abstract:turmeric is a member of the ginger family (zingiberaceae), which is extensively used as a spice, food preservative and colouring material. curcumin is a main bioactive natural compound derived from the rhizome of this plant. curcumin can exist in several tautomeric forms, keto and enol. the keto form is more stable than enol form. silyl ethers have proven to be versatile substrates for...

The keto-enol type tautomerism in anti-thyroid drugs and their selenium analogues are described. The commonly used anti-thyroid drug methimazole exists predominantly in its thione form, whereas its selenium analogue exists in a zwitterionic form. To understand the effect of thione/thiol and selone/selenol tautomerism on the inhibition of peroxidase-catalysed reactions, we have synthesized some ...

The inversion of the keto-enol stability order of dialuric acid on ionization was calculated and verified experimentally. The radical cations in both forms were characterized. The spectrum of the keto form was observed upon direct ionization of dialuric acid under matrix conditions, whereas the enol form was formed upon a sequential electron-proton-proton attachment to alloxan under acidic aque...

Abstract:Turmeric is a member of the ginger family (Zingiberaceae), which is extensively used as a spice, food preservative and colouring material. Curcumin is a main bioactive natural compound derived from the rhizome of this plant. Curcumin can exist in several tautomeric forms, keto and enol. The keto form is more stable than enol form. Silyl ethers have proven to be versatile substrates for...

This paper is a density functional theory (DFT) calculation of intramolecular proton transfer (IPT) in 6-hydroxypicolinic acid (6HPA, 6-hydroxypyridine-2-carboxylic acid) tautomeric forms. The transition state for the enol-to-keto transition is reported in the gas phase and in four different solvents. The planar and non-planar dimer forms of 6HPA keto and enol, respectively, were also studied i...

The titular compound was characterized for the first time using a full range of spectroscopic methods, including UV, IR, 1H, and 13C NMR spectra. In solution, all methods showed keto–enol equilibrium strongly shifted to enol form. X-ray structures determined simple 2-oxosuccinates only form packed as hydrogen-bonded dimer stacks.