The bands in the region of 1043 cm−

The bands in the region of 1043 cm−1 and 1014 cm−1(KOG)and 1027 cm−1(KG) were ascribed to C O stretching vibration.

The band in the region of 649 cm−1(KOG) was due to bending vibration of the C C C(O) and, at the same time, it has a substituent in place of the bond.

The absorption band at 620 cm−1 was due to bending vibration of the C CO C, while there is no substituent in place of the bond.

As far as the position and intensity of various bands of the KG and KOG were concerned, the major bands centered at 1800–1200 cm−1 showed significant change, which shifted to a little lower wave number when the KG was degraded and, at the same time, their intensity was decreased.

The peak at 1723 cm−1 disappeared in the spectra of KOG, these significant changes suggested the KG degradation occurred.