- Microbial transformation of 7-epi-10-deacetylbaccatin III to 10-deacetylbaccatin III
-
The microbial transformation of 7-epi-10-deacetylbaccatin III (7-epi-10-DAB III) to 10-deacetylbaccatin III (10-DAB III) was studied. In this report, seven microorganisms were found to be able to realize the transformation at yields from 20.0% to as high as 70.8%. The optimized conditions such as the solvent, pH value of the medium, the microorganisms, transformation time, and substrate concentration were investigated.
- Feng, Xu,Sun, Lingzhi,Fu, Shaobing,Zou, Zhongmei,Sun, Di-An
-
-
Read Online
- Reinvestigation to the C-7 epimerization of paclitaxel and related taxoids under basic conditions
-
Base-promoted C-7 epimerizations of paclitaxel, 10-deacetylbaccatin III were investigated. It has been found that 13α-OH may play an important role in the equilibrium of C-7 epimers of paclitaxel and related taxoids.
- Fang, Wei-Shuo,Fang, Qi-Cheng,Liang, Xiao-Tian
-
-
Read Online
- Microbial hydrolysis of 7-xylosyl-10-deacetyltaxol to 10-deacetyltaxol
-
Enterobacter sp. CGMCC 2487, a bacterial strain isolated from the soil around a Taxus cuspidata Sieb. et Zucc. plant, was able to remove the xylosyl group from 7-xylosyltaxanes. The xylosidase of this strain was an inducible enzyme. In the bioconversion of 7-xylosyl-10-deacetyltaxol (7-XDT) to 10-deacetyltaxol (10-DT), for the purpose of enhancing the conversion efficiency, the effects of NH4+, oat xylan, temperature, pH value, cell density and substrate concentration on the bioconversion have been systematically investigated. 3.0 mM NH4+, 0.6% oat xylan in the media could enhance the yield of 10-DT; the optimum biocatalytic temperature was 26 °C and optimum pH value was 6.0. The highest conversion rate and yield of 10-DT from 7-XDT reached 92% and 764 mg/L, respectively. In addition, the biocatalytic capacity of the cell cultures remained 66.1% after continuous three batches. These results indicate that converting 7-XDT to 10-DT, a useful intermediate for the semisynthesis of paclitaxel or other taxane-based anticancer drugs by a novel bacterial strain, Enterobacter sp. CGMCC 2487, would be an alternative for the practical application in the future.
- Wang, Kang,Wang, Tingting,Li, Jianhua,Zou, Jianhua,Chen, Yongqin,Dai, Jungui
-
-
Read Online
- Glycosyl hydrolase with beta-xylosidase and beta-glucosidase activities and uses thereof
-
A novel glycosyl hydrolase with activities of beta-xylosidase and beta-glucosidase is provided. Said glycosyl hydrolase can convert 7-xylosyltaxane compounds to 7-hydroxyltaxane compounds.
- -
-
Page/Page column 20
(2015/12/26)
-
- PROCESS FOR THE PURIFICATION 10-DEACETYBACCATINE III FROM 10-DEACETYL-2-DEBENZOYL-2-PENTENOYLBACCATINE III
-
A process for the preparation of 10-deacetyl-7,10-bis-trichloroacetylbaccatine III with HPLC purity higher than 99% and free from 2-debenzoyl-2-pentenoylbaccatine III by purification of 10-deacetyl-7,10-bis-trichloroacetylbaccatineIII followed by alkaline hydrolysis of the protecting groups in position 7 and 10.
