition of the essential oils and the furanocoumarin profiles of CH 2 Cl 2 extracts from underground parts and fruits of nine Heracleum taxa (Apiaceae) from Southeastern Europe were statistically analyzed to evaluate their chemosystematic significance. Eight investigated taxa (H. orphanidis and members of H. sphondylium group: H. sphondylium, H. sibiricum, H. montanum, H. ternatum, H. pyrenaicum subsp. pollinianum, H. pyrenaicum subsp. orsinii and H. verticillatum) belong to the type section of the genus. Additionally analyzed taxon, H. austriacum subsp. siifolium, belongs to H. sect. Wendia. Qualitative and quantitative analysis of the essential oils was performed by GC-FID and GC/MS, and of the furanocoumarins by LC/MS. Furanocoumarins were identified using standards and/or based on UV, MS, 1 H- and ROESY NMR spectra. Multivariate statistics (PCA, nMDS, UPGMA) of analyzed metabolites showed that the investigated taxa were grouped according to their taxonomic classification. PCA revealed the significance of some monoterpenes and (Z)-falcarinol of the underground parts oils, octyl esters of the fruit oils, and most of the total of 12 identified furanocoumarins., (© 2018 Wiley-VHCA AG, Zurich, Switzerland.)

Phenolic compounds and different biological activities of the dry MeOH extracts of the flowers and the herb (aerial parts without flowers) of Laserpitium zernyi Hayek (Apiaceae) were investigated. The total phenolic contents in the extracts were determined spectrophotometrically using Folin-Ciocalteu reagent. In both extracts, apigenin, luteolin, their 7-O-glucosides, and chlorogenic acid were detected by HPLC. Identified phenolics were quantified in both extracts, except luteolin in L. zernyi herb extract. The extracts (p.o.) were tested for anti-edematous activity in a model of carrageenan (i.pl.) induced rat paw edema. Antioxidant activity of the extracts was assessed by FRAP assay and DPPH and • OH radicals scavenging tests. Antimicrobial activity was investigated using broth microdilution test against five Gram-positive and three Gram-negative bacteria, as well as against two strains of Candida albicans. The polyphenol-richer flower extract exerted higher anti-edematous and antioxidant activities. The herb extract exhibited better antimicrobial effect against Micrococcus luteus, Enterococcus faecalis, Bacillus subtilis, and Pseudomonas aeruginosa, while against other tested microorganisms, the activity of both extracts was identical. Demonstrated biological activities of L. zernyi flower and herb extracts represent a good basis for their further investigation as potential new herbal medicinal raw materials., (© 2017 Wiley-VHCA AG, Zurich, Switzerland.)

In this work, the chemical composition, antimicrobial and cytotoxic activity of Heracleum verticillatum Pančić and H. ternatum Velen. root, leaf, and fruit essential oils were investigated. The composition was analyzed by GC and GC/MS. Heracleum verticillatum and H. ternatum root oils were dominated by monoterpenes, mostly β-pinene (23.5% and 47.3%, respectively). Heracleum verticillatum leaf oil was characterized by monoterpenes, mainly limonene (20.3%), and sesquiterpenes, mostly (E)-caryophyllene (19.1%), while H. ternatum leaf oil by the high percentage of phenylpropanoids, with (Z)-isoelemicin (35.1%) being dominant constituent. Both fruit oils contained the majority of aliphatic esters, mostly octyl acetate (42.3% in H. verticillatum oil and 49.0% in H. ternatum oil). The antimicrobial activity of the oils was determined by microdilution method against eight bacterial and eight fungal strains. The strongest effect was exhibited by H. verticillatum root oil, particularly against Staphylococcus aureus, Salmonella typhimurium (MICs = 0.14 mg/ml, MBCs = 0.28 mg/ml), and Trichoderma viride (MIC = 0.05 mg/ml, MFC = 0.11 mg/ml). Cytotoxic effect was determined by MTT test against malignant HeLa, LS174, and A549 cells (IC50 = 5.9 - 146.0 μg/ml), and against normal MRC-5 cells (IC50 > 120.1 μg/ml). The best effect was exhibited by H. verticillatum root oil on A549 cells (IC50 = 5.9 μg/ml), and H. ternatum root oil against LS174 cells (IC50 = 6.7 μg/ml)., (© 2016 Verlag Helvetica Chimica Acta AG, Zürich.)

