Weitere Beiträge zur Kenntnis des Taxins. II. Mitteilung.

Taxol and Derivatives: A Biogenetic Hypothesis

“…Among the derivatives described above, some obviously come from the decomposition of the alkaloidal mixture called taxine (38) which is responsible for the poisonous nature of the yew. The basic character of this mixture is due to the 3-dimethylamino-3phenylpropionic acid (Winterstein's acid) residue which esterifies various nitrogen-free polyhydroxylic taxane compounds (56)(57)(58). Because of the difficulties in isolating such esters, most of them have never been obtained as such except in the form of their desdimethylamino derivatives.…”

“…-Acid hydrolysis of taxine gives (31? )-3-dimethylamino-3-phenylpropionic acid (Winterstein's acid) (56,57,68). Biosynthetic studies on this acid have been reported first by Leete (69) and more recently by Haslam (70).…”

New Minor Taxane Derivatives from the Needles of Taxus canadensis

“…The 1 H and 13 C NMR spectra (Tables 2 and 3) exhibited the usual signals for a taxane skeleton: [10][11][12] four tertiary methyl groups at δ 1.14, 1.74, 1.98, and 0.97, three in the 1 H NMR spectrum. 15,16 Further support was provided by the prominent fragment peaks at m/z 194 and 134 in the FABMS. 16 The location of the Winterstein's acid side chain was deduced to be at C-5 from the long-range correlations of H-5 (δ 5.17) to C-1′ (δ 170.0) in the HMBC spectrum.…”

“…Indeed, this was confirmed with HMBC correlations. The presence of a Winterstein's acid [3‘-( N , N -dimethylamino)-3‘-phenylpropanoyl] moiety in 5 was obtained from the signals at δ 2.17 (6H, s, N-CH 3 ), 2.88 (1H, broad, H-2‘), 3.13 (1H, broad, H-2‘), 3.78 (1H, broad, H-3‘), 7.33 (4H, m, Ph- o , m ), and 7.28 (H, m, Ph- p ) in the 1 H NMR spectrum. , Further support was provided by the prominent fragment peaks at m / z 194 and 134 in the FABMS . The location of the Winterstein's acid side chain was deduced to be at C-5 from the long-range correlations of H-5 (δ 5.17) to C-1‘ (δ 170.0) in the HMBC spectrum.…”

A Brief Survey of Taxus Alkaloids and Other Taxane Derivatives

“…Associated with crude taxine were color reactions which, as Lefebvre discovered, were due to a glucoside that he isolated and called taxicatin (16). 5a R, = R, = H, R, = R, = R6 = CO-CH,, R a C O-CH=C H-C6H3 5b R, : OH, R2 : R3 r R4 í Rj : R6 : H 5c R, = R3 -R4 -H, R2 -Rj -R6 = CO-CK3 5d R, = R4 -H, R2 --R3 : Rj = Ré = CO-CH3 In 1921, Winterstein and Iatrides assigned to taxine the empirical formula C37H51NO10 (17); treatment with acid produced a crystalline nitrogenous compound, C11H15NO2, which appeared to be 3-dimethylamino-3-phenyl propionic acid (18). In 1922, taxine was found in the Japanese yew (T. cuspidata) (19); in 1925, formulas were given for taxinolamine (C21H31NO5), taxic acid (C16H20O5) and taxinol (C19H24O5) produced from taxine (20).…”