Luka Krstulović

Production performance, meat composition and oxidative susceptibility in broiler chicken fed with different phenolic compounds

BACKGROUND Various studies have been conducted to evaluate the effect of phenolic compounds on production animals. Supplementation of animal diets with phytogenic compounds, such as different essential oils and polyphenols, could improve animal productivity as well as the chemical composition and oxidative stability of food derived from those animals. RESULTS During the trial, 80 male broilers of the Ross 308 strain were allocated to four dietary groups: control and three groups supplemented with thymol, tannic acid and gallic acid. Feed utilisation was improved in all experimental groups and tannic acid also improved final body weight. Gallic acid significantly increased n-3 long-chain polyunsaturated fatty acids. A hypocholesterolaemic effect was noticed in all groups in liver, but not in muscle. The glucose lowering effect in serum was noticed in the tannic acid group in comparison to other experimental groups. Oxidative susceptibility was improved by tannic acid in liver and breast and by gallic acid in breast muscle. CONCLUSION The inclusion of phenolic compounds enhanced growth performance, decreased lipid oxidation, decreased cholesterol value and increased beneficial fatty acids content. Positive effects varied depending on phenolic compound used and, therefore, it would be interesting to further investigate synergistic effects of investigated phenolic compound.

Cow colostrum and early milk enriched with eicosapentaenoic and docosahexaenoic fatty acid

The objective of the study was to explore whether it is possible to alter cow colostrum and early milk fatty acid composition with a low level of fat supplement, high in docosahexaenoic (DHA) and eicosapentaenoic (EPA) fatty acid. Diets included a control diet and a diet supplemented with DHA- and EPA-enriched fat supplement. Addition of fat supplement significantly decreased saturated fatty acids, C14:0 and C16:0 and increased the values of monounsaturated fatty acids, polyunsaturated fatty acids (PUFA), n3 fatty acids, EPA, DHA, C18:1n9cis and C18:1n11trans. The percentage of short-chain fatty acids significantly increased with the progress of lactation, while the percentage of PUFA, n3 and n6 significantly decreased. These results showed that fat supplement, high in DHA and EPA, modified the fatty acid profile of colostrum and milk fat and increased the proportion of beneficial fatty acids for human health.

Synthesis, anti-bacterial and anti-protozoal activities of amidinobenzimidazole derivatives and their interactions with DNA and RNA

Abstract Amidinobenzimidazole derivatives connected to 1-aryl-substituted 1,2,3-triazole through phenoxymethylene linkers 7a–7e, 8a–8e, and 9a–9e were designed and synthesised with the aim of evaluating their anti-bacterial and anti-trypanosomal activities and DNA/RNA binding affinity. Results from anti-bacterial evaluations of antibiotic-resistant pathogenic bacteria revealed that both o-chlorophenyl-1,2,3-triazole and N-isopropylamidine moieties in 8c led to strong inhibitory activity against resistant Gram-positive bacteria, particularly the MRSA strain. Furthermore, the non-substituted amidine and phenyl ring in 7a induced a marked anti-bacterial effect, with potency against ESBL-producing Gram-negative E. coli better than those of the antibiotics ceftazidime and ciprofloxacin. UV–Vis and CD spectroscopy, as well as thermal denaturation assays, indicated that compounds 7a and 8c showed also binding affinities towards ctDNA. Anti-trypanosomal evaluations showed that the p-methoxyphenyl-1,2,3-triazole moiety in 7b and 9b enhanced inhibitory activity against T. brucei, with 8b being more potent than nifurtimox, and having minimal toxicity towards mammalian cells. Graphical Abstract

1,3-Dipolarna cikloadicija (I. dio): Dobivanje 1,2,3-triazolnih derivata u nukleozidnoj kemiji

Bakrom katalizirana Huisgenova 1, 3-dipolarna cikloadicija azida i terminalnih alkina kojom regioselektivno nastaju 1, 4-disupstituirani 1, 2, 3-triazoli cesto je primjenjivana metoda sintetske organske kemije. Zahvaljujuci jednostavnim reakcijskim uvjetima, zauzela je znacajno mjesto i u podrucju nukleozidne kemije jer omogucuje dobivanje velikog broja potencijalno bioloski aktivnih spojeva s nizom zanimljivih dodatnih svojstava induciranih uvođenjem 1, 2, 3-triazolnog strukturnog motiva u molekulu.

1,3-Dipolarna cikloadicija (II. dio): Trokomponentne Cu(I) katalizirane klik-reakcije

Cu(I) kataliziranim reakcijama sulfonil- odnosno fosforil-azida i terminalnih alkina nastaje intermedijar ketenimin koji reagira s nukleofilima kao sto su voda, alkoholi, amini, piroli ili indoli, pri cemu nastaju odgovarajuci amidi, imidati, amidini i supstituirani heterocikli, u jednom reakcijskom koraku. Te selektivne reakcije zbivaju se pri blagim reakcijskim uvjetima (sobna temperatura, prisustvo zraka i vode), bez sterickog i elektronskog utjecaja supstituenata na ishod reakcije.

Mass Spectrometry and Theoretical Studies on N–C Bond Cleavages in the N-Sulfonylamidino Thymine Derivatives

AbstractThe reactivity of new biologically active thymine derivatives substituted with 2-(arylsulfonamidino)ethyl group at N1 and N3 position was investigated in the gas phase using CID experiments (ESI-MS/MS) and by density functional theory (DFT) calculations. Both derivatives show similar chemistry in the negative mode with a retro-Michael addition (Path A–) being the most abundant reaction channel, which correlate well with the fluoride induced retro-Michael addition observed in solution. The difference in the fragmentation of N-3 substituted thymine 5 and N-1 substituted thymine 1 in the positive mode relates to the preferred cleavage of the sulfonyl group (m/z 155, Path B) in N-3 isomer and the formation of the acryl sulfonamidine 3 (m/z 309) via Path A in N-1 isomer. Mechanistic studies of the cleavage reaction conducted by DFT calculations give the trend of the calculated activation energies that agree well with the experimental observations. A mechanism of the retro-Michael reaction was interpreted as a McLafferty type of fragmentation, which includes Hβ proton shift to one of the neighboring oxygen atoms in a 1,5-fashion inducing N1(N3)–Cα bond scission. This mechanism was found to be kinetically favorable over other tested mechanisms. Significant difference in the observed fragmentation pattern of N-1 and N-3 isomers proves the ESI-MS/MS technique as an excellent method for tracking the fate of similar sulfonamidine drugs. Also, the observed N-1 and/or N-3 thymine alkylation with in situ formed reactive acryl sulfonamidine 3 as a Michael acceptor may open interesting possibilities for the preparation of other N-3 substituted pyrimidines. Graphical Abstractᅟ

QSAR Analysis of Antitumor Activities of 3, 4-Ethylenedioxythiphene Derivatives

QSAR analysis was performed for the antitumor activity of 27 derivatives of 3,4-ethylenedioxythiophene against six carcinoma cell lines. The best models were obtained with surface area (SAG) in combination with lipohilicity (log P) as descriptors. Results have shown that molecules with smaller solvent accessible surface area and higher lipophilicy should have higher biological activity against carcinoma cell.