Homo- and heterobinuclear Cu²âº and Zn²âº complexes of abiotic cyclic hexaazapyridinocyclophanes as SOD mimics.

The new receptor 3,7,11,15,19,23-hexaaza-1(2,6)-pyridinacyclotetracosaphane (L1) containing a complete sequence of propylenic chains has been synthesised. The acid-base behaviour and Cu²âº and Zn²âº coordination have been analysed by potentiometric measurements in 0.15 M NaClO4 for L1 and for the related compounds 3,7,11,14,18,22-hexaaza-1(2,6)-pyridinacyclotricosaphane (L2), 3,7,10,13,16,20-hexaaza-1(2,6)-pyridinacycloheneicosaphane (L3) and 3,7,10,12,15,19-hexaaza-1(2,6)-pyridinacycloicosaphane (L4). The crystal structure of [(CuH4L2)(H2O)(ClO4)](ClO4)5·3H2O shows an interesting combination of a metal ion coordinated by the pyridine nitrogen atom and the adjacent amine groups of the chain, and a perchlorate anion sitting at the middle of the site defined by the remaining four protonated ammonium groups of L1. Paramagnetic NMR data suggest that imidazole coordinates to the Cu²âº ions as a bridging ligand in a wide pH range. SOD activity for Cu²âº-Cu²âº and Cu²âº-Zn²âº complexes with L1-L4 have been measured by NBT assays at pH 7.4, obtaining some of the lowest values so far reported for SOD mimics. SOD activity has also been checked by chemiluminescence assays using polymorphonuclear leukocytes (PMNLs).

Long-chain fatty alcohols from pomace olive oil modulate the release of proinflammatory mediators.

Pomace olive oil is a by-product of olive oil extraction that is traditionally produced and consumed in Spain. The nonglyceride matter of this oil is a good source of interesting minor compounds, like long-chain fatty alcohols, which are present free or as part of waxes. In the present study, long-chain fatty alcohols were isolated from the nonglyceride fraction of pomace olive oil, and the composition was identified and quantified. The major components of long-chain fatty alcohols were tetracosanol, hexacosanol and octacosanol. We investigated the ability of long-chain fatty alcohols from pomace olive oil to inhibit the release of different proinflammatory mediators in vitro by cells involved in inflammatory processes. Long-chain fatty alcohols significantly and dose-dependently decreased nitric oxide production by RAW 264.7 murine macrophages stimulated with lipopolysaccharide. Western blot analysis showed that nitric oxide reduction was a consequence of the inhibition of inducible nitric oxide synthetase expression. Long-chain fatty alcohols also reduced tumor necrosis factor-alpha and prostaglandin E(2) production, although the potency of inhibition for the latter was lower. On the other hand, long-chain fatty alcohols significantly reduced thromboxane A(2) production in rat peritoneal neutrophils stimulated with the calcium ionophore A-23187. The reduction of eicosanoid release was related to the inhibition of phospholipase A(2) enzyme activity by long-chain fatty alcohols, reaching an inhibitory concentration 50% value of 6.2 microg/ml. These results showed that long-chain fatty alcohols may have a protective effect on some mediators involved in the inflammatory damage development, suggesting its potential value as a putative functional component of pomace olive oil.