To complement a previous UV study, we present a quantitative evaluation of substituent effects on spectroscopic data ((1)H and (13)C NMR chemical shifts as well as FT-IR absorption frequency) applied to N,N'-bisarylmalonamides, using simple and extended Hammett equations as well as the Swain-Lupton equation. Furthermore, the DFT CAM-B3LYP/6-311+G(d,p) method was applied to study the impact of different solvents on the geometry of the molecules and their spectral data. Additionally, experimental data are correlated with theoretical results; excellent linear dependence was obtained. The overall results presented in this paper show that N,N'-bisarylmalonamides are prominent candidates for model molecules.

The chemical composition and antimicrobial activity of essential oils of Laserpitium latifolium and L. ochridanum were investigated. The essential oils were isolated by steam distillation and characterized by GC-FID and GC/MS analyses. All essential oils were distinguished by high contents of monoterpenes, and α-pinene was the most abundant compound in the essential oils of L. latifolium underground parts and fruits (contents of 44.4 and 44.0%, resp.). The fruit essential oil was also rich in sabinene (26.8%). Regarding the L. ochridanum essential oils, the main constituents were limonene in the fruit oil (57.7%) and sabinene in the herb oil (25.9%). The antimicrobial activity of these essential oils as well as that of L. ochridanum underground parts, whose composition was reported previously, was tested by the broth-microdilution method against four Gram-positive and three Gram-negative bacteria and two Candida albicans strains. Except the L. latifolium underground-parts essential oil, the other investigated oils showed a high antimicrobial potential against Staphylococcus aureus, S. epidermidis, Micrococcus luteus, or Candida albicans (minimal inhibitory concentrations of 13.0-73.0 μg/ml), comparable to or even higher than that of thymol, which was used as reference compound., (Copyright © 2015 Verlag Helvetica Chimica Acta AG, Zürich.)

The UV absorption spectra of ten N,N'-bisarylmalonamides have been recorded in the range 200-400 nm in a set of selected solvents. The solute-solvent interactions have been analyzed on the basis of the linear solvation energy relationship (LSER) concept proposed by Kamlet and Taft. The effects of substituents on the absorption spectra have been interpreted by correlating absorption frequencies with Hammett substituent constants. Furthermore, the experimental findings have been interpreted using the DFT CAM-B3LYP/6-311+G(d,p) method. Electronic energies have been calculated using the same method in combination with the implicit solvation model (conductor-like polarizable continuum model, CPCM) as well as with the explicit addition of two molecules of solvent.

A sensitive method for determination of the eight most prescribed drugs used in combined cardiovascular therapy in Serbia was developed and optimized. The method was based on SPE followed by LC/ion trap-MS/MS with positive electrospray ionization. Parameters that affect the SPE were optimized, such as the eluent, sample pH, and sample volume. Good recoveries from groundwater (87.6-120.9%) as well as wastewater (84.5-106.6%) were achieved with this method, except in the case of atorvastatin (26.1 and 45.2%, respectively). The method was applied in the analysis of four river water samples collected in Serbia, as well as nine corresponding groundwater samples. Residues of the P-blockers metoprolol and bisoprolol as well as the anticoagulant clopidogrel were detected for the first time in river water. Groundwater samples did not contain drug residues. Influents and effluents of two wastewater treatment plants showed the predominant presence of metoprolol and enalapril. The removal rate of metoprolol was generally low, whereas enalapril was eliminated with the highest efficiency. Atorvastatin was detected in influents and completely removed in the treatment.

There is growing concern that pollution from petrochemical and oil refinery installations in Pancevo (Serbia) has increased the incidence of various diseases including cancer. The aim of our study was to investigate cancer incidence in Pancevo and to compare it with the region of central Serbia. Cancer incidence data were obtained from the corresponding Serbian Cancer Registries. Systematic local monitoring of benzene, toluene and methyl mercaptane in the atmosphere within Pancevo's industrial area indicated that the average monthly and yearly concentrations often exceeded permitted levels proposed by EU standards (5 microgm(-3)). Cancer incidence was lower in Pancevo than in central Serbia (the standardised incidence for all types of cancers in Pancevo was 218.3 and in central Serbia it was 241.7 per 100,000 inhabitants). The available data do not allow us to correlate air pollution in Pancevo with increased cancer incidence.

