33069-62-4

Usage

Uses

Used in Oncology:
Paclitaxel is used as an antineoplastic agent for the treatment of patients with lung, ovarian, breast cancer, head and neck cancer, and advanced forms of Kaposi's sarcoma. Its unique mechanism of action as a mitotic inhibitor makes it a valuable component in cancer chemotherapy.
Used in Cancer Research:
Paclitaxel is also utilized in the study of the structure and function of microtubules into tubulin, providing insights into the cellular processes involved in cancer development and progression.

History

The toxic ingredients in branches and leaves of Taxus chinensis were separated in 1856 and named “taxine,” which was identified as a kind of white alkaloid’s component. Currently, among all the antitumor drugs, the sale of paclitaxel becomes the first in the world as a well-recognized anticancer drug with potent broad-spectrum activity. In October of 1995, China became the second country with formal production of paclitaxel and its injection in the world. The achievement was gained under the unremitting efforts of researchers in the Institute of Materia Medica, Chinese Academy of Medical Sciences.

Indications

Paclitaxel (Taxol) is a highly complex, organic compound isolated from the bark of the Pacific yew tree. It binds to tubulin dimers and microtubulin filaments, promoting the assembly of filaments and preventing their depolymerization. This increase in the stability of microfilaments results in disruption of mitosis and cytotoxicity and disrupts other normal microtubular functions, such as axonal transport in nerve fibers. The major mechanism of resistance that has been identified for paclitaxel is transport out of tumor cells, which leads to decreased intracellular drug accumulation. This form of resistance is mediated by the multidrug transporter P-glycoprotein.

Preparation

The total synthesis of paclitaxel (Taxol) is described. Double Rubottom oxidation of the bis(silyl enol ether) derived from a tricarbocyclic diketone effectively installed a bridgehead olefin and C-5/C-13 hydroxy groups in a one-step operation. The novel Ag-promoted oxetane formation smoothly constructed the tetracyclic framework of paclitaxel.Total Synthesis of PaclitaxelThe biosynthesis of paclitaxel involves the condensation of the three isoprenyl diphosphate (IPP) units with dimethylallyl diphosphate (DMAPP). Plants are unique in producing IPP and DMAPP by both the mevalonic pathway (MVA) in the cytosol or via the methylerythritol phosphate (MEP) pathway in the plastids.Paclitaxel: biosynthesis, production and future prospects

Therapeutic Function

Antineoplastic

Air & Water Reactions

May be sensitive to prolonged exposure to moisture. .

Health Hazard

TOXIC; inhalation, ingestion or skin contact with material may cause severe injury or death. Contact with molten substance may cause severe burns to skin and eyes. Avoid any skin contact. Effects of contact or inhalation may be delayed. Fire may produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may be corrosive and/or toxic and cause pollution.

Fire Hazard

Flash point data for Paclitaxel are not available. Paclitaxel is probably combustible.

Biological Activity

Antitumor agent; promotes and stabilizes tubulin polymerization, causing cell cycle arrest. Induces autocatalytic activation of caspase-10 in CCRF-HSB-2 cells, triggering apoptosis.

Biochem/physiol Actions

Product does not compete with ATP.

Mechanism of action

Paclitaxel is currently the only known drug that can promote microtubule polymerization and stabilize polymerized microtubules. It can only form on polymerized microtubules and does not react with non-polymerized microtubule protein dipolymers. After coming in contact with paclitaxel, cells will accumulate a large number of microtubules within themselves, which disrupts cell functions, especially cell division, which is forced to cease at the mitotic stage.

Pharmacology

Paclitaxel is mainly used for the treatment of ovarian cancer and breast cancer. The mechanism of it includes: 1. The effects on cell microtubules/tubulin: Inhibition of microtubule depolymerization results in abnormal micro tube bundle arrangement and makes the spindle lose normal function and then induces cell death. 2. In the absence of bird triphosphate (GTP) and microtubule associated protein (MAP), it induces cells to form microtubule lack of function. 3. It significantly sensitized cancer cells to radiotherapy through blocking the cell cycle in the stage of G2 and M . Paclitaxel is mainly metabolized through the liver and enters into the intestine with bile and then eliminated from the body by the feces (90%).

