Optimized Single-Step Recovery of Lipophilic and Hydrophilic Compounds from Raspberry, Strawberry and Blackberry Pomaces Using a Simultaneous Ultrasound-Enzyme-Assisted Extraction (UEAE).

An ultrasound-enzyme-assisted extraction (UEAE) was optimized to extract, simultaneously, the hydrophilic and lipophilic compounds from three berry pomaces (raspberry, strawberry and blackberry). First, an enzyme screening designated a thermostable alkaline protease as the most suitable enzyme to recover, in an aqueous medium, the highest yields of polyphenols and oil in the most efficient way. Secondly, the selected enzyme was coupled to ultrasounds (US) in sequential and simultaneous combinations. The simultaneous US-alkaline enzyme combination was selected as a one-single-step process and was then optimized by definitive screening design (DSD). The optimized parameters were: US amplitude, 20% (raspberry pomace) or 70% (strawberry and blackberry pomaces); pH, 8; E/S ratio, 1% (w/w); S/L ratio, 6% (w/v); extraction time, 30 min; temperature, 60 °C. Compared to conventional extractions using organic solvents, the UEAE extracted all the polyphenols, with around 75% of the active polyphenols (measured by the DPPH● method) and up to 75% of the initial oil from the berry pomaces. Characterized lipophilic compounds were rich in polyunsaturated fatty acids (PUFAs), tocols and phytosterols. The polyphenolics were analyzed by UPLC-MS/MS; characteristic ellagitannins of the Rosaceae family (sanguiin H-6 or agrimoniin, sanguiin H-10, …) and ellagic acid conjugates were found as the major components.

Multi-Criteria Optimization including Environmental Impacts of a Microwave-Assisted Extraction of Polyphenols and Comparison with an Ultrasound-Assisted Extraction Process.

Valorization of wastes and by-products using environmentally friendly technologies with an optimal cost-benefit relationship is a current major issue in agri-food industries. An original tool was recently developed for multi-criteria optimization of an ultrasound-assisted extraction (UAE) process including the assessment of environmental impacts using Life Cycle Assessment. In the present work, this methodology was adapted and applied to another green extraction process, microwave-assisted extraction (MAE), with the same case study, valorization of antioxidant polyphenols from downgraded beet seeds. Once built, the obtained multi-criteria optimization tool was used to investigate performances of the MAE process regarding productivity criteria (polyphenol concentration and antioxidant activity of the extracts), energy consumption and environmental impacts as functions of operating parameters (time, solvent composition, microwave power density, and liquid-solid ratio). The MAE process was optimized under different constraints and compared to the UAE process. For the studied conditions and different investigated scenarios, MAE enabled obtaining extracts with higher polyphenol concentrations and antioxidant activity (approximately 33% and 23% enhancements, respectively), and to strongly reduce extraction duration (by a factor up to 6), whereas UAE enabled reducing the energy consumption (up to 3.6 fold) and the environmental impacts (up to 12% for climate change).

Composition of Guayule (Parthenium argentatum Gray) resin.

Guayule (Parthenium argentatum Gray) is a semi-arid shrub, native from the Chihuahan desert. This plant produces polyisoprene and resin. Polyisoprene is the main focal point of many researches, from structure to properties. Today, some processes are used to extract polyisoprene under its dry form, using solvent extraction, to produce rubber (used in truck or airplane tires) or as an emulsion, to make latex products by dipping (used in medical gloves, condoms, etc.). This article focuses on guayule resin which has some interesting applications in adhesives, coatings, pharmaceuticals, etc. In order to better know the resin composition and to be able to perform comparisons between varieties or seasons, liquid and gas chromatographic analysis methods have been described, for the groups of molecules composing the resin (polyphenols, guayulins, free fatty acids, di and triacylglycerols, argentatins, alkanes, alkanals, sugars, organic acids). Unlike other articles, this study aims to analyze all components of the same resin; the average composition of a guayule resin is given.

Solvent-Free Microwave Extraction of Thymus mastichina Essential Oil: Influence on Their Chemical Composition and on the Antioxidant and Antimicrobial Activities.

