SID 26681509 quarterhydrate is a potent, reversible, competitive, and selective inhibitor of human cathepsin L with an IC₅₀ of 56 nM. SID 26681509 quarterhydrate inhibits in vitro propagation of malaria parasite Plasmodium falciparum and inhibits Leishmania major with IC₅₀s of 15.4 μM and 12.5 μM, respectively. SID 26681509 quarterhydrate shows no inhibitory activity against cathepsin G^[1].

IC50: 56 nM (Human cathepsin L), 0.5 μM (Cathepsin V), 15.4 μM (Plasmodium falciparum), 12.5 μM (Leishmania major)^[1]

After a 4 hr preincubation with cathepsin L, SID 26681509 becomes more potent, demonstrating an IC₅₀ of 1.0 nM. SID 26681509 is determined to be a slow-binding and slowly reversible competitive inhibitor. Through a transient kinetic analysis for single-step reversibility, inhibition rate constants are kon = 24,000 M^-1s^-1 and koff = 2.2 × 10^-5 s^-1 (K_i = 0.89 nM). Molecular docking studies are undertaken using the experimentally-derived X-ray crystal structure of papain/CLIK-148^[1].
SID 26681509 inhibits papain and cathepsins B, K, S, and V with IC₅₀ values determined after one hour ranging from 618 nM to 8.442 μM. SID 26681509 shows no inhibitory activity against the serine protease cathepsin G^[1].
SID 26681509 inhibits cathepsin V activity with an IC₅₀ value of 0.5 μM. SID 26681509 (1-30 μM) blocks high-mobility group box 1 (HMGB1)-induced TNF-α production dose dependently without altering cell viability^[2].

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.

SID 26681509 treatment significantly improves survival in murine models of sepsis and reduces liver damage following warm liver ischemia/reperfusion (I/R) models^[2].

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.

544.16

C₂₇H₃₅N₅O₆S

Room temperature in continental US; may vary elsewhere.

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

In Vitro: 

DMSO : 27 mg/mL (49.62 mM; Need ultrasonic and warming)

Ethanol : 5 mg/mL (9.19 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: ≥ 1.67 mg/mL (3.07 mM); Clear solution

  此方案可获得 ≥ 1.67 mg/mL (3.07 mM，饱和度未知) 的澄清溶液。

  以 1 mL 工作液为例，取 100 μL 16.7 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

• [1]. Shah PP, et al. Kinetic characterization and molecular docking of a novel, potent, and selective slow-binding inhibitor of human cathepsin L. Mol Pharmacol. 2008 Jul;74(1):34-41.

  [2]. Pribis JP, et al. The HIV Protease Inhibitor Saquinavir Inhibits HMGB1-Driven Inflammation by Targeting the Interaction of Cathepsin V with TLR4/MyD88. Mol Med. 2015 Dec;21(1):749-757.