Screening for pharmaceutically important taxoids inTaxus baccata var.Aurea Corr. with CC/SPE/HPLC-PDA procedure

Abstract

Needles of 'the golden yew' Taxus baccata var. Aurea Corr. were extracted with methanol followed by pre-purification of the crude extract and column chromatographic (CC) separation on florisil in gradient mode (an increasing concentration of acetone in dichloromethane). The obtained fractions were concentrated and purified on silanized silica gel SPE cartridges and taxoids eluted with 75% methanol were analysed by HPLC-PDA procedure using Waters Symmetry C(18) column with gradient elution. The applied method enabled not only determination of four taxoids commonly occurring in yew extracts (10-deacetylbaccatin III, baccatin III, paclitaxel and cephalomannine), but also, on the basis of chromatographic behaviour and UV spectrum, 10-deacetylated taxoids (10-deacetylpaclitaxel, 10-deacetylcephalomannine, 7-xyloside-10-deacetylpaclitaxel and 10-deacetyltaxol C) could be detected together with 7-epi-10-deacetylpaclitaxel. From the needles of Taxus baccata var. Aurea Corr. the largest amounts isolated were of 10-deacetylbaccatin III, then 10-deacetylpaclitaxel and 7-xyloside-10-deacetylpaclitaxel, all compounds considered to be paclitaxel precursors in semisynthesis. The efficient mechanism of the separation of 10-acetylated taxoids from their 10-deacetylated derivatives on florisil on the basis of electron acceptor-electron donor interactions is discussed.

Insights into the control of taxane metabolism: Molecular, cellular, and metabolic changes induced by elicitation in Taxus baccata cell suspensions

“…Notably, the main taxanes in the CC cultures were DAT, CEPH and PTX (all bearing the phenylisoserine side chain), suggesting that the attachment of the side chain at C13 of BACIII is probably not a flux-limiting step in PTX biosynthesis. Although doubts remain about whether DAT is formed from BACIII or if it is a transformation product of PTX, significant levels of this taxane have been reported in T. cuspidata (Zhang et al, 2010) and T. wallichiana (McLaughlin et al, 1981), in cell suspensions of T. baccata (Mroczek et al, 2000;Palazon et al, 2003;Onrubia et al, 2010) and T. media (Cusido et al, 2002;Exposito et al, 2010), and in hazel cell cultures (Gallego et al, 2015). DAT and its 7-xylosyl derivative are currently considered as suitable precursors for the semi-synthesis of PTX, because they are found in greater amounts than PTX in yew tree bark, and DAT can be easily transformed into PTX by acetylation at the C10 position.…”

LC‐ESI‐MS analysis of taxoids from the bark of Taxus wallichiana

“…LC-MS combines all the steps of the bench-scale protocol for the identification of components in complex mixtures. Several reports have appeared in the literature, demonstrating the applicability of LC (Mroczek et al, 2000), LC-MS and MS/MS techniques in the analysis of taxanes (Griffini et al, 1993;Hoffmann et al, 1998;Hoke et al, 1994;Kerns et al, 1994Kerns et al, , 1995Madhusudanan et al, 1997;Chang et al, 2000).…”

Taxane's Substituents at C3′ Affect Its Regioselective Metabolism: Different in Vitro Metabolism of Cephalomannine and Paclitaxel

“…Cephalomannine (also known as taxol B) is an analog of paclitaxel commonly occurring in yew extracts (Mroczek et al, 2000). It differs from paclitaxel only in the amide portion; the substituent at the C3Ј position is tigloylamide instead of benzamide (Fig.…”