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Microwave-assisted extraction (MAE) conditions were optimized to improve extract quality of medicinal herb — Hypericum perforatum L. (St. John’s wort) dust. Response surface methodology was applied initially to obtain the highest concentration of total polyphenols in extract solids (MAE-e). St. John’s wort was mixed with 30% ethanol in 50 mL/g solvent to solid ratio, and treated with 170 W microwave power for 40 s to yield an extract with 411.26 ± 6.21 mg GAE/g of polyphenols. This extract contained a significantly higher content of polyphenols (42.50%) and had significantly higher antioxidant activity than the macerate obtained by using European Medicines Agency (EMA) recommended procedure. The advantage of the EMA procedure was the higher yield of extract per gram of plant material. Therefore, another set of MAE conditions was defined to maximize the yield of polyphenols per gram of plant material (MAE-p). The MAE-p extract was produced by using 30% ethanol, 10 mL/g solvent to solid ratio, and 170 W microwave power for 100 s, which was, again, a markedly shorter period than 72 h of maceration. The MAE-p extract had a slightly, but significantly higher yield (5.2%), more polyphenols (8.8%), and improved antioxidant activity compared to the EMA macerate. Antimicrobial activity against several pathogens was stronger for the MAE extracts. The chemical composition of extracts was slightly different and MAE favored extraction of glycosides, in particular, rutin (quercetin-3-O-rutinoside), while the EMA macerate contained quercetin aglycon in the highest concentration. Our study demonstrates that statistically planned experiments allow for significant improvement of the extraction process, which application could facilitate better use of natural resources and deliver more potent extracts than those obtained by currently recommended procedures.

In this study, a spray drying process of yarrow (Achillea millefolium L.) liquid extracts was optimized by using the response surface methodology. The study aimed to determine the influence of temperature (120-195 degrees C), liquid flow rate (3-16.5 cm(3) min(-1)) and dry matter content in the liquid extract (0.3-1.5 %) on the yield of the drying process, the total polyphenols content and the antioxidant activity of the dry powder. Under the tested conditions the yield varied dramatically and ranged from 8 to 75 %, while the effects on the polyphenol content and antioxidant activity were lower. The optimized conditions for the maximum antioxidant activity and maximal yield of the dried extract were as follows: temperature of 130 degrees C, liquid flow rate of 7.5 cm(3) min(-1) and dry matter content of 1.2 %. Under the optimal conditions, the yield was 66 %, while there was a slight decrease in the polyphenol content in the dried extract as compared to that in the liquid extract (145 mg of gallic acid equivalents [GAE] per g of the total dry matter vs. 152 mg GAE g(-1), respectively). Consequently, antioxidant activity of the dry powder was only slightly reduced as compared to that of the liquid extract (DPPH neutralization was 58 vs. 64 %, respectively). The dried yarrow powder preserved its antimicrobial activity against pathogenic bacteria Staphylococcus aureus (MIC value of 10 mg cm(-3)) and Pseudomonas aeruginosa (MIC value of 20 mg cm(-3)).

Medicinal plants and their extracts contain substantial quantities of polyphenols. As metabolically active plant metabolites, polyphenols are food components with a wide range of biological activities. Given their poor absorbability in the digestive tract their activity toward the human host is typically mediated through interaction with intestinal microbes. As a result, polyphenols comprise a novel group of prebiotics. In this study, we tested the effect of five polyphenol-rich extracts from four medicinal herbs on the growth of probiotic and pathogenic microbes. The studied medicinal herbs were Gentiana asclepiadea L. (willow gentian), Hypericum perforatum L. (St. John's wort), Satureja montana L. (winter savory), and Achillea millefolium L. (yarrow). All these plants are traditionally used for the treatment of digestive problems. Extracts were prepared using safe solvent combinations. We tested the impact of addition of plant extracts on the growth of three probiotic lactobacilli and probiotic yeast Saccharomyces boulardii. The effect of addition of plant extracts to liquid media (concentration range 0.25-10 mg/mL) on the growth of probiotics, was tested in vitro. The antimicrobial activity of the extracts was tested against several opportunistic bacteria and yeast. St. John's wort, winter savory, and willow gentian extracts showed a stimulative effect on probiotic yeast growth, while the highest growth-stimulating effect was achieved when microwave-assisted yarrow extract was used in the concentration of 0.5 mg/mL. Under these conditions growth of S. boulardii was increased 130-fold. In addition, the yarrow extract stimulated the growth of Lactiplantibacillus plantarum 299v. The growth of two Lacticasibacillus rhamnosus strains was not stimulated by the addition of any extracts. Our results show that plant polyphenol-rich extracts can influence the growth of microorganisms that are typical members of the intestinal microbiota. For the first time we demonstrate t

