Method for the isolation and purification of taxol and its natural analogues
AssigneeUniversity of Florida
InventorKoppaka V. Rao
Life of this patent
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Abstract
An improved method for isolating taxol and certain clinically important analogues of taxol from a crude extract of a naturally occurring Taxus species comprising treating the extract by reverse phase liquid chromatography on an adsorbent, causing the taxol and the taxol analogues to be adsorbed on the adsorbent, and recovering taxol and the natural analogues of taxol from the adsorbent by elution with an elutant. The compounds thus isolated in pure form are taxol, taxol-7-xyloside, 10-deacetyltaxol, 10-deacetyltaxol-7-xyloside, cephalomannine, cephalomannine-7-xyloside, 10-deacetylcephalomannine-7-xyloside, baccatin III, 10-deacetylbaccatin III, baccatin VI, brevitaxane A, and taxiflorine.
Claims3
A method for bleaching a crude mixture comprising colored impurities, taxol and natural analogues of taxol selected from the group consisting of taxel C, 10-deacetyl taxol C, 10-deacetyltaxol C-7-xyloside, taxol-7-xyloside, 10-deacetyltaxol-7-xyloside, cephalomannine, cephalomannine-7-xyloside, 10-deacetylcephalomannine-7-xyloside, baccatin III, 10-deacetylbaccatin III baccatin VI, brevitaxane A, and taxiflorine, said method comprising
- (a) treating an extract comprising taxol and the natural analogues of taxol and colored impurities by reverse phase liquid chromatography on a single preparative column having a silica gel-based reverse phase particle adsorbent, causing said taxol and said analogues of taxol to be adsorbed on the adsorbent;
- (b) eluting, with a water-miscible organic eluant selected from the group consisting of a lower alcohol, lower aliphatic ketone, lower aliphatic ester, cyclic ester, dimethyl formamide, dimethyl sulfoxide, acetic acid, and acetonitrile, taxol and the natural analogues of taxol from the adsorbent;
- (c) recovering taxol and the natural analogues of taxol in separate fractions of eluate;
- and
- (d) treating said fractions from step (c) with ozone to produce colorless fractions.
An isolated and purified analog of taxol having the following characteristics:
- m.p. 220.degree.-222.degree. C., optical rotation -27.degree. (in chloroform);
- IR (KBr):
- 3570, 3400, 2980, 2930, 1740-1730, 1655, 1590 cm.sup.-1 ;
- NMR (CDCl.sub.3):
- 0.899 (s, 3H), 1.039 (s, 3 H), 1.267 (m, 1H), 1.343 (s, 3H), 1.50 (d, 1H), 1.743 (s, 3H), 1.87 (m, 1H), 2.008 (s, 3H), 2.075 (s, 3H), 2.318 (m, 1H), 2.466 (m, 1H), 2.677 (s, 1H), 2.746 (d, 1H), 4.380 (br, s, 1H), 4.440 (s, 1H), 4.690 (br, s, 1H), 4.823 (s, 1H), 5.180 (s, 1H), 5.565.(dd, 1H), 6.06 (d, 1H), 6.522 (d, 1H), 7.429 (m, 2H), 7.554 (m, 1H), 7.861 (d, 2H),.
- .sup.13 C NMR (DMSO):
- 11.727, 11.957, 20.559, 21.258, 26.405, 27.088, 28.008, 36.511, 38.848, 44.652, 46.657, 61.168, 69.283, 69.594, 70.639, 74.663, 75.165, 77.291, 109.690, 128.677, 129.222, 129.771, 133.221, 134.001, 150.311, 151.271, 164.138, 169.162, 169.337;
- representing the following chemical structure for said analog:
- ##STR18##
An isolated and purified analog of taxol having the following characteristics:
- a colorless crystalline compound, m.p. 266.degree.-268.degree. C.;
- optical rotation, -26.degree. (1% in methanol);
- and when acetylated having the following NMR spectra:
- proton NMR spectrum;
- 1.19, 1.63, 1.78, 1.81, 1.83, 2.01, 2.02, 2.13, 2.30, 2.68, 2.99, 4.21, 4.30, 4.97, 5.52, 5.62, 6.19, 6.32, 6.44, 7.43, 7.58, 7.93;
- carbon NMR spectrum:
- 11.17, 13.2, 20.5, 20.9, 21.5, 21.6, 21.8, 24.9, 27.5, 34.6, 36.7, 43.6, 43.9, 67.50, 67.54, 67.83, 67.96, 68.05, 70.39, 74.53, 75.41, 78.62, 78.85, 84.85, 128.4, 129.42, 129.7, 133.2, 135.9, 146.9, 166.30, 167.98, 169.01, 169.99, 170.21, 170.59, representing the following chemical structure for said analog ##STR19##
Dependencies are inferred from the claim text.