Abstract The essential oil from Citri Reticulatae Pericarpium (EOC) was analyzed by GC/MS. The major component of EOC was found to be d-limonene (92.3% of the total essential oil). Anti-ulcer and antioxidant activities of EOC were evaluated in several gastric ulcer models. The ulcer index or area and biochemical markers of superoxide dismutase (SOD) and malondialdehyde (MDA) were determined. EOC significantly inhibited gastric mucosal lesions induced by ulcerogenic agents with an inhibitory rate of nearly 50% at an oral dose of 85 mg/kg, and exerted a healing effect on acetic acid-induced ulcers with a curative rate of 63%. HCl/EtOH administration caused severe oxidative stress and lipid peroxidation, which was confirmed by significantly decreased SOD activity and increased MDA levels in mice gastric tissues. EOC pretreatment significantly increased SOD activity and decreased MDA levels, indicating that EOC protects the gastric mucosa against development of numerous lesions by inhibiting oxidative stress. These results demonstrate that EOC has anti-ulcerogenic activity and the mechanism underlying its gastric protective effect is associated with its antioxidant properties.

Reaction of aromatic hydrocarbons catalyzed by a novel catalytic system consisting of zinc chloride, acetic acid, sulfuric acid and PEG-800 in aqueous media under PTC conditions results in chloromethylation in good to excellent yield.