Anticancer Research

It is isolated from the bark of Taxus brevifolia generally known as pacific yew. It isprimarily used in ovarian, small, and non-small cell lung cancers and advancedbreast cancer (Shoeb 2006). It binds to tubulin but neither depolymerizes it nor interferes with its assembly (Balunas and Kinghorn 2005). Taxol targets activatorprotein 1 signaling pathways (Singh et al. 2016b).

Clinical Use

Paclitaxel is among the most active of all anticancer drugs, with significant efficacy against carcinomas of the breast, ovary, lung, head, and neck. It is combined with cisplatin in the therapy of ovarian and lung carcinomas and with doxorubicin in treating breast cancer.

Side effects

Myelosuppression is the major side effect of paclitaxel. Alopecia is common, as is reversible dose-related peripheral neuropathy. Most patients have mild numbness and tingling of the fingers and toes beginning a few days after treatment. Mild muscle and joint aching also may begin 2 or 3 days after initiation of therapy. Nausea is usually mild or absent. Severe hypersensitivity reactions may occur. Cardiovascular side effects, consisting of mild hypotension and bradycardia, have been noted in up to 25% of patients.

Toxicology

The major toxicity seen with paclitaxel is a dose-limitingmyelosuppression that normally presents as neutropenia. Thepreviously mentioned hypersensitivity reactions occur but aregreatly reduced by antihistamine pretreatment. Interactionwith the axonal microtubules such as that seen for the vincasalso occurs and leads to numbness and paresthesias (abnormaltouch sensations including burning and prickling). Theagent is also available as an albumin-bound formulation(Abraxane) to eliminate the need for the solubilizing agentsassociated with the hypersensitivity reactions. Other adverseeffects include bradycardia, which may progress to heartblock, alopecia, mucositis, and/or diarrhea. Paclitaxel producesmoderate nausea and vomiting that is short-lived.

Drug interactions

Potentially hazardous interactions with other drugs Antipsychotics: avoid with clozapine (increased risk of agranulocytosis). Cytotoxics: increased risk of neutropenia with lapatinib.

Metabolism

Paclitaxel is highly plasma protein bound (＞90%) anddoes not penetrate the CNS. Metabolism involves CYPmediatedoxidation to give 6 -hydroxypaclitaxel (CYP2C8)and para hydroxylation of the phenyl group attached to the3'-position (CYP3A4). The 6α-hydroxy metabolite normallypredominates, but the para hydroxy metabolite mayoccur to a greater degree in those patients with liver diseaseor when CYP3A4 has been induced. Both metabolites areless active than the parent and do not undergo phase II conjugationreactions. Elimination occurs primarily in the feces,and the elimination half-life is 9 to 50 hours depending onthe infusion period.

Precautions

1. Hermatological toxicity: the main factor in increased dosage limitations; when white blood cells are below 1500/mm3, supplement with G-CSF; when platelets are below 30000/mm3, transfuse component blood.2. Allergic reaction: Aside from preconditions, if there are only minor symptoms such as flushed face, skin reactions, slightly increase heart rate, slightly lowered blood pressure, etc., do not stop treatment and decrease injection speed. If there are serious reactions such as hypotension, vascular edema, difficulty breathing, measles, etc., stop treatment and treat accordingly. Patients with serious allergic reactions should not use paclitaxel in the future.3. Nervous system: Common reactions include numb toes. Approximately 4% patients, especially with high dosage, experience significant sensory and motor difficulty and decreased tendon reflex. There have been individual reports of epilepsy.4. Cardiovascular: Transient tachycardia and hypotension are common and do not usually require attention. However, monitor closely during first hour of injection. Afterwards, only patients with serious injection difficulty require hourly check-ins.5. Join and muscle: Approximately half of the patients will experience some joint and muscle pain within the first 2-3 days following injection, which is related to dosage, and usually subsides after a couple days. Patients who are also administered G-CSF will experience heightened muscle pain.6. Liver and gall: As paclitaxel is mainly excreted through bile, patients with liver and gall diseases must be monitored carefully. Among thousands of cases, 8% of patients experienced increased bilirubin, 23% experienced increased alkaline phosphatase, and 18% experienced increased glutamic-oxalacetic transaminase. However, there is currently no evidence indicating that paclitaxel causes any severe liver damage.7. Other: Digestive tract reactions are common but rarely severe, with few cases of diarrhea and mucosa infection. Slight alopecia is also common.

