Isolation of Active Substances from the Seeds of the Milk Thistle Plant (Silybum marianum) and Determination of Antioxidant Activity

Opisana je izolacija silimarina, smjese dobro definiranih flavonolignana, iz sjemena biljke sikavice (Silybum marianum). Silimarin je ekstrahiran acetonom iz deoleinizirana sjemena bez zagrijavanja. Iskorištenje je iznosilo Y = 4,1 %. Antioksidacijska aktivnost silimarina određena je na sobnoj temperaturi kolorimetrijski 2,2-difenil-1-pikrilhidrazilom (DPPH) pri λ = 515 nm. Aktivnost je određena na temelju smanjenja apsorbancije, kao rezultat promjene boje DPPH iz purpurne u žutu. Dobiveni rezultati pokazuju da je askorbinska kiselina znatno jači antioksidans od ispitivana silimarina, ali je silimarin znatno jači hvatač radikala DPPH od standarda silibinina.Isolation of silymarin, a mixture of well-defined flavonolignans, from the seeds of milk thistle (Silybum marianum) was achieved. Silymarin was extracted from defatted seed with acetone without heating; the yield was Y=4.1 %. The antioxidant activity of silymarin was determined at ambient temperature by means of a 2,2-diphenyl-1-picrylhydrazyl (DPPH) colorimetry with a detection scheme at λ= 515 nm. The activity was evaluated by the decrease in absorbance as the result of a DPPH radical color change from purple to yellow. The results obtained showed that ascorbic acid was a substantially more powerful antioxidant than silymarin, but silymarin was a significantly stronger quencher of DPPH radical than the standard silibinin

Clustering of Lyman alpha emitters at z ~ 4.5

We present the clustering properties of 151 Lyman alpha emitting galaxies at z ~ 4.5 selected from the Large Area Lyman Alpha (LALA) survey. Our catalog covers an area of 36' x 36' observed with five narrowband filters. We assume that the angular correlation function w(theta) is well represented by a power law A_w = Theta^(-beta) with slope beta = 0.8, and we find A_w = 6.73 +/- 1.80. We then calculate the correlation length r_0 of the real-space two-point correlation function xi(r) = (r/r_0)^(-1.8) from A_w through the Limber transformation, assuming a flat, Lambda-dominated universe. Neglecting contamination, we find r_0 = 3.20 +/- 0.42 Mpc/h. Taking into account a possible 28% contamination by randomly distributed sources, we find r_0 = 4.61 +/- 0.6 Mpc/h. We compare these results with the expectations for the clustering of dark matter halos at this redshift in a Cold Dark Matter model, and find that the measured clustering strength can be reproduced if these objects reside in halos with a minimum mass of 1-2 times 10^11 Solar masses/h. Our estimated correlation length implies a bias of b ~ 3.7, similar to that of Lyman-break galaxies (LBG) at z ~ 3.8-4.9. However, Lyman alpha emitters are a factor of ~ 2-16 rarer than LBGs with a similar bias value and implied host halo mass. Therefore, one plausible scenario seems to be that Lyman alpha emitters occupy host halos of roughly the same mass as LBGs, but shine with a relatively low duty cycle of 6-50%.Comment: 23 pages in preprint format, 4 figures, ApJ accepte

Photoelectron Spectroscopy of 9-Substituted Anthracenes

The Hel photoelectron (PE) spectra of anthracene and ten of its 9-substituted derivatives with methyl, t ert-butyl, fluoro; chloro, bromo, methoxy, aldehyde, cyano, nitro and phenyl groups as substituents have been recorded. Systems arising from Jt-ionizations are assigned. The assignment is supported by molecular orbital calculations. The effect of the substituent on the lowest ionization energy is well described by Hammett substituent constants based on the benzene system

Photoelectron Spectra of Lignin Model Compounds

The He I photoelectron (PE) spectra of the 77 lignin subunits were measured and arranged in classes of compounds according to the following functional groups: aldehydes, ketones, alcohols, carboxylic acids, functionalized polymethyl benzenes and miscellaneous lignin subunits. In all spectra the highest occupied molecular orbital (HOMO) was assigned to a jt-orbital

