从红凤菜( Gynura bicolor DC.) 地上部分提取了红色素水溶液。 在 350～ 700nm 范围内的扫描结果显示, 该色素有 2 个吸收峰, 位于 543 nm 和 587 nm 附近。 在 pH 2.2～ 6 .0 的范围内色素较稳定。 加热使其吸收峰值增大, 但波长基本不变。0 .2 mmol L Fe3+引起色素溶液变色并产生大量沉淀;Al3 +也能使其产生沉淀;Cu2 +对该色素的影响较小;Zn2+对其无影响。 氧化剂( H2O2 ) 与还原剂( Na2SO3 ) 均能使该色素褪色。光照对该色素无明显影响。
 

The red pigment has been extracted from the above-ground part of Gynura bicolor DC. In range of
wavelengths 350 -700 nm, this pigment has two absorption peaks with the wavelength of 543 nm and 587 nm.The pigment is stable in the range of pH 2 .2 -6 .0 .Heating increases the value of absorption peak, but the wavelengths change little .Fe³⁺ ( 0 .2 mmol/ L) can alter its color and bring a great deal of precipitation ;Al³⁺ can also bring precipitation ;the influence of Cu²⁺  is small and Zn²⁺ is not notable .Both oxidant( H2O2) and reductant(Na2SO3) can discolor the pigment which has no obvious reaction to illumination .