Chapter 14 The Taxus Alkaloids

Construction of the taxane C-ring epoxy alcohol moiety and examination of its possible involvement in the biogenesis of the taxane 3-oxetanol structure

“…The resulting suspension was filtered through Celite being washed with ether. Removal of the solvent at reduced pressure and flash chromatography of the residue (3 X 25 cm column, 50% ethyl acetate in hexanes) gave the desired alcohol 19 (1.02 9 H, C(CH3)3), 1.28 and 1.26 (2 s, 6 H, C(CH3)2), 1.49 (quint, 2 , H-19), 1.80 (m, 2 , H-16), 2.12 (m, 2 H, = 14. 5 Hz, H-13, H-13'), 3.59 (q, 2 H, J = 6.…”

Taxaceae A.Gray

“…Wehner and Gawatz (2003) described the death of a 14 -year -old boy who obtained such information and followed the instructions. Originally, the structures of taxine I and II were hypothesized from the structures of more stable cinnaminic acid derivatives (Lythgoe 1968). She recovered only to make further attempts later.…”

“…Taxine B appears to be the equivalent of the hypothesized taxine I (Graf et al 1986). Taxines occur in differing proportions in the various species of the genus, with taxine B and its structural isomer isotaxine B (acetyl group on C -9 rather than C -10) reported as the predominant forms in T. baccata but not necessarily in T. cuspidata (Lythgoe 1968;Appling 1984;Graf et al 1986;Jenniskens et al 1996;Adeline et al 1997;Kite et al 2000) (Figures 70.2-70.4). taxol effects, mitosis inhibition, antineoplastic, toxic via long -term action on axonal structure taxine effects mainly on heart; interfere with cardiac conduction; heart block The taxols and their precursor baccatins are of great medical interest because of their antineoplastic effects.…”

Biocatalytic synthesis of some chiral pharmaceutical intermediates by lipases

“…Among the antimitotic agents, paclitaxel (taxol) 5 (4,5), a complex polycyclic diterpene (6), exhibits a unique mode of action on microtubule proteins that are responsible for the formation of the spindle during cell division. In contrast to other "spindle-formation inhibitors," such as vinblastine or colchicine, both of which prevent the assembly of tubulin (7,8), paclitaxel is the only compound known to promote the assembly of microtubules and inhibit the tubulin disassembly process (9).…”