Simple Preparation of Diverse Neoagaro-Oligosaccharides

Abstract

A simple method for obtaining pure and well-defined oligosaccharides was established by hydrolyzing agar with β-agarase from Vibrio natriegens. The conditions for enzymolysis were optimized as follows: a temperature of 45 °C, a pH of 8.5, a substrate concentration of 0.3%, an enzyme amount of 100 U/g and an enzymolysis time of 20 h. Neoagaro-oligosaccharides with different degrees of polymerization were obtained by hydrolyzing agar with β-agarase for different lengths of time. After removing pigments using activated carbon and salts by dialyzing, the enzyme hydrolysis solution was separated with Bio-Gel P2 column chromatography. Neoagaro-oligosaccharides with different degrees of polymerization were acquired. By comparing with authentic standard substances, along with further confirmation by FTIR, MS and NMR, structures of the purified neoagaro-oligosaccharides were identified as neoagarobiose (NA2), neoagaroteraose (NA4), neoagarohexaose (NA6), neoagarooctaose (NA8), neoagaro-decaose (NA10) and neoagarododecaose (NA12) with purities of more than 97.0%. The present study established a method for the preparation of various neoagaro-oligosaccharides that may be of great significance for further study of their bioactivities.

Tyrosinase-Catalyzed Phenol-Mediated Immobilization of β-Agarase on l-Lysine-Coated Magnetic Particles for the Production of Neoagarooligosaccharides from Gelidium amansii

“…The sole presence of two peaks strongly indicates that the hydrolysates mainly contain NA4 and NA6. Finally, the almost identical 13 C NMR spectra (Figures S18 and S19, SI) of NA4 and NA6 followed the typical resonances reported in the literature (detailed discussion on p S27, SI). , The NMR results also imply that Aga2Y5N-TP@Lys@Fe 3 O 4 specifically hydrolyzes the β-(1,4) glycosidic linkage between d -galactose and 3,6-anhydro- l -galactose to produce NAOS with d -galactose residues at the reducing end. − …”

“…Finally, the almost identical 13 C NMR spectra (Figures S18 and S19, SI) of NA4 and NA6 followed the typical resonances reported in the literature (detailed discussion on p S27, SI). 39,40 The NMR results also imply that Aga2Y5N-TP@Lys@Fe 3 O 4 specifically hydrolyzes the β- (1,4) glycosidic linkage between D-galactose and 3,6-anhydro-Lgalactose to produce NAOS with D-galactose residues at the reducing end. 40−43 Hydrolysis time profiles at 45 and 55 °C (Figure 5a) further reveal the differences in NAOS production between free Aga2Y5N and Aga2Y5N-TP@Lys@Fe 3 O 4 .…”

The Potential of Neoagaro-Oligosaccharides as a Treatment of Type II Diabetes in Mice

“…Agar was added to Tris-HCl buffer at 0.3% w / v and the mixture was heated for 10 min in a boiling water bath. Crude β-agarase was added to the cooled agar solution [42,43], and the mixture was incubated in an incubator with shaking (120 rpm; Hunan Xiangyi Laboratory Instrument Development Co., Ltd., H1850, Hunan, China) at 45 °C for 24 h, after which the insoluble component was removed by centrifugation (Shanghai Xinrui Automation Equipment Co., Ltd., Shanghai, China) at 12,000 × g for 30 min. Membrane separation included ultrafiltration to remove proteins and nanofiltration to remove small molecules such as salts, aiming to separate and purify the NAOs, which were further purified by gel column.…”

“…The solution was concentrated and freeze-dried, and the NAOs were analyzed using an HPLC-ELSD system (Waters, Milford, MA, USA). ESI-TOF-MS and NMR were utilized to explore the structure and molecular mass of the NAOs, respectively [43].…”

Green Separation and Extraction Processes: Part I

“…Caustic extraction in a total chlorine free bleaching sequence was investigated for wood chips pulp to make viscose fibers, with complementary utilization of viscose lyes and hemicellulose as a co-product [21]. A feasible approach was established for the preparation of desired neoagaro-oligosaccharides with different degrees of polymerization by regulating the enzymolysis time of β-agarase from marine bacteria [22]. Macroporous resins were screened on their adsorption and de-adsorption characteristics for the amygdalin (a characteristic component of the apricot kernels) in the debitterizing wastewater concentrate [23].…”