Antioxidant, Diabetic and Inflammatory Activities of Alpinia calcarata Roscoe Extract.

BACKGROUND: Alpinia calcarata (AC) Roscoe of Zingiberaceae popularly known as lesser galangal has a widespread occurrence in China, India, Sri-Lanka, Bangladesh, Malaysia, Indonesia and Thailand. Essential oil (Eoil) was obtained from leaves/rhizomes of AC via hydro-distillation process. METHODS: To identify chemical ingredients in oil from leaves/rhizomes of AC through GC/MS technique for volatile components and their anti-oxidant, inflammatory/diabetic activities. RESULTS: The 38 and 65 components were found to make up 99.9 and 99.6 %, respectively in total of Eoil composition of AC leaves/rhizomes. Key chemical constituents were eucalyptol (28.7 % in leaves; 25.4 % in rhizomes), camphor (12.8 % in leaves; 4.2 % in rhizomes), and carotol (9.8 % in leaves; 5.6 % in rhizomes) found in oil of AC leaves/rhizomes. Colorimetric assay showed anti-oxidant activities in leaves and rhizomes are IC50 =71.01±0.71 µg/mL and IC50 =73.83±0.49 µg/mL, respectively in the Eoils. Eoils had high anti-oxidant capabilities in IC50 -values of AC-L-Eoil=43.09±0.82&AC-Rh-Eoil=68.11±0.87 in reducing power in µg/mL was found. Albumin test of rhizome oil had IC50 -values of 15.19±0.25 µg/mL. Concentrations range of 7.81 µg/mL and 250 µg/mL in the Eoils of AC leaves and rhizome, respectively by α-glucosidase inhibition assay. CONCLUSION: Our findings demonstrated that leaf oil was slightly more promising results than rhizome oil of AC extract, which was ultimately showed medicinal potential of secondary metabolites with anti-oxidant, diabetic/inflammatory activities. Further, Eoils of AC have a wide range of pharmacological potential and promising anti-diabetic effects.

Ion-Solvation-Induced Molecular Reorganization in Liquid Water Probed by Resonant Inelastic Soft X-ray Scattering.

The molecular structure of liquid water is susceptible to changes upon admixture of salts due to ionic solvation, which provides the basis of many chemical and biochemical processes. Here we demonstrate how the local electronic structure of aqueous potassium chloride (KCl) solutions can be studied by resonant inelastic soft X-ray scattering (RIXS) to monitor the effects of the ion solvation on the hydrogen-bond (HB) network of liquid water. Significant changes in the oxygen K-edge emission spectra are observed with increasing KCl concentration. These changes can be attributed to modifications in the proton dynamics, caused by a specific coordination structure around the salt ions. Analysis of the spectator decay spectra reveals a spectral signature that could be characteristic of this structure.

Kinetic evidence for the influence of subsurface oxygen on palladium surfaces towards CO oxidation at high temperatures.

Transient state kinetics of the catalytic oxidation of CO with O(2) on Pd-surfaces has been measured under isothermal conditions by using a molecular beam approach. Systematic studies were carried out as a function of reaction temperature and CO+O(2) composition. With sufficient kinetic evidence, we have demonstrated the positive influence of subsurface oxygen towards CO-adsorption and oxidation to CO(2) at high temperatures (600-900 K) on Pd-surfaces, and the likely electronic nature of the surface changes with oxygen in the subsurface. These studies also provide a direct proof for CO-adsorption with a significantly reactive sticking coefficient at high temperatures on Pd-surfaces exhibiting a significant subsurface O-coverage.