n-Heptane isomerization activities of Pt catalyst supported on micro/mesoporous composites

Pt loaded on a series of MCM-48 silica and composites with HZSM-5 zeolite, HY zeolite, or TiO₂ has been prepared and studied for n-heptane isomerization reaction at 200–350 °C. The structural characterization, acid distribution, and morphology of these catalysts were characterized by X-ray diffraction, Fourier transform infrared, UV–Vis diffuse reflectance, scanning electron microscope, temperature-programmed desorption of NH₃, and nitrogen adsorption–desorption methods. The results show that these catalysts have a good selectivity to multi branched isomers, while producing low aromatic compounds. Also, these new composite catalysts prove the catalytic stability during the time of reaction. The most desirable results, and significantly higher n-heptane conversion and isomerization selectivity were achieved with Pt/MCM48-HZSM5 catalyst.

Protective effects of Iranian Achillea wilhelmsii essential oil on acetaminophen-induced oxidative stress in rat liver

CONTEXT

Achillea wilhelmsii C. Koch (Asteraceae) is widely used in Iranian traditional medicine.

OBJECTIVE

This in vivo study evaluates the hepatoprotective role of Iranian A. wilhelmsii oils against acetaminophen-induced oxidative damages in rats.

MATERIALS AND METHODS

The animals were divided into five groups: in negative control and control groups, the DMSO and 500 mg/kg acetaminophen were i.p. injected, respectively. In treatment groups, 100 and 200 mg/kg oils and 10 mg/kg BHT were given i.p. immediately after acetaminophen administration. Then, the hepatic oxidative/antioxidant parameters such as lipid peroxidation (LP), glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), and ferric reducing ability of plasma (FRAP) were measured in time intervals (2, 4, 8, 16, and 24 h) after administrations confirmed by histophatological consideration at 24 h.

RESULTS

The results indicated that acetaminophen caused a significant elevation in SOD activity (8-24 h) and LP and FRAP levels (4 h) paralleled with significant decline in GSH level (4 and 8 h). The apparent oxidative injury was associated with evident hepatic necrosis confirmed in histological examination. The presences of A. wilhelmsii oils (100 and 200 mg/kg) with acetaminophen mitigated significantly the rise in SOD, LP, and FRAP levels and restored the GSH compared with the group treated with acetaminophen. These were confirmed by histological examination indicating the hepatic necrosis reversal by the oils.

DISCUSSION AND CONCLUSION

It can be concluded that concomitant administration of A. wilhelmsii oils with acetaminophen may be useful in reversing the drug hepatotoxicity.