Bax; Bad; Bcl-2; Bcl-XL; caspase-9; Microtubule; tubulin polymerization; tubulin stabilizer
10-Deacetyl-7-xylosyl paclitaxel is a microtubule disruptor. Like paclitaxel, it targets the tubulin protein, binding to the β-tubulin subunit and stabilizing microtubules. This stabilization prevents microtubule depolymerization, leading to cell cycle arrest in the G2/M phase and ultimately inducing apoptosis. Its activity is similar to that of paclitaxel.

Paclitaxel, a natural product originally isolated from Taxus brevifolia, belongs to the most successful anticancer drugs. Nevertheless, its poor water solubility represents a considerable disadvantage in clinical use, and novel derivatives with improved pharmacological features are required. We isolated 7-xylosyl-10-deacetylpaclitaxel from Taxus chinensis, which reveals higher water solubility than paclitaxel. This compound induced mitotic cell cycle arrest and apoptosis as measured by flow cytometry, DNA laddering, and transmission electron microscopy. Pro-apoptotic Bax and Bad protein expression was up-regulated and anti-apoptotic Bcl-2 and Bcl-XL expression down-regulated, which lead to a disturbance of the mitochondrial membrane permeability and to the activation of caspase-9. In turn, caspase-9 activated downstream caspases-3 and -6, but not caspase-8. Bid was also activated by caspase-3. Reversely, treatment with a caspase-10-specific inhibitor could not protect PC-3 cells from 7-xylosyl-10-deacetyl-paclitaxel-triggered apoptosis. Moreover, 7-xylosyl-10-deacetylpaclitaxel had no effect on the expression of CD95 and NF-kappaB proteins, indicating that apoptosis was induced through the mitochondrial-dependent pathway in PC-3 cells[1].
In vitro, 10-Deacetyl-7-xylosyl paclitaxel is expected to have similar activity to paclitaxel as a microtubule stabilizer. It disrupts microtubule dynamics, leading to cell cycle arrest and apoptosis in cancer cells. Its potency is likely comparable to other paclitaxel derivatives, although specific IC50 values are not widely reported.

In vivo, 10-Deacetyl-7-xylosyl paclitaxel is not used as a therapeutic agent. It is a research compound and an impurity or metabolite of paclitaxel. Its in vivo activity would be related to its microtubule-stabilizing properties, similar to paclitaxel, but it is not used clinically.

Assessment of caspase activity. [1]
The activity of caspases was determined by a colorimetric assay based on the ability of caspase-3, -6, -8 and -9 to convert acetyl-Asp-Glu-Val-Asp p-nitroanilide (Ac-DEVD-pNA), acetyl-Val-Glu-Ile-Asp p-nitroanilide (Ac-VEID-pNA), acetyl-Ile-Glu-Thr-Asp p-nitroanilide (Ac-IETD-pNA) and acetyl-Leu-Glu-His-Asp p-nitroanilide (Ac-LEHD-pNA), respectively, into a yellow formazan product [p-nitroaniline (pNA)]. An increase in absorbance at 405 nm was used to quantify the activation of caspases. After exposure for 0, 6, 12 and 24 h, PC-3 cells were collected and rinsed with cold PBS, and then lysed by lysis buffer (40 μl) for 15 min on ice. Cell lysates were centrifuged at 18,000 rpm for 10 min at 4˚C. Activities of caspase-3, -6, -8 and -9 in the supernatant were assayed using a commercial kit. The caspase activities were expressed as percentage of enzyme activity compared to control. Control groups received 0.1% dimethyl sulfoxide. All the experiments were carried out in triplicate.
The in vitro cytotoxicity assay for 10-Deacetyl-7-xylosyl paclitaxel involves treating cancer cell lines with varying concentrations of the compound. Cell viability is assessed using standard colorimetric assays like MTT or SRB after 48-72 hours of treatment, from which the IC50 value is determined. Its ability to stabilize microtubules can be assessed by immunofluorescence microscopy.

