Improved synthesis of sucrose fatty acid monoesters under ultrasonic irradiation

Sucrose monolaurate production from lauric acid through a two-stage process

This work represented the first step toward pioneering the use of a two-stage process for sucrose monolaurate (sucrose ester) production from lauric acid with high productivity and selectivity. In the first stage, lauric acid was firstly converted into methyl laurate via esterification, followed by the transesterification of methyl laurate into sucrose ester in the second stage. In this research, the first stage of process was primarily focused and thoroughly evaluated. Methyl laurate was continuously produced via lauric acid and methanol in a mini fixed-bed reactor. Amberlyst 15 was used as a catalyst. The operating variables were thoroughly investigated and optimized. The optimal condition to achieve 98 wt% yield (99% purity) was as follows: temperature of 110 °C, residence time of 5 min, and feed concentration of 94 g/L. High catalytic stability was observed over the time-on-stream of 30 h. This process provided good productivity compared to the other processes. The methyl laurate obtained from the first stage could be used as a raw material for the second stage to produce sucrose ester, which was demonstrated experimentally. The high selectivity of 95% of sucrose monolaurate was obtained. The continuous production of sucrose ester from lauric acid could be achieved.

Fast and selective synthesis of mono-substituted sucrose methacrylate ester monomer

Sucrose methacrylate (SM) is a key monomer for synthesizing biocompatible polymers with a carbohydrate core. However, controlled SM synthesis is challenging due to the possible formation of regio-isomers. This study describes SM synthesis that involves ultrasound irradiation of a homogeneous basic medium. The selectivity for mono-substituted SM was 86% within 30 min of reaction. The newly developed methodology is faster and more selective than that of mono-substituted SM synthesis already described in the literature.

Natural sucrose esters: Perspectives on the chemical and physiological use of an under investigated chemical class of compounds

The present review describes the chemistry and physiological properties of the sucrose esters (SEs) obtained from natural or synthetic pathways, with emphasis on those that have aliphatic and phenylpropanoid substituents on their sucrose moiety. Synthesis, extraction and characterization methods for the SEs and NSEs are discussed in terms of synthetic procedures, separation techniques and spectroscopic methods. The physiological properties are discussed taking into account the nature of the substituent groups and their regiochemistry (position and number of substitutions) on the sucrose moiety.

Sucrose fatty acid esters: synthesis, emulsifying capacities, biological activities and structure-property profiles

The notable physical and chemical properties of sucrose fatty acid esters have prompted their use in the chemical industry, especially as surfactants, since 1939. Recently, their now well-recognized value as nutraceuticals and as additives in cosmetics has significantly increased demand for ready access to them. As such a review of current methods for the preparation of sucrose fatty acid esters by both chemical and enzymatic means is warranted and is presented here together with an account of the historical development of these compounds as surfactants (emulsifiers). The somewhat belated recognition of the antimicrobial, anticancer and insecticidal activities of sucrose esters is also discussed along with a commentary on their structure-property profiles.

A new synthetic methodology for pyridinic sucrose esters and their antibacterial effects against Gram-positive and Gram-negative strains

Described are the development of a new synthetic method using ultrasonic irradiation and sodium methoxide as catalyst for a series of pyridinic sucrose esters (py-SEs), derived from transesterification of sucrose with picolinic, nicotinic and isonicotinic methyl esters. The reaction was optimized using a 3² x 2 experimental design, the reaction time, temperature and sucrose: methyl ester molar ratio being evaluated. The method proved to be efficient for obtaining monosubstituted esters (≥83%) with high methyl ester consumption (≥79%). The monosubstituted py-SEs were isolated by semipreparative HPLC, characterized by high-resolution mass spectrometry, calorimetry, vibrational spectroscopy, and ¹H and ¹³C NMR. The py-SEs were tested against E. coli, S. aureos, and P. aeruginosa bacteria with minimum inhibitory concentration values equal or inferior to the reference drugs for both E. coli and P. aeruginosa.

Super-swelling lignin-based biopolymer hydrogels for soil water retention from paper industry waste

Sources of pulping red liquor, which is produced by acidic sulfite cooking in paper industry, consisted of lignosulphonate and polysaccharide, commonly considered as waste or byproducts and used in low value, such as surfactant and adhesive are wide and its price is low. Here a novel method for high value-added utilization of the pulp and paper industry waste for fabricating super-swelling biopolymer hydrogels is introduced. In contrast to other costly utilizations, which are needed to separate red liquor or purify hemicellulose and lignin before using, it is first time to directly utilize red liquor to prepare hydrogels without pretreatment. FT-IR, SEM, TGA and XRD are used to determine structure and morphology of hydrogels. It is excited the hydrogels fabricated from acrylic (AA) and industry waste exhibit super-swelling and slow release behaviors in water. Compared with synthetic materials, the hydrogels are at low price to be chosen as candidates for water retention agent for agriculture.

