SKLB-23bb is a potent and selective inhibitor for HDAC6 with an IC₅₀ of 17 nM and shows 25-fold and 200-fold selectivity relative to HDAC1 (IC₅₀=422 nM) and HDAC8 (IC₅₀=3398 nM), respectively.

IC50: 17 nM (HDAC6), 422 nM (HDAC1), 398 nM (HDAC8)^[1]

SKLB-23bb (Compound 23bb) presents low nanomolar antiproliferative effects against panel of cancer cell lines. The antiproliferative activity is ton human malignant melanoma A375 cells and cervical cancer HeLa cells, SKLB-23bb shows the most potent activities with IC₅₀ values of 50 and 49 nM on A375 and HeLa cells, respectively. The antiproliferative activities against 11 kinds of hematological tumors (myelomaU266, RPMI8226 cells, human leukemia MV4-11, K562 cells, and human B cell lymphoma Ramos cells) or solid tumors (ovarian cancer A2780s, SKOV-3 cells, breast cancer SKBR3 cells, liver cancer HepG2 cells, lung cancer H460, A549 cells, cervical cancer HeLa cells and colon cancer HCT116, HT29 cells) cell lines of SKLB-23bb are evaluated by MTT, and the SAHA and ACY-1215 are as positive control. SKLB-23bb shows significant antiproliferative potential with the IC₅₀ values ranging from 14 to 104 nM in these tumor cell lines^[1].

上海金畔生物科技有限公司 has not independently confirmed the accuracy of these methods. They are for reference only.

SKLB-23bb (Compound 23bb) reduces the tumor growth in both the hematological tumor MV4-11 xenograft model and solid tumor HCT116 xenograft model. The significant antitumor activities are observed by intravenous administration of SKLB-23bb at 50 mg/kg on MV4-11 and HCT116 xenograft models. The growth of MV4-11 and HCT116 cancer cell xenografts is suppressed by 55.0% and 76.3% (percent of tumor mass change [TGI] values) after iv administration of SKLB-23bb at 50 mg/kg. The HCT116 xenograft model is also established to investigate the antitumor activity of oral administration of SKLB-23bb. The TGI value of oral administration of SKLB-23bb (25 mg/kg) on HCT116 xenograft model is 60.4%, which is superior to the SAHA group (100 mg/kg, 59.2%). Additionally, the body weight decrease is acceptable and no other adverse effects are observed upon treatment with SKLB-23bb. Low clearance (CL=7.008 L/kg per hour for iv, CL=12.877 L/kg per hour for po) and long terminal half-life (t_1/2=7.658 h for iv, t_1/2=9.62 h for po) are observed in SKLB-23bb. The oral bioavailability of SKLB-23bb is excellent in rats and the bioavailability is up to 47.0%^[1].

上海金畔生物科技有限公司 has not independently confirmed the accuracy of these methods. They are for reference only.

396.44

C₂₁H₂₄N₄O₄

1815580-06-3

Room temperature in continental US; may vary elsewhere.

Powder	-20°C	3 years
	4°C	2 years
In solvent	-80°C	6 months
	-20°C	1 month

In Vitro: 

DMSO : 32 mg/mL (80.72 mM; Need ultrasonic and warming)

*

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。-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。

In Vivo:

请根据您的实验动物和给药方式选择适当的溶解方案。以下溶解方案都请先按照 In Vitro 方式配制澄清的储备液，再依次添加助溶剂：

——为保证实验结果的可靠性，澄清的储备液可以根据储存条件，适当保存；体内实验的工作液，建议您现用现配，当天使用； 以下溶剂前显示的百
分比是指该溶剂在您配制终溶液中的体积占比；如在配制过程中出现沉淀、析出现象，可以通过加热和/或超声的方式助溶

• 1.

  请依序添加每种溶剂： 10% DMSO    40% PEG300    5% Tween-80    45% saline

  Solubility: ≥ 2.5 mg/mL (6.31 mM); Clear solution

  此方案可获得 ≥ 2.5 mg/mL (6.31 mM，饱和度未知) 的澄清溶液。

  以 1 mL 工作液为例，取 100 μL 25.0 mg/mL 的澄清 DMSO 储备液加到 400 μL PEG300 中，混合均匀；向上述体系中加入50 μL Tween-80，混合均匀；然后继续加入 450 μL生理盐水定容至 1 mL。

  将 0.9 g 氯化钠，完全溶解于 100 mL ddH₂O 中，得到澄清透明的生理盐水溶液

• 2.