Cytotoxicity assay.[1]
PC-3 cells were plated in 96-well plates at a density of 1x104 cells per well. After incubation with medium for 24 h, 5 μM 7-xylosyl-10-deacetylpaclitaxel and paclitaxel, respectively, was applied for 48 h. Afterwards, 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide was added to cell cultures at a final concentration of 0.5 mg/ml and incubated at 37˚C for 4 h. Then, the adherent cells were solubilized with 200 μl DMSO. Absorbance at 492 nm was measured using a multi-plate reader.

---

Cell cycle analysis.[1]
PC-3 cells were treated with or without 5 μM 7-xylosyl-10-deacetylpaclitaxel. After incubation for 24 h, cells were collected and stained with 50 μg/ml DAPI. The cell cycle distribution of 10,000 cells was collected by using a flow cytometry. Cell cycle analysis was performed using FloMax software. Determination of apoptosis. Apoptosis was measured by Annexin-V staining according to manufacturer's instructions. After incubation with or without 5 μM 7-xylosyl- 10-deacetylpaclitaxel for 48 h, cells were spun at 1200 x g for 5 min, and the supernatant was decanted. The cell pellet was re-suspended with 100 μl of Annexin-V binding buffer and 5 μl of Annexin-V dye, and was left in dark at room temperature for 15 min. Following incubation, an additional 400 μl of Annexin-V binding buffer was added to each sample.

---

Determination of levels of Fas (CD95).[1]
PC-3 cells were treated with 7-xylosyl-10-deacetyltaxol (5 μM) for 24 h or left untreated. Cells were spun at 1200 x g for 5 min, and the supernatant was decanted. The cell pellet was re-suspended in 10 μl anti-Fas (CD95) antibody, and was left in dark at room temperature for 15 min.

---

Morphology analysis by transmission electron microscopy.[1]
PC-3 cells treated with or without 5 μM 7-xylosyl-10- deacetylpaclitaxel were washed with PBS, centrifuged, and pre-fixed with 2.5% glutaraldehyde in 0.1 M phosphate buffer at 4˚C for 2 h. The cells were then rinsed thoroughly in phosphate buffer and post-fixed in 1% OsO4 at 4˚C for 30 min. After being fixed, the cells were pelleted in 2% agar. Then, cell blocks were prepared, dehydrated through a graded ethanol series, and embedded in Epon 812. The ultra-structure of cells was analyzed in ultra-thin sections in a transmission electron microscope after the sections were stained with uranyl acetate and lead citrate.

---

DNA fragmentation assay. [1]
PC-3 cells were exposed to 5 μM 7-xylosyl-10-deacetylpaclitaxel for 24 and 48 h or left untreated. Then, cells were collected by centrifugation. Total DNA was purified with a DNA isolation kit according to the manufacturer's instructions. The DNA was separated in 2% agarose gel and visualized by ultraviolet illumination after staining with ethidium bromide.
In vitro cell culture studies for 10-Deacetyl-7-xylosyl paclitaxel are performed in cancer cell lines to assess its cytotoxic effects. Cells are treated with varying concentrations of the compound, and cell viability is assessed using an MTT or SRB assay. Cell cycle analysis is performed by propidium iodide staining. Apoptosis is detected by flow cytometry using Annexin V/PI staining.

In vivo animal experiments for 10-Deacetyl-7-xylosyl paclitaxel are not common. However, its antitumor activity could be studied in xenograft models. Its pharmacokinetic properties could also be studied in animal models. It is primarily used as a reference standard in analytical chemistry.

10-Deacetyl-7-xylosyl paclitaxel has a molecular formula of C50H57NO17 and a molecular weight of approximately 944 g/mol. It is a solid compound that is soluble in organic solvents like DMSO. It is typically stored as a powder at -20°C for long-term stability. Its stability is maintained under recommended storage conditions.

Toxicological data for 10-Deacetyl-7-xylosyl paclitaxel are limited, as it is a research compound. As a derivative of paclitaxel, it is expected to have similar toxicological properties, including myelosuppression and neurotoxicity. However, it is not intended for human use. Standard safety precautions should be followed.

[1]. Activation of the mitochondria-driven pathway of apoptosis in human PC-3 prostate cancer cells by a novel hydrophilic paclitaxel derivative, 7-xylosyl-10-deacetylpaclitaxel. Int J Oncol. 2008 Jul;33(1):103-11.

