Self-assembly and antimicrobial activity of cationic gemini surfactants containing triazole moieties.

1,2,3-Triazole-based gemini bis-quaternary ammonium surfactants with varying hydrophobic chain length and ethylene or butylene spacers were synthesized and characterized. Their surface and aggregation properties were analyzed using tensiometry and conductimetry. The gemini surfactants showed significantly lower CMC values compared to their single-tail counterparts and conventional gemini surfactants described in the literature. The micellization and surface adsorption processes in water can be tailored according to the hydrophobic chain and the spacer length and were substantially improved by the presence of the heterocycle. These surfactants are active against various Gram-positive and Gram-negative bacterial stains, as well as fungi. The gemini surfactant with tetradecyl chain and ethylene spacer (Bis 14-2-14) exhibited the highest activity against all investigated microbial strains.

Biodegradable Poly(Butylene Succinate) Nanocomposites Based on Dimeric Surfactant Organomodified Clays with Enhanced Water Vapor Barrier and Mechanical Properties.

Biocomposites based on biodegradable polybutylene succinate (PBS) and organomodified clays (OMt) were prepared by melt blending process. The OMt nanofillers were obtained by ion exchange reaction between sodium montmorillonite (Mt) and gemini surfactants bearing 4-decyloxyphenylacetamide hydrophobic chains and ethylene or hexylene spacer. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and rheological measurement results showed that the investigated hybrids present a uniform dispersion with an exfoliation of clay into the PBS matrix, particularly for short spacer surfactant based composites. The effect of organoclay loading and composition on the thermal, mechanical, and barrier properties was also investigated. High clay loading and long gemini surfactant spacer lead to substantial improvement of Young modulus values by 21%, while low clay content induces a reduction of the hybrid's crystallinity due to strong OMt-PBS interactions. Compared to that of the neat PBS film, a significant reduction of the water vapor permeability (WVP) by 28% was obtained by adding only 3 wt % of PBS/OMt (2) which opens up prospects for this material in the field of food packaging. This study shows that gemini surfactant-modified organoclays can be used as effective nanofillers in a PBS matrix to access to value-added nanocomposites.

Polylactic acid/Gemini surfactant modified clay bio-nanocomposites: Morphological, thermal, mechanical and barrier properties.

To improve PLA's properties and overcome its drawbacks such us poor thermal stability, resistance and gas barrier properties, several studies have been performed using different nanofillers. In this work, PLA nanocomposites reinforced by three organoclays, OMt(8-4-8), OMt(10-4-10) and OMt(12-4-12) at various weight percentages (1 and 3 wt%) were prepared by melt mixing using a twin-screw extruder. The organoclays were obtained from sodium montmorillionite and gemini surfactants bearing different hydrophobic chain lengths. The resulting nanocomposites have been characterized in terms of composition and morphology by X-ray diffraction analysis (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The thermal stability and cold crystallization behavior were accessed by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The effect of clay composition and concentration on the mechanical and rheological properties of the nanocomposites as well as their water vapor permeability has been also investigated. The resulting nanocomposites exhibit a significantly reduced permeability as compared to unfilled PLA and an improved young modulus and toughness at the detriment of ductility.

Modulation of metabolic alterations of obese diabetic rats upon treatment with Salacca zalacca fruits extract using 1H NMR-based metabolomics.

Fruit of salak (Salacca zalacca) is traditionally used and commercialized as an antidiabetic agent. However, the scientific evidence to prove this traditional use is lacking. This research was aimed to evaluate the metabolic changes of obese-diabetic (OBDC) rats treated with S. zalacca fruit extract using proton-nuclear magnetic resonance (1H NMR)-based metabolomics approach. This research presents the first report on the in vitro antidiabetic effect of S. zalacca fruits extract using this approach. The obtained results indicated that the administration of 400 mg/kg bw of 60% ethanolic S. zalacca extract for 6 weeks significantly decreased the blood glucose level and normalized the blood lipid profile of the OBDC rats. The potential biomarkers in urine were 2-oxoglutarate, alanine, leucine, succinate 3-hydroxybutyrate, taurine, betaine, allantoin, acetate, dimethylamine, creatine, creatinine, glucose, phenyl-acetylglycine, and hippurate. Based on the data obtained, the 60% ethanolic extract could not fully improved the metabolic complications of diabetic rats. The extract of S. zalacca fruit was able to decrease the ketones bodies as 3-hydroxybutyrate and acetoacetate. It also improved energy metabolism, involving glucose, acetate, lactate, 2-hydroxybutyrate, 2-oxoglutarate, citrate, and succinate. Moreover, it decreased metabolites from gut microflora, including choline. This extract had significant effect on amino acid metabolism, metabolites from gut microflora, bile acid metabolism and creatine. The result can further support the traditional claims of S. zalacca fruits in management of diabetes. This finding might be valuable in understanding the molecular mechanism and pharmacological properties of this medicinal plant for managing diabetes mellitus.

Correlation of FT-IR Fingerprint and α-Glucosidase Inhibitory Activity of Salak (Salacca zalacca) Fruit Extracts Utilizing Orthogonal Partial Least Square.

Salak fruit (Salacca zalacca), commonly known as snake fruit, is used indigenously as food and for medicinal applications in Southeast Asia. This study was conducted to evaluate the α-glucosidase inhibitory activity of salak fruit extracts in correlation to its Fourier transform infrared spectroscopy (FT-IR) fingerprint, utilizing orthogonal partial least square. This calibration model was applied to develop a rapid analytical method tool for quality control of this fruit. A total of 36 extracts prepared with different solvent ratios of ethanol⁻water (100, 80, 60, 40.20, 0% v/v) and their α-glucosidase inhibitory activities determined. The FT-IR spectra of ethanol⁻water extracts measured in the region of 400 and 4000 cm−1 at a resolution of 4 cm−1. Multivariate analysis with a combination of orthogonal partial least-squares (OPLS) algorithm was used to correlate the bioactivity of the samples with the FT-IR spectral data. The OPLS biplot model identified several functional groups (C⁻H, C=O, C⁻N, N⁻H, C⁻O, and C=C) which actively induced α-glucosidase inhibitory activity.

Investigation of structure-surface properties relationship of semi-fluorinated polymerizable cationic surfactants.

Novel hybrid hydrocarbon/fluorocarbon ammonium type surfactant monomers (surfmers) of the general formula RF (CH2)l N(CH3)2(CH2)mOCOCH=CH2 with (RF=C4F9, C6F13, C8F17, l=4, 6, 11, and m=2-11) were synthesized and characterized. They exhibit very low surface tension as well as low critical micellar concentrations down to 1.39×10(-5)mol/L. Special attention was focused on theeffect of the polymerizable moiety, the length of the hydrocarbon spacers, and the fluorinated chains on surface activities of the reactive surfactants as compared to hydrocarbon surfmer analogs. Results indicate that the acrylic function has a pronounced effect on increasing the hydrophobic micelle character. This was confirmed by surface tensions and average surfaces occupied by these molecules at the water-gas interface. The micellar sizes were investigated by dynamic light scattering.