Mechanism of 1,2-Hydride Shift in Some Carbocations Involved in Steroid Biosynthesis

The mechanism of 1,2-hydride shift in protosteryl C(20) cation (1A) and in dammarenyl C(20) cation (2A) was investigated by the semi-empirical AM1 method and ab initio quantum Chemical calculations (HF/3-21G level). Stationary points 1A/1B and 2A/2B, and the corresponding transition hydrido-bridged structures 1TS and 2TS were located on the energy surface. Process 1A→1B turned out to be energetically more favorable than process 2A→2B by ca. 9 kcal mol-1, mostly due to the unfavorable steric repulsive interaction between the methyl group at C(14) and the β-oriented side chain at C(17) in 1A and the lack of CC-hyperconjugative stabilization in 1A. The exothermicity of processes 1A→1B and 2A→2B was increased by subsequent introduction of substituents (H, Me, i-Pr, and t-Bu) at C(14). The more pronounced trend in 1A→1B proves that the origin of the relative stability of 1B comes from the steric interactions in 1A. Introduction of the halogen atom (F, Cl, and Br), due to its -I effect and relatively small size, changed the direction of the equilibrium 1AY/1BY, and 1AY was found to be by ca. 3 kcal mol-1 more stable than 1BY

Fitokemijski sastav mljevene začinske paprike iz istočne Dunavske regije

This study aimed to evaluate the phytochemical composition of sweet and hot ground paprika originating from different production sites in the Eastern Danube Region, i.e. in Croatia, Serbia and Hungary. Obtained results showed that composition and level of metabolites as well as antioxidant activity in paprika samples varied greatly among different locations. For the first time, clear differences in the chemical composition of sweet and hot paprika obtained from two Hungarian wax pepper cultivars produced in three different states of the Eastern Danube region were determined. Averagely, paprika samples from Croatia had the highest carotenoid content but the lowest levels of phenols and flavonoids. The hot paprika samples from Croatia had the highest content of capsaicin and dihydrocapsaicin. Thus, the results of this investigation indicate that bioactive compounds in paprika can vary greatly depending on their geographical origin. However, this variation can also occur due to different production technology and processing methods. Further investigations and methods need to be employed to determine the factors responsible for variation of content of bioactive compounds in paprika.Cilj ovog istraživanja bio je utvrditi fitokemijski sastav slatke i ljute začinske paprike podrijetlom iz različitih uzgojnih područja u Istočnoj dunavskoj regiji, tj. u Hrvatskoj, Srbiji i Mađarskoj. Dobiveni rezultati pokazali su kako se sastav i razina metabolita, kao i antioksidacijska aktivnost, u uzorcima začinske paprike značajno razlikuju između različitih uzgojnih područja. Prvi su put istaknute jasne razlike u kemijskome sastavu slatkih i ljutih sorata mađarske paprike proizvedene u tri različite države Istočne dunavske regije. Općenito, uzorci paprike iz Hrvatske imali su najveći sadržaj karotenoida, ali najniže vrijednosti fenola i flavonoida. Uzorci ljute paprike iz Hrvatske imali su najveći sadržaj kapsaicina i dihidrokapsaicina, kao i najviše Scovilleovih jedinica ljutine. Stoga, ovo istraživanje ukazuje na prikladnost određenih uzgojnih područja za dobivanje paprike željenoga kemijskoga sastava. Podatci su vrlo zanimljivi i važni za prehrambeno prerađivačku i farmaceutsku industriju, kao i za usmjeravanje regionalnih proizvođača prema dobivanju kvalitetne mljevene paprike

