Arzanol, an anti-inflammatory and anti-HIV-1 phloroglucinol alpha-pyrone from Helichrysum italicum ssp microphyllum
An acetone extract of Helichrysum italicum ssp. microphyllum afforded the phloroglucinol alpha-pyrone arzanol (1a) as a potent NF-kappa B inhibitor. Arzanol is identical with homoarenol (2a), whose structure should be revised. The phloroglucinol-type structure of arzanol and the 1,2,4-trihydroxyphenyl-type structure of the base-induced fragmentation product of homoarenol could be reconciled in lig