Separation and Identification of Anthocyanin Extracted from Mulberry Fruit and the Pigment Binding Properties toward Human Serum Albumin

Abstract

Purple pigments were isolated from mulberry extracts using preparative high-speed countercurrent chromatography (HSCCC) and identified by ESI-MS/MS and high performance liquid chromatography (HPLC) techniques. The solvent system containing methyl tert-butyl ether, 1-butanol, acetonitrile, water, and trifluoroacetic acid (10:30:10:50:0.05; %, v/v) was developed in order to separate anthocyanins with different polarities. Cyanidin 3-O-(6″-O-α-rhamnopyranosyl-β-galactopyranoside) (also known as keracyanin) is the major component present in mulberry (41.3%). Other isolated pigments are cyanidin 3-O-(6″-O-α-rhamnopyranosyl-β-glucopyranoside) and petunidin 3-O-β-glucopyranoside. The binding characteristics of keracyanin with human serum albumin (HSA) were investigated by fluorescence and circular dichroism (CD) spectroscopy. Spectroscopic analysis reveals that HSA fluorescence quenched by keracyanin follows a static mode. Binding of keracyanin to HSA mainly depends on van der Waals force or H-bonds with average binding distance of 2.82 nm. The results from synchronous fluorescence, three-dimensional fluorescence, and CD spectra show that adaptive structure rearrangement and decrease of α-helical structure occur in the presence of keracyanin.

Simultaneous Enrichment and Separation of Four Flavonoids from Zanthoxylum bungeanum Leaves by Ultrasound‐Assisted Extraction and Macroporous Resins with Evaluation of Antioxidant Activities

“…To date, several methods applied to purify flavonoids from plant extracts have been reported, such as liquid-liquid extraction, ion exchange, and high-speed counter-current chromatography (HSCCC) (Biazus, Santana, Souza, Jordão, & Tambourgi, 2007;Elegami et al, 2003;Sheng et al, 2014). Unfortunately, these methods have some shortcomings, including inefficiency, high cost, and poor purity, and HSCCC is a particularly demanding technique, which makes these methods unsuitable for industrialization.…”

Rapid separation of cyanidin-3-glucoside and cyanidin-3-rutinoside from crude mulberry extract using high-performance countercurrent chromatography and establishment of a volumetric scale-up process

“…Therefore, the complicated and time‐consuming conventional column chromatography methods are not suitable for the separation of anthocyanins because chemical degradation or loss of target molecules may occur during multi‐step separation procedures. To overcome such obstacles, many studies have used countercurrent chromatography (CCC) techniques for the one‐ or two‐step separation of anthocyanins from crude plant extracts . CCC is a type of liquid–liquid chromatography that uses liquid mobile and stationary phases; thus, there is no chemical degradation or loss of target analytes .…”

Studies on the interaction between promethazine and human serum albumin in the presence of flavonoids by spectroscopic and molecular modeling techniques

“…The Förster non-radioactive resonance energy transfer theory is very useful to evaluate the possibility of energy trasfer from tryptophan residue of HSA to drugs and calculate the binding distance between them [57]. The energy transfer will take place when the donor can produce fluorescence, the fluorescence emission spectrum of the donor and the absorption spectrum of the acceptor have sufficient overlap, and the distance between the donor and the acceptor is less than 8 nm [58].…”