Separation of hydrophobically modified hyaluronic acid according to the degree of substitution by gradient elution high performance liquid chromatography

Advanced tools for molecular characterization of bio-based and biodegradable polymers

Bio-based and biodegradable materials play a vital role in a sustainable and green economy. These materials must exhibit properties that are similar to or better than the properties of oil- or coal-based materials and require sophisticated synthesis technologies and detailed knowledge of structure-property correlations. For comprehensive molecular structure elucidation, advanced analytical methods, including coupled and hyphenated techniques that combine advanced fractionation and information-rich spectroscopic detectors, are an indispensable tool. One important tool for fractionating complex polymers regarding molecular size is size exclusion chromatography. For fractionating polymers with regard to chemical composition, solvent (or temperature) gradient HPLC has been developed. The combination of different liquid chromatography methods in comprehensive two-dimensional HPLC setups is another important tool. Today, a toolbox of HPLC methods is in place that enables the fractionation of complex bio-based and biodegradable polymers according to the most important molecular parameters including molecular size, composition, functionality, and branching. Here, an overview of the different techniques and some major applications is presented. Some representative developments in the field are discussed, and different techniques, experimental protocols, and applications are highlighted.

Hyaluronic acid production by utilizing agro-industrial waste cane molasses

Hyaluronic acid is a polysaccharide endowed with distinctive biological and physiological competencies. Given its queer properties, hyaluronic acid has exclusive praxis in the cosmetics and medical industries. The surmounting demand for hyaluronic acid is the propulsion behind the necessity for finding the amenable ways for its production. Fermentation progression of Streptococcus zooepidemicus is reckoned as the superlative prompt and ambient approach for hyaluronic acid fabrication. For the unabated advancements in the industrial production of hyaluronan, industrial byproducts utilization is a fateful stile. The recent perusal is to optimize the fermentation production conditions of hyaluronic acid using cane molasses (a byproduct of sugar production) as a carbon source. The impact of different ranges of temperatures (33-41 °C), pH (6-8), and agitation rates (100-250 rpm) on the production process was calibrated using RSM using CCD as a statistical modality. In a 3.7 L bioreactor, 3.31 g/L hyaluronic acid was achieved at 9.74 percent molasses, 36.2 °C, pH 6.46, and a 207 rpm agitation rate using a batch fermentation technique. With a pH of 7, HPLC was conducted at 25 °C using a C18 column at a rate of 0.8 ml/min, and the wavelength was determined using a UV detector. The average retention time was 2.202 min. The FT-IR spectrum's output was also observed, and it matched the standard hyaluronic acid well.

Analysis of Molar Substitution of Hydroxybutyl Group by Zeisel Reaction in Starch Ethers

A new etherified starch, δ-hydroxybutyl starch (δ-HBS), was prepared by utilising 4-chlorobutan-1-ol as the etherifying reagent. The method of Zeisel gas chromatography for the determination of the molar substitution was described. This technique offers a simple and rapid method for quantitative analysis with reproducible results. Meanwhile, the mechanism of the Zeisel reaction was also investigated.