Synthesis of benzothiadiazine derivatives exhibiting dual activity as aldose reductase inhibitors and antioxidant agents.

Several multifunctional benzothiadiazine derivatives were synthesized and examined for their inhibition to the enzyme aldose reductase and in vitro antioxidant activity to identify novel drugs for diabetes and its complications. Most of them exhibited good inhibitory activity. Importantly, a number of compounds demonstrated strong antioxidant activity and one compound in particular was extremely active in the DPPH radical scavenging and MDA inhibition analysis.

Pyridothiadiazine derivatives as aldose reductase inhibitors having antioxidant activity.

A series of aldose reductase (ALR2) inhibitors based on pyridothiadiazine were prepared and evaluated for their activities in ALR2 inhibition, DPPH scavenging, and MDA inhibition. Comparison studies were carried out between analogs having either hydroxyl or methoxy groups substituted on the N2-benzyl side chains of the compounds. Most of the hydroxy-substituted compounds were found to be more potent compared to their methoxy-substituted analogs with respect to DPPH inhibition (>93%) and MDA inhibition (>73%).

Design and synthesis of potent and multifunctional aldose reductase inhibitors based on quinoxalinones.

Quinoxalin-2(1H)-one based design and synthesis produced several series of aldose reductase (ALR2) inhibitor candidates. In particular, phenolic structure was installed in the compounds for the combination of antioxidant activity and strengthening the ability to fight against diabetic complications. Most of the series 6 showed potent and selective effects on ALR2 inhibition with IC50 values in the range of 0.

2-[(E)-1,1-Dioxo-2-(2,4,5-tri-fluoro-benz-yl)-3,4-di-hydro-2H-1,2-benzo-thia-zin-4-yl-idene]acetic acid.

In the asymmetric unit of the title compound, C17H12F3NO4S, there are two conformationally similar mol-ecules in which the heterocyclic thia-zine ring adopts a half-chair conformation, with the dihedral angle between the two benzene rings being 24.84 (8) and 37.42 (8)°.

2-[(Z)-1,1-Dioxo-2-(2,4,5-tri-fluoro-benz-yl)-3,4-di-hydro-2H-1,2-benzo-thia-zin-4-yl-idene]acetic acid.

In the title compound, C17H12F3NO4S, the heterocyclic thia-zine ring adopts a half-chair conformation and the dihedral angle between the benzene rings is 43.28 (9)°. The α,β-unsaturated C=C group is inclined at an angle of 21.

Structure-activity relationships studies of quinoxalinone derivatives as aldose reductase inhibitors.

Novel quinoxalinone derivatives were synthesized and tested for their inhibitory activity against aldose reductase. Among them, N1-acetate derivatives had significant activity in a range of IC50 values from low micromolar to submicromolar, and compound 15a bearing a C3-phenethyl side chain was identified as the most potent inhibitor with an IC50 value of 0.143 μM.

Copper-catalyzed asymmetric synthesis and comparative aldose reductase inhibition activity of (+)/(-)-1,2-benzothiazine-1,1-dioxide acetic acid derivatives.

A copper catalyst system for the asymmetric 1,4-hydrosilylation of the α,β-unsaturated carboxylate class was developed by which synthesis of (+)- and (-)-enantiomers of 1,2-benzothiazine-1,1-dioxide acetates has been achieved with a good yield and an excellent level of enantioselectivity. A comparative structure-activity relationship study yielded the following order of aldose reductase inhibition activity: (-)-enantiomers > racemic > (+)-enantiomers. Further, a molecular docking study suggested that the (-)-enantiomer had significant binding affinity and thus increased inhibition activity.