Isolation of three glucaric acids from Leonurus japonicus Houtt. by using high‐speed countercurrent chromatography combined with semi‐preparative high‐performance liquid chromatography

Abstract

The isomerism of glucaric acids and the complexity of the composition of Leonurus japonicus Houtt. increased the difficulty of the separation of glucaric acids from the herb. In the present study, three glucaric acids were isolated from Leonurus japonicus Houtt. by using high-speed countercurrent chromatography combined with semi-preparative high-performance liquid chromatography. Cation exchange resin chromatography was applied to remove the alkaloids and enrich the glucaric acid fractions. Preliminary separation of the glucaric acid extract by high-speed countercurrent chromatography was carried out at 45°C by using an optimized solvent system of ethyl acetate/n-butanol/formic acid/water (1:1:0.01:2, v/v/v/v) with satisfied stationary phase retention and separation factor. The semi-preparative high-performance liquid chromatography was used for further separation and purification of the target fractions, and three monomeric compounds were obtained with purities of 90.0, 91.0, and 95.3%. UV spectroscopy, NMR spectroscopy, and mass spectrometry were employed to identify their structures, which were assigned as 2-syringyl glucaric acid, 2,4-disyringyl glucaric acid, and 3,4-disyringyl glucaric acid, respectively, and 2,4-disyringyl glucaric acid was reported for the first time.

The Molecular Mechanism of Chloramphenicol and Thiamphenicol Resistance Mediated by a Novel Oxidase CmO in Sphingomonadaceae

“…The high-resolution mass spectrometry and nuclear magnetic resonance (NMR) analysis using a 700 MHz liquid NMR spectrometer (AVANCE III, Bruker Biospin, Switzerland) were employed as described previously (16). The sample for NMR was separated by a high performance preparative liquid chromatography, freeze-dried to a solid powder and locked with deuterated chloroform (CDCl 3 ) (16, 41, 42).…”

“…The sample for NMR was separated by a high performance preparative liquid chromatography, freeze-dried to a solid powder and locked with deuterated chloroform (CDCl3) (16,41,42).…”

Biphasic alcoholysis coupled with high‐speed countercurrent chromatography for high performance on separating phorbol from Croton tiglium Linn extracts

“…The HSCCC was performed by modifying the methods of Chen et al [22] and Li et al [23], on a TBE-300B HSCCC apparatus (Tauto Biotech, Shanghai, China), which was equipped with an electronic controller, an interchangeable triple coil separation column (polytetrafluoroethylene tube, 2.6 mm diameter, 280 ml total capacity), a manual 20 ml loop sample injection valve, a TBP-5002 constantflow pump, a TBD-2000 detector, and a fraction collector. The sample obtained from biphasic alcoholysis was dried by rotary evaporation at 45 • C, and the dryness was used as crude phorbol sample for HSCCC, which was dissolved into solvent system to prepare the sample solution.…”

“…With the technology advancement, high-speed countercurrent chromatography (HSCCC) is developed as a crucial technique for separating lead compounds in natural herb medicines [22][23][24], which has the advantages of simple sample preparation, large sample loading amount, high sensitivity, high efficiency, excellent recovery, high repeatability, and low solvent consumption [25,26]. HSCCC is a continuous and efficient liquid-liquid partition chromatographic separation technology that the stationary and mobile phases are both in the liquid state; in this case, the sample loss and denaturation in the irreversible adsorption and chemical reactions by the solid stationary phase can be avoided, the purity of the product is improved by the continuous eluting process [27][28][29].…”

Rapid screening and isolation of 5‐lipoxygenase inhibitors in Inonotus obliquus and mechanism of action in the treatment of asthma

“…In the separation of 5-LOX inhibitors from Inonotus obliquus extracts, we used semi-preparative liquid chromatography (Semi-preparative LC) combined with consecutive high-speed countercurrent chromatography (HSCCC) for their separation. Semi-preparative LC has advantages over traditional separation methods because it is simple, economical, and rapid, and separates products with high purity [32][33][34][35]. Consecutive HSCCC is a new chromatographic technology that combines the advantages of liquid-liquid extraction and distribution chromatography [36].…”