Solvent-free microwave extraction (SFME) is a combination of microwave heating and dry distillation performed at atmospheric pressure without the addition of water or organic solvents that has been proposed as a green method for the extraction of essential oils from aromatic and medicinal herbs. In this work, SFME and the conventional techniques of steam distillation (SD) and hydrodistillation (HD) were compared with respect to the extraction and antioxidant and antimicrobial activities of Thymus mastichina essential oil. The main constituent of essential oils obtained using different methods was 1,8-cineole (eucalyptol). The results showed that the essential oils extracted by means of SFME in 30 min were quantitatively (yield) and qualitatively (aromatic profile) similar to those obtained using conventional HD over 120 min. In addition, SFME generates less waste and less solvent, consumes less energy, and provides a higher yield for a shorter extraction time, which is advantageous for the extraction of the T. mastichina essential oil compared to SD. The antioxidant and antimicrobial activities of the T. mastichina essential oil obtained from either SFME or conventional extraction methods (SD or HD) showed a similar pattern. Large-scale experiments using this SFME procedure showed a potential industrial application.

Guayule (Parthenium argentatum A. Gray), a Renewable Resource for Natural Polyisoprene and Resin: Composition, Processes and Applications.

Natural rubber is an essential material, especially for plane and truck tyres but also for medical gloves. Asia ranks first in the production of natural rubber, of which the Hevea tree is currently the sole source. However, it is anticipated that this source alone will not be able to fulfill the growing demand. Guayule, a shrub native to northern Mexico and southern United States, may also contribute. This plant not only contains polyisoprene, but also resin, a mixture of lipids and terpenoids. This review summarizes various aspects of this plant, from the usage history, botanical description, geographical distribution and cultivation practices, down to polyisoprene and resin biosynthesis including their distribution within the plant and molecular composition. Finally, the main processes yielding dry rubber or latex are depicted, as well as the properties of the various extracts along with economic considerations. The aim is to provide a wide picture of current knowledge available about this promising crop, a good feedstock candidate for a multiple-product biorefinery.

Review of Alternative Solvents for Green Extraction of Food and Natural Products: Panorama, Principles, Applications and Prospects.

In recent years, almost all extraction processes in the perfume, cosmetic, pharmaceutical, food ingredients, nutraceuticals, biofuel and fine chemical industries rely massively on solvents, the majority of which have petroleum origins. The intricate processing steps involved in the industrial extraction cycle makes it increasingly difficult to predict the overall environmental impact; despite the tremendous energy consumption and the substantial usage of solvents, often the yields are indicated in decimals. The ideal alternative solvents suitable for green extraction should have high solvency, high flash points with low toxicity and low environmental impacts, be easily biodegradable, obtained from renewable (non-petrochemical) resources at a reasonable price and should be easy to recycle without any deleterious effect to the environment. Finding the perfect solvent that meets all the aforementioned requirements is a challenging task, thus the decision for the optimum solvent will always be a compromise depending on the process, the plant and the target molecules. The objective of this comprehensive review is to furnish a vivid picture of current knowledge on alternative, green solvents used in laboratories and industries alike for the extraction of natural products focusing on original methods, innovation, protocols, and development of safe products.

Downscaling of Industrial Turbo-Distillation to Laboratory Turbo-Clevenger for Extraction of Essential Oils. Application of Concepts of Green Analytical Chemistry.

In the effort of innovation towards green analytical chemistry concepts and considering the six principles of green extraction, the industrial turbodistillation process was downscaled into a laboratory apparatus turbo-Clevenger (TC) for the extraction of essential oils. Turbodistillation is used as an industrial purpose for the extraction of essential oils from hard matrixes such as wood, barks, seeds. In this work, a TC and the conventional technique of hydrodistillation (HD, Clevenger apparatus) are used for the extraction of essential oils from three spices with hard structures (Illicium verum, Schinus terebinthifolius, and Cinnamomum cassia) and are compared. This study shows that the essential oils extracted by TC in 30 min were quantitatively (yield and kinetics profile) and qualitatively (aromatic profile) similar to those obtained using conventional hydrodistillation in 3 h. This process, which gave a reduced extraction time, was perfectly adapted to the extraction of hard matrixes.

Laboratory to pilot scale: Microwave extraction for polyphenols lettuce.

Microwave hydrodiffusion and gravity (MHG) technique has been applied to pilot-scale solvent-free microwave extraction (SFME) of polyphenols from Lettuce sativa. Following the dictates of green extraction and with the aim to save time and energy, the lab-scale knowledge on SFME was exploited for the development of a pilot-scale process. The investigation entailed the optimization of all main parameters (temperature, time, extracted water volume, etc.) and we showed that the polyphenols composition profile under SFME was similar to the classic methods though a bit lower in total content. The energy consumption in the optimized procedure (30min) was 1W/g of fresh matrix.

