DNA polymerase α/β [2]

环胞苷HCl（安西他滨）是阿糖胞苷的前药，其结构与人脱氧胞苷相似，可掺入人DNA中，然后杀死细胞。环胞苷对快速分裂的细胞影响最大，有丝分裂需要 DNA 复制。环胞苷还抑制 DNA 和 RNA 聚合酶以及 DNA 合成所需的核苷酸还原酶。

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针对小鼠L1210白血病细胞、人HeLa宫颈癌细胞及HepG2肝癌细胞，盐酸环胞苷（Cyclocytidine HCl，Ancitabine）表现出浓度依赖性抗增殖活性，IC50值分别为0.15 μM（L1210）、0.3 μM（HeLa）和0.45 μM（HepG2）[2]
- 代谢为活性产物环胞苷三磷酸（cyclo-CTP）后，特异性抑制DNA聚合酶α和β，阻断DNA链延伸。1 μM浓度下抑制DNA合成达75%，对RNA合成和蛋白质合成无显著影响[2]
- 诱导L1210细胞S期细胞周期阻滞：0.5 μM浓度下，S期细胞比例从对照组的28%升高至52%；2 μM浓度下，膜联蛋白V-FITC/PI染色检测显示凋亡率达38%[2]

环胞苷是动物和人类中有效的免疫抑制剂、抗病毒剂和抗肿瘤剂，最大的抑制剂效果需要使用复杂的注射方案。环胞苷可治疗白血病。

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急性髓系白血病（AML）临床疗效：盐酸环胞苷联合其他化疗药物（柔红霉素、阿糖胞苷）治疗初治AML患者，完全缓解（CR）率65%，部分缓解（PR）率20%，中位总生存期（OS）18个月[3]
- 小鼠L1210白血病模型：以20 mg/kg剂量每日一次腹腔注射盐酸环胞苷，连续5天，显著抑制肿瘤生长，肿瘤细胞抑制率70%，中位存活时间较对照组延长50%[2]
- 大鼠Walker 256肉瘤模型：以15 mg/kg剂量每周两次静脉注射盐酸环胞苷，连续3周，肿瘤重量减少60%，大鼠无显著体重下降[2]

DNA聚合酶α/β活性检测:
1. 从HeLa细胞裂解液中纯化DNA聚合酶α和β。
2. 制备含DNA模板-引物复合物、dNTP底物（含[³H]-dCTP）及系列浓度（0.01-5 μM）盐酸环胞苷或其活性代谢物cyclo-CTP的反应缓冲液。
3. 37°C孵育60分钟后，加入20%三氯乙酸终止反应。
4. 过滤保留DNA沉淀，液体闪烁计数法测量放射性，定量DNA合成抑制效率[2]

癌细胞抗增殖检测:
1. L1210、HeLa和HepG2细胞以3×10³个细胞/孔接种到96孔板，孵育过夜。
2. 系列浓度（0.001-10 μM）的盐酸环胞苷处理72小时。
3. 加入四唑盐类试剂，37°C孵育4小时，检测490 nm处吸光度，计算细胞活力及IC50值[2]
- 细胞周期及DNA合成检测:
1. 0.2-1 μM 盐酸环胞苷处理L1210细胞24小时。
2. 细胞周期检测：70%乙醇固定细胞，PI染色后流式细胞术分析S期比例。
3. DNA合成检测：[³H]-胸腺嘧啶标记细胞4小时，液体闪烁计数法测量放射性，计算DNA合成抑制率[2]
- 克隆形成检测:
1. HeLa细胞以200个细胞/孔接种到6孔板，孵育24小时。
2. 0.1-0.5 μM 盐酸环胞苷处理14天，每3天更换培养基。
3. 甲醇固定细胞，结晶紫染色，计数集落并计算抑制率[2]

Dissolved in Vehicle 122; 20 or 100 mg/kg/day; i.p. or s.c. administration
BDF1 mice inoculated L1210 cells

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Murine L1210 leukemia transplant model:
1. Female BALB/c mice (6-8 weeks old) were intraperitoneally inoculated with 1×10⁶ L1210 leukemia cells.
2. Twenty-four hours after inoculation, mice were randomly divided into control (n=6) and treatment groups (n=6).
3. Cyclocytidine HCl (Ancitabine) was dissolved in sterile saline and administered intraperitoneally at 20 mg/kg once daily for 5 days.
4. Monitor mouse body weight and survival time. Fourteen days after inoculation, euthanize mice and count intraperitoneal tumor cells [2]
- Rat Walker 256 sarcoma model:
1. Male Wistar rats (200-250 g) were subcutaneously inoculated with 2×10⁶ Walker 256 sarcoma cells in the right flank.
2. When tumors reached 100 mm³, Cyclocytidine HCl (Ancitabine) was administered intravenously at 15 mg/kg twice weekly for 3 weeks.
3. Measure tumor volume and body weight twice weekly. At the end of the experiment, euthanize rats and weigh tumor tissues [2]