Enzymatic Preparation of a Homologous Series of Long-Chain 6- O-Acylglucose Esters and Their Evaluation as Emulsifiers

Sugar fatty acid esters are nonionic surfactants that are widely exploited in the food and cosmetics industries, as well as in the oral care and medical supply fields. Accordingly, new methods for their selective synthesis and the "tuning" of their emulsifying properties are of considerable interest. Herein we report simple and irreversible enzymatic esterifications of d-glucose with seven fatty acid vinyl esters. The foaming and emulsifying effects of the resulting 6- O-acylglucose esters were then evaluated. In accord with expectations, when the length of the alkyl side chain associated with the 6- O-acylglucose esters increases, then their hydrophilic-lipophilic balance (HLB) values decrease, while the stabilities of the derived emulsions improve. In order to maintain good foaming properties, alkyl side chains of at least 9 to 11 carbons in length are required. In the first such assays on 6- O-acylglucose esters, most of those described herein are shown to be nontoxic to the HepG2, MCF-7, LNacp, SW549, and LO-2 cell lines.

Magnetic biocatalysts and their uses to obtain biodiesel and biosurfactants

Nanobiocatalysis, as the synergistic combination of nanotechnology and biocatalysis, is rapidly emerging as a new frontier of biotechnology. The use of immobilized enzymes in industrial applications often presents advantages over their soluble counterparts, mainly in view of stability, reusability and simpler operational processing. Because of their singular properties, such as biocompatibility, large and modifiable surface and easy recovery, iron oxide magnetic nanoparticles (MNPs) are attractive super-paramagnetic materials that serve as a support for enzyme immobilization and facilitate separations by applying an external magnetic field. Cross-linked enzyme aggregates (CLEAs) have several benefits in the context of industrial applications since they can be cheaply and easily prepared from unpurified enzyme extracts and show improved storage and operational stability against denaturation by heat and organic solvents. In this work, by using the aforementioned advantages of MNPs of magnetite and CLEAs, we prepared two robust magnetically-separable types of nanobiocatalysts by binding either soluble enzyme onto the surface of MNPs functionalized with amino groups or by cross-linking aggregates of enzyme among them and to MNPs to obtain magnetic CLEAs. For this purpose the lipase B of Candida antarctica (CALB) was used. The hydrolytic and biosynthetic activities of the resulting magnetic nanobiocatalysts were assessed in aqueous and organic media. Thus, the hydrolysis of triglycerides and the transesterification reactions to synthesize biodiesel and biosurfactants were studied using magnetic CLEAs of CALB. The efficiency and easy performance of this magnetic biocatalysis validates this proof of concept and sets the basis for the application of magnetic CLEAs at industrial scale.

NF-κB inhibitory activity of sucrose fatty acid esters and related constituents from Astragalus membranaceus

Twelve compounds, including six sucrose fatty acid esters (1-6), four galactosyl acylglycerols (7-10), and two sphingolipids (11 and 12), were isolated from the roots of Astragalus membranaceus . Their structures were identified on the basis of spectroscopic analysis. Among the isolated sucrose fatty acid esters, 6'-O-linoleyl sucrose (1) was identified as a new compound, and 6'-O-palmitoyl sucrose (2) and 6-O-palmitoyl sucrose (3) were isolated from nature for the first time. This is the first report on sucrose fatty acid ester components from A. membranaceus. The nuclear factor-κB (NF-κB) inhibitory activity of isolated compounds was measured in HepG2 cells stimulated with TNF-α using a luciferase reporter system. Among them, compounds 1-6 exhibited significant inhibition of NF-κB activation in a dose-dependent manner, with IC50 values ranging from 4.4 to 24.7 μM. Compounds 1-6 also exhibited inhibition of TNF-α-induced expression of iNOS and ICAM-1 mRNA and dose-dependent inhibition of iNOS promoter activity, with IC50 values ranging from 3.3 to 5.0 μM. These data demonstrate the potential of sucrose fatty acid esters from A. membranaceus to prevent and treat inflammatory diseases.