Phosphinothricin (PPT) is one of the most widely used herbicides. PTT targets glutamine synthetase (GS) activity in plants, and its phytotoxicity is ascribed to ammonium accumulation and reactive oxygen species bursts, which drives rapid lipid peroxidation of cell membranes. In agricultural fields, PPT is extensively sprayed on plant foliage; however, a portion of the herbicide reaches the soil. According to the present study, PPT absorbed via roots can be phytotoxic to Arabidopsis, inducing more adverse effects in roots than in shoots. Alterations in plant physiology caused by 10 days exposure to herbicide via roots are reflected through growth suppression, reduced chlorophyll content, perturbations in the sugar and organic acid metabolism, modifications in the activities and abundances of GS, catalase, peroxidase, and superoxide dismutase. Antagonistic interaction of Nepeta rtanjensis essential oil (NrEO) and PPT, emphasizes the existence of complex control mechanisms at the transcriptional and posttranslational level, which result in the mitigation of PPT-induced ammonium toxicity and in providing more efficient antioxidant defense of plants. Simultaneous application of the two agents in the field cannot be recommended; however, NrEO might be considered as the PPT post-treatment for reducing harmful effects of herbicide residues in the soil on non-target plants.

Razviće semena kod skrivenosemenica nastaje kao rezultat procesa dvojnog oplođenja, u kome se jedna spermatična ćelija spaja sa jajnom ćelijom, dok se druga spermatična ćelija spaja sa centralnom ćelijom. Koordinisanо razvićе semenjače, endosperma i embriona nakon oplođenja zavisi od ravnotežnog odnosa roditeljskih genoma, što je preduslov za odvijanje normalnog razvića semena. Narušavanje ravnoteže u genomskom doprinosu roditelja često dovodi do brojnih poremećaja u razviću semena i embriona, a u drastičnim slučajevima može dovesti i do potpunog prekida razvića semena. Ova pojava predstavlja jednu od glavnih prepreka za upotrebu genetičkog inženjerstva u cilju stvaranja apomiktičnih semena, kao i za prevazilaženje međuvrsnih seksualnih reproduktivnih barijera. Jedan od glavnih mehanizama koji narušava ravnotežu odnosa roditeljskih genoma u semenu model biljke Arabidopsis thaliana jeste represija sinteze auksina uz pomoć Polikomb represivnog kompleksa 2 (PRC2). Međutim, ni smanjenje nivoa ekspresiju gena PRC2 kompleksa ni povišavanje nivoa auksina nisu dovoljni da dovedu do apomiksije. Evolutivno konzervisana uloga PRC2 tokom razvića zasniva se na ulozi ovog kompleksa da postranslaciono modifikuje histon H3, a proteini koji prepoznaju posttranslacione modifikacije (PTM) histona, odnosno čitači histonskog koda, često su uključeni u regulaciju razvića u sprezi sa PRC2. Stoga čitači histonskog koda predstavljaju pogodne kandidate za dodatni uticaj na funkciju PRC2 kompleksa. Dosadašnji podaci pokazuju da su čitači histonskih modifikacija biljaka uključeni u veliki broj različitih bioloških i razvojnih procesa u ćeliji, ali da je broj opisanih čitača relativno mali. Predmet istraživanja ove doktorske disertacije jeste regulacija razvića semena kod biljke А. thaliana, sa posebnim osvrtom na ulogu EML proteina u čitanju određenih modifikacija histona, kao i na ulogu ovih proteina u kontroli endogenog nivoa auksina i njegove kompartmentizacije tokom razvića semena. Rezulta, In flowering plants, seed development is initiated by double fertilization of the female gametophyte, whereby one sperm cell fuses with the egg cell, while the second fuses with the central cell. The successful and coordinated interaction between the developing seed compartments (seed coat, endosperm and embryo) depends on the balance in parental genome contributions. Any change in the genomic contribution of one parent often leads to severe defects including seed abortion. This represents one of the main obstacles for the engineering of asexual reproduction through seeds (apomixis), and for generating new interspecies hybrids. The repression of auxin synthesis by the Polycomb Repressive Complex 2 (PRC2) is a major mechanism contributing to sensing genome balance. However, current efforts focusing on identification of regulators decreasing PRC2 or elevating auxin levels have not yet resulted in the production of apomictic seed. Evolutionary conserved role of PRC2 during developmental processes in plants is based on the role of this complex to modify histone H3. Furthermore, proteins involved in recognizing histone posttranslational modifications (PTMs) are often included in the regulation of plant development in conjunction with in PRC2. So far a relatively few plant so-called histone readers have been identified to be instrumental for many developmental processes. Results from this study show that EML1 and EML3, proteins that belong to the EMSY-Like Tudor/Agenet protein family, are H3K36me3 histone readers necessary to maintain parental genome balance in Arabidopsis. By analyzing the mutant phenotypes, our results demonstrate that both EML1 and EML3 are required to prevent seed development before fertilization, and to regulate the balance of parental contributions after fertilization. We hypothesize that EML1 and EML3 function to repress paternal gene expression by regulating auxin transport and signaling...

