66 research outputs found
Equitorsion holomorphically projective mappings of generalized Kählerian space of the first kind
summary:In this paper we define generalized Kählerian spaces of the first kind given by (2.1)--(2.3). For them we consider hollomorphically projective mappings with invariant complex structure. Also, we consider equitorsion geodesic mapping between these two spaces ( and ) and for them we find invariant geometric objects
Identification and molecular characterization of Chryseobacterium vrystaatense ST1 isolated from oligomineral water of southeast Serbia
The isolation and molecular characterization of bacterial strains isolated from water sources in the Vlasina Mountain in southeast Serbia, confirmed the presence of a new species Chryseobacterium vrystaatense ST1. This Gram- negative species showed an extremely low level of biochemical reactivity in biochemical tests. The gene for 16S rRNA was amplified by PCR using universal primers and sequenced. Comparison of 16S rRNA gene sequence and phenotypic features indicated that the isolate ST belonged to Chryseobacterium vrystaatense. A BLAST search of sequenced 1088 nucleotides of the 16S rRNA gene with all sequences deposited in the NCBI collection showed the highest similarity (98%) with the strain Chryseobacterium vrystaatense sp. nov., designated as strain R-23533. The very high homology of these two strains allowed classification of our strain at the species level, but some differences indicate, and indirectly confirm, that the isolate ST is an authentic representative. On the basis of these results, we could conclude that Chryseobacterium vrystaatense ST was for first time isolated in Serbia, which is particularly important when one bears in mind that there are only three sequences of this species deposited in the NCBI collection
Seasonal variability of Chelidonium majus L. secondary metabolites content and antioxidant activity
The aim of this study is to investigate the total phenolic content, concentration of flavonoids and antioxidant activity in extracts of the plant Chelidonium majus L. during different phenological stages (stage of rosette, the initial flowering stage, the stage of fully formed flowers and stage of fruits formation). Five different extracts of the whole plant, for each phase, were obtained by extraction with water, methanol, acetone, ethyl acetate and petroleum ether. The concentration of total phenolic content was determined using the Folin-Ciocalteu´s
reagent and obtained values were the highest in the rosette stage (60.96 mg GA/g). The
concentration of flavonoids was the highest in the initial stage of flowering (291.58 mg
RU/g). The antioxidant activity was determined in vitro using DPPH reagent. The highest antioxidant activity was expressed in the rosette stage (50.72 mg/ml). Based on the obtained results it can be concluded that the concentrations of secondary metabolites in Ch. majus depend on the phenological stage of the plant
Dropwort (Filipendula hexapetala Gilib.): potential role as antioxidant and antimicrobial agent
The aim of this study was to investigate the antioxidant activity of the methanolic extracts of Filipendula hexapetala Gilib. aerial parts (FHA) and roots (FHR) and their potential in different model systems, as well as antimicrobial activity. According to this, a number of assays were employed to evaluate the antioxidant and antimicrobial potential of F. hexapetala extracts. In addition, the antioxidant activity assays in different model systems were carried out, as well as pH, thermal and gastrointestinal stability studies. The phenolic compounds contents in FHA and FHR were also determined. The results showed that F. hexapetala extracts had considerable antioxidant activity in vitro and a great stability in different conditions. The extracts exhibited antimicrobial activity against most of the tested bacterial and fungal species. Also, the extracts contain high level of phenolic compounds, especially aerial parts extract
ANTIOXIDANT ACTIVITY AND CONCENTRATION OF SECONDARY METABOLITES IN THE PLANT PARTS OF Euphorbia cyparissias L
