Abstract:

Apotransferrin was prepared from lactoferrin using acetic acid or citric acid, and the apotransferrin prepared using acetic acid was employed to prepare apotransferrin-chromium complex. The effects of acetic acid and citric acid on the apotransferrin preparation were compared by determining product yield and analyzing chemical structure by means of UV and IR absorption spectroscopy. The preparation conditions of apotransferrin-chromium complex were investigated by one-factorat- a-time experiments, and the product was characterized. Fe3+ could be effectively dissociated from lactoferrin by adjusting pH to 2.25 using acetic acid or to 2.50 using citric acid. Compared to citric acid, the use of acetic acid yielded more apotransferrin, but the apotransferrin products prepared using the two reagents had the same functional groups. The optimal complex conditions of apotransferrin with Cr3+ were as follows: 60－70 ℃, pH 7.0－7.6, molar ratio of apolactoferrin to chromium trichloride 1:2, and stirring duration more than 2 h.

Key words: lactoferrin, chromium trichloride, apotransferrin-chromium complex, infrared absorption spectrum