Simultaneous microwave extraction and separation of volatile and non-volatile organic compounds of boldo leaves. From lab to industrial scale.

Microwave extraction and separation has been used to increase the concentration of the extract compared to the conventional method with the same solid/liquid ratio, reducing extraction time and separate at the same time Volatile Organic Compounds (VOC) from non-Volatile Organic Compounds (NVOC) of boldo leaves. As preliminary study, a response surface method has been used to optimize the extraction of soluble material and the separation of VOC from the plant in laboratory scale. The results from the statistical analysis revealed that the optimized conditions were: microwave power 200 W, extraction time 56 min and solid liquid ratio of 7.5% of plants in water. Lab scale optimized microwave method is compared to conventional distillation, and requires a power/mass ratio of 0.4 W/g of water engaged. This power/mass ratio is kept in order to upscale from lab to pilot plant.

Portable microwave assisted extraction: An original concept for green analytical chemistry.

This paper describes a portable microwave assisted extraction apparatus (PMAE) for extraction of bioactive compounds especially essential oils and aromas directly in a crop or in a forest. The developed procedure, based on the concept of green analytical chemistry, is appropriate to obtain direct in-field information about the level of essential oils in natural samples and to illustrate green chemical lesson and research. The efficiency of this experiment was validated for the extraction of essential oil of rosemary directly in a crop and allows obtaining a quantitative information on the content of essential oil, which was similar to that obtained by conventional methods in the laboratory.

Preliminary biological evaluations of new thalidomide analogues for multiple sclerosis application.

The present work deals with the synthesis of a new series of thalidomide derivatives for therapeutic applications. These compounds were evaluated in vitro on a human endothelial cell line EA.hy926 for their antiproliferative potential and in vivo on an experimental animal multiple sclerosis model called EAE as angiogenesis inhibitors. The preliminary results obtained on EAE assays seem to validate that anti-angiogenesis compounds could be promising tools for the treatment of MS.

New tensio-active molecules stabilize a human G protein-coupled receptor in solution.

Structural characterization of membrane proteins is hampered by the instability of the isolated proteins in detergent solutions. Here, we describe a new class of phospholipid-like surfactants that stabilize the G protein-coupled receptor, BLT1. These compounds, called C(13)U(9), C(13)U(19), C(15)U(25) and C(17)U(16), were synthesized by radical polymerization of Tris(hydroxymethyl) acrylamidomethane in the presence of thioglycerol, first endowed with two hydrocarbon chains with variable lengths (13-17 carbon atoms), as transfer reagent. C(13)U(19), C(17)U(16) or C(15)U(25) significantly enhanced the stability of BLT1 in solution compared to what was obtained with common detergents. These molecules therefore represent a promising step towards the structural characterization of BLT1 and possibly other membrane proteins.

Design, synthesis and preliminary biological evaluations of novel amphiphilic drug carriers.

The synthesis of a new fluorocarbon amphiphilic drug carrier is described. A polyfunctional amino acid endowed with a fluorocarbon chain and a sugar moiety providing the amphiphilic character constitutes the central element of this structure. A (14)C-radiolabelled acetyl group was grafted onto the third function and the bioavailability of this molecule was specified in mice after IV administration. This amphiphilic drug carrier exhibits a rapid and homogeneous distribution to the whole tissues and slow elimination half-lives (higher than one day) through a biliary excretion without any toxicity (no measured DL 50 for concentrations up to 500 mg/kg).

Inhibition of angiogenesis by THAM-derived cotelomers endowed with thalidomide moieties.

The synthesis of a tris(hydroxymethyl)acrylamidomethane (THAM)-derived cotelomer endowed with thalidomide units and a preliminary assessment of its biological activity are described. 4-Carboxy thalidomide and 4-(N-acryloyl) lysine thalidomide derivatives were prepared. The polymerization of these compounds with THAM in the presence of octanethiol as transfer reagent provided a water-soluble telomer bearing several thalidomide units. The ability of this telomer to inhibit angiogenesis in a mouse model of corneal neovascularization was compared to 4-carboxy thalidomide and thalidomide. A significant inhibition in area of neovascularization stimulated by a bFGF pellet was observed only in the mice treated with the telomer.