Physiological Activity of Chinese Lichen (Gyrophora esculenta) Component, Methyl 2,4-Dihydroxy-6-methylbenzoate and the Related Compounds

It was confirmed that there was a higher expression of antioxidant potential in methyl 2,4-dihydroxy-6-methylbenzoate (orsellinic acid methyl ester) (2), which was isolated from methanol extract oil of Chinese lichen Gyrophora esculenta rather than from commercialized ascorbic acid. Taking this into account, 4 types of compounds-(4-7) which are known to be related to compound (2)-have been synthesized by using 2,4-dihydroxy benzoic acid (3) as starting material. After that, some physiological activity tests on these compounds have been conducted in the following aspects: antioxidant potential, cytotoxicity, cytokine suppressant effect and histamine liberation inhibition and the effects have been evaluated, respectively. The result shows that (2) and methyl 2,4-dihydroxybenzoate (4) showed high radical expression in both antioxidant potential and histamine liberation inhibition. It was also found that none of these compounds expresses cytotoxicity.