Table 1.

The cytotoxicity and anti‐HSV effects of compounds in vitro (CC₅₀, IC₅₀, and SI)

Compound	Structure	CC50 (μM)a	IC50 (μM)b		SIc
			HSV‐1	HSV‐2	HSV‐1	HSV‐2
3a		80.7 ± 1.7	365.9 ± 38.3	621.7 ± 18.2	0.2	0.1
4a		118.2 ± 3.6	378.1 ± 19.3	528.7 ± 28.1	0.3	0.2
5a		95.6 ± 2.6	2.2 ± 0.6	3.4 ± 0.3	43.5	28.1
5b		69.6 ± 2.1	30.5 ± 1.2	37.4 ± 1.0	2.3	1.9
5c		109.6 ± 3.8	62.1 ± 0.4	59.7 ± 2.1	1.8	1.8
5d		119.9 ± 2.7	1.8 ± 0.1	2.2 ± 0.4	66.6	54.5
5e		119.2 ± 1.4	5.4 ± 0.8	8.5 ± 0.9	22.1	14.0
5f		111.0 ± 2.6	9.5 ± 1.8	10.8 ± 1.4	11.7	10.3
Acyclovir		459.5 ± 17.3	9.6 ± 0.8	12.5 ± 2.5	47.9	36.8

Note. The inhibition effects on HSV‐1 (F strain) and HSV‐2 (333 strain; multiplicity of infection = 0.1) multiplication in Vero cells were evaluated by cytopathic effect inhibition assay. Results shown are means ± SD from five independent experiments.

Abbreviations: HSV, herpes simplex virus; SI, selectivity index.

^aConcentration required to reduce cell viability by 50% in Vero cells.

^bConcentration required to reduce the cytopathic effect of the virus by 50% at 24 hr p.i.

^cThe ratio of CC₅₀ to IC₅₀ (SI = CC₅₀/IC₅₀).