References

Wani et al.,J. Amer. Chem. Soc., 93,2325 (1971)

InChI:InChI=1/C47H51NO14/c1-25-31(60-43(56)36(52)35(28-16-10-7-11-17-28)48-41(54)29-18-12-8-13-19-29)23-47(57)40(61-42(55)30-20-14-9-15-21-30)38-45(6,32(51)22-33-46(38,24-58-33)62-27(3)50)39(53)37(59-26(2)49)34(25)44(47,4)5/h7-21,31-33,35-38,40,51-52,57H,22-24H2,1-6H3,(H,48,54)/t31?,32-,33+,35?,36?,37+,38?,40?,45+,46-,47+/m0/s1

Synthetic route

1-hydroxy-7β-triethylsilyloxy-9-oxo-10β-acetyloxy-5β,20-epoxytax-11-ene-2α,4,13α-triyl 4-acetate 2-benzoate 13-[(2R,3S)-3-benzoylamino-2-triethylsilyloxy-3-phenylpropanoate] (135365-62-7) → taxol (33069-62-4)

Conditions	Yield
With pyridine; hydrogen fluoride In water; acetonitrile at 0 - 25℃; for 14h;	98%
With pyridine; hydrogen fluoride In water; acetonitrile at 0 - 25℃; for 14h;	98%
With hydrogenchloride In methanol; water at -5 - 30℃; for 27h;	90%
With pyridine hydrogenfluoride In tetrahydrofuran at 25℃; for 1.25h;	80%

Reaxys ID: 15738630 + benzoyl chloride (98-88-4) → taxol (33069-62-4)

Conditions	Yield
Stage #1: With dmap; chloro-trimethyl-silane; diisopropylamine In tetrahydrofuran at 20℃; for 1h; Stage #2: Schwartz's reagent In tetrahydrofuran at 0℃; for 4h; Stage #3: benzoyl chloride With tert-butyl methyl ether; N,N-bis-(2-hydroxyethyl)glycine; sulfuric acid; sodium hydrogencarbonate more than 3 stages;	86.6%

Reaxys ID: 15738631 + benzoyl chloride (98-88-4) → taxol (33069-62-4)

Conditions	Yield
With tert-butyl methyl ether; N,N-bis-(2-hydroxyethyl)glycine; sulfuric acid; pyridinium p-toluenesulfonate; sodium hydrogencarbonate; triethylamine; ethyl vinyl ether; Schwartz's reagent In tetrahydrofuran; water; ethyl acetate at 5 - 20℃; for 24.8333h;	80%

Reaxys ID: 15738641 + benzoyl chloride (98-88-4) → taxol (33069-62-4)

Conditions	Yield
Stage #1: With dmap; chloro-trimethyl-silane; diisopropylamine In tetrahydrofuran at 0℃; for 1h; Stage #2: Schwartz's reagent In tetrahydrofuran at 5℃; for 4h; Stage #3: benzoyl chloride With tert-butyl methyl ether; N,N-bis-(2-hydroxyethyl)glycine; sulfuric acid; sodium chloride more than 3 stages;	76.5%

(2'R,3'S)-2'-ethoxyethyl-7-triethylsilyl taxol (439813-57-7) → taxol (33069-62-4)

