In the HCT-116 cell line cytotoxicity experiment, epothilone B inhibits HCT116 cells with an IC50 of 0.8 nM[1]. An medication that targets microtubules (MT) is called epothilone B, or patupilone. Epothilone B effectively reduces cell growth with an IC50 of 6 nM after 72 hours of treatment, as demonstrated by the MTT cell proliferation experiment, but values ≤1 nM are not cytotoxic. At the non-cytotoxic concentration of 1 nM, epothilone B considerably inhibits transwell cell migration; at 10 nM, the impact is more pronounced[2]. In human medulloblastoma cell lines, epothilone B (Patupilone) is a novel, non-taxane-related, and nonneurotoxic microtubule-stabilizing drug. With an IC50 of 0.53 nM in the D341 cell line, 0.37 nM in the D425Med cell line, and 0.19 nM in the DAOY cell line, epothilone B decreases the proliferative activity in these three cell lines. Epothilone B's effect on clonogenic survival in the D341Med cell line is observed at doses (IC50, 0.50-0.75 nM) that are comparable to the degree of proliferative activity and viability. Nevertheless, at a 10-fold lower concentration of Epothilone B (IC50, 30 pM), the clonogenicity of D425Med and DAOY cells is already significantly decreased. Overall, these findings show that epothilone B has a strong anti-medulloblastoma cell line effect[3].

In contrast, combined treatment exerts a strong supra-additive tumor growth control, with complete tumor regression in the follow-up period (P<0.005, for ionizing radiation or Epothilone B alone vs combined treatment). Treatment with Epothilone B (Patupilone) or ionizing radiation alone results in a partial tumor growth suppression over 10 days[3].

[1]. Synthesis and biological activity of novel epothilone aziridines. Org Lett. 2001 Aug 23;3(17):2693-6.

[2]. Epothilone B inhibits migration of glioblastoma cells by inducing microtubule catastrophes and affecting EB1 accumulation at microtubule plus ends. Biochem Pharmacol. 2012 Aug 15;84(4):432-43.

[3]. The microtubule stabilizer patupilone (epothilone B) is a potent radiosensitizer in medulloblastoma cells. Neuro Oncol. 2011 Sep;13(9):1000-10.

Epothilone B is an epithilone that is epithilone D in which the double bond in the macrocyclic ring has been oxidised to the corresponding epoxide (the S,S stereoisomer). It has a role as an apoptosis inducer, an antineoplastic agent and a microtubule-stabilising agent. It is an epothilone and an epoxide.
Epothilone B is a 16-membered macrolide that mimics the biological effects of taxol.
Epothilone B has been reported in Sorangium cellulosum and Apis cerana with data available.
Patupilone is a compound isolated from the myxobacterium Sorangium cellulosum. Similar to paclitaxel, patupilone induces microtubule polymerization and stabilizes microtubules against depolymerization conditions. In addition to promoting tubulin polymerization and stabilization of microtubules, this agent is cytotoxic for cells overexpressing P-glycoprotein, a characteristic that distinguishes it from the taxanes. Patupilone may cause complete cell-cycle arrest.

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Drug Indication
Investigated for use/treatment in ovarian cancer, lung cancer, brain cancer, breast cancer, and gastric cancer.
Malignant neoplasm of other and unspecified genital organs - Fallopian tube (oviduct, uterine tube), Malignant neoplasm of the retroperitoneum and peritoneum - Peritoneum, unspecified

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Mechanism of Action
The principal mechanism of the epothilone class is inhibition of microtubule function. Microtubules are essential to cell division, and epothilones therefore stop cells from properly dividing. Epothilone B possess the same biological effects as taxol both in vitro and in cultured cells. This is because they share the same binding site, as well as binding affinity to the microtubule. Like taxol, epothilone B binds to the αβ-tubulin heterodimer subunit. Once bound, the rate of αβ-tubulin dissociation decreases, thus stabilizing the microtubules. Furthermore, epothilone B has also been shown to induce tubulin polymerization into microtubules without the presence of GTP. This is caused by formation of microtubule bundles throughout the cytoplasm. Finally, epothilone B also causes cell cycle arrest at the G2-M transition phase, thus leading to cytotoxicity and eventually cell apoptosis.

C27H41NO6S

507.68

507.265

152044-54-7

448013

White to off-white solid powder

1.1±0.1 g/cm3

680.2±55.0 °C at 760 mmHg

95-97ºC

365.2±31.5 °C

0.0±2.2 mmHg at 25°C

1.532

2.29

2

8

2

35

816

7

C[C@H]1CCC[C@@]2([C@@H](O2)C[C@H](OC(=O)C[C@@H](C(C(=O)[C@@H]([C@H]1O)C)(C)C)O)/C(=C/C3=CSC(=N3)C)/C)C

QXRSDHAAWVKZLJ-PVYNADRNSA-N

InChI=1S/C27H41NO6S/c1-15-9-8-10-27(7)22(34-27)12-20(16(2)11-19-14-35-18(4)28-19)33-23(30)13-21(29)26(5,6)25(32)17(3)24(15)31/h11,14-15,17,20-22,24,29,31H,8-10,12-13H2,1-7H3/b16-11+/t15-,17+,20-,21-,22-,24-,27+/m0/s1

(1S,3S,7S,10R,11S,12S,16R)-7,11-dihydroxy-8,8,10,12,16-pentamethyl-3-[(E)-1-(2-methyl-1,3-thiazol-4-yl)prop-1-en-2-yl]-4,17-dioxabicyclo[14.1.0]heptadecane-5,9-dione

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

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

Solubility in Formulation 1: ≥ 2.08 mg/mL (4.10 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 20.8 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.

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Solubility in Formulation 2: ≥ 2.08 mg/mL (4.10 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 20.8 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.

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Solubility in Formulation 3: 2.08 mg/mL (4.10 mM) 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 20.8 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.

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Solubility in Formulation 4: 30% PEG400+0.5% Tween80+5% Propylene glycol :5 mg/mL

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