Figure 3. Determination of correlation between chemical descriptors and anti-herpes simplex virus (HSV) activity of licorice flavonoids, polymethoxyflavonoids and low molecular weight flavonoids (defined as selectivity index (SI) by method II in Table II). 1, Liquiritin apioside; 2, liquiritin 7-apiosylglucose; 3, liquiritin; 4, neoliquiritin; 5, liquiritigenin; 6, isoliquiritin apioside; 7, lucurzid; 8, isoliquiritin; 9, neoisoliquiritin; 10, isoliquiritigenin; 11, tricin; 12, 3,3’,4’,5,6,7,8-heptamethoxyflavone; 13, nobiletin; 14, tangeretin; 15, sudachitin; 16, epigallocatechin gallate; 17, chlorogenic acid; 18, coumaric acid; 20, resveratrol. The data of curcumin, 19, was not included since the SI value could not be obtained (Table II).