We performed a basic behavioral characterization of methanol extracts of four Balkan endemic Stachys taxa: S. anisochila (SA), S. beckeana (SB), S. plumosa (SP) and S. alpina subsp. dinarica (SAD). The behavioral activity of extracts dosed intraperitoneally in the range 100-400 mg/kg was examined in adult male Wistar rats, in the elevated plus maze, spontaneous locomotor activity, and grip strength tests, mainly predictive of anxiolytic, sedative and myorelaxant actions, respectively. All investigated Stachys extracts lacked anxiolytic or myorelaxant activities, while SB at 400 mg/kg exerted an anxiogenic-like effect. The study with the selective antagonist beta-CCt showed that the sedative effect of SAD was only partially mediated by GABAA receptors containing the alpha1-subunit. While discernible, the behavioral effects of SA and SP were not distinct. In all extracts, chlorogenic acid and verbascoside were identified. In SA, SB, and SAD the flavonoid fraction was constituted of isoscutellarein and hypolaetine glycosides, while in SP chrysoeriol and apigenin glycosides were present. The results reveal the psychotropic potential of four endemic Stachys taxa, of which SAD appeared most promising as a natural sedative., (Copyright 2010 John Wiley & Sons, Ltd.)

Acute toxicity in vivo toward rats, of nineteen N-alkyl and N-cycloalkyl fluorocetamides [F-CH(2)-C(O)-NH-R] was correlated with their structure-dependent properties. Used descriptors are: molecular weights (M(w)) and heat of formation (DeltaH(f)) of compounds; molar refractivity (CMR), lipophilicity (ClogP), Broto lipol values, virtual logP, molecular lipophilic potential (MLP), Van der Waals surfaces (VdW SAS) and hydropathicity surface (ILM) of whole molecules; Taft steric parameters (E(s)); E(s) values with Hancock corrections (E(s)(CH)) and Verloop sterimol (B(5)) and (L) parameters of alkyl and cycloalkyl residues; superdelocalizabilities and electron densities on the [NH-C(O)-CH(2)-F] fragment. Strong quantitative structure-activity relationships were assessed. Obtained correlation suggested that lipophilicity, shape and bulkiness of the alkyl and cycloalkyl substituents, particular nearest vicinity of the amide nitrogen, as well charges on the amide moiety are the main factors that influence on the acute toxicity of studied compounds toward rats. Mechanism of toxic action was proposed.

The purpose of the present study was to model the effects of the concentration of Eudragit L 100 and compression pressure as the most important process and formulation variables on the in vitro release profile of aspirin from matrix tablets formulated with Eudragit L 100 as matrix substance and to optimize the formulation by artificial neural network. As model formulations, 10 kinds of aspirin matrix tablets were prepared. The amount of Eudragit L 100 and the compression pressure were selected as causal factors. In vitro dissolution time profiles at 4 different sampling times were chosen as responses. A set of release parameters and causal factors were used as tutorial data for the generalized regression neural network (GRNN) and analyzed using a computer. Observed results of drug release studies indicate that drug release rates vary widely between investigated formulations, with a range of 5 hours to more than 10 hours to complete dissolution. The GRNN model was optimized. The root mean square value for the trained network was 1.12%, which indicated that the optimal GRNN model was reached. Applying the generalized distance function method, the optimal tablet formulation predicted by GRNN was with 5% of Eudragit L 100 and tablet hardness 60N. Calculated difference (f1 2.465) and similarity (f2 85.61) factors indicate that there is no difference between predicted and experimentally observed drug release profiles for the optimal formulation. This work illustrates the potential for an artificial neural network, GRNN, to assist in development of extended release dosage forms.

Electron-ionization-induced mass spectra of N-monosubstituted 2-phenylacetamides were recorded and their fragmentation patterns were studied by metastable-ion analyses. Representative deuterated analogues of these compounds have also been synthesized and their mass spectra compared with those of the unlabelled parent compounds. The most typical fragmentation for N-alkyl-, N-isoalkyl- and N-cycloalkyl-2-phenylacetamides is cleavage of the bond alpha to the carbonyl function, resulting in an ion fragment of m/z 92, following the transfer of hydrogen and elimination of a corresponding ketene. The primary fragmentation process for N-aryl substituted 2-phenylacetamides is the loss of an aromatic hydrogen atom from the molecular ion. The other principal fragmentation processes observed with these compounds are discussed.