Comment on "Autoionization at the surface of neat water: is the top layer pH neutral, basic, or acidic?" by R. Vácha, V. Buch, A. Milet, J. P. Devlin and P. Jungwirth, Phys. Chem. Chem. Phys., 2007, 9, 4736

The surface of near-neutral water is basic due to the adsorption of hydroxide ions, not acidic as has been recently claimed.     

A review of: “Instrumental HPTLC,by W. Bertsch,S. Hara,R. E. Kaiser,and A. Zlatkis,editors, H. Verlag,Heidelberg, West Germany, 1980, 390 pp., cloth bound.”

Abstract

To understand the retention mechanisms involved in reversed-phase micelle chromatography, two models were examined to study the temperature and micelle concentration contribution to the retention process. the first model described the temperature contribution, using the van's Hoff equation, for each of the three equilibria: micelle-to-extra-micelle-mobile-phase, extra-micellar-mobile-phase-to-stationary phase and micelle-to-stationary phase. the second model described the temperature contribution on k' irrespective of the various equilibria involved. It was found that the enthalpy of retention obtained with the second model decreased with increasing micelle concentration. This contradicted a primary assumption in the first model that the equilibrium constants were independent of micelle concentration. No relationship was found between the enthalpy of retention evaluated with either model and the polarity of the partitioned solute molecules. A correlation was found between the entropy of retention and the polarity of these molecules. Fluorescence studies indicated that the micelle solvated molecules were probably located in the core of the micelles which contained other mobile phase components such as 1-propanol and water.     

A New Cerebroside, Asperiamide A, from Marine Fungus Asperillus sp.

Cerebrosides and ceramides[1] have been isolated from a number of marine organisms such as sea stars, sea anemones, gorgonians, sponges, tunicates, dinoflagellates, and green algae. Some cerebroside and ceramides exhibited cytotoxic, antitumor,[2,3] immunostimulatory,[4] antifungal,[5] and antiviral[6] activites. In the search for bioactive components,two water soluble constituents, asperiamide A and adenosine, were isolated from the marine fungus Asperillus sp. The current report describes the structural elucidation of a new compound, aspefiamide A (1) and a known one, adenosine (2).     

Huperzine V, A New Lycopodium Alkaloid from Huperzia serrata

Huperzine V, a new Lycopodium alkaloid, was isolated from the whole plant of Huperzia serrata, and the absolute stereochemistry was determined by X-ray crystallographic analysis.