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 β-d-galactopyranose (β-d-Galp) monosaccharide units connected through glycosidic linkages (i.e, β-d-Galp(1→6)β-d-Galp (1→6)β-d-Galp(1→2)β-d-Galp(1→2)[β-d-Galp(1→6)]β-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.

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A new series of acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibitors were designed based on the structure of tacrine and synthesized in multicomponent Friedlander reaction between 2‐aminobenzonitrile and cycloalkanones. The synthesized tacrine analogs were characterized by spectral data and evaluated for acetylcholinesterase and butyryl cholinesterase inhibitory activity by following Ellman method. Compound 11 a and 11 g with piperazine containing acetamide and butyrylamide chains have shown equal potency to that of tacrine with IC50 values 0.71±0.04 and 1.01±0.03 μM, and 0.52±0.03 and 0.73±0.04 μM, against AChE and BuChE respectively when compared to standard tacrine with IC50 of 0.23±0.4 μM and 0.31±0.03, whereas rivastigmine showed 0.47±0.2 and 0.65±0.02 μM against AChE and BuChE, respectively. Also, some of the potent compounds were tested for liver toxicity and were found to be much safer than tacrine. Thus, these new tacrine analogs with five, six and seven membered ‘C’ rings have emerged as new cholinesterase inhibitors for further exploitation as anti‐Alzheimer's agents. Docking studies of all the molecules disclosed close hydrogen bond interactions within the binding site.

Background: Flavonoids encompasses flavones, isoflavones, flavanones and flavanols each possessing the benzopyranone ring system as the common structural feature, were identified as potent nonsteroidal aromatase inhibitors (NSAIs). Purpose: Azaflavones which were isosteric structural scaffolds of flavonoids were also proven to be potent NSAIs. In order to develop new NSAIs as cytotoxic agents for breast cancer, we designed some 6-bromo-2-substituted azaflavanones and azaflavone derivatives. Method: Azaflavones and Azaflavonones were synthesized by a reaction of 2-amino-6-bromoacetophenone and various aromatic aldehydes to result in different chalcones (4) using Claisen-Schmidt condensation. Further cyclization of chalcones (4), led to tetrahydroquinoline-4-ones (5) using orthophosphoric acid. In the final oxidative step, the desired dihydroquinoline-4ones (6) were obtained. Results: All the synthesized compounds were characterized by using IR, 1 H NMR and ESI-MS data and were evaluated for cytotoxic activity by using MTT assay on MCF-7 cell lines. Conclusion: Compounds with furoyl and pyridyl groups as substituents were found to be potent.

Aims and Objective: Alzheimer’s disease is now a most prevalent neuro degenerative disease of central nervous system leading to dementia in elderly aged population. Numerous pathological changes have been associated in the progression of Alzheimer’s disease. One of such pathological hypothesis is declined cholinergic activity which eventually affects cognitive and memory deficits. Inhibition cholinesterases will apparently elevate acetyl choline levels which is benefactor on cognitive symptoms of the disease. This manuscript describes the new tacrine derivatives tethered to isatin Schiff bases through alkanoyl linker and screened for cholinesterase inhibitory activity. Materials and Methods: Tacrine and two more cycloalkyl ring fused quinolones were synthesized and converted to Ncycloalkyl fused quinoline chloroamides. Isatin Schiff bases were also synthesized by the reaction between isatin and substituted aromatic anilines and in subsequent reaction, isatin Schiff bases were reacted with cycloalkyl fused quinolones to afford anticipated compounds 10a-i, 11a-i and 12a-i. All the compounds have been screened for acetyl and butyryl cholinesterase inhibitory activity and in vivo behavioral studies. Binding interactions of the desired compounds have also been studied by docking them in active site of both cholinesterases. Results: Three compounds 12d, 12e and 12h with propionyl and butyroyl linker between amine and isatin Schiff base scaffold have shown potent acetyl and butyryl cholinesterase inhibitory activity. However most potent cholinesterase inhibitor was 13d with IC50 value of 0.71±0.004 and 1.08±0.02 μM against acetyl and butyryl cholinesterases respectively. The hepatotoxicity of potent compounds revealed that the tested compounds were less hepatotoxic than tacrine and also exhibited encouraging in vivo behavioral studies in test animals. Docking studies of all the molecules disclosed close hydrogen bond interactions within the binding site of both cholinesterases. Conclusion: New cycloalkyl fused quinolones tethered with alkoyl linker to isatin Schiff bases endowed significant and potent cholinesterase inhibitory activities. Few of the compounds have also exhibited lesser hepatotoxicity and all the synthesized compounds were good in behavioral studies. Molecular docking studies also indicated close interactions in active site of cholinesterases.