Taxus spp. Needles Contain Amounts of Taxol Comparable to the Bark of Taxus brevifolia: Analysis and Isolation

Abstract

New sources for the antitumor natural product taxol [1] are needed as demands for this promising cancer chemotherapeutic agent increase. Presently, supplies of taxol for clinical studies are obtained from the bark of Taxus brevifolia, a potentially limited source. Using analytical methods, the needles and stems of six Taxus species have been examined for taxol [1] and 10-deacetylbaccatin III [5], a related compound that can be converted to taxol through a semi-synthetic route. Amounts of taxol comparable to quantities reported from the bark of T. brevifolia were found in the needles of four of the Taxus species investigated. In addition, taxol was isolated from the needles of one Taxus species. Thus, Taxus needles may provide a renewable source of this valuable compound.

Variation of Taxane Content in Needles of Taxus x media Cultivars with Different Growth Characteristics

“…Every year large amount of clippings was pruned from these plants by nurseries. Since needles contain taxanes comparable to their original source (Witherup et al, 1990), these clippings could be utilized to extract paclitaxel and 10-DAB to save patients afflicted by ovarian and breast cancers. By estimation, paclitaxel extracted from 'Hicksii' clippings alone could treat 3,000 to 4,000 ovarian cancer patients annually (Hansen et al, 1999).…”

“…Fast-growing yew trees accumulate a larger amount of biomass in their renewable parts (like needles) in a given period of time than those of a slow growth rate. It was reported that needles contain taxane with an amount comparable to that in its original source (Witherup et al, 1990). Therefore, it is desirable to identify some cultivars which can combine both high taxane content and fast biomass production.…”

Getting to the bottom of Taxol biosynthesis by fungi

“…The organic solution was evaporated to dryness and redissolved in dichloromethane. After two rounds of extraction with water, the organic layer was dried over magnesium sulfate, evaporated to dryness and the residue was redissolved in methanol (Witherup et al 1990). …”

The Presence of Taxol and Related Compounds in Taxus Baccata Native to the Ukraine (Crimea), Georgia, and Southern Russia

“…baccata obtained from its native habitat in the Crimea, Russia, and Georgia was 0.0063% or twice the levels reported by Witherup et al (1990) and Vidensek et al (1990) for T. baccata samples obtained from cultivated material grown in the United States. At this time, it is impossible to know if this difference is due to the drying and processing procedures or the effect of being brought into cultivation.…”

“…& Zucc. ), the hybrid Taxus x media Rehd., and several ornamental forms analyzed in the United States came from commercially grown stock (Vidensek, Lim, Campbell, and Carlson 1990;Witherup, Look, Stasko, Ghiorzi, and Muschik 1990 (Sokolov, Svyazeva, and Kubly 1977). It is disjunctly distributed in the Crimean highlands.…”