Search

Poly(styrene–divinylbenzene)-based adsorption resin has the advantages of high specific surface area, adjustable pore size and other advantages, and has been widely used in the separation and purification of natural products and sewage treatment. However, its adsorption selectivity for specific compounds is poor. Therefore, to improve the selectivity of poly(styrene–divinylbenzene), the boric acid–functionalized monodisperse poly(styrene–divinylbenzene) was synthesized by seed swelling method by adding boric acid–functionalized polymerized monomer in the swelling stage. The static adsorption results showed that this polymer was pH–responsive. When pH> 9.5, the adsorption reached the maximum, and it could be desorbed with a pH

Oleuropein is an important natural compound with many biological activities. How to get high purity oleuropein is an urgent issue to be solved. This study provided a method for separating and purifying high purity oleuropein from olive leaves using boric acid affinity resin and a novel solvent system. And the experimental kinetic and adsorption isotherm data of boric acid affinity resin were well–fitted pseudo–first–order kinetic model and Langmuir isotherm model, respectively. The dynamic desorption experiments showed that ethanol was the most efficient eluent while had the lowest oleuropein purity. However, after the novel solvent system treated only one cycle of adsorption and desorption, the purity of oleuropein increased by 5.55 folds from 12.31 ± 0.42% – 68.30 ± 2.08 %. The results can guide the separation and purification of high purity catechol natural products using boric acid affinity resin and mixed solvent systems.

In the separation of strongly polar antioxidant compounds from natural products using high-speed counter-current chromatography that is target-guided by 2,2-diphenyl-1-picrylhydrazyl high-performance liquid chromatography experimentation, low adsorption ability is encountered due to the strong polarity of the target compounds. In this study, a strategy of novel partition coefficient value calculation was proposed for overcoming this problem. The partition coefficient value was expressed as the ratio of the antioxidant activities of the upper phase and the lower phase. This strategy was used in high-speed counter-current chromatography with a hydrophilic organic/salt-containing aqueous two-phase system for bioassay-guided separation of strongly polar antioxidant compounds from Lycium barbarum L. The antioxidant activity was determined via the radical scavenging activity method using 2,2-diphenyl-1-picrylhydrazyl radicals. A hydrophilic organic/salt-containing aqueous two-phase system of 95% EtOH - sat. (NH4)2SO4 (1:1.8, v/v) was successfully used to separate Lycium barbarum L. extract. Five fractions were collected via high-speed counter-current chromatography separation. The antioxidant activity of the third fraction was the highest. Three compounds were separated via MCI gel column chromatography and Sephadex LH-20 column chromatography from the third fraction, and their antioxidant activities were determined. The antioxidant activities of the three compounds were higher than that of the third fraction. These results demonstrate that this strategy can be used to separate strongly polar antioxidant compounds from natural products.

Resins have been modified with many functional groups by Friedal − Crafts alkylation reaction. In this research, a Friedal − Crafts acylation reaction in combination with commercial BNKX − 5 was first used to synthesize the boric acid − based macroporous resin named BNKX − 5−BA. The adsorption results of the experiments showed that the adsorption capacities of BNKX − 5 and BNKX − 5−BA were all affected by pH, and the adsorption capacities of all target compounds on BNKX − 5−BA increased as the pH value increase, meanwhile opposite results observed for BNKX − 5. Furthermore, the polymers had larger adsorption capacity for larger molecular weight compounds. Adsorption isotherms of taxifolin on BNKX − 5−BA were fitted better to Freundlich model and adsorption kinetic process followed the pseudo–first–order equation. The boric acid affinity, hydrogen bonding, π−π interactions and molecular sieving effect may have been the possible adsorption driving forces. The resin could be absolutely desorbed by 50 %, pH

Previous study in our laboratory confirmed that a novel polypeptide, CS5931 derived from Ciona savignyi possesses potent antitumor activity. In the present study, the full length cDNA of CS5931 precursor, termed Cs-pgrn-1 was cloned. The complete cDNA sequence of this gene consists of 685 bp containing an open reading frame (ORF) of 522 bp (173 amino acid residues). In silico analysis revealed that the polypeptide consists of two identical domains, similar with granulin (GRN) found in other species, and each of the domain encodes a polypeptide identical with CS5931. Phylogenetic analysis confirmed that CS5931 shares high homology with Ciona intestinalis GRN and is conserved during evolution. The polypeptide also shows high similarity with human GRN A, B, and C. Prediction of 3D protein structure revealed the 3D structure of CS5931 is very similar with human GRN A. The CS5931 was expressed using a prokaryotic expression system and the purified polypeptide inhibited the growth of several tumor cell lines in vitro via apoptotic pathway. Our study revealed that CS5931 has the potential to be developed as a novel antitumor agent.