10-Deacetyl-7-xylosyl paclitaxel is a research compound with no clinical approval. It is used as a reference standard for the analytical method development, method validation, and quality control of paclitaxel. It is also used in research to study the structure-activity relationships of taxanes and to develop new anticancer agents.

C50H57NO17

943.9841

943.362

C, 63.62; H, 6.09; N, 1.48; O, 28.81

90332-63-1

90332-63-1

9811678

White to off-white solid powder

1.5±0.1 g/cm3

1068.4±65.0 °C at 760 mmHg

599.9±34.3 °C

0.0±0.3 mmHg at 25°C

1.660

7.18

7

17

14

68

1940

15

O([C@@]12CO[C@@H]1C[C@H](O[C@@H]1OC[C@@H](O)[C@H](O)[C@H]1O)[C@]1(C([C@@H](C3=C(C)[C@@H](OC(=O)[C@H](O)[C@H](C4C=CC=CC=4)NC(C4C=CC=CC=4)=O)C[C@]([C@H]([C@H]21)OC(C1C=CC=CC=1)=O)(O)C3(C)C)O)=O)C)C(=O)C

ORKLEZFXASNLFJ-ODBGVJAMSA-N

InChI=1S/C50H57NO17/c1-25-31(65-45(61)38(56)35(27-15-9-6-10-16-27)51-43(59)28-17-11-7-12-18-28)22-50(62)42(67-44(60)29-19-13-8-14-20-29)40-48(5,41(58)37(55)34(25)47(50,3)4)32(21-33-49(40,24-64-33)68-26(2)52)66-46-39(57)36(54)30(53)23-63-46/h6-20,30-33,35-40,42,46,53-57,62H,21-24H2,1-5H3,(H,51,59)/t30-,31+,32+,33-,35+,36+,37-,38-,39-,40-,42+,46+,48-,49+,50-/m1/s1

[(1S,2S,3S,4S,7R,9S,10S,12R,15S)-4-acetyloxy-15-[(2R,3S)-3-benzamido-2-hydroxy-3-phenylpropanoyl]oxy-1,12-dihydroxy-10,14,17,17-tetramethyl-11-oxo-9-[(2S,3R,4S,5R)-3,4,5-trihydroxyoxan-2-yl]oxy-6-oxatetracyclo[11.3.1.03,10.04,7]heptadec-13-en-2-yl] benzoate

10-deacetyl-7-xylosyl Paclitaxel; 10-Deacetyl-7-xylosyltaxol; Benzenepropanoic acid, b-(benzoylamino)-a-hydroxy-,(2aR,4S,4aS,6R,9S,11S,12S,12aR,12bS)-12b-(acetyloxy)-12-(benzoyloxy)-2a,3,4,4a,5,6,9,10,11,12,12a,12b-dodecahydro-6,11-dihydroxy-4a,8,13,13-tetramethyl-5-oxo-4-(b-D-xylopyranosyloxy)-7,11-methano-1H-cyclodeca[3,4]benz[1,2-b]oxet-9-yl ester, (aR,bS)-; [(1S,2S,3R,4S,7R,9S,10S,12R,15S)-4-acetyloxy-15-[(2R,3S)-3-benzamido-2-hydroxy-3-phenylpropanoyl]oxy-1,12-dihydroxy-10,14,17,17-tetramethyl-11-oxo-9-[(2S,3R,4S,5R)-3,4,5-trihydroxyoxan-2-yl]oxy-6-oxatetracyclo[11.3.1.03,10.04,7]heptadec-13-en-2-yl] benzoate; 7-xylosyl-10-deacetyl taxol; 10-Deacetylpaclitaxel 7-Xyloside; 10-deacetyl-7-xylosyl paclitaxel (62%);

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Note: This product requires protection from light (avoid light exposure) during transportation and storage.

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

DMSO: 33.3~100 mg/mL (35.3~105.9 mM)
H2O: ~1 mg/mL (~1.06 mM)

Solubility in Formulation 1: ≥ 2.5 mg/mL (2.65 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

---

Solubility in Formulation 2: ≥ 2.5 mg/mL (2.65 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly.
Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.

---

View More

Solubility in Formulation 3: ≥ 2.5 mg/mL (2.65 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.

---

 (Please use freshly prepared in vivo formulations for optimal results.)