ANTIOXIDATIVE ACTIVITY AND BER APPEARANCE IN PEPPER FRUITS UNDER INFLUENCE OF BIOSTIMULANT TREATMENT AND HYBRID

U ovom je istraživanju praćena antioksidativna aktivnost ploda paprike, ukupan i komercijalni prinos, broj nekomercijalnih plodova te pojava vršne truleži ploda pod utjecajem tretmana s biostimulatorima i hibrida. Statistički značajno najveća (P≤0,01) antioksidativna aktivnost, određena DPPH metodom, zabilježena je kod tretiranih biljaka paprike Century F1 te je bila u značajnoj pozitivnoj korelaciji (0,526*) s komercijalnim prinosom kod oba hibrida. Općenito, tretman s biostimulatorima pozitivno je utjecao na sve ispitivane pokazatelje kod hibridne paprike Century F1, dok je značajno smanjio pojavu nekomercijalnih plodova i vršne truleži kod Blondy F1, što je u konačnici dalo značajno veći komercijalni prinos kod oba hibrida.Anti-oxidative activity of pepper fruits, total and commercial yield, number of non-commercial and BER fruits under influence of bio-stimulant treatment and pepper hybrid were investigated in this experiment. Significantly highest anti-oxidative activity, determined by DPPH assay, was recorded in treated Century F1 hybrid pepper plants. Also, positive significant correlation (r=0.526*) between commercial yield and anti-oxidative activity appeared. Generally, treatment with bio-stimulants positively influenced all investigated parameters in Century F1 hybrid, while in Blondy F1 significantly decreased number of non-commercial and BER fruits. At the end, compared to untreated plants, treatment resulted in higher commercial yield in both hybrids

ANTIOXIDATIVE ACTIVITY AND BER APPEARANCE IN PEPPER FRUITS UNDER INFLUENCE OF BIOSTIMULANT TREATMENT AND HYBRID

U ovom je istraživanju praćena antioksidativna aktivnost ploda paprike, ukupan i komercijalni prinos, broj nekomercijalnih plodova te pojava vršne truleži ploda pod utjecajem tretmana s biostimulatorima i hibrida. Statistički značajno najveća (P≤0,01) antioksidativna aktivnost, određena DPPH metodom, zabilježena je kod tretiranih biljaka paprike Century F1 te je bila u značajnoj pozitivnoj korelaciji (0,526*) s komercijalnim prinosom kod oba hibrida. Općenito, tretman s biostimulatorima pozitivno je utjecao na sve ispitivane pokazatelje kod hibridne paprike Century F1, dok je značajno smanjio pojavu nekomercijalnih plodova i vršne truleži kod Blondy F1, što je u konačnici dalo značajno veći komercijalni prinos kod oba hibrida.Anti-oxidative activity of pepper fruits, total and commercial yield, number of non-commercial and BER fruits under influence of bio-stimulant treatment and pepper hybrid were investigated in this experiment. Significantly highest anti-oxidative activity, determined by DPPH assay, was recorded in treated Century F1 hybrid pepper plants. Also, positive significant correlation (r=0.526*) between commercial yield and anti-oxidative activity appeared. Generally, treatment with bio-stimulants positively influenced all investigated parameters in Century F1 hybrid, while in Blondy F1 significantly decreased number of non-commercial and BER fruits. At the end, compared to untreated plants, treatment resulted in higher commercial yield in both hybrids

Protektivni učinak mladog in vitro češnjaka kod citotoksičnosti inducirane vodikovim peroksidom u stanicama hepatocelularnog karcinoma