Conditions	Yield
With hydrogenchloride In ethanol; water at 0℃; for 30h;	90%
With hydrogenchloride In ethanol at 0℃; for 72h;	80%

(2'R,3"S)-2'-(2-methoxy-2-propyloxy)-7-triethylsilyl taxol → taxol (33069-62-4)

Conditions	Yield
With pyridine; hydrogen fluoride In water; acetonitrile at 0 - 25℃; for 18h;	99%
Stage #1: (2'R,3"S)-2'-(2-methoxy-2-propyloxy)-7-triethylsilyl taxol With trifluoroacetic acid In water; acetic acid at 20℃; for 7h; Stage #2: With sodium acetate In dichloromethane; water; acetic acid for 0.25h;	26.3 g

Reaxys ID: 15738633 + benzoyl chloride (98-88-4) → taxol (33069-62-4)

Conditions	Yield
With tert-butyl methyl ether; N,N-bis-(2-hydroxyethyl)glycine; sulfuric acid; pyridinium p-toluenesulfonate; sodium hydrogencarbonate; triethylamine; ethyl vinyl ether; Schwartz's reagent In tetrahydrofuran; water; ethyl acetate at -5 - 20℃; for 26.8333h;	43.6%
Stage #1: Schwartz's reagent In tetrahydrofuran at 5℃; for 4h; Stage #2: With N,N-bis-(2-hydroxyethyl)glycine In tetrahydrofuran; ethyl acetate for 0.833333h; Stage #3: benzoyl chloride With tert-butyl methyl ether; sulfuric acid; sodium hydrogencarbonate more than 3 stages;

7-(triethylsilyl)-13-O-[((4S,5R)-2,4-diphenyl-4,5-dihydrooxazol-5-yl)carbonyl]baccatin (158722-23-7) → taxol (33069-62-4)

Conditions	Yield
With hydrogenchloride In methanol at 60 - 80℃; for 3.5h;	80%
With hydrogenchloride In methanol	76%
With hydrogenchloride at 95℃; for 2h;	75%
With hydrogenchloride In methanol at 60℃; for 3h; Hydrolysis;

dmap (1122-58-3) → taxol (33069-62-4)

Conditions	Yield
With hydrogenchloride; water In ethanol at 0 - 20℃; for 2.41667h;	100%

C50H59NO14Si → taxol (33069-62-4)

Conditions	Yield
With hydrogenchloride In water at 20℃;	93.3%

7-O-(2-chloroacetyl)paclitaxel (162081-12-1) → taxol (33069-62-4)

Conditions	Yield
With ammonia In pyridine at 0 - 5℃; for 12h;	84%

13-O-[[(4S,5R)-3-N-benzoyl-4-phenyloxazolidin-2RS-methoxy-5-yl]carbonyl]-7-O-triethylsilylbaccatin III (906370-55-6) → taxol (33069-62-4)

Conditions	Yield
With hydrogenchloride; water In ethanol; ethyl acetate at 45℃; for 4h;	80%

C61H71NO15Si → taxol (33069-62-4)

Conditions	Yield
With acetic acid; trifluoroacetic acid In water at 30℃; Temperature; Concentration;	81%

7-O-(triethylsilyl)paclitaxel (148930-55-6) → taxol (33069-62-4)

Conditions	Yield
With pyridine hydrogenfluoride In tetrahydrofuran Ambient temperature;	100%
With hydrogenchloride; water In ethanol at 20℃; for 2h; Hydrolysis;	100%
With hydrogenchloride In ethanol; water at 0 - 20℃; for 2.41667h;	100%
Multi-step reaction with 9 steps 1: benzoyl peroxide 2: HCl / acetonitrile 3: N-iodosuccinimide, 4 Angstroem sieves / CH2Cl2; tetrahydrofuran 4: H2 / Pd-C / ethyl acetate / 2.5 h / 3102.9 Torr / Ambient temperature 5: bovine intestinal alkaline phosphatase 6: benzoyl peroxide / acetonitrile / 2 h / 0 °C 7: N-iodosuccinimide, 4 Angstroem sieves / CH2Cl2; tetrahydrofuran 8: H2 / Pd-C / ethyl acetate / 2.5 h / 3102.9 Torr / Ambient temperature 9: bovine intestinal alkaline phosphatase, or incubation in mouse plasma at 37 deg C View Scheme
Multi-step reaction with 5 steps 1: benzoyl peroxide 2: HCl / acetonitrile 3: N-iodosuccinimide, 4 Angstroem sieves / CH2Cl2; tetrahydrofuran 4: H2 / Pd-C / ethyl acetate / 2.5 h / 3102.9 Torr / Ambient temperature 5: bovine intestinal alkaline phosphatase View Scheme

