Letrozole (Synonyms: CGS 20267)

Name: Letrozole
Brand: MedChemExpress
SKU: HY-14248
Rating: 5.0 (17 reviews)

Cat. No.: HY-14248 Purity: 99.91%: FAQs
Data Sheet SDS COA Handling Instructions

Molarity Calculator

Letrozole (CGS 20267) is a potent, selective, reversible and orally active non-steroidal inhibitor of aromatase, with an IC₅₀ of 11.5 nM. Letrozole selective inhibits estrogen biosynthesis, and can be used for the research of breast cancer.

For research use only. We do not sell to patients.

Letrozole Chemical Structure

CAS No. : 112809-51-5

Size	Price	Stock	Quantity

Free Sample (0.1 - 0.5 mg)		Apply Now
Solid + Solvent
10 mM * 1 mL in DMSO ready for reconstitution	USD 87	In-stock	Estimated Time of Arrival: December 31
Solution
10 mM * 1 mL in DMSO	USD 87	In-stock	Estimated Time of Arrival: December 31
Solid
100 mg	USD 79	In-stock	Estimated Time of Arrival: December 31
200 mg	USD 85	In-stock	Estimated Time of Arrival: December 31
500 mg	USD 100	In-stock	Estimated Time of Arrival: December 31
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5 g		Get quote

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Customer Review

Based on 17 publication(s) in Google Scholar

Other Forms of Letrozole:

Letrozole-d₄ In-stock

: Letrozole purchased from MedChemExpress. Usage Cited in: Exp Ther Med. 2018 Jun;15(6):5269-5274. [Abstract]; Letrozole significantly increases the protein levels of Ras/ERK1/c-Myc in the classical MAPK pathway.

: Letrozole purchased from MedChemExpress. Usage Cited in: Exp Ther Med. 2018 Jun;15(6):5269-5274. [Abstract]; Detection of the effects of Letrozole and the MAPK pathway on the proliferation of GC-1 spg cells by BrdU. MAPK, mitogen-activated protein kinase; spg, spermatogonia; BrdU, bromodeoxyuridine.

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View All Isoforms

CYP1 CYP2 CYP3 CYP4 CYP11 CYP17 Aromatase/CYP19A1 CYP26 CYP51 CYP2D6 CYP3A4 CYP17A1

Biological Activity
Purity & Documentation
References
Customer Review

Description

IC₅₀ & Target

Aromatase

In Vitro

Letrozole (0.1-100 nM; 24-96 h) significantly inhibits growth of the MCF-7 epithelial breast cancer cells in a dose- and time-dependent manner^[2].
Letrozole (10 nM) significantly suppresses the stimulatory effects of testosterone on MCF-7 cell proliferation^[2].
Letrozole (10 nM; 24-48 h) suppresses the levels of secreted metalloproteinases (MMP‐2 and MMP‐9) in MCF-7 cells^[2].

MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.

Cell Viability Assay^[2]

Cell Line:	MCF-7 cells
Concentration:	0.1, 1, 10, 100 nM
Incubation Time:	24, 48, 96 hours
Result:	Inhibited cells growth in a dose- and time-dependent manner.

In Vivo

Letrozole (3-300 μg/kg; oral gavage once daily for 6 weeks) exhibits anti-tumor effects in rats^[3].

MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.

Animal Model:	Adult female rats bearing mammary tumors^[3]
Dosage:	3, 10, 30, 100, 300 μg/kg
Administration:	Oral gavage once daily for 6 weeks
Result:	Induced complete regression of mammary tumors, with an ED₅₀ of 10-30 μg/kg/day.

Clinical Trial

Molecular Weight

285.30

Formula

C₁₇H₁₁N₅

CAS No.

112809-51-5

Appearance

Solid

Color

White to off-white

SMILES

N#CC1=CC=C(C(N2C=NC=N2)C3=CC=C(C#N)C=C3)C=C1

Structure Classification

Alkaloids

Initial Source

Shipping

Room temperature in continental US; may vary elsewhere.

