No abstract

No abstract

No abstract

No abstract

No abstract

Seven elements, namely, arsenic, lead, cadmium, copper, zinc, iron and manganese were determined in 31 samples of Serbian plum brandies by applying atomic spectrometry techniques. Flame atomic absorption spectrometry was used for quantification of copper, iron, zinc, manganese, lead and cadmium; and hydride generation atomic spectrometry absorption for arsenic quantification. Measured concentrations of heavy metals and arsenic was assessed according to the Serbian regulations, official regulations of some other countries and in respect of microelements content in other similar distilled alcoholic beverages. Amounts of microelements in maximal recommended daily and weekly intake of plum brandy were determined. The influence of production (home made and industrial), type of wooden barrel (oak and mulberry), and duration of ageing process on the content of Zn, Cu, Fe and Mn in plum brandies, as well as coefficient of correlation between Cu content and pH value were also studied. [Projekat Ministarstva nauke Republike Srbije, br. 172053

Tetradenia riparia (Hochstetter) Codd belongs to the Lamiaceae family and it was introduced in Brazil as an exotic ornamental plant. A previous study showed its antimicrobial, acaricidal and analgesic activities. Two compounds were isolated from essential oil of T. riparia leaves and identified as 9β,13β-epoxy-7-abietene (1), a new one, OPEN ACCESSMolecules 2014, 19 515 and 6,7-dehydroroyleanone (2), already reported for another plant. The structure of these compounds was determined by spectroscopic analysis and by comparison with literature data. The cytotoxic activities of the essential oil and compounds 1 and 2 were determined by a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay, and by tumor cells MDA-MB-435 (human breast carcinoma), HCT-8 (human colon), SF-295 (human nervous system) and HL-60 (human promyelocytic leukemia). The essential oil and compound 1 showed high cytotoxic potential of the cell lines SF-295 (78.06% and 94.80%, respectively), HCT-8 (85.00% and 86.54%, respectively) and MDA-MB-435 (59.48% and 45.43%, respectively). Compound 2 had no cytotoxic activity. The antioxidant activity was determined by 2,2-diphenyl-1-picryl-hydrazyl (DPPH), β-carotene-linoleic acid system and 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assays. The inhibitory concentration (IC 50 in µg mL −1 ) for essential oil and compound 2 was, respectively 15.63 and 0.01 for DPPH; 130.1 and 109.6 for β-carotenelinoleic acid and 1524 and 1024 for ABTS. Compound 1 had no antioxidant activity. By fractioning the oil, it was possible to identify two unpublished compounds: 1 with high cytotoxic potential and 2 with high antioxidant potential.

Seed extracts from eight grape cultivars (Vitis vinifera) growing in Serbia were screened for their polyphenolic composition by means of HPLC/ /PDA/ESI/MS analysis. The study revealed 34 phenolic compounds belonging to the following groups: flavan-3-ol monomers, proanthocyanidins, flavonols, hydroxycinnamic acid and hydroxybenzoic acid derivatives. The quantities of the main constituents were determined using PDA/HPLC. Qualitative and quantitative differences among the cultivars were observed.The phenolic compounds in grapes can be divided into two main groups: phenolic acids (localized mainly in the skin and pulp) and flavonoids. The most common phenolic acids in grape include cinnamic and benzoic acid derivatives. Flavonoids include colorless flavan-3-ols, flavonols and red and blue anthocyanins. 5 The most abundant phenolics isolated from grape seeds and skins are flavan-3-ols (catechin and epicatechin) and their oligomers and polymers (proanthocyanidins). The outer seed coat contains the majority of both the monomeric and polymeric flavan-3-ols (2 to 5 times more than the endosperm). 6 Grape skins also contain anthocyanins which contribute to their red or blue color. 7,8 Various conditions (time, solvent, and the manner) for the extraction of polyphenols from grape seeds are described in the literature. Due to the acidic lability of interflavan linkages within proanthocyanidins and the susceptibility of polyphenols to oxidation, a valid extraction method should provide for the complete as possible extraction of the polyphenolics while limiting their degradation. 9 Methanol/water 10,11 or acetone/water systems 12 are the common solvents used for extracting polyphenols from grape seeds. In particular, lower molecular weight polyphenols, such as phenolic acids, anthocyanins, and flavanol monomers and oligomers, are well extracted with methanol, while the higher molecular weight flavanols are better extracted with aqueous acetone than with methanol. [13][14][15][16] Several methods for the analysis of polyphenols have been proposed in the literature. Most of them are based on high performance liquid chromatography (HPLC) coupled with either a photodiode array (PDA) detector or a mass spectrometer (MS). Reverse phase columns are favorable, using acetonitrile and acidic water solutions as eluents. 17 Since UV detection depends upon the chemical structure of a molecule, several wavelengths could be selected for monitoring. Red-colored anthocyanins show an absorbance maximum at around 520 nm; yellow-colored flavonols display an absorbance maximum at around 360 nm; hydroxycinnamic acids can be specifically detected by their high absorbance around 320 nm. Flavan-3-ols show no specific absorbance and have a maximum around 280 nm, as do all the above-mentioned phenolics. 18 Many studies proved that procyanidins and other polyphenolics from grape seed could be the key compounds responsible for various beneficial effects for human health. 19,20 These effects are mainly associated with the antioxidant activity of the phenol...