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Biperiden, an antiparkinsonian anticholinergic drug, has been found to inhibit enzymatic hydrolysis of butyrylthiocholine iodide, which is catalyzed by serum cholinesterase. By measuring the difference in the basic and inhibitory hydrolysis reaction rates, in the presence of biperiden as an inhibitor, it is possible to develop a kinetic method for its determination. Both systems, enzyme-substrate-chromogen and enzyme-substrate-chromogen-inhibitor, were characterized by biochemical parameters (KM = 0.326 – 0.330 mmol dm-3; Vmax = 40 - - 99 μmol dm-3 min-1), while inhibition was defined as non-competitive with the constant of inhibition Ki = 6.142 μmol dm-3. The reaction conditions have been optimized followed by determination of the calibration curve, the corresponding equation and the limits of detection and quantification yielding 3.84 and 12.80 nmol dm-3, respectively. Using the calibration chart, it is possible to determine biperiden in different samples in the concentration range of 0.035–35.940 μmol dm-3. Influence of a number of substances, found in the sample, on the reaction rate was also examined. The optimized method was applied for determination of biperiden in pharmaceutical preparations. Accuracy of the method was tested using the standard addition method. The proposed method has good sensitivity, selectivity, it is simple and fast, and above all easily accessible, and thus applicable in biochemical and pharmaceutical laboratories.

The eggplant is a vegetable that has been used more in recent years thanks to the low calories versus high content of phenolic compounds. This study aimed to determine total phenolic, flavonoid, proanthocyanidin, and saponin content using spectrophotometric assays and antioxidant activity using 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH), 2,2'-azinobis(3-ethylbenzothiazol-6sulpho-nate (ABTS), total reducing power (TRP), ferric reducing antioxidant power (FRAP), and cupric reducing antioxidant capacity (CUPRAC) assassin peel and pulp of eggplant cultivars Robi, Tudela, Vernal, Aragon, and Rosa Bianca. The average total saponin content (TSC) in peel was 116.34 μg DSGE mg-1 DW (diosgenin equivalents per mg of extract's dry weight), whereas in pulp was slightly lower (107.86 μg DSGE mg-1 DW). A similar trend was observed for total phenolic content (TPC) (24.54 μg GAE mg-1 DW (gallic acid equivalents per mg of extract's dry weight) in peel and 15.88 μg GAE mg-1 DW in pulp); total proanthocyanidin (TP) (2.74 μg CE mg-1 DW (catechin equivalents per mg of extract's dry weight) in peel and 1.24 μg CE mg-1 DW in pulp) and total flavonoid content (TFC) (0,05 μg RE mg-1 DW (rutin equivalents per mg of extract's dry weight) in peel and 0.02 μg RE mg-1 DW in pulp). Principal component analysis (PCA) and cluster analysis (CA) methods were applied on the antioxidant activity (ABTS, DPPH, TRP, FRAP, and CUPRAC) and total bioactive compounds content (TSC, TPC, TP and TFC) parameters in order to reveal the relationships between analyzed samples. As a result of these approaches, analyzed samples were grouped into two groups. [ABSTRACT FROM AUTHOR]

Primary role of peroxidase enzyme is to decompose endogenous hydrogen peroxide, when oxygen radical is being replaced by a less potent radical, which is its cosubstrates oxidized form. During this study, catalytic activity of horseradish peroxidase has been observed in the presence of antioxidants from vitamin group, such as C, E and A, i.e. their water-soluble forms. It was found that vitamin E showed no effect on the enzyme activity and fate of cosubstrate radicals from the group of benzidine derivatives. Vitamin C proceeds enzymatic reaction showing its antioxidative character, and absorbs electrons from radicals, bringing cosubstrate back to its relaxed state. On the other hand, vitamin A plays a role of uncompetitive peroxidase inhibitor, which is visible through decreasing initial rate of catalytic reaction, and is reflected as virtual decrease of enzyme concentration. Furthermore, it prolongs life of endogenous hydrogen peroxide, which could potentially lead to oxidative stress of cells. This inhibitory effect can be used in analytical purpose, for determination of retinol acetate content in a sample.

Propranolol, a widely used beta-blocker, inhibits the reaction of enzyme cholinesterase hydrolysis. Measurements of the hydrolysis rate differences between and inhibited reactions, allows the development of a kinetic method for its determination. Both systems, enzyme-substrate-chromogen and enzyme-substrate-chromogen-inhibitor, were characterized through biochemical kinetic parameters (KM = 0.326-0.330 mmol/L; Vmax = 40-42.99 μmol/Lmin), inhibition type was recognized as competitive, and inhibition constant, Ki, was determined to be 22.60 μmol/L. The detection and quantification limits were calculated as 0.004 and 0.0136 μmol/L, respectively. Accuracy and precision of proposed methods were tested. Proposed method is characterized with good sensitivity, selectivity, simplicity and rapidity, thus it is convenient for clinical applications.