Garlic is a valuable source material for medicines due to its known antitumor, hypolipidaemic, antioxidant, and immunomodulatory effects. This study compares the protective effects of conventionally grown (CG) and in vitro propagated garlic (PG) against hydrogen peroxide-induced cytotoxicity in HepG2 cells and their antioxidant activity. Garlic used in this study was obtained by planting garlic cloves or by planting the transplants of PG directly in the field. At the end of the vegetation period, CG and PG were sampled and extracts prepared for the experiment. Compared to conventionally grown garlic bulbs, PG leafy part yielded significantly higher content of polyphenols, flavonoids and alliin, and also showed equal or higher antioxidant activity, measured by the cell viability test, GSH and ROS level. Moreover, PG can be produced in less time (shorter vegetation period) and with significantly less material (cloves). Significantly higher content of alliin, polyphenols, and flavonoids and significantly higher yield of plant biomass in PG has a great potential to become a new production model with improved garlic properties as a medicine material.Češnjak je vrijedan izvor ljekovitih sastojaka te je i dalje vrlo raširen, posebice zbog svojih antitumorskih, hipolipidemičkih, antioksidacijskih i imunomodulatornih svojstava. Ovo istraživanje pokazuje protektivni učinak te antioksidacijsko djelovanje konvencionalno uzgojenog i češnjaka uzgojenog iz in vitro presadnica. Češnjak korišten u ovom istraživanju dobiven je sadnjom češnjeva (CG) ili in vitro presadnica (PG) izravno u tlo. Nakon završetka vegetacije, CG i PG češnjak su uzorkovani te su pripremljeni ekstrakti kako bi se usporedilo njihovo protektivno djelovanje te antioksidacijska aktivnost. Utvrđeno je kako metoda uzgoja koja je rezultirala krajnjim prinosom lukovice kod CG ili nadzemnog dijela kod PG češnjaka značajno utječe na povećanje sadržaja polifenola, flavonoida, antioksidacijski učinak i na sadržaj alina. Također, ispitano je protektivno djelovanje ekstrakata češnjaka na prethodno induciranu citotoksičnost vodikovim peroksidom kod HepG2 stanica. Na temelju testa stanične vijabilnosti, sadržaja GSH i ROS-a utvrđeno je kako PG češnjak može biti jednako ili više učinkovit u svom ljekovitom i antioksidacijskom djelovanju u odnosu na CG češnjak. Nadalje, PG u usporedbi s CG češnjakom može se proizvesti u kraćem vegetacijskom razdoblju, u kojem se ostvaruje veći prinos korištenjem manje originalnog reprodukcijskog materijala (češnjeva). Na kraju, potrebno je istaknuti kako značajno veći sadržaj alina, polifenola i flavonoida, uz istovremeni značajno veći prinos biomase, utvrđen kod PG češnjaka, eventualno donosi novi uzgojni model češnjaka s povećanim sadržajem bioaktivnih komponenti, što poboljšava funkcionalnost češnjaka kao izvora ljekovitih sastojaka

Does plant growing condition affects biodistribution and biological effects of silver nanoparticles?

Among the many different types, silver nanoparticles (AgNPs) are the most commercialized and applied engineered nanoparticles in a wide range of areas, including agriculture. Despite numerous studies on their safety and toxicity of AgNPs, data on their effect and interactions with terrestrial plants are largely unknown. This study aimed to investigate the effect of growing conditions on the response of pepper plants (Capsicum annuum L.) to citrate-coated AgNPs. Growth parameters, biodistribution, and defence response were examined in peppers grown hydroponically or in soil substrate. In addition, the effects of nano and ionic form of silver were compared. The leaves and stems of peppers grown in substrate showed a higher bioaccumulation compared to hydroponically cultivated plants. The nano form of silver accumulated to a higher extent than ionic form in both leaves and stems. Both silver forms inhibited pepper growth to a very similar extent either through hydroponic or substrate growing settings. Unlike other studies, which investigated the effects of unrealistically high doses of AgNPs on different plant species, this study revealed that vascular plants are also susceptible to very low doses of AgNPs. Both silver forms affected all parameters used to evaluate oxidative stress response in pepper leaves ; plant pigment and total phenolics contents were decreased, while lipid peroxidation and hydrogen peroxide level were increased in treated plants. Similar biological effects of both nano and ionic Ag forms were observed for both substrate and hydroponic growing systems

Potential ecotoxicological effects of antimicrobial surface coatings: a literature survey backed up by analysis of market reports