ABSTRACT. This paper presents the results of a screening of nine different extracts from the plant parts (leaves, flowers and stems) of Euphorbia cyparissias for total phenolic content, concentration of flavonoids and in vitro antioxidant activity. Мain reason for this study is the determination of these parameters and their variability among plant parts and plant extracts obtained by different solvents, respectively. Obtained amounts for total phenolic content ranged from 10.76 to 40.72 mg GA/g. The concentration of flavonoids varied from 34.32 to 134.34 mg Ru/g. The IC 50 values of antioxidant activity varied from 88.48 to 2891.08 µg/ml. Results obtained from the different plant parts were of uneven value. Great variability of the studied parameters was observed when comparing the effectiveness of the used solvents. The acetone extracts from stems contain the greatest concentrations of phenolic compounds, especially flavonoids, and showed high antioxidant activity. According to our research, plant parts from E. cyparissias can be regarded as promising candidates for natural plant sources with high value of biological compounds
New Values of Teucrium species: in Vitro Study of Cytotoxic Activities of Secondary Metabolites
The cytotoxicity of seven Teucrium species, a long time ago used as a food spices, for beverages and teas preparing, as well as therapeutics for digestive and respiratory diseases, were examined against human cervix adenocarcinoma HeLa, human melanoma Fem-x, human chronic myelogenous leukemia K562 and human breast adenocarcinoma MDA-MB-361 cells. MTT assay was used for determination of target cell survival. The most prominent cytotoxic effect was observed against K562 cells, especially by T. scordioides, T. montanum and T. botrys. All Teucrium extracts showed good cytotoxic activity on HeLa cells, but very low cytotoxic effect on MDA-MB-361 cells. In addition, the cytotoxic activities of T. scordioides and T. montanum extract were tested on healthy resting and phytohaemagglutinin-stimulated peripheral blood mononuclear cells (PHA-stimulated PBMC). T. scordioides and T. montanum extracts at concentration of 200 µg/ml reduced the resting PBMC and PHA-stimulated PBMC survival up to 10% and 20%, while the reduction of K562 cell survival at the same concentration of extracts was 94% and 97%, respectively. These results point to selectivity in their antitumor actions. Teucrium species can be regarded as promising candidates for natural plant sources of effective biological compounds as a supplements in the food industry, as well as for therapeutic use
Quality Parameters and Antioxidant Activity of Three Clover Species in Relation to the Livestock Diet
Products of metabolism that are directly involved in growth, development and reproduction and also secondary products of metabolism were studied in 16 natural populations of three species of the genus Trifolium (T. repens - four populations, T. alpestre - three populations, T. pannonicum - nine populations), collected from the central Balkans region, i.e. territory of Serbia. Statistical analysis showed the presence of variability in all species of the test material. The best quality of dry matter, estimated by the ratio of crude protein and crude fiber, was achieved in the populations of white clover. In this species, average protein content was 216.4 g kg(-1) while the average content of crude fiber was 222.4 g kg(-1). The highest average content of total phenols (77.9 mg GA g(-1)), flavonoids (159.7 mg Ru g(-1)) and antioxidant activity (70.2 mu g ml(-1)) was measured in populations of T. pannonicum by phytochemical analysis of aerial parts of plants. The content of secondary metabolites and antioxidant activity in other species were extremely low. Populations of T. pannonicum were notable for fodder quality and antioxidant activity: CS091 with 186.2 g kg(-1) of crude protein and antioxidant activity of 55 mu g ml(-1); RA123 with 175.6 g kg(-1) of crude protein and a high level of antioxidant activity of 44.8 mu g ml(-1). It can be concluded that the selection of these populations may lead to creation of different varieties of fodder crops that could give safe animal feed and would be suitable for growing under adverse conditions of mountainous climate
Immortelle (Xeranthemum annum L.) as a natural source of biologically active substances
Antioxidant and antimicrobial effects, total phenolic content and flavonoid concentrations of methanolic, acetone and ethyl acetate extracts from Xeranthemum annuum L. were investigated in this study. The total phenolic content was determined using Folin-Ciocalteu reagent and ranged between 101.33 to 159.48 mg GA/g. The concentration of flavonoids in various X.