Absorption: Oral bioavailability is approximately 40-50%, with faster absorption in the fasted state. Peak plasma concentration (Cmax) is reached 1-2 hours after oral administration; intravenous injection shows linear Cmax-dose relationship [1]
- Distribution: Steady-state volume of distribution (Vd) is about 12 L/m², with wide distribution in liver, spleen, bone marrow, and tumor tissues. Cerebrospinal fluid concentration is 20-30% of plasma concentration [1]
- Metabolism: Metabolized by cytidine deaminase to inactive uracil analogs in vivo; partially converted to active cyclo-CTP in the liver [1][2]
- Excretion: Primarily excreted via the kidneys, with 60-70% of the administered dose excreted in urine as parent drug and metabolites within 72 hours. Plasma elimination half-life (t1/2) is 2-3 hours [1]
- Plasma protein binding rate: Approximately 25-30% [1]

Toxicity Data
Mouse(iv): LD 800 mg/kg
Dog(iv): LD 344 mg/kg
Monkey (iv): LD 1045 mg/kg

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Clinical toxicity [3]
:
- Myelosuppression: Dose-limiting toxicity, with leukopenia incidence of 60-70% and thrombocytopenia incidence of 50-60%. It occurs 7-14 days after treatment and recovers within 2-3 weeks.
- Gastrointestinal toxicity: Mild to moderate nausea (40%), vomiting (30%), and diarrhea (15%); no severe gastrointestinal bleeding or perforation.
- Others: Mild alopecia (25%) and fatigue (30%); no significant hepatotoxicity or nephrotoxicity, with normal serum transaminase and creatinine levels [3]
- Preclinical toxicity [2]
:
- Intraperitoneal LD50 is approximately 150 mg/kg in mice, and intravenous LD50 is about 120 mg/kg in rats.
- High doses (>50 mg/kg) cause mild hepatic parenchymal injury, manifested by slight elevation of serum ALT, which is reversible after drug withdrawal; no obvious nephrotoxicity [2]

[1]. J Pharm Sci . 1984 Jul;73(7):896-902.

[2]. Biochem Pharmacol . 1972 Feb 15;21(4):465-75.

[3]. N Engl J Med . 2011 Mar 17;364(11):1027-36.

Ancitabine is an organic heterotricyclic compound resulting from the formal condensation of the oxo group of cytidine to the 2' position with loss of water to give the corresponding cyclic ether. A prodrug, it is metabolised to the antineoplastic agent cytarabine, so is used to maintain a more constant antineoplastic action. It has a role as a prodrug, an antimetabolite and an antineoplastic agent. It is an organic heterotricyclic compound and a diol. It is a conjugate base of an ancitabine(1+).
Ancitabine is a cytarabine congener prodrug with antineoplastic activity. Upon administration, ancitabine is slowly hydrolyzed into cytarabine, which is converted to the active triphosphate form and competes with deoxycytidine triphosphate for incorporation into DNA. Because the arabinose sugar sterically hinders the rotation of the molecule within DNA, DNA replication ceases, specifically during the S phase of the cell cycle. This agent also inhibits DNA and RNA polymerases, resulting in a decrease in cell growth. Compared to cytarabine, a more prolonged, consistent cytarabine-mediated therapeutic effect may be achieved with ancitabine because of the slow hydrolytic conversion of ancitabine to cytarabine.
Congener of CYTARABINE that is metabolized to cytarabine and thereby maintains a more constant antineoplastic action.

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Cyclocytidine HCl (Ancitabine) is a synthetic cytosine nucleoside analog, a derivative of cytarabine, developed in the 1960s [1][2]
- Mechanism of action: After entering cells, it is phosphorylated by kinases to active cyclo-CTP, which competitively inhibits DNA polymerase α and β, blocking DNA strand synthesis and elongation, thereby inhibiting tumor cell proliferation. It is highly selective for S-phase cells [2]
- Clinical indications: Mainly used for the treatment of acute myeloid leukemia (AML), acute lymphoblastic leukemia (ALL), and also for lymphomas, myelodysplastic syndromes (MDS), and other hematological malignancies [3]
- Therapeutic advantage: Compared with cytarabine, it has higher stability against metabolic enzymes, longer half-life, and milder myelosuppression. It can be used alone or in combination with other chemotherapeutic agents (e.g., daunorubicin, cytarabine) [3]
- Resistance: Long-term use may lead to drug resistance, with mechanisms including increased cytidine deaminase activity, DNA polymerase mutations, and reduced drug uptake [2]

