TABLE 4.

Anti-HSV-1 activity of triterpenes.

Compound	Origin	Inhibitory rate (%) a			IC50 (μM)	Prediction result	Probability
		5 μM	10 μM	25 μM
1	Isodon japonicus	‒	‒	0.00 ± 11.89	‒	inactive	0.8848
2		‒	‒	‒2.99 ± 8.99	‒	active	0.5265
3		‒	‒	‒4.82 ± 12.38	‒	inactive	0.9522
4	Pfaffia glomerata	‒	‒	7.64 ± 10.72	‒	inactive	0.7321
5		‒	‒	‒4.36 ± 23.98	‒	active	0.8738
6		‒	‒	12.39 ± 16.94	‒	inactive	0.5545
7		‒	‒	‒29.00 ± 6.81*	‒	inactive	0.9923
8		‒	‒	‒21.60 ± 11.92	‒	inactive	0.8345
9		‒	‒	‒2.48 ± 6.80	‒	‒ b	‒ b
10		5.85 ± 8.40	27.49 ± 8.92**	83.33 ± 41.11**, c	14.13	active	0.6441
11		14.56 ± 15.02	36.83 ± 17.39**	51.82 ± 9.61**	13.06	active	0.8005
12		4.42 ± 8.12	2.77 ± 11.62	24.72 ± 10.22*	‒	active	0.9833
13		9.52 ± 11.74	2.38 ± 17.69	27.55 ± 11.00	‒	‒ b	‒ b
14		‒	‒	10.09 ± 20.33	‒	inactive	0.7969
15		‒	‒	‒16.03 ± 8.69	‒	inactive	0.6087
16	Inonotus obliquus	−2.49 ± 8.74	0.00 ± 12.87	27.19 ± 5.52**	‒	inactive	0.7212
17		‒	‒	‒3.67 ± 1.53 d	‒	inactive	0.9756
18		‒	‒	1.24 ± 3.80	‒	active	0.9791
19		‒	‒	20.42 ± 8.49	‒	inactive	0.6141
20		‒	‒	19.03 ± 9.25	‒	inactive	0.9740
		conc.	5 μM	25 μM
oleanolic acid	positive control		9.02 ± 4.22	21.40 ± 11.56*	‒	‒	‒
		conc.	2.5 μM	10 μM
acyclovir	positive control		57.51 ± 11.88**	96.01 ± 11.76**	3.08	‒	‒

IC₅₀ = 50% inhibitory concentration.

^aSignificantly different from the control group, ^* p < 0.05, **p < 0.01.

^bCompounds 9 and 13 were judged to be outside the applicability domain.

^cThe cell viability of compound 10 at 25 μM was 14.64 ± 2.88%. Compound 10 did not show the cytotoxicity at 10 μM (104.0 ± 9.28%).

^dThe cell viability of compound 17 at 25 μM was 16.84 ± 9.50%.