Multiple copper chlorophyll analogues were detected in the chewing gum
product containing the copper chlorophyll dye using a HPLC apparatus
with photodiode array detection. The main components among these analo
gues were assumed to be 10-hydroxy copper chlorophyll a and b by IR, F
AB/mass and NMR spectrometry. Since these copper chlorophyll analogues
were main components in the commercial food additive dye, ''copper ch
lorophyll'', it was clear that these analogues in the chewing gum prod
uct were carried over from this food additive. The 10-hydroxy pheophyt
ins, which are precursors of these copper chlorophyll analogues, were
detected from the extract of silkworm excreta, the original material o
f this dye. These copper chlorophyll analogues were possibly produced
by the metalation reaction between the copper and the 10-hydroxy pheop
hytins which might be generated from the oxidation of pheophytins, lik
e ''allomerization reaction'', during the process of the synthesis of
the original material and its storage. It is possible that these analo
gues have already been the main components in the original dye.