Current Organic Chemistry - Volume 18, Issue 23, 2014

The growing impact of environmental concerns of industrial processes carried out to the development of the socalled “Green Chemistry” approaches. By these technologies, the use of any hazardous substances within the synthesis of chemicals, nutraceuticals or therapeutics, is avoided, and considerable safety and biocompatibility advantages are raised. Among the different products prepared by Green Chemistry, high molecular weight antioxidants show remarkable appeal within the scientific community by virtue of their advantageous chemical and biological properties. These functional materials have been prepared by different synthetic strategies, classified in condensation methods, radical grafting and enzymatic catalysis. This review summarizes the chemical mechanisms of these strategies, and elucidates some of the most significant applications of the obtained products.

Lysophospholipids (LPLs), including glycerolysophospholipids and lysosphingolipids, constitute a group of important lipid mediators. What is more, dietary LPLs have a positive impact towards health, apparently without meaningful side effects. Since the total chemical synthesis of fully active, enantiomerically pure LPLs is a very complicated challenge, the present review is devoted to biotransformations based on the action of various phospholipases and lipases that additionally fully meet the green chemistry concept. We also discuss the benefficial effects of bioactive lysophospholipids, focusing on lysophosphatidic acid, lysophosphatidylcholine, lysophosphatidylglycerol, sphingosylphosphorylcholine, lysophosphatidylinositol, lysophosphatidylserine, lysophosphatidylethanolamine, cyclic phosphatidic acid, and sphingosine- 1-phosphate. Besides, we detail their structure, enzymatic routes of in vivo generation, the main routes of enzymatic digestion in the gut and isolation of phospholipids from natural sources with carbon dioxide supercritical extraction-based processes.

The “diseases of affluence” are defined as particular medical conditions determined by an increasing wealth in a society and to the consequent increase in life expectancy and change in lifestyle. Unhealthy dietary habits and additional risk factors (smoking, alcohol consumption, poor physical exercise) have been recognized as important triggering agents for the diseases of affluence. Increasing evidence linked a correct dietary intake to a clear reduction of the risk of developing most of these pathologies. Therefore a big effort is now concentrated on studying food from a functional (pharmaceutical) point of view together with the nutritional point of view leading to the raise of the “nutraceutical” science. Our laboratory has for many years focused its research on the functional properties of wheat sprout. The sprout is the functionally richest growth stage of wheat (and possibly of many other vegetables) and we previously demonstrated that an extract from wheat sprouts possess a large amount of antioxidant molecules and a consequently wide range of biological activities. In this mini review, we summarize the data obtained from our attempt to separate and characterize the molecular components of this extract. The characterization revealed two main classes of functional molecules: an hydrophilic peptidic fraction and moderately hydrophobic polyphenolic fractions. Both the classes exert a remarkable activity that explains the functional properties already demonstrated for the whole wheat sprout extract.

Prebiotics is an exciting concept in human nutrition and digestive function for which many physiological and health claims have already been made. There are only few oligosaccharides like inulin, trans galacto-oligosaccharides and lactulose which fulfil all the three strict criteria of prebiotics. The interest in the present prebiotic research has been to justify the health claims of new and unexplored experimental materials using these criteria for prebiotics. Most of the currently available prebiotics in the market are manufactured using chemical or synthetic approach. Synthetic oligosaccharides use chemical processing like isomerisation of lactose for lactulose, trans-galactosylation of lactose for trans-galactooligosaccharides and trans-fructosylation for production of oligofructose. Conversion of sucrose to fructose oligosaccharides is the frequently used method. The enzymes like β-glucosidases, β-galactosidases, β-fructosidase are used for hydrolysis of polysaccharides into oligosaccharides. Conversion of the normal starch to resistant nature is another approach for developing the prebiotics. Synthesis or sequential extractions of prebiotic involve processing of materials with various chemicals. The chemical waste materials of such processes are a big issue for disposal. Thus, use of current chemical approach for the oligosaccharide synthesis need to be reassessed and modified. This can be done using green chemistry approach maintaining the safety issues for health. There is a need of research for finding out better alternatives in production of prebiotics. Use of fruits and vegetables for multifunctional food supplements provides safe alternative for improving the health. Present paper attempts the critical review of reported studies on prebiotic development with an emphasis on green chemistry approaches.

β-Ketosulfones are an important class of oxygen-containing extremely versatile compounds in organic chemistry. They attract the interest of chemists due to their interesting biological properties and synthetic applications on natural products and organic compounds. In this review we summarise the methods of synthesis and also the reactivity of β- ketosulfones with the main focus on the position where the reaction takes place, including desulfonylation methodologies.

Investigation of polyol synthesis from rapeseed oil as a raw material, which is easily available in EU, is essential for the development of industrial biotechnology in order to meet green chemistry requirements and sustainability goals of polyurethane (PU) consumers. The objective of this research was to develop a green synthetic route for polyol production from rapeseed oil as it is yet a new research area without any definite methodology to follow. During this study, the two stage biopolyol synthesis was investigated: epoxidation and hydrolysis. The reaction parameters were determined for epoxidation process using commercially available enzyme - lipase Novozym 435 and in situ generated peracid from linoleic acid. Due to instability of the immobilization carrier of lipase Novozym 435, the hydrolysis reaction was explored by applying ion exchange resin, Amberlyst-15, with strongly acidic sulfonic group as a reusable catalyst. The obtained results conclusively demonstrated a sustainable chemo-enzymatic process for the synthesis of polyol from rapeseed oil.