Storage

Powder	-20°C	3 years
	4°C	2 years
In solvent	-80°C	2 years
	-20°C	1 year

Solvent & Solubility

In Vitro:

DMSO : 50 mg/mL (175.25 mM; Need ultrasonic; Hygroscopic DMSO has a significant impact on the solubility of product, please use newly opened DMSO)

Preparing
Stock Solutions

Concentration Solvent Mass	1 mg	5 mg	10 mg

1 mM	3.5051 mL	17.5254 mL	35.0508 mL
5 mM	0.7010 mL	3.5051 mL	7.0102 mL
10 mM	0.3505 mL	1.7525 mL	3.5051 mL

View the Complete Stock Solution Preparation Table

* Please refer to the solubility information to select the appropriate solvent. Once prepared, please aliquot and store the solution to prevent product inactivation from repeated freeze-thaw cycles.
Storage method and period of stock solution: -80°C, 2 years; -20°C, 1 year. When stored at -80°C, please use it within 2 years. When stored at -20°C, please use it within 1 year.

Molarity Calculator
Dilution Calculator

Mass (g) = Concentration (mol/L) × Volume (L) × Molecular Weight (g/mol)

Concentration _(start) × Volume _(start) = Concentration _(final) × Volume _(final)

This equation is commonly abbreviated as: C₁V₁ = C₂V₂

In Vivo:

Select the appropriate dissolution method based on your experimental animal and administration route.

For the following dissolution methods, please ensure to first prepare a clear stock solution using an In Vitro approach and then sequentially add co-solvents:
To ensure reliable experimental results, the clarified stock solution can be appropriately stored based on storage conditions. As for the working solution for in vivo experiments, it is recommended to prepare freshly and use it on the same day.
The percentages shown for the solvents indicate their volumetric ratio in the final prepared solution. If precipitation or phase separation occurs during preparation, heat and/or sonication can be used to aid dissolution.

Protocol 1

Add each solvent one by one: 10% DMSO 40% PEG300 5% Tween-80 45% Saline
Solubility: ≥ 2.08 mg/mL (7.29 mM); Clear solution

This protocol yields a clear solution of ≥ 2.08 mg/mL (saturation unknown).
Taking 1 mL working solution as an example, add 100 μL DMSO stock solution (20.8 mg/mL) to 400 μL PEG300, and mix evenly; then add 50 μL Tween-80 and mix evenly; then add 450 μL Saline to adjust the volume to 1 mL.
Preparation of Saline: Dissolve 0.9 g sodium chloride in ddH₂O and dilute to 100 mL to obtain a clear Saline solution.
Protocol 2

Add each solvent one by one: 10% DMSO 90% (20% SBE-β-CD in Saline)
Solubility: ≥ 2.08 mg/mL (7.29 mM); Clear solution

This protocol yields a clear solution of ≥ 2.08 mg/mL (saturation unknown).
Taking 1 mL working solution as an example, add 100 μL DMSO stock solution (20.8 mg/mL) to 900 μL 20% SBE-β-CD in Saline, and mix evenly.
Preparation of 20% SBE-β-CD in Saline (4°C, storage for one week): 2 g SBE-β-CD powder is dissolved in 10 mL Saline, completely dissolve until clear.
Protocol 3

Add each solvent one by one: 10% DMSO 90% Corn Oil
Solubility: ≥ 2.08 mg/mL (7.29 mM); Clear solution

This protocol yields a clear solution of ≥ 2.08 mg/mL (saturation unknown). If the continuous dosing period exceeds half a month, please choose this protocol carefully.
Taking 1 mL working solution as an example, add 100 μL DMSO stock solution (20.8 mg/mL) to 900 μL Corn oil, and mix evenly.

In Vivo Dissolution Calculator

Please enter the basic information of animal experiments:

Dosage

mg/kg

Animal weight
(per animal)

Dosing volume
(per animal)

μL

Number of animals

Recommended: Prepare an additional quantity of animals to account for potential losses during experiments.

Please enter your animal formula composition:

DMSO +

Tween-80 +

Saline

Recommended: Keep the proportion of DMSO in working solution below 2% if your animal is weak.

