Structural Characterisation and Assessment of the Novel Bacillus amyloliquefaciens RK3 Exopolysaccharide on the Improvement of Cognitive Function in Alzheimer's Disease Mice.

In this study Bacillus amyloliquefaciens RK3 was isolated from a sugar mill effluent-contaminated soil and utilised to generate a potential polysaccharide with anti-Alzheimer's activity. Traditional and molecular methods were used to validate the strain. The polysaccharide produced by B. amyloliquefaciens RK3 was purified, and the yield was estimated to be 10.35 gL-1. Following purification, the polysaccharide was structurally and chemically analysed. The structural analysis revealed the polysaccharide consists of α-d-mannopyranose (α-d-Manp) and ß-d-galactopyranose (ß-d-Galp) monosaccharide units connected through glycosidic linkages (i.e., ß-d-Galp(1→6)ß-d-Galp (1→6)ß-d-Galp(1→2)ß-d-Galp(1→2)[ß-d-Galp(1→6)]ß-d-Galp(1→2)α-d-Manp(1→6)α-d-Manp (1→6)α-d-Manp(1→6)α-d-Manp(1→6)α-d-Manp). The scanning electron microscopy and energy-dispersive X-ray spectroscopy imaging of polysaccharides emphasise their compactness and branching in the usual tubular heteropolysaccharide structure. The purified exopolysaccharide significantly impacted the plaques formed by the amyloid proteins during Alzheimer's disease. Further, the results also highlighted the potential applicability of exopolysaccharide in various industrial and pharmaceutical applications.

Synthesis of new multivalent metal ion functionalized mesoporous silica and studies of their enhanced antimicrobial and cytotoxicity activities.

In the present study, we have reported the synthesis of a transition metal (Me = Ti, V, and Pd) incorporated into MCM-41 mesoporous molecular sieves (Si/Me = 20) synthesized by the sol-gel method. Their physicochemical properties were studied in detail by standard techniques like low angle powder X-ray diffraction (XRD), scanning electron microscopy-energy-dispersive X-ray spectroscopy (SEM-EDXS), transmission electron microscopy (TEM), N2 adsorption/desorption studies, and thermogravimetric-differential thermal (TG-DTA) analysis and spectral studies like Fourier transform infrared spectroscopic analysis (FT-IR), diffuse reflectance ultraviolet-visible spectroscopic analysis (UV-Visible-DRS), and X-ray photoelectron spectroscopy (XPS). The XRD patterns prove that the material's phase identity is the same irrespective of metal incorporation. SEM displayed the uniform shape and size of the nanoparticles. The presence of elements such as Ti, V, Pd, Si and O in respective materials is revealed using the EDXS analysis. Around 30% weight loss arose upon calcination from room temperature to 800 °C. BET surface area analysis presented that the parent materials have a high surface area (1024 m2 g-1) which was reduced upon metal incorporation. FT-IR analysis exhibited the framework vibrations of the synthesised materials. UV-Visible-DRS analysis indicated the presence of tetrahedrally coordinated transition metal ions. The multivalent-metal-ion-functionalized mesoporous materials showed significant enhancement in potent antimicrobial and anticancer activity. The antimicrobial activity is because of its low lipophilicity, which no longer allows the materials to enter via the lipid membrane. Thus, the new materials neither obstruct the metal-binding sites nor inhibit the growth of microbe enzymes. Further, the results show that the transition metal ion-containing mesoporous materials possessing good anticancer activity arising from their excessive surface area to volume ratio provided appropriate association with a tumour cell due to the direct penetration of mesoporous materials into the cell wall, causing membrane damage and cell death.