Predmet ove disertacije je iskorišćenje otpadnih sirovina koje su dobijene u procesu prerade jagorčevine (Primula veris), rastavića (Equisetum arvense) i hajdučke trave (Achillea millefolium) za dobijanje biološki aktivnih ekstrakata bogatih polifenolima..., The subject of this dissertation is the utilization of waste materials from the processing of primrose (Primula veris), horsetail (Equisetum arvense) and yarrow (Achillea millefolium) for obtaining biologically active and polyphenol-rich extracts...

The subject of this dissertation is the utilization of waste materials from the processing of primrose (Primula veris), horsetail (Equisetum arvense) and yarrow (Achillea millefolium) for obtaining biologically active and polyphenol-rich extracts..., Predmet ove disertacije je iskorišćenje otpadnih sirovina koje su dobijene u procesu prerade jagorčevine (Primula veris), rastavića (Equisetum arvense) i hajdučke trave (Achillea millefolium) za dobijanje biološki aktivnih ekstrakata bogatih polifenolima...

Mixed medicinal plant waste was composted with addition of novel bacterial strains belonging to the genera Streptomyces, Paenybacillus, Bacillus and Hymenobacter. The composting was followed by assessment of chemical and biological parameters including C/N ratio, loss of organic matter, phosphorous and potassium content as well as CO2 generation and dehydrogenase activity during 164 days. The selected mesophilic bacterial starters had a potential to significantly reduce the period of mixed herb waste decomposition, from about 6 months to about 2.5 months. Based on the seed germination index of four plants (Fagopirum esculentum, Thymus vulgaris, Cynara scolimus and Lavandula officinalis) the germination and radial root growth of the investigated plants was improved by the inoculated compost. The germination index of all tested species on the mature inoculated composts was in average 60% higher compared to the control compost. The research indicates that the mesophilic starter addition into the herbs waste can contribute to the speed of waste decomposition and lead to the improvement of biofertilization effect of the obtained compost.

Mixed medicinal plant waste was composted with addition of novel bacterial strains belonging to the genera Streptomyces, Paenybacillus, Bacillus and Hymenobacter. The composting was followed by assessment of chemical and biological parameters including C/N ratio, loss of organic matter, phosphorous and potassium content as well as CO2 generation and dehydrogenase activity during 164 days. The selected mesophilic bacterial starters had a potential to significantly reduce the period of mixed herb waste decomposition, from about 6 months to about 2.5 months. Based on the seed germination index of four plants (Fagopirum esculentum, Thymus vulgaris, Cynara scolimus and Lavandula officinalis) the germination and radial root growth of the investigated plants was improved by the inoculated compost. The germination index of all tested species on the mature inoculated composts was in average 60% higher compared to the control compost. The research indicates that the mesophilic starter addition into the herbs waste can contribute to the speed of waste decomposition and lead to the improvement of biofertilization effect of the obtained compost.