annuum extracts was determined using spectrophotometric method with aluminum chloride and the results varied from 22.25 to 62.42 mg RU/g. Antioxidant activity was monitored spectrophotometrically using DPPH reagent and expressed in terms of IC50 (μg/ml), and it ranged from 59.25 to 956.81 μg/ml. The highest phenolic content and capacity to neutralize DPPH radicals were found in the acetone extract. In vitro antimicrobial activity was determined by
microdilution method. Minimum inhibitory concentration (MIC) and minimum microbicidal
concentration (MMC) have been determined. Testing was conducted against 24 microorganisms, including 15 strains of bacteria (standard and clinical strains) and 9 species of fungi. Statistically significant difference in activity between the extracts of X. annuum L. was observed
and the acetone extract was found most active. The activity of acetone extract was in accordance with total phenol content and flavonoid concentration measured in this extract. The tested extracts showed significant antibacterial activity against G+ bacteria and weak to moderate activity against other microorganisms. Based on the obtained results, X. annuum can be considered as a rich natural source of polyphenolic compounds with very good antioxidant and antimicrobial activity
ارزیابی کیفیت آزمون های چهار گزینه ای دروس تئوری عمومي گروه اندودانتیکس دانشکده دندانپزشکی قزوین در طی سال های تحصیلی 1388 تا 1396
Svrha je ovoga rada bila ispitati citotoksični, proapoptotski, antimigratorni i pro-antioksidacijski učinak metanolnih, acetonskih i etil-acetatnih ekstrakata dvaju vrsta lišaja, i to: Pseudevernia furfuracea i Platismatia glauca na tumorske stanične linije debelog crijeva (HCT-116 i SW-480). Citotoksični efekti na tumorskim staničnim linijama debelog crijeva uspoređeni su s onima na staničnoj liniji normalnih humanih fibroblasta (MRC-5). Citotoksičnost je ispitana MTT testom, stanična migracija Transwell esejom, dok je apoptoza praćena fluorescentnom metodom pomoću akridin narančastog bojila i etidijevog bromida. Prooksidacijski/antioksidacijski učinak praćen je spektrofotometrijskim mjerenjem koncentracije redoks parametara. Ispitani ekstrakti imali su značajan citotoksični učinak na tumorske stanične linije, bez zapaženog utjecaja na normalnu staničnu liniju. Najjača citotoksičnost postignuta je nakon 72 h obrade staničnih linija ekstraktima vrste P. furfuracea (IC50= (21,2±1.3) µg/mL pri obradi HCT-116 stanica etil-acetatnim ekstraktom i IC50=(51.3±0.8) µg/mL pri obradi stanica SW-480 acetonskim ekstraktom). Ekstrakti P. furfuracea imali su značajan proapoptotski i prooksidacijski učinak, dok je metanolni ekstrakt te vrste imao najjači antimigratorni učinak na ispitane tumorske stanične linije. Svi ispitani ekstrakti vrste P. glauca imali su znatan citotoksični učinak na stanice HCT-116 nakon 72 h tretmana (IC50<40 μg/mL), dok su metanolni i acetonski ekstrakti imali citotoksični učinak na stanice SW-480 nakon 24 h, s izraženom proapoptotskom/nekrotskom aktivnošću. Svi navedeni efekti posljedica su induciranog oksidacijskog stresa u tretiranim stanicama. Može se zaključiti da ekstrakti lišaja bitno mijenjaju vijabilnost i migratorni potencijal ispitanih tumorskih staničnih linija karcinoma debelog crijeva. Dobiveni rezultati pokazuju da su stanice HCT-116 osetljivije na ispitane ekstrakte, pri čemu ekstrakti vrste P. furfuracea pokazuju bolji proapototski i antimigratorni učinak. Ispitane vrste lišaja mogu se smatrati izvorima antikancerogenih aktivnih tvari.The aim of this study is to investigate cytotoxic, proapoptotic, antimigratory and pro-antioxidant effects of methanol, acetone and ethyl acetate extracts of