Tetrin A

21-[(3-Amino-3,6-dideoxy-β-D-mannopyranosyl)oxy]-1,3,5,25-tetrahydroxy-11,12-dimethyl-9-oxo-10,27-dioxabicyclo[21.3.1]heptacosa-7,13,15,17,19-pentene-24-carboxylic acid