TABLE 6.

Inhibition of cell cycle progression by rapamycin and analogs^a

Compound	Incorporation of [3H]dTTP into nucleic acids (%) at indicated time and compound concentration
	21–24 h				45–48 h
	1 nM	10 nM	100 nM	1 μM	1 nM	10 nM	100 nM	1 μM
Rapamycin	92	48	27	20	99	46	10	7
Prolylrapamycin	98	65	26	21	103	91	22	7
4-Hydroxyprolyl-26-demethoxy-rapamycin	87	86	80	67	111	98	98	71

^aThe control experiment was the incorporation of [³H-dTTP] into nucleic acids in the 536 cell line in the presence of 0.1% DMSO (100%).