C54H60ClNO18S2 → C52H59NO17S2 + taxol (33069-62-4)

Conditions	Yield
With ammonia In methanol at 0℃; for 1.5h; Inert atmosphere;	A 67% B 88 mg

13-[(2'R,3'S)-3'-benzoylamino-3'-phenyl-2'-hydroxypropinonyl]-7-trichloroacetylbaccatin III (1033962-72-9) → taxol (33069-62-4)

Conditions	Yield
With methanol; ammonium acetate In tetrahydrofuran for 4h;	80%
With ammonium acetate In tetrahydrofuran; methanol for 4h;	80%

2'-O-benzoyl-3'-N-debenzoyl-paclitaxel (307923-51-9) → taxol (33069-62-4)

Conditions	Yield
With anthranilic acid; triethylamine In tetrahydrofuran; ethyl acetate	65%
In dimethyl sulfoxide at 20℃;

C130H180N2O28Si4 → taxol (33069-62-4)

Conditions	Yield
With tetrabutyl ammonium fluoride In tetrahydrofuran for 5h;	91.8%

C124H168N2O28Si4 → taxol (33069-62-4)

Conditions	Yield
With tetrabutyl ammonium fluoride In tetrahydrofuran for 5h;	91.5%

C62H73NO16Si (718627-80-6) → taxol (33069-62-4)

Conditions	Yield
With hydrogenchloride In tetrahydrofuran; methanol; water for 0.666667h;	82%

succinic acid anhydride (108-30-5) + C52H60N2O16S2 → C56H64N2O19S2 + taxol (33069-62-4)

Conditions	Yield
With dmap; triethylamine In dichloromethane at 0 - 20℃; for 12h; Inert atmosphere;	A 29% B 80 mg

2’-TES-7-TROC-taxol (219780-99-1) → taxol (33069-62-4)

Conditions	Yield
With acetic acid; zinc	84%
With acetic acid; zinc at 20℃; for 16h; deacylation;	84%

13-(O-2R-hydroxy-3S-amine-phenylpropionyl)-baccatin III (133524-70-6) + benzoyl chloride (98-88-4) → taxol (33069-62-4)

Conditions	Yield
With dipotassium hydrogenphosphate; potassium dihydrogenphosphate; sodium chloride In tetrahydrofuran; water at 20℃; for 0.25 - 0.5h;	70%
With triethylamine In acetonitrile at 20℃; for 0.5h; Purification / work up;
With triethylamine In acetonitrile at 20℃; for 0.5h;

acetic anhydride (108-24-7) + 10-deacetylpaclitaxel (78432-77-6) → taxol (33069-62-4)

Conditions	Yield
Stage #1: 10-deacetylpaclitaxel With Chloroacetamide In tetrahydrofuran at 100℃; for 3h; Stage #2: acetic anhydride In tetrahydrofuran at 100℃; for 3h; Stage #3: With methanol; sodium hydrogencarbonate; thiourea at 20℃; for 1h; Product distribution / selectivity;	78.8%
Stage #1: 10-deacetylpaclitaxel With pyridine; Chloroacetamide at 20℃; for 1h; Stage #2: acetic anhydride With pyridine In tetrahydrofuran at 100℃; for 0.5h; Stage #3: With methanol; sodium hydrogencarbonate; thiourea at 20℃; for 1h; Product distribution / selectivity;	60%
Stage #1: 10-deacetylpaclitaxel With Chloroacetamide In tetrahydrofuran at 100℃; for 3h; Stage #2: acetic anhydride In tetrahydrofuran at 100℃; for 3h; Stage #3: With sodium hydrogencarbonate; thiourea In methanol at 20℃; for 1h; Product distribution / selectivity;

