Assufulvenal, a Novel Bis-sesquiterpene from Joannesia princeps^,

Abstract

From the root bark of Joannesia princeps assufulvenal (l), an unusual fulvenic plant constituent with a bis-sesquiterpene skeleton has been isolated. Its structure was elucidated by spectroscopic methods and corroborated by X-ray crystallographic analysis.Joannesia princeps Vell. (Euphorbiaceae) is indigenous to subtropical and coastal regions of Brazil.2 It grows into a large tree even on poor soil and is named "anda assu" by the native people.2 The plant is cultivated in Africa and Asia.3 Its seeds contain an oil that is applied in folk medicine as a strong purgative4 and also has been used for industrial purpose^.^ The stem bark and the leaves are reported t o be fish toxins.6 Preliminary studies revealed extracts of the root bark to exhibit significant antibacterial, antifungal, and cytotoxic activity. Cyperenal and cyperenol have been detected as the major bioactive principle^.^

Natural disesquiterpenoids

“…87 Moreover, 82 was also found in a deep-sea gorgonian Pseudothesia sp. 88 Recently, two analogues named assufulvenal 84 89 and 2,12 0 -bis-hamazulenyl 85 90 were characterized from the root bark of Joannesia princeps and the essential oil of Ajania fruticulosa, respectively. Their structures were corroborated by X-ray crystallographic analysis, and the absolute configuration of the former dimer was determined by multiple scattering X-ray experiments.…”

Natural sesquiterpenoids

“…The bis-sesquiterpene assafulvenal 300, which is formed from a guaiane and a patchoulane sesquiterpene, has been isolated from the root bark of Joannesia princeps, and its structure has been determined by X-ray analysis. 302 A guaiazulene pigment 301 has been found in the gorgonian Calicogorgia granulosa. 303 Known guaiane derivatives have been obtained from Lepechinia urbaniana 304 and Rubus rosifolius.…”