3-(4-Piperidinyl)- and 3-(8-aza-bicyclo[3.2.1]oct-3-yl)-2-phenyl-1H-indoles as bioavailable h5-HT2A antagonists

A series of 3-(4-piperidinyl)- and 3-(8-aza-bicyclo[3.2.l]oct-3-yl)-2-phenyl-1H-indoles have been prepared and evaluated as ligands for the h5-HT_2A receptor. 3-(8-Phenethyl-8-aza-bicyclo[3.2.l]oct-3-yI)-2-phenyl-1H-indole is a high-affinity (1.2 nM), selective (>800 fold over h5-HT_2C and hD₂ receptors) antagonist at the h5-HT_2A receptor with oral bioavailability in rats.     

The histone methylase KMTox interacts with the redox-sensor peroxiredoxin-1 and targets genes involved in Toxoplasma gondii antioxidant defences

The ability of living cells to alter their gene expression patterns in response to environmental changes is essential for viability. Oxidative stress represents a common threat for all aerobic life. In normally growing cells, in which hydrogen peroxide generation is transient or pulsed, the antioxidant systems efficiently control its concentration. Intracellular parasites must also protect themselves against the oxidative burst imposed by the host. In this work, we have investigated the role of KMTox, a new histone lysine methyltransferase, in the obligate intracellular parasite Toxoplasma gondii . KMTox is a nuclear protein that holds a High Mobility Group domain, which is thought to recognize bent DNA. The enzyme methylates both histones H4 and H2A in vitro with a great preference for the substrate in reduced conditions. Importantly, KMTox interacts specifically with the typical 2-cys peroxiredoxin-1 and the binding is to some extent enhanced upon oxidation. It appears that the cellular functions that are primarily regulated by the KMTox are antioxidant defences and maintenance of cellular homeostasis. KMTox may regulate gene expression in T. gondii by providing the rapid re-arrangement of chromatin domains and by interacting with the redox-sensor TgPrx1 contribute to establish the antioxidant 'firewall' in T. gondii .     

C, N, P concentrations and requirements of flowering Posidonia oceanica

The carbon, nitrogen and phosphorus contents in flowering and nonflowering shoots were compared after an important flowering event occurred in the Posidonia meadow of the Bay of Calvi. The flower formation caused a significant increase of C and a significant decrease of N concentrations in intermediate and adult leaves. Minimum daily requirements in mgshoot^-1day^-1 of 3.4 and 4.8 of C, 0.09 and 0.09 N, 0.01 and 0.02 of P respectively for nonflowering and flowering shoots were calculated. It shows that additional quantities of C and P are required for the inflorescence elaboration. The unchanged quantity of N required by the shoot for the inflorescence elaboration and the significant modification of N concentration in intermediate and adult leaves suggests that N is limited in the environment and that an efficient resorption of N occurs from leaves to ensure the inflorescence formation.