Estudo one-pot da aplicação do Catalisador de Grubbs de Primeira Geração em metátese da piperina e eugenol e atividade carcinogênica

Abstract

The synthesis of new compounds from olefin metathesis has been widely studied in scientific circles to carry out molecular modifications with the purpose of obtaining molecules with greater biological activity when compared to naturally occurring. Piperine (PIP) and eugenol (EUG) are abundant molecules in nature with biological and pharmacological activities well-known. Thus, the aim of this study was to obtain new compounds from the reaction by metathesis of PIP and EUG olefins, as well as to evaluate the carcinogenicity and anticarcinogenicity of these molecules through the epithelial tumor detection test (ETT) in Drosophila melanogaster. Self-metathesis and cross-metathesis reactions of PIP and EUG were carried out at 50°C, for 24, 48 and 96 h and ratio catalyst:substrate of Ru:PIP:EUG of 1:0.5:0.5 and 1:5:5 mol. The products were characterized by a gas chromatograph-coupled mass spectrometer (GC-MS) and discussed in relation to the physical and steric characteristics of the catalyst and the properties of the substrates. For the ETT, third-stage larvae from the crossing between virgin females wts/TM3, Sb1 with males mwh/mwh were transferred to flasks containing 2g of instant mashed potato, with different concentrations (60, 120, 180 and 360mg/kg of mashed potato) of PIP or EUG. For the carcinogenic and anticarcinogenic assay, the preparations were moistened with 7mL of distilled water and 7mL of methyl methanesulfonate (MMS - 3mM) or doxorubicin (DXR - 0.125mg/mL), respectively. Emerging adults were fixed in 70% ethanol and analyzed for the occurrence of tumors. Comparisons between the frequency of tumors in treatments and controls were performed using the chi-square test, at 5% probability. A dimeric eugenol species was observed for the metathesis of EUG olefins, in a Ru:PIP:EUG ratio of 1:0.5:0.5 mol, at all times studied and in an additional experiment at 70°C for 48 h. When the ratio Ru:PIP:EUG was 1:5:5 mol, this product was not observed. Isomerization processes were also observed at all temperatures and catalyst: substrate ratio. Increasing the amount of substrates increased the yield of reactions. In D. melanogaster, PIP was not toxic and showed carcinogenic activity at concentrations of 180 and 360mg/kg of puree. In co-treatment, inhibitory effect to damage induced by MMS was observed for the concentrations of PIP 60, 120 and 180mg/kg. The EUG showed toxic potential at all concentrations evaluated and a carcinogenic effect was observed at EUG 120, 180 and 360 mg/kg. However, EUG, in all concentrations, had a modulating effect, inhibiting DXR-induced carcinogenesis in co-treatment. This study demonstrated that, under the evaluated reaction conditions, there was no cross-metathesis reaction, possibly due to the chelation effect of the double coordination of PIP. Biological tests revealed a protective effect of PIP at concentrations of 60 and 120mg/kg of puree, which are promising for future studies aimed at the treatment of neoplasms. As for the EUG, a protective effect was not evidenced, as it was toxic and carcinogenic, although it showed an inhibitory activity when associated with DXR.