Flexure parallel mechanism (FPM) possessing selective actuation (SA) feature can be used as a micropositioner. The design of SA FPMs consists of type synthesis of parallel mechanisms possessing the required number of degree of freedom (DOF), geometric arrangement of the structure to obtain the SA and conversion of the kinematic mechanism into the flexure mechanism. This paper focuses on the SA ...

Despite the ubiquitous use of phosphoramidite chemistry in the synthesis of biophosphates, catalytic asymmetric phosphoramidite transfer remains largely unexplored for phosphate ester synthesis. We have discovered that a tetrazole-functionalized peptide, in the presence of 10-Å molecular sieves, functions as an enantioselective catalyst for phosphite transfer. This chemistry in turn has been us...

The glucosidic precursor of marmelo lactones was synthesized by employing a common intermediate which had been used for the synthesis of the glucosidic precursor of marmelo oxides. The synthesis was performed by modifying the former procedure. Monochloroacetyl was adopted to protect both the glucose and aglycon hydroxyl groups for selective transesterification in the presence of the glycosyl es...

The enantioselective total synthesis of thapsigargin, a potent, selective inhibitor of the Ca2+ pump SERCA, is described. Starting from ketoalcohol 8, key steps involve regioselective introduction of the internal olefin at C4-C5, judicious protecting group choice to allow chelation-controlled reduction at C3, and chemoselective introduction of the angelate ester function at C3-O. A selective es...

As a continuous research for discovery of new COX-2 inhibitors, chemical synthesis, in vitro biological activity and molecular docking study of anew group of 1,4-dihydropyridine (DHP) derivatives were presented. Novel synthesized compounds possessing a COX-2 SO2Me pharmacophore at the para position of C-4 phenyl ring, different hydrophobic groups (R1) at C-2 position and alkoxycarbonyl groups (...

Sphingosine 1-phosphate (S1P) is involved in hyper-proliferative diseases such as cancer and pulmonary arterial hypertension. We have synthesized inhibitors that are selective for the two isoforms of sphingosine kinase (SK1 and SK2) that catalyze the synthesis of S1P. A thiourea adduct of sphinganine (F02) is selective for SK2 whereas the 1-deoxysphinganines 55-21 and 77-7 are selective for SK1...

Nitro compounds are an important class of organic molecules with broad application in synthesis, medicinal chemistry, and materials science. Among the variety methodologies available for their direct oxidation primary amines represents attractive alternative route. Efforts towards development oxidative procedures synthesis nitro derivatives have spanned over past decades, leading to a wide prot...

5,6-Dichloro-1-beta-D-ribofuranosylbenzimidazole (DRB) inhibits RNA synthesis in L-929 cells (mouse fibroblast line) and HeLa cells (human epitheloid carcinoma line) within 2 min of addition of the compound to the medium. By removing DRB from the medium, the inhibition is promptly and completely reversed after treatment of cells for as long as 1 h or even longer. The inhibitory effect of DRB on...