- -
-
Page/Page column 2
(2009/12/23)
-
- Biological degradation of taxol by action of cultured cells on 7-acetyltaxol-2″-yl glucoside
-
Biodegradation pathways of taxol in cultured cells of Synechocystis sp. PCC 6803, Synechococcus sp. PCC 7942, Marchantia polymorpha, Nicotiana tabacum, and Glycine max were investigated using a water-soluble taxol derivative, 7-ace-tyltaxol-2″-yl glucoside, as the substrate. Although cyanobacteria, Synechocystis sp. PCC 6803 and Synechococcus sp. PCC 7942, and a lower plant, M. polymorpha, catalyzed the epimerization at 7-position of taxol skeleton, no epimerization occurred with higher plants, N. tabacum and G. max. On the other hand, Synechocystis sp. PCC 6803, Synechococcus sp. PCC 7942, M. polymorpha, and N. tabacum catalyzed hydrolysis at 13-position of taxol to give baccatin III and 10-deacetyl baccatin III. Both cyanobacteria cells also deacetylated 7-epi-baccatin III at its 10-position. M. polymorpha and G. max deacetylated at 10-position of taxol. Copyright
- Shimoda, Kei,Mikuni, Katsuhiko,Nakajima, Kiyoshi,Hamada, Hatsuyuki,Hamada, Hiroki
-
p. 362 - 363
(2008/09/20)
-
- SEMI-SYNTHETIC ROUTE FOR THE PREPARATION OF PACLITAXEL, DOCETAXEL, AND 10-DEACETYLBACCATIN III FROM 9-DIHYDRO-13-ACETYLBACCATIN III
-
A novel semisynthetic route has been provided in the preparation of docetaxel and paclitaxel. This new process involves the conversion of 9-dihydro-13-acetylbaccatinIII to docetaxel and paclitaxel by the step of converting 9-dihydro-13-acetylbaccatin III into 7-O-triethylsilyl-9,10-diketobaccatin III, and adding docetaxel and paclitaxel side chain precursors, respectively, to form a new class of taxane intermediates, such as 7-O-triethylsilyl-9,10-diketodocetaxel and 7-O-triethylsilyl-9,10-diketopaclitaxeltaxel. These new intermediates then by a series reduction, acetylation of the 10-hydroxyl position for paclitaxel and finally deprotection to yield docetaxel and paclitaxel, the most important anti-cancer drugs.
- -
-
Page/Page column 7
(2008/06/13)
-
- CONVERSION 9-DIHYDRO-13-ACETYLBACCATIN III TO 10-DEACETYLBACCATIN III
-
The present invention relates to a process is provided for the conversion of 9-dihydro-13-acetylbaccatin to 10-deacetylbaccatin III. The process includes four specific interrelated steps. The first step involves protecting the 7-hydroxyl group of 9-dihydro-13-acetylbaccatin and converting that 7-hydroxyl-protected 9-dihydro-13-acetylbaccatin to 7, 13-diacetyl-9-dihydrobaccatin III. The second step involves reacting that 7, 13-diacetyl-9-dihydrobaccatin III with 4-methylmorpholine N-oxide in a suitable solvent and oxidizing that reaction product to yield 7, 13-diacetylbaccatin. The third step involves deacetylating that 7, 13-diacetyl-9-dihydrobaccatin III to yield 7-acetylbaccatin III. The fourth and final step involves converting that 7-acetylbaccatin III to 10-deacetylbaccatin III.
- -
-
Page/Page column 9
(2008/06/13)
-
- A PROCESS FOR THE PURIFICATION OF 10-DEACETYLBACCATINE III FROM 10-DE ACET YL-2- DEBENZOYL-2-PENTENOYLBACCATINE III
-
A process for the preparation of 10-deacetyl-7,10-bis- trichloroacetylbaccatine III with HPLC purity higher than 99% and free from 2-debenzoyl-2-pentenoylbaccatine III by purification of 10-deacetyl-7,10-bis- trichloroacetylbaccatineIII followed by alkaline hydrolysis of the protecting groups in position 7 and 10.
- -
-
Page/Page column 6
(2008/06/13)
-
- The Reductive Fragmentation of 7-Hydroxy-9,10-dioxotaxoids
-
The retro-aldol reductive fragmentation of different structural types of 7-hydroxy-9,10-dioxotaxoids was investigated, showing that the reaction is typical of taxanes and requires cerium(III) promotion with NaBH4 in protic medium and alkylboron (aluminium) hydrides in aprotic solvents. The resulting 7,8-seco-taxanes are key intermediates for the synthesis of a novel class of anticancer taxanes endowed with a unique pattern of in vivo biological activity. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003.
