Search

Hydroxylated biphenyl moiety is embedded in many structures of bioactive natural products. Some of them are present in compounds of high biological relevance like ellagitannins, vancomicin, biphenomicins, others, structurally less sophisticated, are natural occurring dimers of 4-substituted 2-methoxyphenols, e.g. guaiacyl unit. In our continuing study on phenols and their C2-symmetry dimers serving as the basis for the generation of ligands for functionally and structurally discreet biological receptors1, we have prepared a small collection of natural and natural-like hydroxylated biphenyls and monomers generally bearing a guaiacyl unit as main motif. Dimers have been prepared by C-C coupling reaction with inorganic oxidizing reagents starting from the corresponding monomer or functionalized from commercial 4,4?-dihydroxybiphenyl 9. Unsaturated monomer and dimers have been prepared by Claisen-Schimdt condensation of vanillin and vanillin dimer, respectively, with the corresponding ketone. Biphenyl 9 and compound 8 are known to be in vitro inhibitors of tyrosinase, a key enzyme in melanine biosynthesis involved in determining the colour of mammalian skin and hair, in unfavorable enzymatic browning of plant-derived foods and in insects molting process. Tyrosinase inhibitory activity have been detected via spectrophotometric assay in compounds, 1, 2, 4, 7, 10, 11 and 12, structurally related to 9 and 8, and in insects molting trial. Viability (80%) of compounds 1, 2, 4, 7, 8 and 10 in PC12 cells, a neuronal cell model, have been observed at concentration > 10 uM. In order to improve the biological activity of the guaiacyl unit present in phenols and C2-dimers1, we have planned to introduce a ferrocene unit because of the promising results observed in medicinal field when a metallocene moiety is embedded with bioactive compounds. Their electrochemical potential and cytotoxic activity in PC12 cells have been evaluated in comparison with data of the corresponding compounds lacking in ferrocene unit. All ferrocenylchalcones showed a reversible behavior, but not the saturated analog of compound 6.

The hazelnut agro-ecosystem is generally characterized by a high complexity and a relative stability in space and time, also due to its abundant arthropod fauna including several groups of beneficial organisms. Therefore the research was conducted to investigate the predatory insects belonging to Heteroptera on hazelnut in Piedmont (NW Italy) and in Sardinia. In 2005, predatory Heteroptera were fortnightly sampled in nine hazel groves: six intensively cropped in Piedmont and three unmanaged in Sardinia. Presence-and-Absence data achieved during field-surveys were analyzed applying the centroid clustering method. Predatory bug communities of Piedmont and Sardinia formed separate clusters. In both regions, the family Miridae was the most abundant and rich in species, with nine and eight species in the agro-ecosystems of Piedmont and Sardinia, respectively. Few species of the families Anthocoridae and Nabidae were collected: in most cases, they occurred occasionally and in low amounts in the investigated orchards.

Open field capture trials of Culex pipiens with C02 traps, type CDC, were carried out using an experimental device consisting of a 3 metre long cubic cage. No differences in the individua1 efficiency of the traps were found, and the trap catches was not affected by position with regard to the 4 cardinal points (the side of the cage). In contrast, significant differences were detected between the highest leve1 of capture, recorded in any side, and the two lowest levels, recorded in other cardinal points. This rank significance, excluding position, can likely be explained by the influence of an variable environmental factor, such as the wind. No significant differences in captures were found between traps kept at 120 and 175 cm from the ground. The effects of quantity of released C02 were studied using clusters of 4 traps, al1 switched on and some baited. Previously, no significant differences between baited and non-baited traps in the sarne cluster had been observed. Clusters having 2 baited traps were compared with clusters with either 1 or 4 baited traps. No significant differences were found.

An endemic species of Ascalaphidae living exclusively in the Italian peninsula has been named for over a century Libelloides italicus Fabricius (1781). This is the case of a long-term, established, nomenclatorial situation which has apparently caused no problems. Unfortunately, Fabricius' type does not correspond to the Italian ascalaphid. Thus an old dispute has been re-opened and so the chronology concerning it are discussed. In conclusion, Ascalaphus italicus Fabricius, 1781 is a junior synonym of Libelloides coccajus (Denis & Schiffermuller, 1775, syn. n.,) and a senior synonym of Ascalaphus meridionalis De Charpentier, 1825. There are two possible names for the Italian ascalaphid: Libelloides latinus (Lefebvre, 1842)(comb. n.), that is its valid name, and Ascalaphus petagnae Costa, 1855 which is its junior synonym.