WARNING: This product is for research use only, not for human or veterinary use.

MedKoo CAT#: 202380

CAS#: 865311-47-3

Description: Quarfloxin, also known as Quarfloxacin and CX-3543, is a fluoroquinolone derivative with antineoplastic activity. Quarfloxin disrupts the interaction between the nucleolin protein and a G-quadruplex DNA structure in the ribosomal DNA (rDNA) template, a critical interaction for rRNA biogenesis that is overexpressed in cancer cells; disruption of this G-quadruplex DNA:protein interaction in aberrant rRNA biogenesis may result in the inhibition of ribosome synthesis and tumor cell apoptosis.

Chemical Structure

CAS# 865311-47-3

Theoretical Analysis

MedKoo Cat#: 202380
Name: Quarfloxin
CAS#: 865311-47-3
Chemical Formula: C35H33FN6O3
Exact Mass: 604.25982
Molecular Weight: 604.67
Elemental Analysis: C, 69.52; H, 5.50; F, 3.14; N, 13.90; O, 7.94

Size Price Shipping out time Quantity
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Pricing updated 2021-03-04. Prices are subject to change without notice.

Quarfloxin is not in stock, may be available through custom synthesis. Minimum 1 gram order is requested. Current shipping out time is about 4 -5 months after order is received.

Synonym: CX 3543; CX-3543; CX 3543; Quarfloxacin

IUPAC/Chemical Name: 5-fluoro-N-(2-((S)-1-methylpyrrolidin-2-yl)ethyl)-3-oxo-6-((R)-3-(pyrazin-2-yl)pyrrolidin-1-yl)-3H-benzo[b]pyrido[3,2,1-kl]phenoxazine-2-carboxamide.


InChi Code: InChI=1S/C35H33FN6O3/c1-40-13-4-7-24(40)8-10-39-35(44)26-20-42-29-15-21-5-2-3-6-22(21)16-30(29)45-34-31(42)25(33(26)43)17-27(36)32(34)41-14-9-23(19-41)28-18-37-11-12-38-28/h2-3,5-6,11-12,15-18,20,23-24H,4,7-10,13-14,19H2,1H3,(H,39,44)/t23-,24+/m1/s1

SMILES Code: O=C(C1=CN2C3=C(C(N4C[C@H](C5=NC=CN=C5)CC4)=C(F)C=C3C1=O)OC6=CC7=CC=CC=C7C=C26)NCC[C@H]8N(C)CCC8

solid powder

>98% (or refer to the Certificate of Analysis)

Shipping Condition:
Shipped under ambient temperature as non-hazardous chemical. This product is stable enough for a few weeks during ordinary shipping and time spent in Customs.

Storage Condition:
Dry, dark and at 0 - 4 C for short term (days to weeks) or -20 C for long term (months to years).

Soluble in DMSO, not in water

Shelf Life:
>2 years if stored properly

Drug Formulation:
This drug may be formulated in DMSO

Stock Solution Storage:
0 - 4 C for short term (days to weeks), or -20 C for long term (months).

HS Tariff Code:

Handling Instructions:

Preparing Stock Solutions

The following data is based on the product molecular weight 604.67 Batch specific molecular weights may vary from batch to batch due to the degree of hydration, which will affect the solvent volumes required to prepare stock solutions.

Select a batch to recalculate based on the batch molecular weight:
Concentration / Solvent Volume / Mass 1 mg 5 mg 10 mg
1 mM 1.15 mL 5.76 mL 11.51 mL
5 mM 0.23 mL 1.15 mL 2.3 mL
10 mM 0.12 mL 0.58 mL 1.15 mL
50 mM 0.02 mL 0.12 mL 0.23 mL

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1. Bayes, M.; Rabasseda, X.; Prous, J. R., Gateways to clinical trials. Methods Find Exp Clin Pharmacol 2007, 29, (1), 53-71.

