SN-38 是拓扑异构酶 I 抑制剂伊立替康的活性代谢产物，抑制DNA和RNA合成的IC50分别为 0.077 和 1.3 μM。

SN-38 is an active metabolite of CPT-11.

After oral dosing, peak SN-38 concentrations occurrs within 1 h, and the The percent unbound SN-38 lactone in murine plasma at 1000 ng/mL is 3.4 +/- 0.67%, whereas at 100 ng/mL the percent unbound is 1.18 +/- 0.14%. SN-38 lactone AUCs in micebearing human neuroblastoma xenografts are greater than in nontumor-bearing animals. [2]

Topoisomerase I Assay: One unit (the minimum amount for full relaxation of 0.5 μg SV40 DNA under the conditions of this study) of topoisomerase I, 0.5 μL of the test compounds, and 0.5μg SV40 DNA are added sequentially to the reaction buffer, which is composed of 25 mM Tris-HCl (pH 7.5), 50 mM KC1, 5 mM MgCl2, 0.25 mM EDTA disodium salt, 0.25 mM dithiothreitol, 15μg /mL bovine serum albumin, and 5% glycerol. Then, the reaction mixture (50 μL) is incubated for 10 min at 37 °C, and the reaction is terminated by treatment with 7.5 μL of a solution consisting of 1% sodium dodecyl sulfate, 20 mM EDTA disodium salt, and 0.5 mg/mL proteinase K for an additional 30 min at 37°C. The samples are mixed with 5 μL of the loading buffer containing 10 mM Na2HPO4, 31.3% sucrose, and 0.3% bromophenol blue. Relaxed (form Ir) DNA is separated from supercoiled (form I) and nicked (form II) DNA by electrophoresis on 0.8% agarose gel at 50 mA and 20 V for 17 h in the presence of 2 μg/mL chloroquine, 10 mM EDTA, 30 mM NaH2PO4, and 36 Mm Tris-HCl (pH 7.8). After electrophoresis, the gel is stained with 0.05% ethidium bromide and photographed with UV light (302 nm). The amount of DNA is quantified using a densitometer.

MTT assay(Only for Reference)

86639-52-3

C22H20N2O5

392.411

NK012;7-乙基-10-羟基喜树碱;伊立替康杂质B;SN 38

DMSO:39.2 mg/mL (100 mM)
Powder: -20°C for 3 years
In solvent: -80°C for 2 years