Herpes simplex virus 1 4 Herpes simplex virus 2 4 antiviral activity 4 brassinosteroid 4 drug selectivity 4 nonhuman 4 stigmasterol 4 structure activity relation 4 unclassified drug 4 unindexed drug 4 2 alpha 3 alpha 22,23 tetrahydroxy 5 alpha stigmastan 6 one 2 2 alpha 3 alpha 22,23 tetrahydroxy homo 7 oxastigmastan 6 one 2 2 alpha 3 alpha 5 alpha 22,23 pentahydroxystigmatan 6 one 2 2 alpha 3 alpha dihydroxy 5 alpha stigmast 22 en 6 one 2 2 alpha 3 alpha dihydroxy 6 alpha fluoro 5 alpha stigmast 22 ene 2 2,3,22,23 bisacetyliden 2 alpha 3 alpha 22,23 tetrahydroxy 5 alpha sigmastan 6 one 2 2alpa,3alpha dihydroxy 6alpha fluoro 5alpha stigmast 22 ene 2 2alpha,3alpha dihydroxystigmast 22 en 6 one 2 2alpha,3alpha,22,23 tetrahydroxy 5alpha fluorostigmastan 6 one 2 2alpha,3alpha,22,23 tetrahydroxy 5alpha stigmastan 6 one 2 2alpha,3alpha,22,23 tetrahydroxy beta homo 7 oxastigmastan 6 one 2 2alpha,3alpha,5alpha,22,23 pentahydroxystigmastan 6 one 2 3 alpha 22,23 trihydroxy 5 alpha stigmastan 6 one 2 3 alpha fluoro 22,23 dihydroxy 5 alpha stigmastan 6 one 2 3 beta 5 alpha dihydroxystigmast 22 en 6 one 2 3 beta acetoxy 22,23 dihydroxy 5 alpha stigmastan 6 one 2 3 beta acetoxy 22,23 trihydroxy 5 alpha stigmastan 6 one 2 3 beta acetoxy 5 alpha 22,23 trihydrostigmastan 6 one 2 3 beta bromo 5 alpha 22,23 trihydroxystigmastan 6 one 2 3 beta bromo 5 alpha hydroxystigmast 22 en 6 one 2