Phytochemical and biochemical analysis of selected species of subfamily Polygonoideae (Polygonaceae A. L. de Jussieu 1789) from Central and Western Balkan regions.

U ovoj doktorskoj disertaciji prikazani su rezultati istraživanja 15 vrsta  biljaka  koje  pripadaju  rodovima Rumex,  Polygonum, Bistorta,  Persicaria i  Fagopyrum,  podfamilije  Polygonoideae, familije  Polygonaceae,  sakupljenih  na  teritoriji  centralnog  i zapadnog  Balkana u periodu od 2009-2011. godine. Sprovedena istraživanja  su  se  odvijala  u  dva  pravca:  fitohemijska  i biohemijsko-biološka  ispitivanja.  Predmet  analiza  bili  su ekstrakti  herbi  i  rizoma  ispitivanih  biljaka.  Fitohemijska ispitivanja  obuhvatila  su,  pored  spektrofotometrijskog određivanja  ukupnih  fenola,  ukupnih  flavonoida  i  ukupnih antrahinonskih jedinjenja, i određivanje sadržaja 51 komponente iz standardne smeše različitih klasa fenolnih jedinjenja LC-MSMS  metodom,  odnosno  hromatografsko  profilisanje  ekstrakata LC-DAD-MS  metodom.  Odabirom  nekoliko  različitih  model sistema  za  merenje  antioksidantne  aktivnosti  (neutralizacija DPPH  radikala,  redoks  kapacitet  -  FRAP  test,  skevindžer aktivnost  prema  superoksidanjon  radikalu,  NO  radikalu  i  OH radikalu,  kao  i  inhibicija  lipidne  peroksidacije)  procenjen  je antioksidantni  potencijal  ekstrakata,  dok  je  za  procenu  njihove antiinflamatorne  aktivnosti  korišćen  potencijal  inhibicije biosinteze medijatora inflamacije u humanim trombocitima (kao model  sistemu).  Mikrobiološka  ispitivanja  su  obuhvatila određivanje  potencijala  ovih  vrsta  u  inhibiciji  rasta  serije  gram pozitivnih i gram negativnih sojeva batkerija. Konačno, urađena je  analiza  korelacije  hemijskog  sastava,  biološke  aktivnosti  i pripadnosti taksonomskim grupama.Phytochemical  and  biochemical  analysis  of  herbal  and  root ethanol  extracts  of  15  species  belonging  to  different  genera (Rumex,  Polygonum,  Bistorta,  Persicaria and  Fagopyrum)  of subfamily  Polygonoideae,  was  examined.  Phytochemical characterization  included  spectrophotometric  determination  of total  phenolic,  total  flavonoids  and  total  anthraquinone  contents, quantification  of  51  secondary  metabolites  by  LC/MS/MS analysis  and  chromatographic  fingerprinting by  LC/DAD/MS technique,  of  prepared  extracts.  The  antioxidant  activity  was evaluated  by  measuring  ferric  reducing  ability  (FRAP)  of  the extracts and their radical scavenging capacity towards DPPH, OH, NO and O2– radicals, and inhibition of lipid peroxidation). Antiinflammatory activity was evaluated by LC/MS/MS monitoring of selected  metabolites  (12-(S)-HHT,  12(S)-HETE,  PGE2 ,  PGF2α, and TXB2) formed in cyclooxygenase and lipoxygenase pathways of arachidonic acid metabolism. Human platelets were used as a source  of  enzymes,  while  inflammation  was  induced  by calcimycin. The antibacterial activity of prepared  extracts against nine  bacterial  strains  was  evaluated  by  microtiter  assay  with resazurin as a colorimetric growth indicator

Phytochemical and biochemical analysis of selected species of subfamily Polygonoideae (Polygonaceae A. L. de Jussieu 1789) from Central and Western Balkan regions.

