Effect of chain length and aldehydic function on some biological properties of parropolyenes

Parropolyenes, also called parroenes, parrodienes and psittacofulvines, are aldehydes costituted of an unsaturated chain ranging from 8 to 18 carbon atoms. These compounds have been isolated from the plumage of parrots and are also synthesized in the laboratory. Parropolyenes have antiproliferative and antioxidant activities. We investigated the effect of chain length and the role of aldehydic function of some parropolyenes by comparing their biological activities with those of their corresponding alcohols. Trans, trans-Δ2,4-hexadienal at a concentration of 100 μM significantly inhibited the growth of SH-SY5Y cells after 72 h of incubation. The corresponding alcohol was less effective. All-trans-Δ2,4,6-octatrienal and all-trans-Δ2,4,6,8,10-dodecapentaenal were more effective since significant inhibition of growth was observed at a concentration of 10 μM. Again, the corresponding alcohols were less effective. All-trans-Δ2,4,6-octatrienal and all-trans-Δ2,4,6,8,10-dodecapentaenal at 1 μM concentration protected 2-deoxyribose from degradation by ferrous ions. Trans, trans-Δ2,4-hexadienal at the same concentration does not show this protective effect. The protection increased with increasing parropolyene chain length. No significant difference was observed between aldehydes and their corresponding alcohols. Parropolyenes increased the rate of lysis of erythrocyte membrane in a lactoperoxidase-potassium iodide-hydrogen peroxide assay. The cytolytic effect increased with increasing parropolyene chain length. In this assay no difference was observed between aldehydes and alcohols. In all assays the effects were concentration dependent.