C57H73NO15Si (115437-19-9) → taxol (33069-62-4)

Conditions	Yield
With hydrogenchloride; ethanol at 0℃; for 30h;	89%

Upstream product

• 108-24-7 acetic anhydride 
• 114915-17-2 C₅₀H₅₂Cl₃NO₁₆ 
• 202390-88-3 2',3'-O,N-[(S)-(p-Methoxybenzylidene)]-7-O-(triethylsilyl)paclitaxel 
• 152565-19-0 taxol-2'-chloroacetyl 
• 64180-78-5 4-bromopent-4-en-1-ol 
• 35804-44-5 ethyl 4-bromo-4-pentenoate 
• 143615-00-3 (2R,3S)-3-amino-3-phenyl-2-hydroxypropionic acid ethyl ester 
• 144787-20-2 (2R,3S)-3-azido-2-hydroxy-benzenepropanoic acid ethyl ester 
• 162084-46-0 (S)-1-Hydroxy-4,6,6-trimethyl-5-[1-phenylsulfanyl-meth-(E)-ylidene]-3-triisopropylsilanyloxy-cyclohex-3-enecarbaldehyde 
• 260249-48-7 C₆₁H₇₁NO₁₆Si 
• 260249-49-8 C₅₉H₆₉NO₁₅Si 
• 260249-52-3 C₅₉H₆₉NO₁₅Si 
• 260249-47-6 C₅₉H₆₇N₃O₁₄Si 
• 78432-77-6 10-deacetylpaclitaxel 

Downstream Products

• 503178-23-2 3-Benzoylamino-2-hydroxy-3-phenyl-propionic acid methyl ester 
• 117527-60-3 2'-(N,N-dimethylglycyl)taxol 
• 131966-78-4 2',7-bis(N,N-dimethylglycyl)taxol 
• 148930-54-5 (2aR,4S,4aS,6R,9S,11S,12S,12bS)-6,12b-bis(acetyloxy)-9-({(2R,3S)-3-(benzoylamino)-3-phenyl-2-[(triethylsilyl)oxy]propanoyl}oxy)-4,11-dihydroxy-4a,8,13,13-tetramethyl-5-oxo-2a,3,4,4a,5,6,9, 10,11,12,12a,12bdodecahydro-1H-7,11-methanocyclodeca[3,4]benzo[1,2-b]oxet-12-yl benzoate 
• 117527-54-5 2'-t-BOC-L-phenylalanyltaxol 
• 132073-91-7 2'-<3-(N,N-diethylamino)propionyl>taxol methanesulfonate 
• 32981-86-5 10-deacetylbaccatin III 
• 32981-85-4 methyl (2R,3S)-3-benzoylamino-2-hydroxy-3-phenylpropanoate 
• 71629-92-0 10-deacetyl-7-epi-baccatin III 
• 78432-77-6 10-deacetylpaclitaxel 
• 146139-03-9 C₄₇H₅₁NO₁₄ 
• 105454-04-4 7-epipaclitaxel 
• 148121-24-8 10-deacetoxy-paclitaxel 
• 115441-21-9 uretaxol 

