Table 2.

The reported potential inhibitors of CTSK.

Compound	Formula	Chemical Structure	Bioactivity	Reference
Odanacatib	C25H27F4N3O3S		Inhibitor, IC50 = 0.2 nM (Human), IC50 = 1 nM (Rabbit); odanacatib (30 mg/kg/day, orally) can persistently suppress bone resorption in OVX monkeys.	[155,164,165]
MK-0674	C26H27F6N3O2		Inhibitor, IC50 = 0.4 nM	[166]
L-873724	C23H26F3N3O3S		Inhibitor, IC50 = 0.2 nM	[167,168]
Balicatib/AAE581	C23H33N5O2		Inhibitor, IC50 = 1.4 nM; IC50 = 56 nM (Rat); IC50 = 480 nM (mouse)	[169]
NC-2300/VEL-0230	C14H24NO5 -		Inhibitor, IC50 = 46 nM; IC50 = 319 nM (Rat); IC50 = 102 nM (mouse)	[169]
Gü1303	C20H22N4O3		Inhibitor, Ki = 0.91 nM	[170]
Gü2602	C16H22N4O3		Inhibitor, Ki = 0.013 nM	[170]
Cathepsin K inhibitor 2	C30H33F4N5O3			[171]
Cathepsin inhibitor 1	C20H24ClN5O2		Inhibitor, IC50 = 5.5 nM	[172]
Relacatib/ SB-462795	C27H32N4O6S		Inhibitor, Ki = 0.041 nM	[149,173]
BML-244	C11H21NO3		Inhibitor, 1 μM	[174]
4S-7-cis-methylazepanone	C27H32N4O6S		Inhibitor, Ki = 0.16 nM (human)	[173]
4S-parent azepanone	C26H30N4O6S		Inhibitor, Ki = 0.16 nM (human)	[173,175]
Compound 24	C40H47N5O7		Inhibitor, Ki = 0.0048 nM (human); Ki = 4.8 nM (rat)	[175]
ONO-5334	C21H34N4O4S		Inhibitor, Ki = 0.10 nM (human); Ki = 0.049 nM (rabbit); Ki = 0.85 nM (rat)	[176,177]
2-Cyanopyrimidine	C5H3N3		Inhibitor, IC50 = 170 nM	[178]
LHVS	C28H37N3O5S		Inhibitor, 5 μM (Osteoclasts)	[179]
L-006235/L-235	C24H30N6O2S		Inhibitor, IC50 = 5 nM	[142,150,180]
calpeptin 1/Cbz-Leu-Nle-H	C20H30N2O4		Inhibitor, IC50 = 0.11 nM	[181]
Boc-Nle-H	C11H21NO3		Inhibitor, IC50 = 51 nM	[181]
Inhibitor 9			Inhibitor, Ki = 10 nM	[182]
Inhibitor10			Inhibitor, Ki = 120 nM	[182]
Compound rac-34a	C22H23F2N2OS		Inhibitor, IC50 = 0.46 nM	[183]
Compound (−)34a			Inhibitor, IC50 = 0.28
Compound (+)34a			Inhibitor, IC50 = 7.1
Compound rac-34b	C21H19F3N2O		Inhibitor, IC50 = 36	[183]
Compound rac-34c	C22H22Cl2N2OS		Inhibitor, IC50 = 0.58	[183]
Compound rac-38a	C22H23FN2OS		Inhibitor, IC50 = 4.2	[183]
Compound rac-38b	C22H23FN2OS		Inhibitor, IC50 = 3.7	[183]
Compound 1a			R = H, Inhibitor, IC50 = 0.47	[178]
Compound 1b			R = 3-CH3, Inhibitor, IC50 = 0.46
Compound 1c			R = 4-CH3, Inhibitor, IC50 = 0.19
Compound 1d			R = 3-Cl, Inhibitor, IC50 > 1
Compound 1e			R = 4-Cl, Inhibitor, IC50 = 0.35
Compound 1f			R = 3-OCH3, Inhibitor, IC50 > 1
Compound 1g			R = 4-OCH3, Inhibitor, IC50 = 0.06
Tri-Ring P3 Benzamide-Containing Aminonitriles			Inhibitor, Ki < 0.003 nM	[180]
			Inhibitor, Ki < 0.00025 nM
Nonpeptidic Cyanamides			Inhibitor, IC50 = 0.05–13.7 μM	[142]
Compound 4a			R= GlyOMe, Inhibitor, IC50 = 0.1 mM	[184]
Compound 4d			R= L-AsnOMe, Inhibitor, IC50 = 0.4 mM	[184]
Amentoflavone			R1 = R2 = R3 = H, Inhibitor, IC50 = 1.88 μM	[185]
Podocarpusflavone A,			R1= R3 = H, R2 = CH3, Inhibitor, IC50 = 2.51 μM	[185]
7′′,4′′′-dimethylamentoflavone			R1= R2 = CH3, R3 = H, Inhibitor, IC50 = 1.57 μM	[185]
Bilobetin			R1= R2 = H, R3 = CH3, Inhibitor, IC50 = 1.55 μM	[185]
2,3-dihydroamentoflavone	C30H18O10		Inhibitor, IC50 = 1.39 μM	[185]
Hinokiflavone	C30H18O10		Inhibitor, IC50 = 8.797 μM	[185]
Kushennol F	C25H28O6		Inhibitor, IC50 = 27.24 nM	[186]
Sophoraflavone G	C25H28O6		Inhibitor, IC50 = 1.54 nM	[186]
A series ofketoamides with varying P1 moieties			Inhibitor, IC50 = 0.77–12,000 nM	[187]