Bleaching of cotton fabric with tetraacetylhydrazine as bleach activator for H2O2

Tetraacetylhydrazine (TH) as bleach activator for H₂O₂ cotton bleaching was synthesized and characterized by ¹H NMR, ¹³C NMR and MS spectra. TH has better solubility than that of TAED. The CIE whiteness index (WI), H₂O₂ decomposition rate and bursting strength were employed to investigate the performance of H₂O₂/TH bleaching system. By addition of TH, WI and H₂O₂ decomposition rate increased significantly at 70 °C. Bleaching temperature, NaHCO₃ concentration and bleaching time were also discussed in detail and the loss of bursting strength is not clear. By using benzenepentacarboxylic acid (BA) as a fluorescent probe for hydroxyl radical detection, the bleaching process of H₂O₂/TH system was investigated. Acetylhydrazine and diacetylhydrazine were also utilized to further confirm the process. In addition, bimolecular decomposition was investigated by using 9,10-dimethylanthracene (DMA) as fluorescent probe of ¹O₂. Based on these experimental results, the bleaching mechanism of H₂O₂/TH system was proposed.

Cytotoxic isovaleryl sucrose esters from Ainsliaea yunnanensis: reduction of mitochondrial membrane potential and increase of reactive oxygen species levels in A549 cells

Eight isovaleryl sucrose esters, named ainslosides A–H (1–8), were isolated from Ainsliaea yunnanensis Franch.

Thermotropic liquid crystalline glycolipids

Are the liquid crystalline properties of the materials of living systems important in biological structures, functions, diseases and treatments? There is a growing consciousness that the observed lyotropic, and often thermotropic liquid crystallinity, of many biological materials that possess key biological functionality might be more than curious coincidence. Rather, as the survival of living systems depends on the flexibility and reformability of structures, it seems more likely that it is the combination of softness and structure of the liquid-crystalline state that determines the functionality of biological materials. The richest sources of liquid crystals derived from living systems are found in cell membranes, of these glycolipids are a particularly important class of components. In this critical review, we will examine the relationship between chemical structure and the self-assembling and self-organising properties of glycolipids that ultimately lead to mesophase formation.