  请依序添加每种溶剂： 10% DMSO    90% (20% SBE-β-CD in saline)

  Solubility: ≥ 2.5 mg/mL (6.31 mM); Clear solution

  此方案可获得 ≥ 2.5 mg/mL (6.31 mM，饱和度未知) 的澄清溶液。

  以 1 mL 工作液为例，取 100 μL 25.0 mg/mL 的澄清 DMSO 储备液加到 900 μL 20% 的 SBE-β-CD 生理盐水水溶液中，混合均匀。

  将 2 g 磺丁基醚 β-环糊精加入 5 mL 生理盐水中，再用生理盐水定容至 10 mL，完全溶解，澄清透明
• 3.

  请依序添加每种溶剂： 10% DMSO    90% corn oil

  Solubility: ≥ 2.5 mg/mL (6.31 mM); Clear solution

  此方案可获得 ≥ 2.5 mg/mL (6.31 mM，饱和度未知) 的澄清溶液，此方案不适用于实验周期在半个月以上的实验。

  以 1 mL 工作液为例，取 100 μL 25.0 mg/mL 的澄清 DMSO 储备液加到 900 μL玉米油中，混合均匀。

• [1]. Yang Z, et al. Discovery of Selective Histone Deacetylase 6 Inhibitors Using the Quinazoline as the Cap for the Treatment of Cancer. J Med Chem. 2016 Feb 25;59(4):1455-70.

A375, A2780s, SKBR3, HepG2, HeLa, HCT116, A549, and SKOV-3 cells are cultured in DMEM. RPMI8226, K562, H460, HT29, and Ramos cells are cultured in RPMI-1640 medium. MV4-11 cells are cultured in IMDM. All media contains 10% fetal bovine serum (FBS), 100 units/mL Penicillin, and 100 μg/mL Streptomycin. Cells are incubated at 37 °C in a humidified atmosphere of 5% CO₂. Cells in logarithmic phase are seeded into 96-well culture plates at densities of 3000-5000 cells per well and subsequently treated with various concentrations of compounds (e.g., SKLB-23bb;10, 100, 1000, and 10000 nM) for 72 h in final volumes of 200 μL. Upon end point, 20 μL of MTT (5 mg/mL) is added to each well, and the cells are incubated for an additional 1-3 h. After carefully removal of the medium, the precipitates are dissolved in 150 μL of DMSO via mechanically shaking, and then absorbance values at a wavelength of 570 nm are taken on a spectrophotometer. IC₅₀ values are calculated using percentage of growth versus untreated control^[1].

上海金畔生物科技有限公司 has not independently confirmed the accuracy of these methods. They are for reference only.

Mice^[1]
For the MV4-11 and Ramos xenograft models, MV4-11 and Ramos cells (107 cells in 100 μL of serum-free IMDM) are injected subcutaneously into the right flanks of 5- to 6-week-old female NOD/SCID mice. For the HCT116 xenograft, HCT116 cells (107 cells in 100 μL of serum-free DMEM) are injected subcutaneously into the right flanks of 5- to 6-week-old female Balb/c nude mice. When the size of the formed xenografts reach 100-150 mm3, the mice are randomly divided (6 mice per group in MV4-11 model, 8 mice per group in Ramos model, and 7 mice per group in HCT116 model) into control group and treated groups. The mice in the experimental groups receive intravenous (iv) injection (50 mg/kg) or oral administration (25 mg/kg) of SKLB-23bb every 2 days. The mice in the vehicle group receive iv injection or oral administration of equal amount of physiological saline containing 5% ethanol and 5% Cremophor EL. Those in the SAHA or LBH-589 or ACY-1215 groups (positive controls) receive ip injection (50 mg/kg for SAHA and 10 mg/kg for LBH-589, dissolved in physiological saline containing 10% DMSO and 45% PEG400 to a concentration of 10 mg/mL) or oral administration (100 mg/kg for SAHA and 40 mg/kg for ACY-1215, dissolved in the same way described above) every 2 days. Tumor burden is measured every 2 days by a caliper. Tumor volume (TV) is calculated. The day that treatment started is defined as day 0. At the end of the experiment, mice are sacrificed and tumors are collected and weighed^[1].
Rats^[1]
SKLB-23bb is administered to SD rats ntravenously (iv) at 12 mg/kg body weight and orally at 12 mg/kg body weight. Blood samples are taken, and the plasma is analyzed for concentration of SKLB-23bb using an LC-MS/MS system^[1].

上海金畔生物科技有限公司 has not independently confirmed the accuracy of these methods. They are for reference only.

• [1]. Yang Z, et al. Discovery of Selective Histone Deacetylase 6 Inhibitors Using the Quinazoline as the Cap for the Treatment of Cancer. J Med Chem. 2016 Feb 25;59(4):1455-70.