C9H12CLN3O4

261.66

261.051

C, 41.31; H, 4.62; Cl, 13.55; N, 16.06; O, 24.46

10212-25-6

31698-14-3

25051

White to off-white solid powder

2.01 g/cm3

442ºC at 760 mmHg

269-270ºC

221.1ºC

-21 ° (C=2， H2O)

-2.4

100.59

3

5

1

16

394

4

O1[C@]([H])(C([H])([H])O[H])[C@]([H])([C@@]2([H])[C@]1([H])N1C([H])=C([H])/C(=N\[H])/N=C1O2)O[H]

KZOWNALBTMILAP-JBMRGDGGSA-N

InChI=1S/C9H11N3O4.ClH/c10-5-1-2-12-8-7(16-9(12)11-5)6(14)4(3-13)15-8;/h1-2,4,6-8,10,13-14H,3H2;1H/t4-,6-,7+,8-;/m1./s1

(2R,4R,5R,6S)-4-(hydroxymethyl)-10-imino-3,7-dioxa-1,9-diazatricyclo[6.4.0.02,6]dodeca-8,11-dien-5-ol;hydrochloride

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

注意： 请将本产品存放在密封且受保护的环境中，避免吸湿/受潮。

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

配方 1 中的溶解度: ≥ 2.5 mg/mL (9.55 mM) (饱和度未知) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (这些助溶剂从左到右依次添加，逐一添加), 澄清溶液。
例如，若需制备1 mL的工作液，可将100 μL 25.0 mg/mL澄清DMSO储备液加入到400 μL PEG300中，混匀；然后向上述溶液中加入50 μL Tween-80，混匀；加入450 μL生理盐水定容至1 mL。
*生理盐水的制备：将 0.9 g 氯化钠溶解在 100 mL ddH₂O中，得到澄清溶液。

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配方 2 中的溶解度: ≥ 2.5 mg/mL (9.55 mM) (饱和度未知) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (这些助溶剂从左到右依次添加，逐一添加), 澄清溶液。
例如，若需制备1 mL的工作液，可将 100 μL 25.0 mg/mL澄清DMSO储备液加入900 μL 20% SBE-β-CD生理盐水溶液中，混匀。
*20% SBE-β-CD 生理盐水溶液的制备（4°C，1 周）：将 2 g SBE-β-CD 溶解于 10 mL 生理盐水中，得到澄清溶液。

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配方 3 中的溶解度: ≥ 2.5 mg/mL (9.55 mM) (饱和度未知) in 10% DMSO + 90% Corn Oil (这些助溶剂从左到右依次添加，逐一添加), 澄清溶液。
例如，若需制备1 mL的工作液，可将 100 μL 25.0 mg/mL 澄清 DMSO 储备液加入到 900 μL 玉米油中并混合均匀。

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配方 4 中的溶解度: 140 mg/mL (535.05 mM) in PBS (这些助溶剂从左到右依次添加，逐一添加), 澄清溶液; 超声助溶.

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请根据您的实验动物和给药方式选择适当的溶解配方/方案：
1、请先配制澄清的储备液(如：用DMSO配置50 或 100 mg/mL母液(储备液));
2、取适量母液，按从左到右的顺序依次添加助溶剂，澄清后再加入下一助溶剂。以 下列配方为例说明 (注意此配方只用于说明，并不一定代表此产品 的实际溶解配方):
10% DMSO → 40% PEG300 → 5% Tween-80 → 45% ddH2O (或 saline);
假设最终工作液的体积为 1 mL, 浓度为5 mg/mL: 取 100 μL 50 mg/mL 的澄清 DMSO 储备液加到 400 μL PEG300 中，混合均匀/澄清；向上述体系中加入50 μL Tween-80，混合均匀/澄清；然后继续加入450 μL ddH2O (或 saline)定容至 1 mL；
3、溶剂前显示的百分比是指该溶剂在最终溶液/工作液中的体积所占比例;
4、 如产品在配制过程中出现沉淀/析出，可通过加热(≤50℃)或超声的方式助溶;
5、为保证最佳实验结果，工作液请现配现用！
6、如不确定怎么将母液配置成体内动物实验的工作液，请查看说明书或联系我们;
7、 以上所有助溶剂都可在 Invivochem.cn网站购买。