Methyl isoeugenol

Methyl isoeugenol is an isomer of methyleugenol with higher skin sensitization activity than methyleugenol.

Skin. In a worldwide multicenter study on 218 dermatitis patients with proven fragrance sensitization, 16 (7.3 percent) reacted positively to 5 percent methyl isoeugenol.

Subchronic toxicity. Rats fed 30, 100, 300 mg/kg/day for 28 days showed only minor high-dose changes such as serum chemistry alterations, increased liver weight and white blood cell counts, with no toxicological significance.

Metabolism is similar to methyleugenol but 4-O-demethylation is more important. Principal metabolites are 3,4-dimethoxycinnamic acid and 3,4-dimethoxybenzoic acid as glycine conjugates, and 3-methoxy-4-hydroxycinnamic acid.

Methyl isoeugenol exists in two geometric isomers, (E)- and (Z)-, both occurring in Sri Lankan citronella oil. Although structurally close to methyleugenol, this compound does not have an IFRA limit for cancer risk.