The Hexosamine of Chrondroitin Sulphuric Acid. 125 



substances displayed mutirotation and reached equilibrium 

 simultaneously. Also in its melting point and in its solubility 

 the amino sugar differed from glucosamine. Finally the osazones 

 of the two substances differed in their melting points and in their 

 solubility in alcohol and in water. 



On the basis of these data it seems justified to conclude that the 

 hexosamine is not identical with glucosamine, but is isomeric to it. 



Work on the configuration of the sugar is in progress. 



Substance. 



Crystal- 

 form. 



Rotation. 

 Initial. | Final. 



l«ln°°= 



Solubility. 



Melting Point. 



Glucosamine hydro- 



Short 



+ 101. 6 



+ 73.65 



Difficultly sol. in 



Decomposes 





thick 







80 per cent. 



slowly above 





prisms. 







EtOHjinsol.in 



200°. 











abs. EtOH. 







Needles. 







Difficultly sol. in 



Melts with de- 











abs. EtOH. 



composition 













206 0 . 



Hexosamine hydro- 



Long 



+129.5 



+93-82 



Easily sol. in 80 



Melts with de- 



chloride 



prismatic 







per cent. 



composition 





needles. 







EtOH; diffi- 



1 8o° 











cultly sol. in 













abs. EtOH. 







Long 







Easily sol. in 



175-180 0 





needles. 







EtOH; sol. in 













hot H2O. 





