| 摘要 |
The invention comprises hydroxy-alkyl sulphonic acid esters of the acidic chlorins and rhodins and alkali metal salts of such esters, which chlorins and rhodins have been produced by the hydrolysis of chlorophylls a and b. They may be prepared by reacting a sultone with a water-soluble chlorophyll derivative obtained by the alkaline hydrolysis of chlorophylls a and b essentially in the presence of a catalytic amount of water. The reaction can be carried out entirely in aqueous solution or in an organic solvent such as toluene 1,4, dioxan or acetone with water present. One or more of the free carboxyl groups (as an alkali metal salt) of the chlorophyll derivatives is believed to react with the sultone to give an ester, e.g. with 1,3-propyl sultone to give R.CO.O(CH2)3SO2-ONa, where R represents the rest of the chlorin or similar chlorophyll derivative. The term "chlorophyll" includes compounds in which the chelated magnesium of chlorophyll properly so called has been replaced by hydrogen or by another metal, preferably a heavy metal, such as copper. Examples describe the reaction of sodium copper chlorophyllin, sodium potassium chlorophyllin and sodium chlorophyllin with 1,3-propyl sultone. The compounds may be used for imparting a green colour to canned peas and vegetables and for colouring various other foodstuffs (see Division A2). |