Relevant academic research and scientific papers

Semi-synthesis of paclitaxel from naturally occurring glycosidic precursors

Paclitaxel, an antitumor drug effective on ovarian and breast carcinomas, is currently being produced both by direct isolation from the bark of Taxus brevifolia and by semi-synthesis from a natural precursor, 10-deacetyl baccatin III. Although other potential precursors such as 10-deacetyl paclitaxel-7-xyloside were known since 1984, their conversion to paclitaxel could not be achieved because of the lack of suitable methodology for hydrolyzing the xylose residue, compatible with the stability of the compound. A method is described here using periodate, followed by phenylhydrazine, to effect deglycosidation of 10-deacetyl paclitaxel-7-xyloside to form 10-deacetyl paclitaxel. In addition, by including an intermediate acetylation step before the reaction with phenylhydrazine, 'direct' conversion of this xyloside to paclitaxel itself, is described. Because 10-deacetyl paclitaxel-7-xyloside occurs at >0.1% in the bark of Taxus brevifolia, its successful hydrolytic conversion to paclitaxel represents an extremely important reaction for the enhanced availability of this drug.

CoA recycling by a benzoate coenzyme A ligase in cascade reactions with aroyltransferases to biocatalyze paclitaxel analogs

A Pseudomonas CoA ligase (BadA) biocatalyzed aroyl CoA thioesters used by a downstream N-benzoyltransferase (NDTNBT) in a cascade reaction made aroyl analogs of the anticancer drug paclitaxel. BadA kept the high-cost aroyl CoA substrates at saturation for the downstream NDTNBT by recycling CoA when it was added as the limiting reactant. A deacylated taxane substrate N-debenzoyl-2′-deoxypaclitaxel was converted to its benzoylated product at a higher yield, compared to the converted yield in assays in which the BadA ligase chemistry was omitted, and benzoyl CoA was added as a cosubstrate. The resulting benzoylated product 2′-deoxypaclitaxel was made at 196% over the theoretical yield of product that could be made from the CoA added at 50 μM, and the cosubstrates benzoic acid (100 μM), and N-debenzoyl-2′-deoxypaclitaxel (500 μM) added in excess. In addition, a 2-O-benzoyltransferase (mTBT) was incubated with BadA, aroyl acids, CoA, a 2-O-debenzoylated taxane substrate, and cofactors under the CoA-recycling conditions established for the NDTNBT/BadA cascade. The mTBT/BadA combination also made various 2-O-aroylated products that could potentially function as next-generation baccatin III compounds. These ligase/benzoyltransferase cascade reactions show the feasibility of recycling aroyl CoA thioesters in vitro to make bioactive acyl analogs of paclitaxel precursors.

A clickable caging group as a new platform for modular caged compounds with improved photochemical properties

A 6-bromo-7-hydroxycoumarin-4-ylmethyl (Bhc) caged compound having a click-modifiable chemical handle was designed and synthesized. This molecule was applied to the synthesis of modular caged paclitaxels (PTXs) in which additional functional units could be easily installed. This system was used to prepare water-soluble caged PTXs with improved photolysis efficiencies.

Intermediate compound for preparing paclitaxel, synthetic method of intermediate compound and synthetic method of paclitaxel

The invention relates to an intermediate compound for preparing paclitaxel, a synthetic method of the intermediate compound and a synthetic method of paclitaxel. The intermediate compound for preparing paclitaxel is selected from at least one of compounds shown in the specification, wherein Ts represents p-toluenesulfonyl, TES represents triethylsilyl, TMS represents trimethylsilyl, and Ms represents methylsulfonyl. The paclitaxel can be prepared with high yield by taking the intermediate compounds as raw materials, the structure of the paclitaxel can be easily modified, a series of lead compounds can be screened out to research the biological activity of the paclitaxel, and the paclitaxel is believed to have a breakthrough in the field of research and development of tumor drugs. The synthesis method of the paclitaxel and the intermediate thereof has the advantages of chirality controllability, high yield, high product purity, simplicity, high efficiency, wide raw material source, cheap and easily available reagents, simple reaction, simple operation, greenness, environmental protection and suitableness for industrial large-scale production.

Total Synthesis of Paclitaxel

The total synthesis of paclitaxel (Taxol) is described. Double Rubottom oxidation of the bis(silyl enol ether) derived from a tricarbocyclic diketone effectively installed a bridgehead olefin and C-5/C-13 hydroxy groups in a one-step operation. The novel Ag-promoted oxetane formation smoothly constructed the tetracyclic framework of paclitaxel.