This paper has demonstrated the valorization of inexpensive and readily available restaurant waste containing most consumed food and beverage residues as adsorbents for methylene blue dye. Coffee, tea, lettuce and citrus waste have been utilized without any pre-treatment, thus the adsorption capacities and dye removal efficiency were determined. Coffee waste showed the highest adsorbent capacity, followed by tea, lettuce and citrus waste. The dye removal was more effective as dye concentration increases from 5 up to 60 mg/L. The favorable results obtained for lettuce waste have been especially encouraged, as this material has not been commonly employed for sorption purposes. Equilibrium data fitted very well in a Freundlich isotherm model, whereas pseudo-second- order kinetic model describes the process behavior. Restaurant waste performed rapid dye removal at no cost, so it can be adopted and widely used in industries for contaminated water treatment., Metilen plavo je bazna boja sa strukturom heterocikličnog aromatičnog jedinjenja, koja se u dobu savremenog društva često koristi za bojenje raznih tipova materijala. Efluenti iz industrije boja predstavljaju jednu od najproblematičnijih vrsta otpadnih voda za tretiranje, usled njihove velike biološke i hemijske potrebe za kiseonikom. Pored toga, toksičnost i teško razgradiva priroda boja mogu značajno uticati na fotosintetičku aktivnost vodenog sveta. Adsorpcijom na čvrstim nosačima mogu se ukloniti, odnosno, svesti na minimum razni tipovi zagađivača, zbog čega ova tehnika ima široku primenu u kontroli zagađenja voda. S tim u vezi, ispitivana je mogućnost iskorišćenja sirovog otpada iz restorana za adsorpciju i uklanjanje boje metilen plavo iz vodenih rastvora. U radu su određivani adsorpcioni kapaciteti otpadnih sirovina najčešće konzumiranih namirnica, uključujući kafu, čaj, zelenu salatu i mešavinu citrusnog voća (citrusa). Proces adsorpcije izveden je u šaržnom režimu, uz mešanje na tresilici, u uslovima ambijentalne temperature. Efikasnost procesa praćena je u zavisnosti od promene koncentracije boje u radnim rastvorima. Pokazano je da otpadna kafa ispoljava najviši adsorpcioni kapacitet, a za njom otpadni čaj, zelena salata i citrusi, redom. Nakon 30 min odigravanja reakcije, na kafi se vezalo gotovo 90%, dok na čaju 80%, zelenoj salati 60% i citrusima 30% od početne koncentracije rastvora boje. Vezivanje boje na adsorbentima bilo je efikasnije u slučajevima kada je koncentracija rastvora boje rasla od 5 do 60 mg/L. Na osnovu ispitivanja najčešće primenjivanih modela izo- termi za definisanje adsorpcione ravnoteže, pronađeno je da su ravnotežni podaci, u slučajevima svih vrsta adsorbenata, bili u skladu sa Frojndlihovom adsorpcionom izotermom. S tim u vezi, smatra se da je proces odigravanja reakcije baziran na interakcijama između molekula boje i funkcionalnih grupa na heterogenoj površini adsorbenata. Kinetika i mehanizam reakcija opisani su po principu mod

