Table 2. SAR of PEG Linker Length and Active-Site Inhibitors.

entry	compound no.	PEG repeats	active-site inhibitor	pS6K IC50 (nM)	p4EBP1 IC50 (nM)	pAKT IC50 (nM)	selectivity
1	20	8	PP121	0.22	1.0	17	17.0
2	24	6		0.24	31	110	3.5
3	18	8	PP242	0.28	1.4	18	12.9
4	25	6		0.59	370	120	0.3
5	19	8	BGT226	0.02	0.06	0.52	8.7
6	26	6		0.03	0.08	0.74	9.3
7	16	8	MLN	0.42	1.1	3.1	2.8
8	27	6		0.26	1.1	5.2	4.7
9	28	5		0.37	25	33	1.3