FLAVONOIDS AND RELATED COMPOUNDS 



187 



apigenidin 



An example of an anthocyanin containing both sugar and acid residues is salvianin from 

 Salvia splendens: 



\ / 







II 



.CH=CHCO 



0-G-LUCOSE-0-&LUCOSE 



I I 







C=0 C=0 



i 



H- 



CHo 



I * I ^ 



0=C0CH3 0=C0CH3 



The exact locations of the methyl malonate residues is not known, but this example illus- 

 trates the possible complexity to be found in this group. 



Some general rules can be given regarding the dependence of color on methylation 

 and glycosylation. Methylation increases the redness, while increase in free hydroxyl 

 groups or addition of a 5-glycosidic group increases the blueness. However, the depend- 

 ency of color on pH and the presence of copigments and metal cations makes these rules 

 of little value unless one is dealing with a pure pigment. 



Table 5 lists some well-known anthocyanins with their particular glycosylation and 

 sources. Many, of course, are found in more than one plant. 



TABLE 5. SOME WELL-KNOWN ANTHOCYANINS 



