The spectral properties of CPIa and CPIb were similar to that of CPI. The absorption spectra of CPa1 and CPa2 were similar,both having red maxima at 667 nm and peaks in the blue at 431.5 nm.

• CPa1和 CPa2的吸收光谱相似；其红峰和蓝峰的位置分别位于667和431.；5nm 处。