This review was initiated by the COST action CA15114 AMICI “Anti-Microbial Coating Innovations to prevent infectious diseases,” where one important aspect is to analyze ecotoxicological impacts of antimicrobial coatings (AMCs) to ensure their sustainable use. Scopus database was used to collect scientific literature on the types and uses of AMCs, while market reports were used to collect data on production volumes. Special attention was paid on data obtained for the release of the most prevalent ingredients of AMCs into the aqueous phase that was used as the proxy for their possible ecotoxicological effects. Based on the critical analysis of 2,720 papers, it can be concluded that silver-based AMCs are by far the most studied and used coatings followed by those based on titanium, copper, zinc, chitosan and quaternary ammonium compounds. The literature analysis pointed to biomedicine, followed by marine industry, construction industry (paints), food industry and textiles as the main fields of application of AMCs. The published data on ecotoxicological effects of AMCs was scarce, and also only a small number of the papers provided information on release of antimicrobial ingredients from AMCs. The available release data allowed to conclude that silver, copper and zinc are often released in substantial amounts (up to 100%) from the coatings to the aqueous environment. Chitosan and titanium were mostly not used as active released ingredients in AMCs, but rather as carriers for other release-based antimicrobial ingredients (e.g., conventional antibiotics). While minimizing the prevalence of healthcare-associated infections appeared to be the most prosperous field of AMCs application, the release of environmentally hazardous ingredients of AMCs into hospital wastewaters and thus, also the environmental risks associated with AMCs, comprise currently only a fraction of the release and risks of traditional disinfectants. However, being proactive, while the use of antimicrobial/antifouling coatings could currently pose ecotoxicological effects mainly in marine applications, the broad use of AMCs in other applications like medicine, food packaging and textiles should be postponed until reaching evidences on the (i) profound efficiency of these materials in controlling the spread of pathogenic microbes and (ii) safety of AMCs for the human and ecosystems

Determination of intact parabens in the human plasma of cancer and non-cancer patients using a validated fabric phase sorptive extraction reversed-phase liquid chromatography method with uv detection

Parabens have been widely employed as preservatives since the 1920s for extending the shelf life of foodstuffs, medicines, and daily care products. Given the fact that there are some legitimate concerns related to their potential multiple endocrine-disrupting properties, the development of novel bioanalytical methods for their biomonitoring is crucial. In this study, a fabric phase sorptive extraction reversed-phase liquid chromatography method coupled with UV detection (FPSE-HPLC-UV) was developed and validated for the quantitation of seven parabens in human plasma samples. Chromatographic separation of the seven parabens and p-hydroxybenzoic acid was achieved on a semi-micro Spherisorb ODS1 analytical column under isocratic elution using a mobile phase containing 0.1% (v/v) formic acid and 66% 49 mM ammonium formate aqueous solution in acetonitrile at flow rate 0.25 mL min−1 with a 24-min run time for each sample. The method was linear at a concentration range of 20 to 500 ng mL−1 for the seven parabens under study in human plasma samples. The efficiency of the method was proven with the analysis of 20 human plasma samples collected from women subjected to breast cancer surgery and to reconstructive and aesthetic breast surgery. The highest quantitation rates in human plasma samples from cancerous cases were found for methylparaben and isobutylparaben with average plasma concentrations at 77 and 112.5 ng mL−1 . The high concentration levels detected agree with previous findings for some of the parabens and emphasize the need for further epidemiological research on the possible health effects of the use of these compounds

Fate and transformation of silver nanoparticles in different biological conditions

The exploitation of silver nanoparticles (AgNPs) in biomedicine represents more than one third of their overall application. Despite their wide use and significant amount of scientific data on their effects on biological systems, detailed insight into their in vivo fate is still lacking. This study aimed to elucidate the biotransformation patterns of AgNPs following oral administration. Colloidal stability, biochemical transformation, dissolution, and degradation behaviour of different types of AgNPs were evaluated in systems modelled to represent biological environments relevant for oral administration, as well as in cell culture media and tissue compartments obtained from animal models. A multimethod approach was employed by implementing light scattering (dynamic and electrophoretic) techniques, spectroscopy (UV–vis, atomic absorption, nuclear magnetic resonance) and transmission electron microscopy. The obtained results demonstrated that AgNPs may transform very quickly during their journey through different biological conditions. They are able to degrade to an ionic form and again reconstruct to a nanoparticulate form, depending on the biological environment determined by specific body compartments. As suggested for other inorganic nanoparticles by other research groups, AgNPs fail to preserve their specific integrity in in vivo settings