Preparative isolation and purification of two benzoxazinoid glucosides from Acanthus ilicifolius L. by high-speed counter-current chromatography.
The first preparative separation of two benzoxazinoids, (2R)-2-O-beta-d-glucopyranosyl-2H-1,4-benzoxazin-3(4H)-one (HBOA-Glc) and (2R)-2-O-beta-d-glucopyranosyl-4-hydroxy-2H-1,4-benzoxazin-3(4H)-one (DIBOA-Glc), by means of high-speed counter-current chromatography (HSCCC) from the n-butanol extract of Acanthus ilicifolius L. is presented. The two-phase solvent system containing ethyl acetate-n-butanol-0.5%NH(4)OH (2:3:5, v/v/v, system B) was selected for the one-step HSCCC separation of HBOA-Glc and DIBOA-Glc according to the partition coefficient values (K) for target compounds and the separation factor (alpha) between the two target compounds. In the one-step HSCCC separation using solvent B, from 100mg n-butanol extract of A. ilicifolius, 6.3 mg HBOA-Glc and 6.8 mg DIBOA-Glc were isolated with purities of 90.3% and 80.2%, respectively. In order to obtain the two target compounds with higher purity, a second separation process was developed comprising two steps. In the two-step separation, the sample was first pre-purified by HSCCC using ethyl acetate-n-butanol-water (2:3:5, v/v/v, system A) solvent system and then purified using solvent system B. A 100-mg amount of the n-butanol extracts of A. ilicifolius was separated to yield 5.8 mg of HBOA-Glc and 4.8 mg of DIBOA-Glc with purities of 97.1% and 94.8%, respectively, which were directly used for NMR analyses.
Yin
Hao
H
Guangdong Key Laboratory of Marine Material Medica, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, Guangdong, China.
Zhang
Si
S
Luo
Xiongming
X
Liu
Yonghong
Y
D027901:Acanthaceae / Q000737:chemistry*; D048588:Benzoxazines / Q000302:isolation & purification*; D003377:Countercurrent Distribution / Q000379:methods*; D005960:Glucosides / Q000302:isolation & purification*; D019906:Nuclear Magnetic Resonance, Biomolecular
C533011:(2R)-2-O-beta-D-glucopyranosyl-2H-1,4-benzoxazin-3(4H)-one; C533012:(2R)-2-O-beta-D-glucopyranosyl-4-hydroxy-2H-1,4-benzoxazin-3(4H)-one; D048588:Benzoxazines; D005960:Glucosides