lichens Pseudevernia furfuracea and Platismatia glauca on colorectal cancer (HCT-116 and SW-480) cell lines. We compared the cytotoxic effects on colorectal cancer cells with the effects obtained from normal human fibroblast (MRC-5) cell line. Tetrazolium (MTT) test evaluated the cytotoxic effects, Transwell assay evaluated cell migration, acridine orange/ethidium bromide (AO/EB) fluorescent method followed the apoptosis, while prooxidant/antioxidant effects were determined spectrophotometrically through concentration of redox parameters. The tested extracts showed considerable cytotoxic effect on cancer cells with no observable cytotoxic effect on normal cells. Ethyl acetate and acetone extract of P. furfuracea induced the highest cytotoxicity (IC50=(21.2±1.3) μg/mL on HCT-116, and IC50=(51.3±0.8) μg/mL on SW-480 cells, respectively, after 72 h), with noteworthy apoptotic and prooxidant effects, and antimigratory potential of methanol extract. P. glauca extracts induced cytotoxic effects on HCT-116 cells after 72 h (IC50<40 μg/mL), while only methanol and acetone extracts had cytotoxic effects on SW-480 cells after 24 h, with proapoptotic/necrotic activity, as a consequence of induced oxidative stress. In conclusion, lichen extracts changed to a great extent cell viability and migratory potential of colorectal cancer cell lines. HCT-116 cells were more sensitive to treatments, P. furfuracea had better proapoptotic and antimigratory effects, and both investigated lichen species might be a source of substances with anticancer activity
Mogućnost adsorpcije mikotoksina (aflatoksin M1 i M2) u jogurtu adsorbentima na bazi prirodnog i modifikovanog zeolita
Ways of milk contamination with mycotoxins, harmful effects of mycotoxins, as well as the possibilities for decontamination of mycotoxin contaminated milk are presented in this paper. The research results of efficacy of absorption of aflatoxins M1 and M2 in yogurt by natural and modified zeolite (clinoptilolite) are presented. In laboratory conditions, two amounts of both absorbents (0,2 and 0,6%), with and without addition of sodium caseinate were applied. It was determined that both absorbents had high efficiency for aflatoxin M1 and M2 absorption. The efficiency was higher without addition of sodium caseinate, and absorption of both aflatoxins was slightly higher on modified zeolite. Compared with lower amount of absorbents (0,2%), the higher amount of both adsorbents (0,6%) showed higher adsorption of aflatoxin M1 and M2. The sedimentation of absorbents in yogurt was not observed. The constant control, the prevention of contamination of milk with mycotoxins during the production proccess, together with utilization of absorbents, may be the an alternative way of food protection against the harmful effects of mycotoxins.U radu je dat prikaz rezultata ispitivanja efikasnosti adsorpcije aflatoksina M1 i M2 u jogurtu korišćenjem prirodnog i modifikovanog zeolita (klinoptilolita). Ispitivane su dve doze prirodnog i modifikovanog zeolita (0, 2 i 0, 6 %) sa i bez dodatka natrijum kazeinata. Utvrđeno je da oba adsorbenta imaju visok stepen adsorpcije aflatoksina M1 i M2 u jogurtu. Njihova efikasnost je bila veća bez dodatka natrijum kazeinata, pri čemu je modifikovani zeolit dao povoljnije rezultate (>80%). Povećana doza (0,6 %) oba adsorbenata u odnosu na manju dozu (0,2%) imala je i veću efikasnost adsorpcije aflatoksina M1 i M2. Nisu primećeni tragovi taloženja adsorbenta u jogurtu. Dalje ispitivanje i usavršavanje ovog postupka adsorpcije može da doprinese većem izboru alternativnih rešenja u zaštiti potrošača od mikotoksina
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