4.4.3. CD

The samples were dissolved in precooled 0.5 M acetic acid to obtain a final concentration of 0.1 mg/mL. The sample solutions were centrifuged at 14,010× *g* for 10 min at 4 ◦C (Neofuge 15R, Shanghai Lishen Scientific Equipment Co., Ltd., Shanghai, China), and then the supernatants were measured using a CD spectropolarimeter (Chirascan, Applied Photophysics Ltd., Leatherhead, UK). The spectrum was recorded at 260–190 nm wavelengths at 15 ◦C in 0.1 nm steps with a response time of 1 s.
