Homogeneous HA/HC Polysaccharides Hyaluronan (HA) and chondroitin (CH) are two important Glycosaminoglycans that widely exist on the cell surface and in the extracellular matrix. They are able to interact with cytokines, cell adhesion molecules, selectins and enzymes to regulate intracellular signaling pathways [1]. Also, they have various applications in pharmaceuticals...

The Mitsunobu reaction uses triphenylphosphine (PPh3) and diethyl azodicarboxylate (DEAD) to convert a 1° or 2° alcohol into a wide variety of final products, dependent on the mildly acidic nucleophile (H-Nuc) used. H-Nuc transfers its proton to the zwitterionic adduct formed from PPh3 attacking the DEAD. The resulting phosphonium intermediate...

Negishi cross coupling The use of organozinc reagents in the Negishi (Pd- or Ni-catalyzed) cross-coupling reaction with organohalides allows for a much greater functional group tolerance than in the Kumada cross-coupling reaction. Other benefits include high reactivity, high regio- and stereoselectivity, few side reactions and little toxicity. Unlike the addition...

Perkin Reaction Generating α,β-unsaturated carboxylic acids (cinnamic acid derivatives) in the presence of a weak base from aromatic aldehydes with the anhydrides of aliphatic carboxylic acids is known as the Perkin reaction. An enolate intermediate is made from the anhydride, which undergoes a condensation reaction with benzaldehyde, followed by an...

NU7441 (KU-57788) as NHEJ Inhibitors Biological Activity NU7441 selectively inhibits DNA-dependent protein kinase (DNA-PK), a DNA repair enzyme that catalyzes NHEJ, required to repair lethal DSBs. It exhibits ATP-competitive inhibition kinetics, reducing the frequency of NHEJ while increasing the rate of HDR. [1] Target (in cell-free assays)  IC50[ 1 ]...

AZT as HDR Inhibitors Biological Activity Approved by the FDA in 1987,[1] and still used in combination treatment, azidothymidine (AZT) is a thymidine (nucleoside) analogue that is phosphorylated in the host (by enzymes of the thymidine-phosphorylation pathway) to AZT-triphosphate, which inhibits viral (HIV-1) reverse transcriptase activity about 100-fold better than...