Acarbose EP Impurity A

(3S,4R,5R)-4-(((2R,3R,4R,5R,6R)-5-(((2S,3S,4R,5R,6S)-3,4-dihydroxy-6-methyl-5-(((1S,4S,5S,6S)-4,5,6-trihydroxy-3-(hydroxymethyl)cyclohex-2-en-1-yl)amino)tetrahydro-2H-pyran-2-yl)oxy)-3,4-dihydroxy-6-(hydroxymethyl)tetrahydro-2H-pyran-2-yl)oxy)-1,3,5,6-tetrahydroxyhexan-2-one