The co-solvents required include: DMSO, . All of co-solvents are available by MedChemExpress (MCE). , Tween 80. All of co-solvents are available by MedChemExpress (MCE).

Calculation results:

Working solution concentration: mg/mL

Method for preparing stock solution: mg drug dissolved in μL DMSO (Stock solution concentration: mg/mL).

The concentration of the stock solution you require exceeds the measured solubility. The following solution is for reference only. If necessary, please contact MedChemExpress (MCE).

Method for preparing in vivo working solution for animal experiments: Take μL DMSO stock solution, add μL . μL , mix evenly, next add μL Tween 80, mix evenly, then add μL Saline.

If the continuous dosing period exceeds half a month, please choose this protocol carefully.

Please ensure that the stock solution in the first step is dissolved to a clear state, and add co-solvents in sequence. You can use ultrasonic heating (ultrasonic cleaner, recommended frequency 20-40 kHz), vortexing, etc. to assist dissolution.

Purity & Documentation

Purity: 99.91%

Select Batch:

Data Sheet (276 KB) SDS (0 KB)

COA (248 KB) HNMR (240 KB) RP-HPLC (246 KB) LCMS (95 KB)

Handling Instructions (2659 KB)

References

[1]. Bhatnagar AS, et, al. Highly selective inhibition of estrogen biosynthesis by CGS 20267, a new non-steroidal aromatase inhibitor. J Steroid Biochem Mol Biol. 1990 Dec 20;37(6):1021-7. [Content Brief]

[2]. Mitropoulou TN, et, al. Letrozole as a potent inhibitor of cell proliferation and expression of metalloproteinases (MMP-2 and MMP-9) by human epithelial breast cancer cells. Int J Cancer. 2003 Mar 20;104(2):155-60. [Content Brief]

[3]. Schieweck K, et, al. Anti-tumor and endocrine effects of non-steroidal aromatase inhibitors on estrogen-dependent rat mammary tumors. J Steroid Biochem Mol Biol. 1993 Mar;44(4-6):633-6. [Content Brief]

Complete Stock Solution Preparation Table

Optional Solvent	Concentration Solvent Mass	1 mg	5 mg	10 mg	25 mg

DMSO	1 mM	3.5051 mL	17.5254 mL	35.0508 mL	87.6271 mL
	5 mM	0.7010 mL	3.5051 mL	7.0102 mL	17.5254 mL
	10 mM	0.3505 mL	1.7525 mL	3.5051 mL	8.7627 mL
	15 mM	0.2337 mL	1.1684 mL	2.3367 mL	5.8418 mL
	20 mM	0.1753 mL	0.8763 mL	1.7525 mL	4.3814 mL
	25 mM	0.1402 mL	0.7010 mL	1.4020 mL	3.5051 mL
	30 mM	0.1168 mL	0.5842 mL	1.1684 mL	2.9209 mL
	40 mM	0.0876 mL	0.4381 mL	0.8763 mL	2.1907 mL
	50 mM	0.0701 mL	0.3505 mL	0.7010 mL	1.7525 mL
	60 mM	0.0584 mL	0.2921 mL	0.5842 mL	1.4605 mL
	80 mM	0.0438 mL	0.2191 mL	0.4381 mL	1.0953 mL
	100 mM	0.0351 mL	0.1753 mL	0.3505 mL	0.8763 mL

Letrozole Related Classifications

Help & FAQs

Do most proteins show cross-species activity?
Species cross-reactivity must be investigated individually for each product. Many human cytokines will produce a nice response in mouse cell lines, and many mouse proteins will show activity on human cells. Other proteins may have a lower specific activity when used in the opposite species.

Keywords:

Letrozole112809-51-5CGS 20267CGS20267CGS-20267Cytochrome P450AutophagyCYPsaromataseestrogenbreastcancerInhibitorinhibitorinhibit

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Letrozole (Synonyms: CGS 20267)

Customer Review

Other Forms of Letrozole:

Letrozole Related Antibodies

15 Publications Citing Use of MCE Letrozole

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References

Customer Review

Letrozole Related Antibodies

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Complete Stock Solution Preparation Table

Letrozole Related Classifications

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