TABLE 1.

Effect of 4′-substituted D4T analogs on HIV

Compound	EC50 (μM)a	ID50 (μM)b
D4T	1.3 ± 0.4	98.0 ± 10.8
4′-Methyl D4T	>100d	>100
4′-Vinyl D4T	>100d	>100
4′-Ethynyl D4T	0.25 ± 0.14d	>256c
4′-Methylethynyl D4T	4.0 ± 1.6	>100
4′-Chloroethynyl D4T	>100	63.3 ± 20.8
4′-Allyl D4T	>100	>100
4′-Cyano D4T	7.0 ± 2.6	>100

^aEC required to achieve 50% protection from HIV in MT-2 cells. Numbers represent means and standard deviations obtained from three separate experiments and derived from antiviral curves generated using triplicate samples at each concentration.

^bConcentration required to inhibit MT-2 cell growth by 50%. Numbers represent means and standard deviations obtained from three separate experiments and derived from toxicity curves generated using triplicate samples at each concentration.

^cThe highest concentration tested.

^dEC₅₀ reported previously (19).