One of the most powerful synthetic transformations with the ability to stereospecifically create new carbon-carbon bonds by simple orbital reorganization are electrocyclic reactions. One of the most recognized electrocyclic reactions is known as Nazarov cyclization. This reaction involves the conversion of divinyl ketones to cyclopentenones by activation with a Brønsted or Lewis acid. It was or...

Aluminium phthalocyanines substituted to different degrees with hydrophilic sulphonic acid and hydrophobic phthalimidomethyl groups were investigated in vivo as new agents for the photodynamic therapy of malignant tumours. Parameters studied included the photodynamic action on EMT-6 mammary tumours in BALB/c mice, the therapeutic window and the potential for direct cell killing, assayed via an ...

Proteins bearing the prosthetic group Fe protoporphyrin IX (or closely related groups) are now recognized to function in the transport of oxygen, in the catalytic activation of O~ and H~O~, and in the shuttling of electrons from dehydrogenases tQ the oxygen-activating enzymes. The structure of this prosthetic compound is a complex one. Attention in the past has been focused mainly on the import...

Chromic acid degradation of a d-urobilin, obtained after incubation of bilirubin in fecal bacterial cultures, gave methylvinylmaleimide and methylethylmaleimide. The d-urobilin, molecular weight 588, C(33)H(40)-N(4)O(6), clearly showed the presence of both vinyl and ethyl resonances in the nuclear magnetic resonance spectrum. These results point unambiguously to a urobilin structure with one vi...

Poly (vinyl alcohol) membranes were prepared by in-situ crosslinking of poly (vinyl alcohol) with glutaraldehyde as a crosslinking agent and hydrochloric acid as catalyst and the membranes were used to separate mixtures of IPA and water. Effects of feed composition, operating temperature, vacuum pressure and Reynolds number on permeation performance of the membranes were evaluated. The results ...

The kinetic parameters of ethylene combustion in the presence of acetic acid, i.e., during the synthesis of vinyl acetate and in the absence of acetic acid, have been measured in the temperature range 413–453 K over Pd supported on a high surface area SiO2 (600 m 2/g) at pressures ranging from 5.0 to 15.0 kPa of C2H4 and 1.0 to 10.0 kPa of O2. CO2 formation as a function of the partial pressure...

Thermo Gravimetric Analysis (TGA) analysis was employed to investigate activation energy (Ea) for the process of degrading of poly(o-toluidine) (POT) applying Horwitz & Metzger, Coats & Redfern and Chan et al., methods. POT was synthesized by chemical oxidative polymerization method using Ammonium per Sulphate (APS) as an oxidant while Dodecylbenzene Sulphonic Acid (DBSA) and sul...