TABLE 3.

In vitro activity of d- and l-enantiomers of analogs with 3′ oxygen or 3′ sulfur substitutions against HIV RT with the K65R mutation

Compound	Mean IC50 (μM) ± SDa			P
	HIV-1WT	HIV-165R	Fold increaseb
d-enantiomers
(+)-3TC	1.20 ± 0.56	32.9 ± 10	27	<0.0001
(+)-FTC	11.6 ± 3.4	>90	7.7	<0.0001
D-DOC	0.34 ± 0.07	3.57 ± 1.4	11	<0.0001
D-DOFC	0.89 ± 0.56	5.41 ± 1.6	6.1	<0.0001
(−)-DOTCc	6.34 ± 1.74	65.5 ± 37	10	<0.01
DXG	3.60 ± 0.31	21.8 ± 8.2	6.0	<0.005
FLG	1.02 ± 0.41	4.05 ± 0.89	4.0	<0.005
FLT	0.18 ± 0.05	0.41 ± 0.03	2.3	<0.005
l-enantiomers
(−)3TC	0.78 ± 0.48	60.5 ± 66.8	77	<0.0001
(−)-FTC	0.17 ± 0.07	3.75 ± 1.75	22	<0.0001
L-DOC	0.082 ± 0.04	0.66 ± 0.18	8.1	<0.001
L-DOFC	0.032 ± 0.01	0.34 ± 0.21	10	<0.0005
(+)-DOTCc	11.2 ± 4.4	>90	8.1	<0.001

^aMeans ± standard deviations from at least three independent experiments.

^bFold increase in IC₅₀ relative to wild-type results.

^cAssay done with MT-2 cells (see Materials and Methods).