Compoundswith two phenolic OH groups like curcumin possess efficient antioxidant and anti-inflammatory activity. We synthesized
p-cresol dimer (2,2'-dihydroxy-5,5'-dimethylbiphenol,
2a) and
p-methoxyphenol dimer (2,2'-dihydroxy-5,5'-dimethoxybiphenol,
2b) by
ortho-ortho coupling reactions of the parent monomers,
p-cresol (
1a) and
p-
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Compoundswith two phenolic OH groups like curcumin possess efficient antioxidant and anti-inflammatory activity. We synthesized
p-cresol dimer (2,2'-dihydroxy-5,5'-dimethylbiphenol,
2a) and
p-methoxyphenol dimer (2,2'-dihydroxy-5,5'-dimethoxybiphenol,
2b) by
ortho-ortho coupling reactions of the parent monomers,
p-cresol (
1a) and
p-methoxyphenol (
1b), respectively. Their antioxidant activity was determined using the induction period method, and their cytotoxicity towards RAW 264.7 cells was also investigated using a cell counting kit. The stoichiometric factors
n (number of free radicals trapped by one mole of antioxidant moiety) for
2a and
2b were 3 and 2.8, respectively, being greater than those for
1a and
1b. The ratio of the rate constant of inhibition to that of propagation (k
inh/k
p) for
2a and
2b was similar to that for 2-
t-butyl-4-methoxyphenol (BHA), a conventional food antioxidant. The 50% inhibitory dose (ID
50) declined in the order
1b >
1a >>
2b >
2a > BHA. The cytotoxicity for
2a and
2b was significantly greater than that for the parent monomers (
p < 0.001), but smaller than that for BHA (
p < 0.01). Compounds
2a and
2b may be useful as food antioxidants.
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