Separation and purification of α-glucosidase inhibitors from Polygonatum odoratum by stepwise high-speed counter-current chromatography combined with Sephadex LH-20 chromatography target-guided by ultrafiltration–HPLC screening

Extraction of cocoa proanthocyanidins and their fractionation by sequential centrifugal partition chromatography and gel permeation chromatography

“…In a study by Yang, Li, and Wan [9], the main individual tannins from black tea were purified, whereby theaflavin, theaflavin-3-gallate, theaflavin-3-gallate, and theaflavin-3,3-digallate were obtained in a separation process using a combination of HSCCC and a chromatographic separation with Sephadex LH-20. Also, Zhou, Liang, Zhang, Zhao, Guo, and Shi [10] obtained a purification of glucosidase inhibitors from Polygonatum odoratum by HSCCC and a following separation with Sephadex LH-20. A study done by Cheel, Minceva, Urajová, Aslam, Hrouzek, and Kopecký [11] used also preparative CPC separation followed by gel permeation chromatography to obtain on 50 mg of crude soil cyanobacteria extract a yield of 3.5 mg Aeruginosin-865, with a purity over 95 % as determined by HPLC.…”

Rapid Screening for α-Glucosidase Inhibitors from Gymnema sylvestre by Affinity Ultrafiltration–HPLC-MS

“…α-Glucosidase, an enzyme secreted in the small intestinal chorionic epithelium, has been proved to catalyze the cleavage of oligosaccharides and disaccharides into monosaccharides during the final step in the digestions of the carbohydrates. Studies showed that α-glucosidase inhibitors can delay or reduce the digestion and absorption of carbohydrates, and thus decrease the postprandial blood glucose level (Khan et al, 2014; Zhou et al, 2015). α-Glucosidase inhibitors, which were classified as the oral hypoglycemic agents of third category (e.g., acarbose and voglibose) and exhibited significant inhibition on postprandial blood glucose in the T2DM patients, have been recommended as a first line therapy by IDF (International Diabetes Federation) and AACE (American Association of Clinical Endocrinologists).…”

“…The conventional approaches for screening the bioactive ingredients from natural products require bioassay-guided repeated column chromatography isolations, which are labor-intensive, time-consuming and low efficiency, and sometimes lead to the incidences of false positives/negatives with relatively high risk of failure by reason of irreversibly adsorption, decomposition, dilution effects (Zhang et al, 2013; Xiao et al, 2015; Zhou et al, 2015). Derived from the urgent needs of high-throughput screening of bioactive compounds in recent years, a combinational method of bio-affinity ultrafiltration and high performance liquid chromatography coupled with electrospray mass spectrometry (HPLC-ESI-MS/MS) has been proposed.…”

Separation of polar antioxidants from Rhizoma Polygonatum Odorati by high-speed counter-current chromatography with a hydrophilic solvent system

“…[11][12] Our previous study evaluated the antioxidant and α-glucosidase inhibitory activities of ethyl acetate fraction of Rhizoma Polygonatum Odorati and then systematically isolated the bioactive compounds. [6,7,13] Surprisingly, although the popularity of usage and research for many years, the detailed information regarding the chemical composition and relevant activities in n-butanol fraction of Rhizoma Polygonatum Odorati is scarce. The investigation of highly polar compounds in n-butanol fraction has been hampered mostly because of their difficult and laborious isolation procedures.…”

“…[23][24] Notably, a series of highly polar solvent systems, composed of hydrophilic organic solvent (e.g., ethanol and methanol) and inorganic salt solution, have recently been developed to purify highly polar compounds (e.g., catecholamines, basic dyes, sulfonic acids, zwitter ions, nucleotides, and their derivatives). [22,[24][25][26][27] As part of our ongoing efforts on isolation and evaluation of bioactive compounds from medicinal herbs, [6,7,13,[16][17][18] a hydrophilic solvent system, composed of n-butanol-ethanol-2 M ammonium sulfate aqueous solution, is firstly developed to isolate highly polar antioxidants from n-butanol fraction of Rhizoma Polygonatum Odorati target-guided by DPPH-HPLC assay. Followed by further purification on Sephadex LH-20 column chromatography, we yield nine highly polar antioxidants with purities over 98.0%, which include four nucleosides, cytidine (1), uridine (4), guanosine (5), and adenosine (8); two nucleobases, guanine (3) and adenine (6); and three amino acids, tyrosine (2), phenylalanine (7), and tryptophan (9).…”