New sulfurated derivatives of valproic acid with enhanced histone deacetylase inhibitory activity

One dithiolthione and two new methanethiosulfonate derivatives of valproic acid (VPA) were synthesized and tested in vitro as histone deacetylase (HDAC) inhibitors. The new molecules, as well as their sulfurated moieties, exhibited a much stronger inhibition of HDAC enzymatic and antiproliferative activities and histone hyperacetylation than VPA. ACS 2 is the most interesting compound among the new VPA derivatives and its sulfurated moiety, 5-(4-hydroxyphenyl)-3H-1,2-dithiole-3-thione, also known to be a metabolite of anethole trithione, seems to contribute significantly to its activity. This is the first time that HDAC inhibitory activity is described for dithiolethiones and thiosulfonates.     

Complexation of 2-hydroxynicotinic and 3-hydroxypicolinic acids with zinc(II). Solution state study and crystal structure of trans-diaqua-bis-(3-hydroxypicolinato)zinc(II)

The interactions between zinc(II) and the two ligands 2-hydroxynicotinic acid (HNic) and 3-hydroxypicolinic acid (HPic) have been investigated by means of potentiometric titrations in aqueous 0.6 m (Na)Cl at 25 °C. In both cases, only mononuclear complexes are formed. The qualitative and quantitative results obtained have been confirmed in part by UV-Vis spectrophotometry and ¹H NMR spectroscopy. The complex trans-diaqua-bis-(3-hydroxypicolinato)zinc(II) was obtained as a crystal and examined by X-ray crystallography. The thermodynamic results allow drawing some conclusions regarding the extent of Zn(II) interference in a hypothetical chelation therapy treatment of aluminium or iron overload with these two ligands.     

Ferritin from the spleen of the Antarctic teleost Trematomus bernacchii is an M-type homopolymer.

Ferritin from the spleen of the Antarctic teleost Trematomus bernacchii is composed of a single subunit that contains both the ferroxidase center residues, typical of mammalian H chains, and the carboxylate residues forming the micelle nucleation site, typical of mammalian L chains. Comparison of the amino-acid sequence with those available from lower vertebrates indicates that T. bernacchii ferritin can be classified as an M-type homopolymer. Interestingly, the T. bernacchii ferritin chain shows 85.7% identity with a cold-inducible ferritin chain of the rainbow trout Salmo gairdneri. The structural and functional properties indicate that cold acclimation and functional adaptation to low temperatures are achieved without significant modification of the protein stability. In fact, the stability of T. bernacchii ferritin to denaturation induced by acid or temperature closely resembles that of mesophilic mammalian ferritins. Moreover iron is taken up efficiently and the activation energy of the reaction is 74.9 kJ.mol(-1), a value slightly lower than that measured for the human recombinant H ferritin (80.8 kJ.mol(-1)).     

Influence of diet on sex differentiation of Hippolyte inermis Leach (Decapoda: Natantia) in the field

The gut contents of the shrimp Hippolyte inermis were investigated for 1 year along a depth transect through a seagrass bed. Besides size, sex and weight of all individuals were recorded. The diets of immature and adult individuals were compared to detect any influence of food on sex development, since previous investigations indicated a correlation of the life cycle of this protandric species with the abundance of algal food in the environment, and laboratory experiments demonstrated the effect of diatoms of the genus Cocconeis on the direct development of females. Results indicated that the shrimp is an opportunistic herbivore, able to feed on both plant and animal items, with a preference for macroalgae and diatoms present on the leaves of Posidonia oceanica. Small females, deriving from direct differentiation, had a diet significantly different from that of males. The difference was due to a larger abundance of microalgae in the guts of young females. The influence of microalgal food on the sex reversal mechanism of this species, previously detected through laboratory experiments, was demonstrated to control the life cycle of H. inermis in the field.     

A new minimal synthetic medium for germ-tube production in Candida albicans

A new minimal synthetic medium, with low amount of glucose, without aminoacids, vitamins and neutral pH, which induces germ-tubes production in Candida albicans, is reported in this work. The results indicate a perfect agreement between the germ-tube test performed with the standard method in human or animal serum and this test performed in minimal synthetic medium. In this medium the germ-tube test for the presumptive identification of Candida albicans can be performed with the same formality, time and reproducibility as those in human or animal serum. This constitutes an interesting finding because it is easy to prepare, to store and is highly reproducible.     

Synthesis of novel nitric oxide (NO)-releasing esters of timolol

A novel class of timolol derivatives with nitric oxide (NO)-donating moieties achieved chemical stability yet under physiologically relevant conditions released timolol and NO. Hindered esters A were designed and synthesized, whose ‘triggered’ release relied on enzymatic hydrolysis of the nitrate ester in A to B, that in turn cyclized to liberate timolol.     

The effect of CuSO4 for establishing in vitro culture,and the role nitrogen and iron sources in in vitro multiplication of Corylus avellana L. cv. Tonda Gentile Romana

Abstract

In the present work, we have used copper sulphate (CuSO₄·5H₂O) enriched medium for effective control of visible and latent contamination. Among the different concentrations used, 1.25–2.5?mg/L resulted the most appropriate. In addition, the role of different nitrogen source and concentrations (NH₄NO₃ and KNO₃), as different iron source (FeEDTA and FeEDDHA) has been investigated in the proliferation and rooting phases of European hazelnut (cv. Tonda Gentile Romana). The normal concentration of nitrogen present in Murashige and Skoog medium is too high for hazelnut micropropagation cv. Tonda Gentile Romana. A reduction of total nitrogen, accompanied by a reduction of ammonium forms, resulted in a better quality of the shoots. Similar results have been obtained when the common iron source FeEDTA has been replaced by the same concentration of FeEDDHA. An increase in rooting occurs when the amount of nitrogen was reduced in the rooting medium, particularly when the NH₄NO₃ was not present.     

Caratteri ed Affinitá Della Flora Briologica Nell'africa Mediterranea

Riassunto

L'A. esamina i componenti fondamentali della flora briologica dell'Africa settentrionale mediterranea, in relazione con i tipi climatici. Distingue un Elemento mediterranco (coi gruppi: stenomediterraneo, euri-mediterraneo, mediterraneo-montano, mediterraneo-atlantico, mediterraneo-steppico, saharo-sindico), atlantico, circumboreale, orofilo-boreale, ipsofilo-boreale, aralo-caspico, cosmopolita ed endemico.