Molecular Imaging Mass Spectrometry

Molecular imaging mass spectrometry (IMS) is a recently developed method for direct determination of spatial distribution of biopolymers, preferably proteins on cell surface and tissues. Imaging mass spectrometry data are mainly based on Matrix-Assisted Laser Desorption/Ionization- Time of Flight (MALDI TOF). The MALDI TOF based imaging mass spectrometry was applied for determination of changes in kidney tissue of sensitive mice after poisoning with aristolochic acid I. The second application presented here were changes in the gastric tissue in mice after infection with Helicobacter pylori, as a model of gastric cancer in humans caused by this pathogen microorganism. Molecular imaging mass spectrometry can be applied in medicine, mostly for identification of candidate biomarkers for malignant and non-malignant diseases. Furthermore, imaging MS has almost unlimited capacity in agriculture, food technology and biotechnology, e. g. for monitoring, process development and quality control of manufactured tissue of animal, plant and microbial origin.Razvoj masene spektrometrije u posljednjih 20 godina i primjena ove metode u analitici makromolekula, prije svega proteina i ugljikohidrata, otvorio je nove perspektive za uporabu ove metode u medicini, biotehnologiji i ostalim biodisciplinama. Ova se metoda može primijeniti i u novim područjima, kao što su mikroelektronika, geokemija i površinska analitika, posebice nanotehnologija.1 Imaging mass spectrometry (IMS) je jedna vrsta sinteze dviju tehnika, histokemije i masene spektrometrije. Ova metoda omogućava optički prikaz rasporeda raspodjele malih i velikih molekula u uzorku, pa čak i makromolekula kao što su proteini i polisaharidi. 2 Optimalizacija masene spektrometrije, ali također i veliki napredak u razvoju instrumentacije dodatni su razlog za sve veći interes za ovu metodu u mnogim interdisciplinarnim područjima medicine, biotehnologije, ali ianorganskim tehnologijama i znanosti o materijalima (material science).1 Imaging MS daje mogućnost izravnog praćenja prostorne raspodjele molekula u stanicama ili tkivu. Za dobivanje molekularne distribucije u adekvatno pripravljenom uzorku najčešće se primjenjuju Matrix-Assisted Laser Deionisation (MALDI) Time of Flight (TOF) ili Secondary Ion Mass Spectrometry (SIMS)4. Pomoću MALDI TOF dobiva se slika prostorne raspodjele velikih molekula, prije svega proteina. Rezolucija ove metode je 25 μm, što je još uvijek nedovoljno da se prati raspored komponenata na razini stanice, ali novi instrumenti omogućavaju i bolju rezoluciju u području od oko 10 μm. SIMS je metoda koja se primjenjuje za praćenje prostorne raspodjele malih molekula, najčešće biološki aktivnih supstancija. 1,5,6 MALDI TOF je pak metoda izbora za analizu prostorne distribucije makromolekula, najčešće proteina i polipeptida. IMS se do sada primjenjivala za patološke studije i analizu biomarkera,3,7-10 za analizu tumora, kao glioblastoma,3 karcinoma debeloga crijeva,11 metastaza u jetri,12 kod praćenja promjena u moždanom tkivu kod Alzheimerove bolesti10 i ostalih promjena u živčanom tkivu,14 kod nefrotoksiciteta13 itd. Na sl. 1 prikazan je princip određivanja raspodjele makromolekula pomoću MALDI TOF masene spektrometrije. Nakon rezanja tankog sloja i fiksiranja, tkivu se dodaje određena supstancija (matrix) koja omogućava optimalnu ionizaciju i mobilizaciju makromolekula. Vrijeme letenja (time of flight) je obrnuto proporcionalno vrijednosti kvocijenta fragmentirane mase i (pozitivnog) naboja m/z. Računalo automatski upravlja sveobuhvatnim snimanjem površine (screening) i daje površinsku sliku rasporeda molekule određene m/z vrijednosti. To se vidi i na slici 4 koja daje raspodjelu molekule s m/z vrijednosti od 7.791 u uzorku bubrega miša otrovanog aristolohijskom kiselinom I (AA I). Na slici 4 je prikazan raspored triju različitih molekula u istim uzorcima. Model miša tretiranog s AA I i AA II je izoliran jer postoje opravdani pokazatelji da je kronično trovanje ovom suspstancijom jedan od uzroka endemskog nefritisa (EN). Endemski nefritis je kronično oboljenje bubrega, proširen u endemskim područjima u donjem toku rijeke Dunava. U Hrvatskoj se ova bolest pojavljuje u određenim selima Brodske Posavine zapadno od Slavonskog Broda. Bakterija Helicobacter pylori je uzročnik infekcije želuca, koja dovodi do kroničnoga gastritisa i, godinama nakon infekcije, do karcinoma. Model miša, inficiranog s Helicobacter pylori pokazuje da 15 dana nakon infekcije dolazi do promjene u raspodjeli proteina, i da protein s m/z vrijednosti 9,962 gotovo nestaje s maseno-spekrometrijskog profila. Ovi pokusi su prvi koraci u definiranju molekulskih promjena kod karcinogeneze želuca, definiciji novih biomarkera za otkrivanje rizika i prognozu kod ove zloćudne bolesti. - IMS je tehnika kojom se kombinira histologija i masena spektrometrija MALDI TOF. - IMS trenutačno nalazi primjenu u medicini, za identifikaciju kandidata za biomarkere za maligne i druge bolesti. - Kao tehnika, imaging mass spectrometry ima velike perspektive za primjenu u agrikulturi, prehrambenoj tehnologiji i biotehnologiji i to za kontrolu kvalitete i praćenja promjena u biljnim, životinjskim tkivima i mikrobnim stanicama tijekom procesa proizvodnje

