Eight New Prenylcoumarins fromPhebalium clavatum

Abstract

The aerial parts of Phebalium clavatum yielded eight new 3-prenylated coumarins, phebaclavin A-H (1-8). Their structures were established on the basis of their NMR and mass spectral data. In addition, seven known compounds were also isolated, including two 8-geranyloxy linear furocoumarins previously obtained from Phebalium tuberculosum ssp. megaphyllum, included in the same section of the genus.

The First Total Synthesis of Phebaclavin A and C

“…It was reported that they have been widely used in the fields of biology, medicine and polymer science. 1 In continuation of our systematic research on this class of coumarins, we now attempt to synthesize a series of new phebaclavin A-H family, which were recently isolated from the aerial parts of phebalium clavatum by Muyard et al, 2 with a view to evaluated their biological properties. Moreover, because of Muyard proposing the biosynthetic homogeneity of all the phebaclavins, the prenyl side chains at C(3) of phebaclavin D-H can be considered as arising from bio-or chemical oxidation of that present at the same position in phebaclavin A and C. In the literature, there are only a few general strategies for the construction of the 3-substituted coumarin and its derivative.…”

Constituents from the Leaves of Phellodendron amurense var. wilsonii and Their Bioactivity

“…The IR bands at 3368 and 1688 cm -1 revealed the presence of hydroxyl and conjugated ester carbonyl groups. The UV spectrum exhibited absorption maxima at 298 (sh) and 332 nm similar to those for a 7-oxygenated coumarin . Accordingly, a bathochromic shift of 46 nm in the UV absorption maxima was also observed after addition of NaOAc .…”

Flavonoids and Coumarins from Leaves ofPhellodendron chinense

“…The UV and IR spectral data were also similar to those of a 7-oxygenated coumarin [8]. The chemical shifts and multiplicities of aromatic proton signals in 1 H-NMR spectrum indicated the presence of a 6,7-disubstituted coumarin skeleton.…”

“…The UV and IR absorptions were typical of a 7-oxygenated coumarin [8]. In the aromatic region, a pair of doublets and an ABX pattern signals were consistent with a 7-substituted coumarin skeleton.…”