Table 6. Tetrahydroprydine N-substituent variants.

Protective activity of tetrahydropyridine N-alkyl variants in the zebrafish hair cell protection assay. NA – not active (HC₅₀ > 25 μM).

	R	HC50 (μM)
1		3.12
49		3.50
50		4.51
51		5.56
52		1.49
53		1.22
54		1.36
55		1.83
56		1.89
57		2.40
58		2.83
59		NA
60		NA
61		1.10
62		0.56
63		0.71
64		0.62
65		0.47
66		0.11
67		0.10