Characterization of the interactions between coumarin-derivatives and acetylcholinesterase: Examination by NMR and docking simulations.

Alzheimer's disease (AD) is one of the most common forms of dementia and a significant threat to the elderly populations, especially in the Western world. The rapid hydrolysis of the principal neurotransmitter into choline and acetate by acetylcholinesterase (AChE) at synapses causes the loss of cognitive response that becomes the real cause of AD. Therefore, inhibition of AChE is the most fundamental therapy among currently available treatments for AD.

Crude to leads: a triple-pronged direct NMR approach in coordination with docking simulation.

The screening of compounds that bind to the target of interest (specific proteins) plays a vital role in drug discovery. Usually, the identification of biologically active compounds is done from a library of structurally known compounds. However, we successfully illustrate here, that NMR techniques including saturation transfer difference (STD), transfer nuclear Overhauser spectroscopy (TrNOESY) and STD-TOCSY (total correlation spectroscopy) in combination with separation methods not only enable the rapid and comprehensive screening of active components, but also their unequivocal structural characterization.

In vitro antituberculosis activities of the constituents isolated from Haloxylon salicornicum.

In vitro antituberculosis activities of fractions and pure compounds (1-20) including seven triterpenes, two alkaloids, two cycloheximide derivatives, two coumarins six sterol derivatives and a long chain alcohol, respectively, isolated from Haloxylon salicornicum were determined against Mycobacterium tuberculosis H37Rv. Actively growing cultures were tested by rapid colorimetric method while the stationary phase cultures were tested by drug exposure methods for bactericidal activity. The MIC values were found to be 50 microg/ml for compounds 15, 19 and 20 where as rest of the compounds invariably showed MIC value of 100 microg/ml against the logarithmic phase culture.

Bioactive aristolactams from Piper umbellatum.

Four alkaloids named piperumbellactams A-D (1-4) were isolated from branches of Piper umbellatum together with known N-hydroxyaristolam II (5), N-p-coumaroyl tyramine (6), 4-nerolidylcatechol (7), N-trans-feruloyltyramine, E-3-(3,4-dihydroxyphenyl)-N-2-[4-hydroxyphenylethyl]-2-propenamide, beta-amyrin, friedelin, apigenin 8-C-neohesperidoside, acacetin 6-C-beta-d-glucopyranoside, beta-sitosterol, its 3-O-beta-d-glucopyranoside and its 3-O-beta-d-[6'-dodecanoyl]-glucopyranoside. Glycosidase inhibition, antioxidant and antifungal activities of these compounds were evaluated. Compounds 1-3 showed moderate alpha-glucosidase enzyme inhibition with IC50 values 98.