Prenylated bianthrones and vismione F from Psorospermum febrifugum

The roots of Psorospermum febrifugum collected in Malawi contained together with the known vismione D and geranyloxyemodin four new compounds: vismione F and the three bianthrones A₁, A_3a and A_3b. All the isolated compounds contained C- or O-geranyl substituents and showed a close biogenetic relationship.     

Prenylated anthranoids from Psorospermum species

The chemical composition of the root extracts of two Psorospermum sp. from the Ivory Coast is reported. Together with previously known compounds, acetylvismione F and 2-geranylemodin anthrone were isolated from P. corymbiferum, and vismione G from P. glaberrimum. Geranyl substitution is confirmed to be a typical feature of this genus.     

7,2′,4′-Trihydroxy-3′-methoxyisoflavone from zollernia paraensis

Three further compounds have been isolated from Zollernia paraensis: 2,7-dihydroxy-4′-methoxy-3-phenylcoumarin, (±)-5,7-dihydroxy-2′,4′-dimethoxyisoflavanone and the new 7,2′,4′-trihydroxy-3′-methoxyisoflavone.     

2-Isoprenylemodin and 5,5′-dimethoxysesamin from vismia guaramirangae

The secondary metabolises γ-hydroxyferruginin A, madagascin, chrysophanic acid, physcion, β-caryophyllene, humulene, sitosterol, sesamin and a rare triterpene, dammaradienol were isolated from the bark and exudate of Vismia guaramirangae. The structures of a new anthraquinone, 2-isoprenylemodin, and of a new lignan, 5,5′-dimethoxysesamin, were established on the basis of chemical and spectroscopic evidence.     

A cyclohexadienone and a cyclohexenone from halleria lucida

Two new compounds, a cyclohexadienone, hallerone and a cyclohexenone, halleridone, were isolated from Halleria lucida. Their structures were established on the basis of spectroscopic data and by chemical behaviour. Hallerone was converted into halleridone.     

A re-assestment of p-hydroxybenzaldehyde in sorghum bicolor seedlings

Free p-hydroxybenzaldehyde is present in seedlings previously heated to inactivate hydrolytic enzymes and in chloroform extracts of the surface. It is also present in epicuticular wax removed from plants by mechanical means.     

2,4,2′-Trihydroxy-4′-methoxybenzil from Zollernia paraensis

A new phenolic compound, isolated from the wood of Zollernia paraensis, has been shown to be 2,4,2′-trihydroxy-4′-methoxybenzil by spectral data and synthesis.