- Appendino, Giovanni,Noncovich, Alain,Bettoni, Piergiorgio,Dambruoso, Paolo,Sterner, Olov,Fontana, Gabriele,Bombardelli, Ezio
-
p. 4422 - 4431
(2007/10/03)
-
- Process for the preparation of 10-deacetylbaccatin III
-
The present invention discloses a process for the conversion of a mixture of taxol analogues 7-xylosyl-10-deacetylbaccatin taxols of the formula 2 where R is C6H5, CH3C=CHCH3 or C5H11 into 10-deacetylbaccatin III of the formula 1 by dissolving the taxol analogue of formula 2 in a polar solvent, reacting the resultant solution with a base, and isolating 7-xylosyl-10-deacetylbaccatin III, dissolving the 7-xylosyl-10-deacetylbaccatin III in a polar solvent, reacting the resultant solution with a periodate to cleave the diol system of the xyloside into dialdehyde, treating the generated dialdehyde in an organic acid medium with an amine salt and isolating 10-deacetylbaccatin III of formula 1.
- -
-
-
- A mild and efficient approach for the deprotection of silyl ethers by sodium periodate
-
A mild and efficient method for the deprotection of silyl ethers is reported. The most often used silyl protecting groups, such as TBDMS, TIPS, TMS, TES, TIBS, TPS can be cleaved by NaIO4 furnishing the corresponding alcohol in high yields. This method can be used for a wide range of substrates.
- Wang, Mijuan,Li, Chun,Yin, Dali,Liang, Xiao-Tian
-
p. 8727 - 8729
(2007/10/03)
-
- Beta-Lactams useful for preparation of substituted isoserine esters using metal alkoxides
-
β-lactams are disclosed which are useful for preparing N-acyl, N-sulfonyl and N-phosphoryl substituted esters by reaction with a metal alkoxide.
- -
-
-
- Process for the preparation of 10-deacetylbaccatin III
-
The present invention discloses a process for the conversion of a mixture of taxol analogues 7-xylosyl-10-deacetylbaccatin taxols of the formula 2 where R is C6H5, CH3C═CHCH3or C5H11into 10-deacetylbaccatin III of the formula 1 by dissolving the taxol analogue of formula 2 in a polar solvent, reacting the resultant solution with a base at a temperature of 20-50° C. for a time period in the range of 20-40 hours, and isolating 7-xyloxyl-10-deacetylbaccatin III, dissolving the 7-xylosyl-10-deacetylbaccatin III in a polar solvent, reacting the resultant solution with a periodate at 20-40° C. for a time period in the range of 20-40 hours to cleave the diol system of the xyloside into dialdehyde, treating the generated dialdehyde in an organic acid medium with salts of amine at 0-40° C. for 12-18 hours and isolating 10-deacetylbaccatin III of formula 1.
- -
-
-
- Conversion of 9-dihydro-13-acetylbaccatin III to baccatin III and 10-deacetyl baccatin III
-
Novel methods and synthetic intermediates to prepare baccatin III and 10-deacetylbaccatin from readily available 9-dihydro-13-acetylbaccatin III are described. Selective protection and deprotection of the C-7 hydroxyl functionality provides an entry into facile synthesis of novel taxol intermediates, as well as, providing new methods for the preparation of paclitaxel and docetaxel in large scale. Selective oxidation of the C-9 hydroxyl without the need for protection of the C-7 hydroxyl is described.
