描述：Leptomycin B (CI 940; LMB) is a potent inhibitor of the nuclear export of proteins. Leptomycin B inactivates CRM1/exportin 1 by covalent modification at a cysteine residue. Leptomycin B is a potent antifungal antibiotic blocking the eukaryotic cell cycle.

来源：Bacterium/Streptomyces sp

储存/保存方法：Store at -20℃ for one year（Powder）；Store at 2-4℃ for two weeks；Store at -20℃ for six months after dissolution.

别名：来普霉素B; Elactocin；LMB；Mantuamycin

外观：White to off-white powder

可溶性/溶解性：DMSO : 100 mg/mL (184.94 mM; Need ultrasonic)

靶点：CRM1/exportin 1

In vitro(体外研究)：

Leptomycin B (LMB) is very potent in vitro against various cancer cell lines (IC50 values in the 0.1 to 10 nM range). Leptomycin B (LMB) inhibits SiHa, HCT-116, and SKNSH cells with IC50s of 0.4, 0.3 and 0.4 nM for a 72 hour exposure, respectively.
Leptomycin B (LMB) (0.5 nM) displays a synergistic effect on Gefitinib (0–32 μM)-induced cytotoxicity in A549 and H460 cell line. The simultaneous treatments of Gefitinib (0–32 μM) and Leptomycin B (0.5 nM) show synergistic cytotoxic effect on A549 as compared to Gefitinib alone at both 24 and 48 hours.

In vivo(体内研究)：

Leptomycin B (LMB) is poorly tolerated in vivo. Maximum tolerated dose (MTD) is 2.5 mg/kg for LMB (single i.v.) in HCT-116 tumor–bearing mice.The limited in vivo efficacy of Leptomycin B is due to off-target effects because our nuclear export inhibitors (NEIs) retain the potent inhibition of CRM1, but are clearly better tolerated in vivo.

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