Giulia Ottavia Bianchetti

Detailed Chemical Composition of Condensed Tannins via Quantitative 31P NMR and HSQC Analyses: Acacia catechu, Schinopsis balansae, and Acacia mearnsii

The chemical composition of Acacia catechu, Schinopsis balansae, and Acacia mearnsii proanthocyanidins has been determined using a novel analytical approach that rests on the concerted use of quantitative (31)P NMR and two-dimensional heteronuclear NMR spectroscopy. This approach has offered significant detailed information regarding the structure and purity of these complex and often elusive proanthocyanidins. More specifically, rings A, B, and C of their flavan-3-ol units show well-defined and resolved absorbance regions in both the quantitative (31)P NMR and HSQC spectra. By integrating each of these regions in the (31)P NMR spectra, it is possible to identify the oxygenation patterns of the flavan-3-ol units. At the same time it is possible to acquire a fingerprint of the proanthocyanidin sample and evaluate its purity via the HSQC information. This analytical approach is suitable for both the purified natural product proanthocyanidins and their commercial analogues. Overall, this effort demonstrates the power of the concerted use of these two NMR techniques for the structural elucidation of natural products containing labile hydroxy protons and a carbon framework that can be traced out via HSQC.

Bleaching systems in domestic laundry detergents: a review

Laundry detergent is an indispensable commodity which is used by consumers worldwide. The global market for laundry detergents is in the region of

Process for manufacturing aqueous compositions comprising peracids

60.9 billion (2012, based on retail value), of which

Acidic limescale removal compositions

11.7 billion comes from Western Europe. Non-chlorine bleach was incorporated in a detergent for the first time just over a century ago and it remains an important component of detergents, particularly powder detergents. Detergent development is mainly carried out in industrial laboratories and, as a result, relatively few papers have been published in this area. The aim of this review is to compile this information, along with that contained in the patent literature and other sources, to give future researchers a more comprehensive overview of this important topic. Specifically, oxygen-based bleaching systems have been examined, with focus on their development through the years. Current research targets as described by the available literature are also discussed, such as the development of better bleaching species, alternative bleach systems, and steps to incorporate a bleaching system in liquid laundry detergents (a key development which continues to elude researchers).