Latamoxef Impurity 16

(7S) -7- (3- (((7R) -2-carboxy-7-methoxy-3- (((1-methyl-1H-tetrazol-5-yl) thio) methyl) -8-oxo-5-oxa-1-azabicyclo[4.2.0]oct-2-en-7-yl) amino) -2- (4-hydroxyphenyl) -3-oxopropanamido) -7-methoxy-3- (((1-methyl-1H-tetrazol-5-yl) thio) methyl) -8-oxo-5-oxa-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid