Michela Furlan

Influence of ancillary ligands in the coordination mode of P and As carbonyl stabilized ylides on Pt(II) systems. X-ray structure of trans-[Pt(PPh3)2(CF3) {OC(OCH3)C(H) (PPh3)}] [BF4]·0.5CH2Cl2

Abstract The carbonyl stabilized P and As Ph3PHCOR (RCH3, Ph, OCH3) and Ph3ASCHCOR (RCH3, PH, OCH3) have been reacted with some platinum(II) complexes bearing ancillary ligands with different steric hindrance, in order to determine the factors that influence the C- versus O-coordination mode of the ylides. Thus, the reactions of [(dppe)PtCl2] and [(dppv)PtCl2] with Ph3PCHCOR (R^z.dbnd;CH3, Ph) give the O-coordinated complexes, while with Ph3PCHCOOCH3 they give the corresponding C-coordinated derivatives. The reactions of trans-[PPh3)2(CF3)Pt(solv)]+BF−4 yieldd the O-coordinated compounds and the reactions with [Pt(C3H5)Cl]4 give selectivity the C-coordinated derivatives as well as the reactions with the dimer [ PlCl(P(Bu 2 ) 2 C(Me) 2 C H 2 }] 2 . The derivative trans-[Pt(PPh3)2(CF3){OC(OCH3)=C(H)(PPh3)}][BF4]] crystallizes in the triclinic group P1 (No. 2), a = 10.385(4), b = 14.844(5), c = 18.511(6) →A , α = 96.46(2), β=99.79(2), γ = 97.00(2)°, V = 2765(1) a A 3 , Z = 2 . The values of coordination distances and of the PtOC angle appear influenced by steric factors.

AuIII binding to C5 of the model nucleobase 1,3-dimethyluracil (1,3-DimeU): Preparation and X-ray crystal structures of trans-K[Au(CN)2Cl(1,3-DimeU−)] and of two derivatives

Abstract The reaction of trans-K[Au(CN)2Cl2] with 1,3-dimethyluracil (1,3-DimeU) gives trans-K[Au(CN)2Cl(1,3-DimeU−–C5)] (1) which contains the 1,3-dimethyluracil-5-yl entity (1,3-DimeU−–C5) bound to AuIII. Complex 1 represents the first example of an X-ray structurally characterized organogold(III) complex of a nucleobase. Further reaction with purine model nucleobases (nb) such as 9-ethylguanine (9-EtGH), 9-methyladenine (9-MeA), and 1-methylcytosine (1-MeC) leads to mixed nucleobase complexes of type trans-[Au(CN)2(1,3-DimeU−–C5)(nb)] (nb=9-MeA, 2a; nb=9-EtGH, 3a; nb=1-MeC, 4a) or to compounds containing the protonated purine base Hnb+ and [Au(CN)2X(1,3-DimeU−–C5)]− as a counter ion (X=Cl or CN), e.g. [9-MeAH][Au(CN)2Cl(1,3-DimeU−–C5)]·H2O (2b) and [9-EtGH2][Au(CN)3(1,3-DimeU−–C5)] (3b). The crystal structures of 1, 2b, and 3b were determined. The C-bound nucleobase exerts a distinct trans-influence, as evident from long Au–Cl bonds in 1 and 2b (2.340(3) A and 2.358(6) A) and a long bond (2.082(7) A) between Au and the cyano ligand trans to 1,3-DimeU− in 3b.

Cathelicidins: An Ancient Family of Fish Antimicrobial Peptides

Abstract Cathelicidins are an important family of antimicrobial peptide effectors of innate immunity in vertebrates. While their mammalian counterparts have been extensively characterized in the last two decades, data on fish cathelicidins have only recently been gathered. This review covers the available recent insights on fish cathelicidins regarding their evolution, protein structures, gene expression, antimicrobial, and immunomodulatory properties, highlighting the similarity and the differences with the mammalian ones. The picture that emerges is that of a group of immune effectors that has been subjected to intense pressure for variation in single species of salmonids, cods, and a few other families of bony fish to address the great variety of associated microorganisms and pathogens. Genes of fish cathelicidins have been shown to be highly responsive to bacteria; moreover, experimental data suggest both direct antibacterial activity and modulation of other immune effectors. These functions, which still need to be fully characterized, indicate cathelicidins as an important and effective defense line in fish.

Induced expression of cathelicidins in trout (Oncorhynchus mykiss) challenged with four different bacterial pathogens

Cathelicidins are an important family of antimicrobial peptide effectors of innate immunity in vertebrates. Two members of this group, CATH‐1 and CATH‐2, have been identified and characterized in teleosts (ray‐finned fish). In this study, we investigated the expression of these genes in different tissues of rainbow trout challenged with 4 different inactivated pathogens. By using qPCR, we detected a strong induction of both cath‐1 and cath‐2 genes within 24 hours after intraperitoneal inoculation with Lactococcus garvieae, Yersinia ruckeri, Aeromonas salmonicida, or Flavobacterium psychrophilum cells. Up to 700‐fold induction of cath‐2 was observed in the spleen of animals challenged with Y. ruckeri. Moreover, we found differences in the intensity and timing of gene up‐regulation in the analyzed tissues. The overall results highlight the importance of cathelicidins in the immune response mechanisms of salmonids.