Spectrofluorimetric and HPLC Determination of Morin in Human Serum

Morin is a flavonol antioxidant. In ethanol-water mixtures (70 wt% of ethanol) it reacts with Al3+ to give Al(Morin)(2) in the pH range 3-6. The conditional stability constant of this complex at 298 K was found to be log beta(2) = 16.96 +/- 0.02 at pH 4.40. The complex shows strong fluorescence emission at 500 nm upon excitation at 410 nm. The fluorescence intensity is pH dependent with maximum emission at pH 4.40. Since the complexation reaction enhances the fluorescence of morin, this property was used for the determination of morin in human serum. A linear dependence of the intensity of fluorescence of the complex on the concentration of morin was obtained in morin concentration range from 1.5-30.5 ng mL(-1), relative standard error of measurements was 1.4%. The LOD was 0.02 ng mL(-1) while LOQ was 1.0 ng mL(-1). Serum concentration of morin was also determined using HPLC as a reference method. A C-18 Hypersil Gold AQ column was used with acetonitrile-0.1% v/v phosphoric acid (30:70% v/v) as the mobile phase at 1.0 mL min(-1) flow rate and UV detection at 250 nm. Acceptable relative standard errors (less than 5%) between determinations obtained by the two methods indicate that the fluorescence method is reliable

Chemical analysis and antimicrobial activity of methanol extracts of celandine (Chelidonium majus L.) plants growing in nature and cultured in vitro

Projekat ministarstva br. 143026B i 143041

Investigation on antibacterial synergism of Origanum vulgare and Thymus vulgaris essential oils

Essential oils are well known as strong antimicrobial agents of plant origin. In spite of this, the antimicrobial synergism of essential oils isolated from different plant species is poorly investigated. The following study examines the synergism of the essential oils of Origanum vulgare L. and Thymus vulgaris L against pathogenic bacteria, Staphylococcus aureus and Salmonella typhimurium. First, the antibacterial effect of the oils was tested, and the minimal inhibitory concentrations (MIC) of both oils were determined using the microdilution method. To test whether the oils act synergistically, every possible combination of essential oil concentrations was used in a dynamic checkerboard method. The results indicated that the oils indeed acted synergistically with fractional inhibitory concentration indexes of 0.45 and 0.50. [Projekat Ministarstva nauke Republike Srbije, br. 173032

Antioxidant and antimicrobial activity of Cynara cardunculus extracts

The whole, fresh involucral bracts of cardoon, Cynara cardunculus L. (Compositae), were extracted with EtOH and an aqueous suspension of the obtained EtOH extract was partitioned successively with CHCl3, EtOAc and n-BuOH, leaving a residual water extract. All obtained extracts were evaluated for their antioxidant and antimicrobial properties. The antioxidant potential was evaluated using following in vitro methods: FRAP (ferric reducing antioxidant power) assay, and scavenging of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical. Antimicrobial activity was estimated using a microdilution technique against food-borne, mycotoxin producers and human pathogenic bacteria and micromycetes. The following bacteria were tested: Salmonella typhimurium, Escherichia coli, Bacillus subtilis, Staphylococcus epidermidis, Staphylococcus aureus, as well as micromycetes: Aspergillus niger, Aspergillus ochraceus, Aspergillus flavus, Penicillium ochrochloron, Penicillium funiculosum, Trichoderma viride, Fusarium tricinctum and Alternaria alternata. Results showed that all extracts possessed concentration-dependent antioxidant activity. In biological assays, C. cardunculus extracts showed antimicrobial activity comparable with standard antibiotics.This is peer-reviewed version of the folowing article: Kukić, J.; Popović, V.; Petrović, S.; Mucaji, P.; Ćirić, A.; Stojković, D.; Soković, M. Antioxidant and Antimicrobial Activity of Cynara Cardunculus Extracts. Food Chem. 2008, 107 (2), 861–868. [https://doi.org/10.1016/j.foodchem.2007.09.005