Asymmetric Total Synthesis of Taxol

Taxol is one of the most famous natural diterpenoids and an important anticancer medicine. Taxol represents a formidable synthetic challenge and has prompted significant interest from the synthetic community. However, in all the previous syntheses of Taxol, there have been no reports of closing the desired eight-membered ring through C1-C2 bond formation. Furthermore, the existence of Taxol-resistant tumors and side effects of Taxol make the development of new approaches to synthesize Taxol and its derivatives highly desirable. Here, we report the asymmetric total synthesis of Taxol using a concise approach through 19 isolated intermediates. The synthetically challenging eight-membered ring was constructed efficiently by a diastereoselective intramolecular SmI2-mediated pinacol coupling reaction to form the C1-C2 bond. The unique biomimetic oxygen ene reaction and the newly developed facile tandem C2-benzoate formation and C13 side chain installation improved the efficiency of the synthesis. The mild oxygen ene reaction under light conditions would be an alternative reaction involved in Taxol biosynthesis. This new convergent approach will allow the diverse creation of Taxol derivatives to enable further biological research.

Two-Phase Synthesis of Taxol

Taxol (a brand name for paclitaxel) is widely regarded as among the most famed natural isolates ever discovered, and has been the subject of innumerable studies in both basic and applied science. Its documented success as an anticancer agent, coupled with early concerns over supply, stimulated a furious worldwide effort from chemists to provide a solution for its preparation through total synthesis. Those pioneering studies proved the feasibility of retrosynthetically guided access to synthetic Taxol, albeit in minute quantities and with enormous effort. In practice, all medicinal chemistry efforts and eventual commercialization have relied upon natural (plant material) or biosynthetically derived (synthetic biology) supplies. Here we show how a complementary divergent synthetic approach that is holistically patterned off of biosynthetic machinery for terpene synthesis can be used to arrive at Taxol.

Method for synthesizing paclitaxel from cephalomannine (by machine translation)

The method comprises the following steps: (≥ 9997%) bases as a raw material, N - Butene keys on the side chains of the bases 13 through low-temperature acid hydrolysis; and protecting; and NH (NH-7 ') in the side chains 2, 13 -'. 2 The method has the advantages of mild 7 and 2 controllable reaction conditions, low cost, high yield, high product purity, low impurity content, and suitability for industrial production and market popularization and application 99%. the method comprises the following steps: synthesizing and converting paclitaxel crude product through crystallization, carrying out one-time column chromatography and primary recrystallization purification to obtain paclitaxel. (by machine translation)

Process of synthesizing paclitaxel from 10-deacetyltaxol

The invention relates to a process of synthesizing paclitaxel from 10-deacetyltaxol (10-DAT). The process includes: taking 10-DAT as the starting raw material, conducting acetic anhydride acetylation,and under an alkaline condition, hydrolyzing the 2'-acetyl with dimethylamine to obtain paclitaxel. The route has the characteristics of short steps, shortened production cycle, no need for side chain, and reduction of the raw material cost.

Dual-sensitive targeted nanoparticle preparation for loading chemotherapeutic drugs and preparation method

The invention provides a dual-sensitive targeted nanoparticle preparation for loading chemotherapeutic drugs and a preparation method. The nanoparticle preparation comprises an amphiphilic polymer. The amphiphilic polymer comprises gelatin and at least one chemotherapeutic drug molecule. Each chemotherapeutic drug molecule is chemically bonded to the gelatin via a first chemical group, and the backbone of each first chemical group comprises a disulfide bond. The disulfide bonds with redox sensitivity can be broken to release drugs when the concentration of glutathione around tumor tissues is high. The gelatin, as a substrate of an MMP-2 enzyme, can be degraded into small particles around the tumor tissues by the overexpressed MMP-2 enzyme, so that the permeability in the tumor tissues is improved, and the dual-sensitive drugs are released.