2. Brennan, A. B.; Long, C. J.; Bagan, J. W.; Schumacher, J. F.; Spiecker, M. M. Surface topographies for non-toxic bioadhesion control. US20100226943A1.

3. Drygin, D.; Siddiqui-Jain, A.; O'Brien, S.; Schwaebe, M.; Lin, A.; Bliesath, J.; Ho, C. B.; Proffitt, C.; Trent, K.; Whitten, J. P.; Lim, J. K. C.; Von, H. D.; Anderes, K.; Rice, W. G., Anticancer Activity of CX-3543: A Direct Inhibitor of rRNA Biogenesis. Cancer Res. 2009, 69, (19), 7653-7661.

4. Hurley, L. H.; Guzman, M. Combination cancer chemotherapy. WO2007137000A2, 2007.

5. Lim, J.; Whitten, J. P. Drug administration methods. WO2007143587A1, 2007.

6. Neidle, S., Human telomeric G-quadruplex: the current status of telomeric G-quadruplexes as therapeutic targets in human cancer. FEBS J. 277, (5), 1118-1125.

7. O'Brien, S.; Siddiqui-Jain, A. Targeting quadruplex sequences in human nucleic acids by identifying interacting quinoline and porphyrin derivatives. WO2007056113A2, 2007.

8. Ryckman, D. M.; Drygin, D.; Whitten, J. P.; Anderes, K.; Trent, K.; Darjania, L.; Haddach, M.; O'Brien, S.; Rice, W. G. Methods for treating aberrant cell proliferation disorders. US20080318938A1, 2008.

9. Tian, M.; Zhang, X.; Pan, R.; Zhao, C.; Tang, Y., Structure of G-quadruplex in the oncogene c-myc promoter and small ligands targeting the G-quadruplex. Huaxue Jinzhan 22, (5), 983-992.

10. Whitten, J. P.; O'Brien, S. Methods for treating ophthalmic disorders. US20080318939A1, 2008.

11. Whitten, J. P.; Pierre, F.; Regan, C.; Schwaebe, M.; Yiannikouros, G. P.; Jung, M. Preparation of fused quinolone analogs which inhibit cell proliferation and/or induce cell apoptosis. US20060074089A1, 2006.

12. Whitten, J. P.; Pierre, F.; Regan, C.; Schwaebe, M.; Yiannikouros, G. P.; Jung, M. Preparation of fused quinolone analogs which inhibit cell proliferation and/or induce cell apoptosis. WO2006034113A2, 2006.

13. Whitten, J. P.; Pierre, F.; Regan, C.; Schwaebe, M.; Yiannikouros, G. P.; Jung, M. Process for the preparation of benzothiazole and phenoxazine compounds. US20060063761A1, 2006.

14. Whitten, J. P.; Schwaebe, M.; Siddiqui-Jain, A.; Moran, T. Preparation of substituted quinobenzoxazine analogs as antitumor agents. US20060029950A1, 2006.

Additional Information

Clinical trial news:  Quarfloxin is a ground-breaking small-molecule targeted cancer therapeutic derived from the validated fluoroquinolone class of drugs. Rationally designed to selectively inhibit ribosomal RNA (rRNA) biogenesis in cancer cells, quarfloxin disrupts the interaction between the Nucleolin protein and a G-quadruplex DNA structure in the ribosomal DNA (rDNA) template, a critical interaction for rRNA biogenesis and one that is amplified in cancer cells. As a result, quarfloxin selectively induces apoptotic cell death in cancers. Many commercialized cancer therapeutics act indirectly on rRNA Biogenesis through upstream modulators, but quarfloxin is the first agent to directly target this cancer-specific aberrant cell function. According to  news released on June 19, 2011, Cylene Pharmaceuticals announced the initiation of a Phase II clinical trial of quarfloxin (CX-3543) in patients with carcinoid/neuroendocrine tumors (C/NET), which are malignant cancers arising from neural crest cells.