The preparation of pure yellow Monascus pigments makes the
study of their basic characters become possible. The absorbance
of yellow Monascus pigments had a maximum peak at 395 nm
(Fig. 5A). This result is consistent with the literature data [26].
Very interestingly, yellow Monascus pigments exhibited no aminophilic
reaction in spite of the very similar structure between yellow
Monascus pigments and orange ones (Fig. 5B), which provided the
basic evidence between structure and activity. It is reported that
orange Monascus pigments exhibit strong teratogenic effect on
check embryo, the corresponding toxicity of yellow Monascus pigments
reduces markedly, while that of red Monascus pigment derivates
with amino acid residues is much less comparison to that of
orange ones. The antibacterial activity of Monascus pigments also
exhibits a similar trend [12,13]. Similarly, the cytotoxicity of
Monascus pigments on human cancer cell gastric carcinoma cell
BGC-823 indicates that only orange Monascus pigments exhibit a