(S)-(+)-cAMPtothecin是一种从喜树中分离出来的 DNA 拓扑异构酶 I 的特异性抑制剂，也是一种生物碱。

(S)-(+)-Camptothecin is a specific inhibitor of DNA topoisomerase I (Topo I), isolated from Camptotheca acuminata.

在携带结肠癌,肺癌,乳腺癌,胃癌,和卵巢癌等移植瘤的小鼠中,Camptothecin（8 mg/kg ）能够抑制肿瘤细胞生长.

在HCT116细胞中,Camptothecin（5 μM）诱导蛋白酶体介导的MLL5蛋白降解,其导致Ser392处p53的磷酸化。在许多人类肿瘤细胞系中IC50=（37-48 nM）,如HT29,LOX,SKOV3和SKVLB细胞,Camptothecin能够在纳摩尔级别表现出细胞毒性作用。

Topoisomerase I Cleavable Complex Assay: Topoisomerase I is isolated from calf thymus and is devoid of topoisomerase II. All reactions are carried out in 10 mL volumes of reaction buffer (50 mM Tris-HCl, pH 7.5, 100 mM KCl, 0.5 mM EDTA, and 30 pg/mL BSA) in microtiter plates. Camptothecin is dissolved in DMSO at 10 mg/mL and serially diluted in 96-well microtiter plates to which the 32P end-labeled pBR322 DNA and topoisomerase enzyme are added. The reaction mixture is incubated at room temperature for 30 min and then the reaction stopped by adding 2 mL of a mixture of sodium dodecyl sulfate and proteinase K (1.6% and 0.14 mg/mL final concentrations, respectively). The plates are heated at 50 °C for 30 min, 10 mL of standard stop mixture containing 0.45 N NaOH is added in order to generate single-stranded DNA, and the samples are electrophoresed in 1.5% agarose gels in TBE buffer. Gels are blotted on nitrocellulose paper, dried, and exposed to X-ray film. The units of cleavage are calculated from the autoradiographs and plotted against the log drug concentration. The IC50 values are then obtaine

Tumor cells are plated in 100 μL of medium in 96-well microtiter plates at a density of 1500 to 4000 cells per well and allowed to adhere overnight. Cells are incubated with Camptothecin for 48 hours and then with fresh medium for 48 hours. Camptothecin at each concentration is added in quadruplicate. Following a 4-hour incubation of treated cells with MTT, the reduced dye product is extracted from the cells with 0.2 mL of DMSO followed by 50 μL of Sorensen's buffer. The plates are shaken briefly, and the absorbance at 570 nm is read and quantitated. Curves are fitted to the MTT assay data using a four-parameter logistic equation.(Only for Reference)

7689-03-4

C20H16N2O4

348.36

NSC-100880;CPT;Campathecin;(S)-(+)-Camptothecin;喜树碱

DMSO:10 mM
Powder: -20°C for 3 years
In solvent: -80°C for 2 years