In this study the content of chloroplast pigments (chlorophyll a, b, a+b, and carotenoids) in the leaves of Geranium macrorrhizum L., Doronicum columnae Ten., Aegopodium podagraria L. and Tussilago farfara L. from a beech forest that had undergone fire on Vidlič Mountain was determined. The same species of plants from a place that had not been exposed to fire were taken as controls. Chloroplast pigments were determined from acetone extracts of these plants spectrophotometrically. In the first year after the fire the content of chlorophyll a, b and a+b in Geranium macrorrhizum L. and Doronicum columnae Ten. was greater than in the plants not exposed to fire. The results were the opposite for Aegopodium podagraria L. and Tussilago farfara L. These differences can be attributed to the different physiology of the plants and consequently their different adaptation patterns. The carotenoid content was higher in the plant species at the fire site than in the area not exposed to fire.

A new reaction is suggested and a new method is elaborated for determination of micro amounts of Sn(II) based on its inhibiting effect on the oxidation of {4-bis[n-(dimethylamino) phenyl]methylene-2,5-cyclohexadiene-1-ilydene}dimethyl-ammonium chloride (crystal violet CV) by H2O2. The method sensibility is 0.4 μg/cm3. The probable relative error is 2.8-12.8 % for Sn(II) in the concentration interval of 3 to 0.8 μg/cm3. The kinetic equation for this process is given. The influence of some other ions on the reaction rate was tested. The method was applied to the determination of Sn(II) in a sample of microalloy.

The chemical composition of the essential oil and the volatiles obtained by static headspace (HS) of Inula oculus-christi L. is presented. The GC-MS analysis of the hydrodistilled oil resulted in the identification of 90 components, representing 92.7% of the oil. The most abundant compounds were: caryophyllene oxide (9.8%), trans-longipinocarveol (9.2%), eucalyptol (7.3%) and intermedeol (6.2%). The major constituent of I. oculus-christi L. HS volatiles was eucalyptol (87.4%). The antioxidant activity was evaluated by four different methods: 2,2-diphenyl-1-picryl-hydrazylhydrate free radical assay (DPPH), 2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) method, total reducing power (TRP), ferric reducing antioxidant power (FRAP), and cupric reducing antioxidant capacity (CUPRAC). Total phenolic content in (TPC) examined oil was 177.95 µg GAE/mg oil. Radical scavenging potential of the oil was promising RSC-DPPH was 57.4% and RSC-ABTS was 82.7%. [ABSTRACT FROM AUTHOR]

Copyright of Chemical Industry / Hemijska Industrija is the property of Association of Chemical Engineers and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Phytochemical analysis by GC and GC/MS of the essential oil samples obtained from fresh shoots and flowers of Saponaria officinalis L. allowed the identification of 96 components in total, comprising 94.7% and 86.0% of the total oils compositions, respectively. Regarding the shoots essential oil, the major of 87 identified volatile compounds were phytol (14.1%), tricosane-6,8-dione (13.4%), patchouli alcohol (7.9%) and tricosane (7.2%), whereas patchouli alcohol (20.0%), heneicosane (11.5%) and tricosane (8.4%) were dominant among the 66 volatiles in the flower oil. Nonterpenoid compounds had the highest contribution in S. officinalis shoots essential oil (53.7%), while in the flower oil, constituents were almost evenly distributed between the oxygenated sesquiterpenoid (41.2%) and nonterpenoid compounds (39.5%). [ABSTRACT FROM AUTHOR]

