Lopinavir EP Impurity D 

Chemical Name: (1R,3R)-1-[(1R)-1-[[2-(2,6-Dimethylphenoxy)acetyl]amino]-2-phenylethyl]-3-[[(2R)-3-methyl-2-[2-oxotetrahydropyrimidin-1(2H)-yl]butanoyl]amino]-4-phenylbutyl hydrogen sulfate (as per EP);