Xanthan gum is a polysaccharide used as a food additive and rheology modifier . It is produced by fermentation of glucose or sucrose by the Xanthomonas campestris bacterium.
Xanthone is an organic compound with the molecular formula c13h8o2. It can be prepared by the heating of phenyl salicylate.  in 1939, xanthone was introduced as an insecticide and it currently finds uses as ovicide for codling moth eggs and as a larvicide.  xanthone is also used in the preparation of xanthydrol which used in the determination of urea levels in the blood.
Xylene, xylol or dimethylbenzene, C6H4 (CH3)2 is the one which is derived from benzene. Según la posición relativa de los grupos metilo en el anillo bencénico, se diferencia entre orto-, meta-, o para- xileno (o con sus nombres sistemáticos 1,2-; 1,3-; y 1,4-dimetilbenceno). According to the relative position of methyl groups in the benzene ring, differs between ortho-, meta-or para-xylene (or their systematic names 1,2 -, 1,3 - and 1,4-dimethylbenzene).
Xylene cyanol can be used as a colour marker to monitor the process of agarose gel electrophoresis and polyacrylamide gel electrophoresis. Bromophenol blue and orange G can also be used for this purpose.