Copyright of Chemical Industry / Hemijska Industrija is the property of Association of Chemical Engineers and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Negative effects of available antibiotics and the constant development of bacterial resistance motivate a search for new antimicrobial agents. Aromatics plants have traditionally been used as antibacterial agents and are well accepted today as a source of antioxidants. The present study evaluated the antibacterial activities and antioxidant capacity of eight aromatic plants, indigenous to the flora of the Balkan Peninsula, which are used as medicinal plants in traditional medicine. The plants studied were Hyssopus officinalis , Angelica pancicii, Angelica sylvestris, Laserpitium latifolium , Achillea grandifolia, Achillea crithmifolia, Artemisia absinthium and Tanacetum parthenium . The antimicrobial activities of methanolic extracts of the plant tissues against 16 bacterial isolates of Escherichia coli , Pseudomonas aeruginosa , Klebsiella sp. , Proteus mirabilis , Acinetobacter sp. , Staphylococcus aureus , Streptococcus pyogenes , Streptococcus pneumoniae and Enterococcus faecalis were investigated using a microwell dilution assay. Minimal inhibitory concentration (MIC) of the extracts ranged from 6.3 to 100 mg mL -1 , and minimal bactericidal concentration (MBC) ranged from 12.5 to 100 mg mL -1 . Antioxidant potential of the extracts was analyzed as contents of total phenols and flavonoids; radical scavenging activity by the ABTS + and DPPH methods, and reducing power by the iron (III) to iron (II) reduction assay, and the ferric reducing antioxidant power assay (FRAP). Results of antioxidative activities from the 4 methods demonstrated similar sequence of activity: A. crithmifolia > A. grandifolia > H. officinalis > A. absinthium > T. parthenium > L. latifolium > A. pancicii > A. sylvestris. The total content of polyphenols and flavonoids in the methanol extracts of the studied species positively correlated with their antioxidant properties, confirming their major role in antioxidant activity of these species. [ABSTRACT FROM AUTHOR]

BACKGROUND In Serbia, delicatessen fruit alcoholic drinks are produced from autochthonous fruit-bearing species such as cornelian cherry, blackberry, elderberry, wild strawberry, European wild apple, European blueberry and blackthorn fruits. There are no chemical data on many of these and herein we analysed volatile minor constituents of these rare fruit distillates. Our second goal was to determine possible chemical markers of these distillates through a statistical/multivariate treatment of the herein obtained and previously reported data. RESULTS Detailed chemical analyses revealed a complex volatile profile of all studied fruit distillates with 371 identified compounds. A number of constituents were recognised as marker compounds for a particular distillate. Moreover, 33 of them represent newly detected flavour constituents in alcoholic beverages or, in general, in foodstuffs. With the aid of multivariate analyses, these volatile profiles were successfully exploited to infer the origin of raw materials used in the production of these spirits. It was also shown that all fruit distillates possessed weak antimicrobial properties. CONCLUSION It seems that the aroma of these highly esteemed wild-fruit spirits depends on the subtle balance of various minor volatile compounds, whereby some of them are specific to a certain type of fruit distillate and enable their mutual distinction. © 2014 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Copyright of Chemical Industry / Hemijska Industrija is the property of Association of Chemical Engineers and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The chemical composition of the essential oil of the aerial parts of the Ajuga chamaepitys (L.) Schreber ssp. chia (Schreber) Arcangeli collected on Vidlic Mountain (Serbia) from two neighboring localities: normal environmental conditions (NEC) and post ire environmental conditions (PFEC) has been studied by GC and GC/MS. Thirty eight compounds were identified in NEC oil and thirty four in PFEC oil accounted 98.3 % and 98.2 % of the total oil, respectively. The major constituents of NEC and PFEC oil were: α-pinene (10.9%, 5.4%), β-pinene (22.0%, 14.8%), germacrene D (16.2%, 26.8%), germacrene B (5.9%, 13.6%) and viridilorol (6.0%, 5.7%), respectively. The antioxidant properties of both oils were evaluated employing electron transfer antioxidant assays: Folin-Ciocalteu, DPPH and reducing power assay Fe (III) to Fe(II). Both oil samples had approximately equal and moderate activity in reducing Fe(III) to Fe(II) and Mo(VI) to Mo(V), and weak radical scavenging activity. This is the first report on the content and composition of the essential oil of A. chamaepitys ssp. chia grows in Serbia and also the first report about its antioxidant activity. [ABSTRACT FROM AUTHOR]

Nutrients play an essential role in many metabolic processes whose deficiency or excess can be harmful to the plant itself and through the food chain to both animals and humans. Medicinal plants used in the food and pharmaceutical industries can be contaminated with increased concentrations of heavy metals. The plant species Seseli rigidum and Seseli pallasii from the Balkan Peninsula are used in traditional medicine and spices in the diet, so it was necessary to determine the mineral composition to ensure their safe application. In this work, the mineral composition was determined in medicinal species of the genus Seseli using inductively coupled plasma with optical emission spectrometry (ICP-OES). Two multivariate statistic methods –principal component analysis (PCA) and hierarchical cluster analysis (HCA) were applied to distinguish samples regarding their mineral composition. The mineral composition of both studied species is following the literature data. The results obtained using multivariate statistics methods agree and distinguish certain parts of the tested plants based on the highest content of micro, macro, or trace elements. [ABSTRACT FROM AUTHOR]