U ovoj doktorskoj disertaciji prikazani su rezultati istraživanja 15 vrsta  biljaka  koje  pripadaju  rodovima Rumex,  Polygonum, Bistorta,  Persicaria i  Fagopyrum,  podfamilije  Polygonoideae, familije  Polygonaceae,  sakupljenih  na  teritoriji  centralnog  i zapadnog  Balkana u periodu od 2009-2011. godine. Sprovedena istraživanja  su  se  odvijala  u  dva  pravca:  fitohemijska  i biohemijsko-biološka  ispitivanja.  Predmet  analiza  bili  su ekstrakti  herbi  i  rizoma  ispitivanih  biljaka.  Fitohemijska ispitivanja  obuhvatila  su,  pored  spektrofotometrijskog određivanja  ukupnih  fenola,  ukupnih  flavonoida  i  ukupnih antrahinonskih jedinjenja, i određivanje sadržaja 51 komponente iz standardne smeše različitih klasa fenolnih jedinjenja LC-MSMS  metodom,  odnosno  hromatografsko  profilisanje  ekstrakata LC-DAD-MS  metodom.  Odabirom  nekoliko  različitih  model sistema  za  merenje  antioksidantne  aktivnosti  (neutralizacija DPPH  radikala,  redoks  kapacitet  -  FRAP  test,  skevindžer aktivnost  prema  superoksidanjon  radikalu,  NO  radikalu  i  OH radikalu,  kao  i  inhibicija  lipidne  peroksidacije)  procenjen  je antioksidantni  potencijal  ekstrakata,  dok  je  za  procenu  njihove antiinflamatorne  aktivnosti  korišćen  potencijal  inhibicije biosinteze medijatora inflamacije u humanim trombocitima (kao model  sistemu).  Mikrobiološka  ispitivanja  su  obuhvatila određivanje  potencijala  ovih  vrsta  u  inhibiciji  rasta  serije  gram pozitivnih i gram negativnih sojeva batkerija. Konačno, urađena je  analiza  korelacije  hemijskog  sastava,  biološke  aktivnosti  i pripadnosti taksonomskim grupama.Phytochemical  and  biochemical  analysis  of  herbal  and  root ethanol  extracts  of  15  species  belonging  to  different  genera (Rumex,  Polygonum,  Bistorta,  Persicaria and  Fagopyrum)  of subfamily  Polygonoideae,  was  examined.  Phytochemical characterization  included  spectrophotometric  determination  of total  phenolic,  total  flavonoids  and  total  anthraquinone  contents, quantification  of  51  secondary  metabolites  by  LC/MS/MS analysis  and  chromatographic  fingerprinting by  LC/DAD/MS technique,  of  prepared  extracts.  The  antioxidant  activity  was evaluated  by  measuring  ferric  reducing  ability  (FRAP)  of  the extracts and their radical scavenging capacity towards DPPH, OH, NO and O2– radicals, and inhibition of lipid peroxidation). Antiinflammatory activity was evaluated by LC/MS/MS monitoring of selected  metabolites  (12-(S)-HHT,  12(S)-HETE,  PGE2 ,  PGF2α, and TXB2) formed in cyclooxygenase and lipoxygenase pathways of arachidonic acid metabolism. Human platelets were used as a source  of  enzymes,  while  inflammation  was  induced  by calcimycin. The antibacterial activity of prepared  extracts against nine  bacterial  strains  was  evaluated  by  microtiter  assay  with resazurin as a colorimetric growth indicator

Plant mediated synthesis of zero valent iron nanoparticles and its chracterisation

Nanoscale zero valent-iron (nZVI) particles represent an important material for diverse environmental applications because of the exceptional electron-donating properties, which can be exploited for applications such as reduction, catalysis, adsorption, and degradation of a broad range of pollutants. The search for “green” strategies leads to the advancement in the plantmediated synthesis of ZVI nanoparticles.Within the framework of this work, the possibility of synthesis of nano zerovalent iron (nZVI) was investigated using extracts of oak, mulberry, green tea, pomelo peel, fresh orange peel and orange peel that was previously dried. Also, the subject of the investigation was the characterization of the obtained nanomaterials

Optimization of extraction conditions for secondary biomolecules from various plant species

Extraction of plant secondary metabolites is an essential step in isolation of natural products. Non-optimized extraction conditions can lead to losses, degradation and modification of the biomolecules. In this paper, the influence of different solvent mixtures, solvent amounts, temperature, extraction time, and procedures for defatting on yield and profile of various classes of secondary metabolites was investigated. Rumex alpinus was used for the extraction of anthraquinones, Glycine max for isoflavonoids, Chaerophyllum bulbosum for flavonoids and phenolic acids, Anthriscus sylvestris for lignans and coumarins, alkaloids were extracted from Lupinus albus and sesquiterpene lactones from Artemisia absinthium. Extraction efficiency was evaluated by use of LC-DAD-ESI-MS/MS. The compromise extraction solvent for all of the examined compounds is 80 % methanol, mixed in ratio 13 : 1 with plant material. Maceration should last for six hours, repeated four times with fresh solvent. Defatting of the extracts does not lead to significant losses of the compounds of interest. It is acceptable to use extraction and evaporation temperature of 60ºC, while the extracts should be stored in the dark, on -20ºC. [Projekat Ministarstva nauke Republike Srbije, br. 172058

In Vitro Study of Two Edible Polygonoideae Plants: Phenolic Profile, Cytotoxicity, and Modulation of Keap1-Nrf2 Gene Expression

Polygonum aviculare and Persicaria amphibia (subfam. Polygonoideae) are used in traditional cuisines and folk medicine in various cultures. Previous studies indicated that phytochemicals obtained from Polygonoideae plants could sensitize chemoresistant cancer cells and enhance the efficacy of some cytostatics. Here, the cytotoxic properties of chemically characterized ethanol extracts obtained from P. aviculare and P. amphibia, individually and in combination with doxorubicin (D), were determined against hepatocarcinoma HepG2 cells. Phenolic composition, cell viability, cell cycle, apoptosis, and the expression of Keap1 and Nrf2 were examined by following methods: LC-MS/MS, LC-DAD-MS, MTT, flow cytometry, and qRT-PCR. Extracts were rich in dietary polyphenolics. Synergistic cytotoxicity was detected for extracts combined with D. The observed synergisms are linked to the interference with apoptosis, cell cycle, and expression of Keap1-Nrf2 genes involved in cytoprotection. The combined approach of extracts and D could emerge as a potential pathway of chemotherapy improvement