FUH fuh [[(2~{R},3~{S},5~{R})-5-[5-methyl-2,4-bis(oxidanylidene)pyrimidin-1-yl]-3-oxidanyl-oxolan-2-yl]methoxy-oxidanyl-phosphoryl] [(2~{R},3~{R},4~{S},5~{R},6~{R})-6-methyl-3,5-bis(oxidanyl)-4-[[(3~{R})-3-oxidanylbutanoyl]amino]oxan-2-yl] hydrogen phosphate FUH