Uvae ursi folium (Arctostaphylos uva ursi, Ericaceae) is the best known and most widely used herbal urinary antiseptic. In traditional medicine, other Ericaceae species are also used for the treatment of urinary tract infections. The present study investigates antimicrobial activity of five species of Ericaceae family native to the Balkan Peninsula: Arbutus unedo, Bruckenthalia spiculifolia, Calluna vulgaris, Erica arborea and Erica carnea. Ethanolic extracts were tested against 10 different gram-positive and gram-negative bacteria by the disc diffusion technique, where standard tetracycline, streptomycin and penicillin discs and discs containing crystal violet (1 mg/ml) and solvent (70.0% v/v ethanol) were used as controls. The most prominent antibacterial effect was achieved on Staphylococcus aureus with extracts of Calluna vulgaris and Erica carnea. Tested samples showed no activity against the gram-negative strains Pseudomonas aeruginosa, Escherichia coli and Klebsiella pneumoniae. Inhibitory effects on the growth of gram-positive bacteria were more potent. The exception is Arbutus unedo ethanol extract which exhibited certain activity against a laboratory strain of wild Escherichia coli. Antimicrobial activity of the ethanolic extracts against 10 tested strains of bacteria in disc diffusion assay was generally weak, even for sample in which HPLC determination confirmed the presence of arbutin (secondary metabolite responsible for most of the antibacterial activity of Uvaeursi folium)., Najpoznatiji i najviše korišćeni biljni uroantiseptik je list uve, Uvaeursi folium (Arctostaphylos uva ursi, Ericaceae). U tradicionalnoj medicini često se i druge vrste familije Ericaceae spominju u lečenju urinarnih infekcija. Provera antimikrobne aktivnosti izvršena je za sledeće biljne vrste ove familije koje samostalno rastu u flori Balkanskog poluostrva: Arbutus unedo, Bruckentalia spiculifolia, Calluna vulgaris, Erica arborea i Erica carnea. Antimikrobna aktivnost etanolnih ekstrakata listova ispitivana je diskdifuzionom metodom, korišćenjem 10 sojeva gram pozitivnih i gram negativnih bakterija, pri čemu su kao kontrole korišćeni standardni diskovi tetraciklina, streptomicina i penicilina, kao i diskovi sa rastvorom kristalvioleta (1 mg/ml) i rastvarača (70.0% v/v etanol). Pseudomonas aeruginosa, Escherichia coli i Klebsiella pneumoniae nisu osetljive ni na jedan od ispitivanih ekstrakata. Kao najbolji rezultati mogu se izdvojiti aktivnosti ekstrakta Calluna vulgaris i Erica carnea na bakterijski soj Staphylococcus aureus. Testirani uzorci uglavnom ispoljavaju antimikrobnu aktivnost prema gram pozitivnim sojevima. Izuzetak je etanolni ekstrakt vrste Arbutus unedo, koji ispoljava određenu antimikrobnu aktivnost prema laboratorijskom soju Escherichia coli. Antimikrobna aktivnost etanolnih ekstrakata prema 10 testiranih bakterijskih sojeva u diskdifuzionoj metodi je veoma slaba, čak i za uzorak za koji je HPLC analizom utvrđeno prisustvo arbutina (sekundarni metabolit odgovoran za uroantiseptično dejstvo lista uve).

The importance of coffee waste utilization is based on the fact that it contains a large amount of biologically valuable components. Preparation of espresso coffee produces substantial quantities of polyphenolic acids that have a significant antioxidant activity. In this work, the contents of polyphenols and antioxidant activity of extracts obtained from spent espresso coffee were analyzed using different solvent systems. A 70% solution of methanol and a 70% solution of ethanol and distilled water were used as solvents. The total amounts of polyphenols were determined by the Folin-Ciocalteu method, while the antioxidant activities were determined by DPPH inhibition (2,2-diphenyl-1-picrylhydrazyl) and FRAP (Ferric Reducing Antioxidant Power). Both methods confirmed that the order of antioxidant activity of obtained dried extracts is as follows: water extract lt methanol extract lt ethanol extract, which was in accordance with their polyphenols content. Mild prooxidant activity was observed in the concentration of 200 μg/ml while investigating the DPPH inhibition. Prooxidant activity is a characteristic of some polypenolic acids that is considered to be one of the mechanisms of anticancer activity. The inhibition of DPPH radical, expressed by IC50 values, was compared with the results of the commercial antioxidants such are ascorbic acid and BHT (butylated hydroxytoluene). Comparing the IC50 values of ascorbic acid and BHT with the IC50 values of tested extracts it can be concluded that waste coffee extracts could be a good source of natural antioxidants., U radu je određivan sadržaj polifenola i antioksidativna aktivnost osušenih ekstrakata otpadne espreso kafe dobijenih primenom različitih rastvarača. Kao rastvarači, u ekstrakcijama su korišćeni 70% rastvor metanola, 70% rastvor etanola i destilovana voda. Određen je ukupan sadržaj polifenola i antioksidativna aktivnost metodama inhibicije DPPH (2,2-difenil-1-pikrilhidrazil) radikala i FRAP (engl. ferric reducing antioxidant power). Inhibicija DPPH radikala je izražena preko IC50 vrednosti, a rezultati su poređeni sa rezultatima komercijalnih antioksidanata, askorbinskom kiselinom i BHT (butil-hidroksi-toluen). Obe metode su potvrdile da je redosled antioksidativne aktivnosti dobijenih suvih ekstrakta sledeći: vodeni ekstrakt lt metanolni ekstrakt lt etanolni ekstrakt. Poređenjem sa vrednostima IC50 za askorbinsku kiselinu i BHT može se zaključiti da ekstrakti otpadne kafe mogu biti dobar izvor prirodnih antioksidanata.