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

Temperature response of sucrose palmitate solutions: Role of ratio between monoesters and diesters

HYPOTHESIS

Aqueous solutions of long-chain water-soluble sucrose ester surfactants exhibit non-trivial response to temperature variations, revealing a peak in viscosity around 40-50 °C. While previous investigations have explored the structures within sucrose stearate systems at various constant temperatures, a comprehensive understanding of the entire temperature dependence and the underlying molecular factors, contributing to this phenomenon is currently missing.

EXPERIMENTS

Temperature dependent properties and supramolecular structures formed in aqueous solutions of commercial sucrose palmitate were examined using SAXS/WAXS, DSC, optical microscopy, rheological measurements, NMR, and cryo-TEM.

FINDINGS

The underlying mechanism governing this unusual behavior is revealed and is shown to relate to the mono- to di-esters ratio in the solutions. Solutions primarily containing sucrose monoesters (monoesters molecules ≳ 98% of all surfactant molecules) exhibit behavior typical of nonionic surfactants, with minimal changes with temperature. In contrast, the coexistence of mono- and di-esters results in the formation of discrete monodisperse diester particles and a network of partially fused diester particles at low temperature. As the temperature approaches the diesters' melting point, wormlike mixed micelles form, causing a viscosity peak. The height of this peak increases significantly with the diester concentration. Further temperature increase leads to fluidization of surfactant tails and formation of branched micelles, while excess diester molecules phase separate into distinct droplets.

Phanerosides A-X, Phenylpropanoid Esters of Sucrose from the Rattans of Phanera championii Benth

Twenty-four new phenylpropanoid esters of sucrose, phanerosides A-X (1-24), were isolated from an EtOH extract of the rattans of Phanera championii Benth. (Fabaceae). Their structures were elucidated on the basis of comprehensive spectroscopic data analysis. A wide range of structural analogues were presented due to the different numbers and positions of acetyl substituents and the structures of phenylpropanoid moieties. Phenylpropanoid esters of sucrose were isolated from the Fabaceae family for the first time. Biologically, the inhibitory effects of compounds 6 and 21 on NO production in LPS-induced BV-2 microglial cells were better than that of the positive control, with IC₅₀ values of 6.7 and 5.2 μM, respectively. The antioxidant activity assay showed that compounds 5, 15, 17, and 24 displayed moderate DPPH radical scavenging activity, with IC₅₀ values ranging from 34.9 to 43.9 μM.

The useful biological properties of sucrose esters: Opportunities for the development of new functional foods

Sucrose esters have been deployed as surfactants in many food products since the 1950s. In addition to their useful physical characteristics, sucrose esters also have interesting biological properties that enhance their utility. This review critically examines the broad suite of biological activities that has been attributed to both synthetically-derived and naturally-occurring sucrose esters. These include insecticidal, molluscicidal, plant growth-regulating, anti-microbial, anti-tumor, anti-oxidant, anti-depressive, neuro-protective, anti-inflammatory and anti-plasmodial effects. In addition to providing a summary of the structure-activity profiles of sucrose esters, the various known mechanisms-of action of these compounds are also discussed. Furthermore, since sucrose esters are well-known surfactants, the potential to advantageously apply their industrially desirable physical characteristics in combination with their biological properties is considered. Recent advances in synthetic chemistry that have facilitated the deployment of biologically active sucrose esters as food additives are also described.

A review on the synthesis of bio-based surfactants using green chemistry principles

OBJECTIVES

With increasing awareness of the potential adverse impact of conventional surfactants on the environment and human health, there is mounting interest in the development of bio-based surfactants (which are deemed to be safer, more affordable, are in abundance, are biodegradable, biocompatible and possess scalability, mildness and performance in formulation) in personal care products.

METHOD

A comprehensive literature review around alkyl polyglucosides (APGs) and sucrose esters (SEs) as bio-based surfactants, through the lens of the 12 green chemistry principles was conducted. An overview of the use of bio-based surfactants in personal care products was also provided.

RESULTS

Bio-based surfactants are derived primarily from natural sources (i.e. both the head and tail molecular group). One of the more common types of bio-based surfactants are those with carbohydrate head groups, where alkyl polyglucosides (APGs) and sucrose esters (SEs) lead this sub-category. As global regulations and user mandate for sustainability and safety increase, evidence to further support these bio-based surfactants as alternatives to their petrochemical counterparts is advantageous. Use of the green chemistry framework is a suitable way to do this. While many of the discussed principles are enforced industrially, others have only yet been applied at a laboratory scale or are not apparent in literature.

CONCLUSION

Many of the principles of green chemistry are currently used in the synthesis of APGs and SEs. These and other bio-based surfactants should, therefore, be considered suitable and sustainable alternatives to conventional surfactants. To further encourage the use of these novel surfactants, industry must make an effort to implement and improve the use of the remaining principles at a commercial level.

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.