Erythroivorensin: A novel anti-inflammatory diterpene from the root-bark of Erythrophleum ivorense (A Chev.).

The stem- and root-bark of Erythrophleum ivorense (A Chev., family, Fabaceae) are routinely employed in the West African traditional medicine to treat inflammation and a variety of other disease conditions. Although the chemistry and pharmacology of cassaine-type diterpene alkaloids isolated from the stem-bark of the plant are fairly established, the root-bark has not yet been investigated. In the present study, the crude aqueous-alcohol extract of the root-bark was demonstrated to display a time- and dose (30-300 mg/kg p.o.)-dependent anti-inflammatory effect in chicks. Comprehensive chromatographic analysis coupled with spectroscopic and X-ray study further allowed the assignment of one of the major anti-inflammatory constituents as a novel cassaine-type diterpene, erythroivorensin. The other major constituents were known anti-inflammatory compounds: a triterpene, betulinic acid and a flavonoid, eriodictyol. The dose (10-100mg/kg p.o.)-dependent anti-inflammatory effects of the three compounds were either comparable or more significant than the positive control, diclofenac.