Effect of fermentation conditions on content of phenolic compounds in red wine

The evidence of compounds that increase the nutritive value of red wines has been presented in a number of papers. These compounds include catechins and proanthocyanidins among others. Their protective effect on the cardiovascular system and anticarcinogenic properties has been proved. The effect of maceration conditions and increased solid grape parts content, seed in the first place, on the content of phenolic compounds of wine was investigated. Several micro-trials were performed with Cabernet sauvignon sort; in some variants time and temperature of maceration were varied, while the ratio of residual stem and content of seed was increased several times, resulting in a significant change of phenolic compounds content in the obtained wine samples. The presence of ripe stem yielded good results, but only during six days of maceration, while in the case of longer maceration, the change of colour quality was negative. Supplementary quantities of seeds during maceration resulted in an increase of total phenols and catechins. A significant influence on colour of wines was also observed, especially in wines obtained applying shorter maceration

Cardiotoxicity of fire gases

Prikazani su direktni i indirektni uzroci hipoksije miokarda u požarima. Među prvima su zapreke u opskrbi kisikom, tj. hipoksija u samoj atmosferi požara i karboksihemoglobinemija, a među drugima su zapreke u korištenju kisika, tj. .teško fizičko i psihofizičko opterećenje, karboksimioglobin u miokardu i inhibicija citokromoksidaze cijanovodikom. Kao dodatna opasnost za miokard navedeni su klorirani ugljikovodici (gašenje) i njihovi pirolitički produkti (fozgen). Opširnije je opisana kardiotoksičnost ugljik-monoksida s posebnim osvrtom na Haldaneov učinak i na ponavljane ekspozicije (vatrogasci, pušači, vozači u gustom prometu). Spomenuto je i djelovanje ugljik-monoksida na agregaciju trombocita kao i djelovanje na ubrzanje ateroskleroze. Zbog čestog izgaranja plastlke što sadrži dušika (poliuretani, poliaikrilonitrili, poliamidi .itd.) suvremeni požari proizvode i cijanovodik, pa je opisano i njegovo djelovanje na miokard. Kardiotoksičnost halogeniranih ugljikovodika, proučavana prethodno i vlastitim radovima, posebno je važna za vatrogasce zbog upotrebe halona za gašenje požara. Kod incineracija (smeća) može se u atmosferi pojaviti i tetraklordibenzodioksin (TCDD).Direct and indirect causes of myocardial hypoxia in fires are described. Among the former are the defects in oxygen supply and access i.e. hypoxia in the fire atmosphere and carboxyhaemoglobinaemia, while among the latter are the defects in oxygen disposal and use due to heavy physical and psychophysical efforts, the presence of carboxymyoglobin in the heart muscle and the inhibition of cytochrome oxydase by cyanides. As an additional hazard to the heart muscle chlorinated hydrocarbons (fire extinguishers) or their products (phosgene) should also be considered. The cardiotoxicity of carbon monoxide is presented in detail with special regard to the Haldane effect and repeated exposures (firemen, smokers, drivers of motor vehicles in dense traffic). A possible thrombocyte aggregation effect of carbon monoxide as well as its possible role in the long-term development of atherosclerosis are also dealt with. Because of the frequency of fires involving nitrogen-containing polymers such as polyurethanes, polyacrilonitriles and polyarnides hydrogen cyanide may be produced and its toxic cardiac action should be taken into consideration. The cardiotoxicrty of halogenated hydrocarbons investigated earlier, is outlined is being .important for firemen using halones extinguishers. The appearance of tetrachlorodibenzodioxin (TCDD) in incineration of garbage is also mentioned

Formaldehyde in present-day environmental toxicology

Prikazana je eko-toksikološka važnost formaldehida, osobito u njegovoj primjeni kao sastavnog dijela sintetskih smola koje se masovno upotrebljavaju u tekstilnoj, građevinskoj, drvnoj i kemijskoj industriji, u industriji namještaja, gume i plastike itd. Opisana su kemijska, fizička i biološka svojstva tog plina izvanredne reaktivnosti, a zatim glavni izvori njegovih emisija u profesionalnoj i općoj ekološkoj ekspoziciji. Iscrpno su prikazani tehnološki procesi primjene formaldehidnih smola, a zatim patološke promjene, koje su podijeljene na toksične, alergijske, mutagene i karcinogene, a s obzirom na lokalizaciju kao dermatološke i respiratorne.The importance of formaldehyde from the point of view of environmental toxicology is presented with special regard to the numerous applications of formaldehyde-containing synthetic resins in the textile industry, in building, wood and furniture, rubber, plastics and chemical industries, in medicine, etc. The chemical, physical and physiological properties of this gas of high chemical reactivity are described, as well as the main sources of its emanations in occupational and general environments. The technological processes in which formaldehyde resins are used are reviewed and the pathological changes provoked by them, both dermatologic and respiratory, are presented. According to their nature the pathological formaldehyde effects are divided into toxic, allergic, mutagenic and carcinogenic