Current Chemical Biology - Volume 8, Issue 1, 2014

Bioconversion of glycyrrhizin (GL) to glycyrrhetinic acid (GA) and 3-oxo-GA by A. niger NRRL 595 was compared using free and immobilized fungus cells and spores. Two immobilization techniques were adopted; namely the entrapment of the fungus cells and spores in calcium alginate beads, as well as their adsorption on glass wool. The bioconversion efficiencies of the immobilized fungus cells and spores were less than those obtained with the free cells. On the other hand, re-utilization of fungal cells and spores adsorbed on glass wool appeared to be the most successful treatment, especially the immobilized spores as their productivity increased gradually and reached 93% at the third run. This yield was of higher magnitude than that obtained by the free cells (86.78 %), and also they maintained about 50 % of their productivity during 28 days (i.e., 7 successive cycles). These results can be considered to be the first report describing the possibility of using the immobilized microbial cells and spores in the bioconversion of GL.

Glycosidase inhibitors are important compounds that can interfere with several biosynthetic processes including N-linked glycosylation and the biosynthesis of several glycoproteins. Understanding the biogenesis of naturally occurring glycosidase inhibitors would be a crucial step towards the chemical synthesis of analogues of choice. This review focuses on the current knowledge regarding the biosynthesis of a series of polyhydroxylated saturated nitrogen heterocycles including nojirimycin and swainsonine among others, with a potent biological activity as inhibitors of glycosidases and transglycosidases.

A new 2-chloro-4’methoxy benzoin (2C4MB) with chemical formula (C15H13ClO3) was synthesized by benzoin condensation. The single crystal XRD study of 2C4MB was also carried out in order to confirm its structure and conformation. The anti-depressant activity of 2C4MB was also carried out on albino mice as test animal. The results of the antidepressant studies of 2C4MB correlated with the docking calculations performed on proteins 3GWU, 3GWV, and 3GWW.

Chitin and its deacetylated derivative, chitosan, are natural polymers that have been proposed to be used in a wide range of applications. Due to their natural origin, both chitin and chitosan cannot be defined as a unique chemical structure but as a family of polymers which present a high variability in their chemical and physical properties. This variability is related not only to the origin of the samples but also to their method of preparation. Due to this variability, the success of the polymer on each application depends on the properties of the polymer. In a previous review, we highlighted the relationship between the physicochemical properties of the polymers and their behavior. In the last three years, new data regarding this topic has been published; this update includes this new information. Moreover, new applications (fiber formation and cosmetic) that were not previously reviewed due to the extension of the topic are included.

The aim of this study is to evaluate by in vitro tests the antioxidant and antimicrobial effects of various extracts from Algerian Rhanterium adpressum flowers. The effect of different solvents; (methanol-water) and (acetone-water) with varying polarities concentration (50-90%, v/v) on the extraction of phenolic compounds was studied. Total phenolic content (TPC), total flavonoid content (TFC) and proanthocyanidins content assays were used for the determination of phenolic compounds. The results of antioxidant tests assessed by DPPH, ABTS and phosphomolybdenum showed that flowers extracts of Rhanterium adpressum expressed a considerable activity. Results of antimicrobial activity using agar hole diffusion method indicated moderate antibacterial effect. Screening analysis of phenolic content in these extracts suggested that these biologically active components are responsible for the antioxidant and antimicrobial activities.