Taxanes from the roots of Taxus x media cv Hicksii

The plants of genus taxus commonly known as yew tree have been used since the ancient times for their magic, poisonous and pharmacological properties. Studies devoted to chemical constitution of extracts of several Taxus genera have been extensively developed during the last years, according to the well documented anticancer activity of taxol. The bark of several yew species has been thoroughly investigated, but very few studies have been done on the constituents of roots. The roots of an ornamental variety of yew (T. x media cv Hicksii) gave a series of taxane and abeotaxane pseudoalkaloids. Both N-alkylated O (5) esters (taxines) and N-acylated O (13) esters (Taxols) were isolated, some of them in glycosidic form. Besides known compounds, some new taxines, taxols and abeotaxanes were isolated and their structures fully elucidated

New cyclopeptide alkaloids from Ziziphus mucronata

Ziziphus mucronata (rhamnaceae), known in South Africa as the "buffalo thorn", is reported to have numerous magico-medicinal uses. Pharmacological investigations have shown sedative, analgesic, anti-inflammatory and antibacterial activities. The alkaloid extract of the roots afforded as main component the already known cyclopeptide alkaloid mucronine-D. Among the minor compounds O-demethyl mucronine-D, and a new cyclopeptide alkaloid, which is an isomer of sativanine-K, were isolated. The structure of the three compounds have been mainly determined through recent 1D- (selective excitation) and 2D-NMR (long-range C-H correlation and ROESY)