- -
-
-
- Acid catalyzed conversions of taxoids
-
Treatment of 10-deacetylbaccatin-III and baccatin-III with dilute HCl affords 10-deacetylbaccatin-V and baccatin-V, respectively. 10-Deacetylbaccatin-V is also obtained when 10-deacetylbaccatin-III is treated with ZnCl2 or ZnBr2 in MeOH. These two Lewis acids convert baccatin-III to 10-deacetylbaccatin-III as well 10-deacetylbaccatin-V. BF3.OEt2 in CH2Cl2 opens the oxetane ring of 7,13-diacetylbaccatin-III to form two regioisomeric products while BBr3 in the same solvent leads to the contraction of its A-ring along with the oxetane cleavage. CF3COOH contracts the A-ring of 7-acetylbaccatin-III and 7,13-diacetylbaccatin-III.
- Das, Biswanath,Srinivas,Ravindranath,Ramesh,Venkataiah,Das, Ratna
-
p. 667 - 670
(2007/10/03)
-
- Process for converting 9-dihydro-13-acetylbaccatin III into taxol and derivatives thereof
-
Process for preparing taxol, baccatin III and 10-deacetylbaccatin III by oxidation of 9-dihydro-13-acetylbaccatin III.
- -
-
-
- Tricyclic and tetracyclic taxanes
-
The synthesis of taxol and other tricyclic and tetracyclic taxanes.
- -
-
-
- The chemistry of the taxane diterpene: Stereoselective reductions of taxanes
-
Stereoselective reductions of taxanes are detailed. Chelation- controlled reductions employing SmI2 are described for the stereoselective reduction of the 9-keto functionality of the diterpene moiety of several taxanes. In all cases the 9β-hydr
- Georg, Gunda I.,Harriman, Geraldine C. B.,Datta, Apurba,Ali, Syed,Cheruvallath, Zacharia,Dutta, Dinah,Vander Velde, David G.,Himes, Richard H.
-
p. 8926 - 8934
(2007/10/03)
-
- Synthetic process for the preparation of tricyclic and tetracyclic taxanes
-
Process for the synthesis of taxol and other tricyclic and tetracyclic taxanes.
- -
-
-
- Tricyclic and tetracyclic taxanes
-
The synthesis of taxol and other tricyclic and tetracyclic taxanes.
- -
-
-
- Synthesis and evaluation of C-seco paclitaxel analogues
-
Starting from 7,9diTes-10-dehydro C-secobaccatin III (4a), C-seco analogues of paclitaxel retaining biological activity were synthesised.
- Appendino, Giovanni,Danieli, Bruno,Jakupovic, Jasmin,Belloro, Emanuela,Scambia, Giovanni,Bombardelli, Ezio
-
p. 4273 - 4276
(2007/10/03)
-
- Synthetic process for the preparation of taxol and other tricyclic and tetracyclic taxanes
-
Process for the synthesis of taxol and other tricyclic and tetracyclic taxanes.
- -
-
-
- Synthesis of modified baccatins via an oxidation-reduction protocol
-
(12R)-7-trietylsilyl-11-dihydro-10-deacetylbaccatin III (2), -deacetylbaccatin III (4) and the 7,8-seco baccatin III (5a) were synthesized from 10-deacetylbaccatin III via an oxidation-reduction protocol.
- Appendino, Giovanni,Jakupovic, Jasmin,Cravotto, Giancarlo,Enriu, Renata,Varese, Marcella,Bombardelli, Ezio
-
p. 3233 - 3236
(2007/10/02)
-
- Method for the isolation and purification of taxane derivatives
-
An improved method for isolating certain clinically important taxane derivatives from the crude extract of a naturally occurring Taxus species comprising treating the extract by reverse phase liquid chromatography on an adsorbent; causing the taxane derivatives to be adsorbed on the adsorbent; and recovering the taxane derivatives from the adsorbent by elution with an elutant. The taxane derivatives thus isolated in pure form are taxol, taxol-7-xyloside, 10-deacetyitaxol, 10-deacetyltaxol-7-xyloside, cephalomannine, cephalomannine-7-xyloside, 10-deactylcephalomannine-7-xyloside, baccatin III, 10-deacetylbaccatin III, baccatin VI, and brevitaxane A.
