The dried seeds of Iris lactea have been used in traditional Chinese medicine. Previous studies have been focused on irisquinones while other chemical components are rarely reported.
WANG Honglun and his team try to establish an efficient high-speed counter-current chromatography (HSCCC) separation method with continuous sample load (CSL) and double-pump balancing (DPB) mode to isolate proanthocyanidins from I. lactea.
Firstly, an ethyl acetate extract of I. lacteal was pre-fractionated by silica column chromatography for the enrichment of proanthocyanidins.
Secondly, the enriched proanthocyanidins sample (EPS) was further fractionated by HSCCC with a two-phase solvent system ethyl acetate: n-butanol: water (9:1:10, v/v/v) using DPB mode. The flow rate of the two phases was 2.2mL/min, the revolution speed was 900 rpm, the separation temperature was 30 °C and the detection wavelength was 280nm.
Finally, the structures of the three isolated proanthocyanidins were elucidated by spectroscopic methods and compared with published data.
Under the optimized conditions, 600mg of the EPS with six continuous injections (100mg/time) was fractionated, yielding 57mg of prodelphinidin B3, 198mg of procyanidin B3, and 162mg of procyanidin B1, at purities of 97.2%, 98.1%and 97.3%, respectively.
The HSCCC separation method with CSL and DPB proved to be rapid, convenient and economical, constituting an efficient strategy for the isolation of proanthocyanidins.
Figure. Chemical structures of (1) prodelphinidin B3, (2) procyanidin B3, and (3) procyanidin B1.
Additional Information:
1 Author Information: LV Huanhuan, YUAN Zhenzhen, WANG Xiaoyan, WANG Zhenhua, SUO Yourui, WANG Honglun.
Correspondence: hlwang@nwipb.cas.cn.
2 Published: Phytochem. Anal. 26: 444–453, 2015.