[³H]BrCPT labeling of topoisomerase I is enhanced greatly by the presence of DNA; very little labeling of isolated topoisomerase I or isolated DNA occurrs. Even in the presence of DNA, [³H]BrCPT labeling of topoisomerase I is inhibited by camptothecin, suggesting that both CPT and BrCPT bind to the same site on the DNA-topoisomerase I binary complex^[1] . With increasing concentrations of camptothecin, closed circular pRR322 DNA (form I) is converted to nicked circular DNA (form 11). This apparent nicking activitv of camptothecin required DNA topoisomerase I^[2] .

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

NCT NumberSponsorConditionStart DatePhaseNCT00333502NewLink Genetics Corporation|Lumos PharmaCancer|Solid TumorMay 2006Phase 1|Phase 2NCT00059917Memorial Sloan Kettering Cancer Center|National Cancer Institute (NCI)Unspecified Adult Solid Tumor, Protocol SpecificJanuary 2003Phase 1

348.35

C??H??N?O?

7689-03-4

喜树碱

O=C1C2=C([C@@](O)(CC)C(OC2)=O)C=C(N1C3)C(C3=C4)=NC5=C4C=CC=C5

Room temperature in continental US; may vary elsewhere.

4°C, protect from light

*In solvent : -80°C, 6 months; -20°C, 1 month (protect from light)

In Vitro: 

DMSO : 7.69 mg/mL (22.08 mM; Need ultrasonic)

H₂O : < 0.1 mg/mL (insoluble)

Preparing
Stock Solutions

ConcentrationSolventMass1 mg5 mg10 mg1 mM2.8707 mL14.3534 mL28.7068 mL5 mM0.5741 mL2.8707 mL5.7414 mL10 mM0.2871 mL1.4353 mL2.8707 mL

*

请根据产品在不同溶剂中的溶解度选择合适的溶剂配制储备液；一旦配成溶液，请分装保存，避免反复冻融造成的产品失效。
储备液的保存方式和期限：-80°C, 6 months; -20°C, 1 month (protect from light)。-80°C 储存时，请在 6 个月内使用，-20°C 储存时，请在 1 个月内使用。

• [1]. Hertzberg RP, et al. Irreversible trapping of the DNA-topoisomerase I covalent complex. Affinity labeling of the camptothecin binding site. J Biol Chem. 1990 Nov 5;265(31):19287-95.

  [2]. Hsiang YH, et al. Camptothecin induces protein-linked DNA breaks via mammalian DNA topoisomerase I. J Biol Chem. 1985 Nov 25;260(27):14873-8.

  [3]. Luzzio MJ, et al. Synthesis and antitumor activity of novel water soluble derivatives of camptothecin as specific inhibitors of topoisomerase I. Synthesis and antitumor activity of novel water soluble derivatives of camptothecin as specific inhibitors of topoisomerase I.