TABLE 3.

Half-life (t½) in pH 7.4 and in buffer containing α-chymotrypsin (Kahns, Friis, Bundgaard, 1993).

t½
Buffer with α-chymotrypsin
Compound	R1	R2	Buffer pH 7.4	0.25 mg/mL	0.50 mg/mL	1.0 mg/mL
(35)	CH 2 OH	H	38 min	33 min	35 min	32 min
(36)	CH 2 OH	CH2C6H5	63 min	65 min	64 min	63 min
(37)	H	H	stable	9.6 h	4.9 h	2.3 h
(38)	H	CH2C6H5	stable	15.0 h	7.5 h	3.9 h

Phosphate buffer, 0.1 M (pH 7.4). Bold is to emphasize it is correspondent to hydroxymethyl derivative.