- -
-
-
- Method for the isolation and purification of taxol and its natural analogues
-
An improved method for isolating taxol and certain clinically important analogues of taxol from a crude extract of a naturally occuring Taxus species comprising treating the extract by reverse phase liquid chromatography on an adsorbent, causing the taxol and the taxol analogues to be absorbed 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.
- -
-
-
- Reactivity of baccatin III derivatives towards samarium II reagents
-
A study of the reactivity of 10-deacetylbaccatin III (1) towards samarium II reagents in the presence of various proton donors led to efficient synthesis of 9β-dihydro-10-deacetylbaccatin III (7) and 2-debenzoyl-9β-dihydro-10-deacetyl-baccatin III (9).
- Py, Sandrine,Khuong-Huu, Francoise
-
p. 1661 - 1664
(2007/10/02)
-
- THE CHEMISTRY OF TAXANES: REACTIONS OF TAXOL AND BACCATIN DERIVATIVES WITH LEWIS ACIDS IN APROTIC AND PROTIC MEDIA
-
Several Lewis acids were shown to cleanyl open the oxetane ring of taxol and baccatin derivatives.The reaction is shown to proceed via anchimeric assistance by the C-4 acetate group.Several minor products, including a novel derivative possessing a bridged C-ring, were also isolated.A mechanistric rationale is provides for all compounds formed.When taxol derivatives were treated with Lewis acids in methanol, ester cleavage reactions were observed.We provide conditions that are selective for C-10 acetate cleavage and for C-13 side-chain methanolysis.
- Chen, Shu-Hui,Huang, Stella,Wei, Jianmei,Farina, Vittorio
-
p. 2805 - 2828
(2007/10/02)
-
- New Oxetane-type Taxanes from Taxus wallichiani Zucc.
-
The needles of Taxus wallichiani Zucc. gave the novel oxetane-type taxane diterpenoids 2 and 5, whose structures have been established on the basis of spectroscopic data and chemical reactions.The acid-catalysed rearrangement of 10-deacetylbaccatin III ha
- Appendino, Giovanni,Oezen, Hasan Cetin,Gariboldi, Pierluigi,Torregiani, Elisabetta,Gabetta, Bruno,et al.
-
p. 1563 - 1566
(2007/10/02)
-
- Processes of converting taxanes into 10-deacetylbaccatin III
-
A process for the preparation of a compound of formula (I) STR1 comprising contacting a mixture containing at least one taxane compound having an ester linkage at the C-13 position with at least one borohydride reducing salt in a reaction solvent in the presence of a Lewis acid.
- -
-
-
- Improved protection and esterification of a precursor of the taxotere and taxol side chains
-
(4S,5R)-N-BOC-2,2-dimethyl-4-phenyl-5-oxazolidinecarboxylic acid 8 was prepared and efficiently esterified by conveniently protected baccatins 9a,b. Smooth deprotection in formic acid gave the N-deprotected intermediates of Taxotere and taxol. This protocol did not generate any epimerization at C-2′ and constitutes a pratical method to prepare Taxotere, taxol and analogs.
- Commercon,Bezard,Bernard,Bourzat
-
p. 5185 - 5188
(2007/10/02)
-
- Anitleukemic Alkaloids from Taxus wallichiana Zucc.
-
A new antileukemic taxane alkaloid, cephalomannine (1a), has been isolated from leaves, stems, and roots of Taxus wallichiana Zucc.Cephalomannine is closely related to taxol (1b), a previously characterized antileukemic alkaloid, which also occurs in T. wallichiana but in lesser amounts than cephalomannine.The new alkaloid and its hydrolysis products were characterized by nuclear magnetic resonance, mass spetroscopy, and X-ray crystallography; taxol and two cytotoxic taxane congeners were also identified.
- Miller, Roger W.,Powell, Richard G.,Smith, Cecil R.
-
p. 1469 - 1474
(2007/10/02)
-