Antimicrobial activity of lozenge with garlic bulb powder

According to the tested antimicrobial activity of constituents and their chemical characteristics, a new formulation of oral antiseptic was made based on garlic bulb powder and its active principles with strong antimicrobial activity against a wide range of bacteria and fungi. The antimicrobial activity of garlic bulb powder, allicin and the lozenge with 15% of garlic powder was tested using broth microdilution method. The tested garlic powder, as well the lozenge, have shown very high antimicrobial activity with MIC 1.25-5.00 mg/ml, and 1.87-7.50 mg/ml, respectively. The major compound, allicin, was highly active at a very low concentration. The minimal inhibitory concentration of allicin was from 6.25-12.50 μg/ml for antibacterial activity and 0.4 μg/ml for antifungal activity. Those concentrations are comparable with concentrations of commercially available antibiotics and fungicides. The formulation of an antiseptic with herbal constituents, high antibacterial and antifungal activity and pleasant taste could be an alternative to classical pharmaceutical oral antiseptics.Na osnovu ispitane antimikrobne aktivnosti komponenata i njihovih hemijskih karakteristika, napravljena je nova formulacija oralnog antiseptika koji kao aktivnu komponentu ima prašak belog luka čiji sastojci pokazuju veoma izraženu aktivnost protiv širokog spektra bakterija i gljive Candida albicans. Antimikrobna aktivnost praška belog luka, alicina i lozengi sa 15% praška belog luka je ispitivana bujon mikrodilucionom metodom. Testiran prašak belog luka, kao i lozenge imaju veoma jaku antimikrobnu aktivnost sa minimalnim inhibitornim koncentracijama (MIC) 1,25-5,00 mg/ml (prašak belog luka) i 1,87-7,50 mg/ml (lozenge). Glavna aktivna komponeta belog luka, alicin, pokazuje antimikrobnu aktivnost u veoma niskim koncentracijama. Minimalne inhibitorne koncentracije alicina se kreću od 6,25-12,5 μg/ml protiv bakterija i 0,4 μg/ml protiv gljivice Candida albicans. Ove koncentracije se mogu uporediti sa koncentracijama komercijalnih antibiotika i fungicida. Naši rezultati su u skladu sa prethodnim ispitivanjima alicina i različitih ekstrakta belog luka, i potvrđuju najvažniju ulogu alicina u antimikrobnoj aktivnosti. Veoma je važna visoka aktivnost ovako formulisanog oralnog preparata protiv gljivice C. albicans koja je čest uzročnik infekcija usne duplje. Formulisan proizvod sa antiseptičkim osobinama karakteriše stanje čvrstog rastvora gde su aktivne supstance molekularno-disperzno ugrađene u obliku dobro rastvornog polimernog matriksa (sorbitola) velike specifične površine. Dobra rastvorljivost polimernog matriksa i velika specifična površina omogućuju zadovoljavajuću brzinu otpuštanja aktivnih principa iz belog luka (alicin). Pored visoke antimikrobne aktivnosti, lozenge poseduju prijatan ukus i osvežavaju dah, pa se mogu koristiti kao prirodni antiseptik u prevenciji i terapiji infekcija sluzokože usta i ždrela. Formulacija antiseptika sa biljnim sastojcima i visokom antibakterijskom i antifungalnom aktivnošću može biti alternativa farmaceutskim oralnim antisepticima.Projekat ministarstva br. 173021, br. 34012 i br. 17303

Antimicrobial activity of aqueous extract of Laetiporus sulphureus (Bull.: Fr.) Murill

Wood-rotting basidiomycete, Laetiporus sulphureus (Bull.: Fr.) Murill., also known as chicken of the woods, is known for its nutritional value. In this study, aqueous extract obtained from L. sulphureus was investigated for its antimicrobial properties using microdilution in vitro assay. Plant, animal and human pathogens, as well as food spoilage agents, were tested. Aqueous extract obtained from L. sulphureus showed strong activity against the tested microorganisms in a dose dependent manner. Considering that there is a constant emerging of pathogen resistance to the known synthetic agents, there is an undeniable need for new therapeutical drugs and preservatives in food industry. Thus, these results that indicate activity of natural products may be of practical use.Gljiva mrke truleži, Laetiporus sulphureus (Bull.: Fr) Murill., poznata i kao šumsko pile, već je poznata po svojoj nutritivnoj vrednosti. U ovoj studiji ispitivana je antimikrobna sposobnost vodenog ekstrakta L. sulphureus, mikrodilucionom in vitro metodom. Biljni, životinjski i humani patogeni, kao i prouzrokovači kvarenja hrane su testirani. Vodeni ekstrakt dobijen od L. sulphureus pokazao je snažnu aktivnost na testirane mikroorganizme uz doznu zavisnost. S obzirom da postoji konstantni porast rezistentnosti patogena na poznate sintetičke agense, potreba za novim terapeutskim lekovima i konzervansima u prehrambenoj industriji je neophodnost. Stoga, rezultati koji ukazuju na aktivnost prirodnih produkata mogu biti od velikog praktičnog značaja.Projekat ministarstva br. 14304

The Phenotype Variability, of the Racka Sheep in the Republic of Serbia

ΔΕΝ ΔΙΑΤΙΘΕΤΑΙ ΠΕΡΙΛΗΨΗThe intensification of sheep production, by permanent genetic selection and the development of breeding technology, has led to the creation of highly productive sheep breeds. In this way, many highly productive breeds were created which could demonstrate their high production potentials only under perfect conditions of nutrition, accommodation and care. Preservation of indigenous breeds is of great importance in order to protect and safeguard those breeds and, in this way, it is possible to restore some of the characteristics that are lost during intensive selection, which are mostly related to resistance. The Racka sheep (Serbian: Vitoroga žuja) is considered to be an autochthonous breed and a genetic resource in the Republic of Serbia. As a primitive breed with low productivity, it offers no economic profitability and, thus, there is no great interest in its breeding. According to the FAO data from 2008-2014, the number of these sheep ranges from 500 to 1000. The objective of this study was to determine the phenotypic variability and to assess the external measurements of the Racka sheep. One-hundred fifty Racka breed ewes were included in this study. The effects of three farms on the phenotypic characteristics and their body indexes were calculated. The significance of the research is reflected in the advancement of this breed and in the assessment of the possibilities of selection work in these herds