Synthesis, surfactant properties and antimicrobial activities of methyl glycopyranoside ethers

Recent advances in synthesis of carbohydrate-based surfactants: Comprehensive review and future perspective

This review aims to explore the rapid development of carbohydrate-based surfactants (CBS) as sustainable, biocompatible, and eco-friendly alternatives to conventional petrochemical-derived surfactants. It aims to assess how CBS, derived from renewable resources, are redefining the landscape of surfactant technologies in the context of increasing global demand for environmentally responsible materials. The review presents a comprehensive analysis of recent innovations in the synthesis of CBS, focusing on strategies that utilize abundant carbohydrate-rich feedstocks such as cellulose, pectin, hemicellulose, and starch. It discusses the physicochemical principles underlying CBS design and examines current synthesis approaches, structural modifications, and functional performance trends. The findings highlight that the unique amphiphilic nature of CBS facilitates the formation of stable emulsions, micelles, and other self-assembled systems critical for industrial and biomedical applications. These advances demonstrate CBS's growing utility and versatility and underscore their potential as green, multifunctional materials poised to play a significant role in future sustainable technologies. This review concisely delves into the most recent synthetic developments in carbohydrate-based surfactants (CBS), particularly emphasizing molecular design strategies that exploit the inherent structural diversity and functionality of renewable carbohydrate feedstocks and also highlights emerging structure-function paradigms and delineates future directions for scalable, bio-based surfactant design in industrial and biomedical sectors.

In Vitro Assessment of Immunobiological Effectivity of Synthetic Non-Ionic Glycolipids

Immunobiological activity of selected decyl and (thio)dodecyl hexopyranosides based on d-glucose, d-galactose, N-acetyl d-glucosamine and d-mannose and their effect on leukemia cell lines L1210 and HL-60 and Candida's biofilm were studied. Alkyl d-glucosides and d-galactosides showed mainly similar antiproliferative properties on leukemia cell lines, while N-acetyl d-glucosaminides revealed diverse properties with lower efficacy. Also, the cytokine response of RAW 264.7 macrophages was significantly influenced by the type of sugar moiety and (thio)alkyl chain length. Contrary to the proliferation results, d-glucosides and d-galactosides did not reveal so evident similarities in induction of cytokines. The C. albicans biofilm treatment with the (thio)alkyl glycosides resulted in a significant reduction of Candida cell proliferation resembling the structure and concentration differences of glycosides. The activity of tested derivatives (GalOC12 > GlcOC12 ≈ ManOC12 > GlcNAcOC12) against the C. albicans azole-sensitive clinical strain biofilm differ from the efficacy against C. albicans multiazole-resistant clinical strain biofilm (GlcOC12 > ManOC12 ≈ GalOC12 > GlcNAcOC12). The obtained data clearly demonstrated that the structure of saccharide unit caused different bioimmunological behaviour of such glycosides regardless of the same aglycone length.

Effect of methanol extract of Plectranthus esculentus N.E.Br tuber and its fractions on indices of benign prostatic hyperplasia in Wistar rats

ETHNOPHARMACOLOGICAL RELEVANCE

Many ethnopharmacological properties (anti-tumor, etc.) have been credited to Plectranthus esculentus tuber but the scientific basis has not been established.

AIM OF THE STUDY

To evaluate the effect of methanol extract of P. esculentus tuber (MEPET) (phase 1) and its fractions (phase 2) on benign prostatic hyperplasia (BPH) in rats.

MATERIALS AND METHODS

The study was conducted in two phases. Phase 1, thirty-five male albino rats (6 weeks old) were divided into seven groups of five rats each: normal control (NC) received olive oil (subcutaneously) and water (orally); disease control (DC) received testosterone propionate (TP) (3 mg/kg) and water; test groups (1,2,3 and 4) received TP + MEPET at 100, 200, 400, 600 mg/kg respectively; positive control, received TP + finasteride (5 mg/70 kg). After 28 days, their relative prostate weights (RPW) and prostate specific antigen (PSA) were determined. Phase 2, thirty rats were divided into 6 groups of 5 rats each: NC received olive oil (subcutaneously daily) and dimethyl sulfoxide (DMSO) (orally); DC received TP (3 mg/kg), and DMSO; test group 1 received TP and aqueous fraction of MEPET (400 mg/kg); test group 2 received TP and methanol fraction of MEPET (400 mg/kg); test group 3 received TP, and ethyl acetate fraction of MEPET (400 mg/kg); positive control received TP and finasteride (5 mg/70 kg). After 28 days, their erythrocyte sedimentation rates, RPW, prostate levels of PSA, DHT, inflammatory, apoptotic markers and prostate histology were determined.

RESULTS

Ethyl acetate fraction of MEPET modulated most of the parameters of BPH in the rats in a manner akin to finasteride as corroborated by prostate histology.

CONCLUSIONS

EFPET could be useful in the treatment of BPH.

Cytotoxicity and Antibacterial Efficacy of Betaine- and Choline-Substituted Polymers

Cationic charge has been widely used to increase polymer adsorption and flocculation of dispersions or to provide antimicrobial activity. In this work, cationization of hydroxyethyl cellulose (HEC) and polyvinyl alcohol (PVA) was achieved by covalently coupling betaine hydrochloride and choline chloride to the polymer backbones through carbonyl diimidazole (CDI) activation. Two approaches for activation were investigated. CDI in excess was used to activate the polymers' hydroxyls followed by carbonate formation with choline chloride, or CDI was used to activate betaine hydrochloride, followed by ester formation with the polymers' hydroxyls. The first approach led to a more significant cross-linking of PVA, but not of HEC, and the second approach successfully formed ester bonds. Cationic, nitrogen-bearing materials with varying degrees of substitution were obtained in moderate to high yields. These materials were analyzed by Fourier transform infrared spectroscopy, nuclear magnetic resonance, polyelectrolyte titration, and kaolin flocculation. Their dose-dependent effect on the growth of Staphylococcus aureus and Pseudomonas aeruginosa, and L929 mouse fibroblasts, was investigated. Significant differences were found between the choline- and betaine-containing polymers, and especially, the choline carbonate esters of HEC strongly inhibited the growth of S. aureus in vitro but were also cytotoxic to fibroblasts. Fibroblast cytotoxicity was also observed for betaine esters of PVA but not for those of HEC. The materials could potentially be used as antimicrobial agents for instance by coating surfaces, but more investigations into the interaction between cells and polysaccharides are necessary to clarify why and how bacterial and human cells are inhibited or killed by these derivatives, especially those containing choline.

Evaluation of surface active and antimicrobial properties of alkyl D-lyxosides and alkyl L-rhamnosides as green surfactants

The use of carbohydrates, as a part of surface-active compounds, has been studied due to their biodegradability and nontoxic profile. A series of alkyl glycosides containing d-lyxose and l-rhamnose with alkyl chains of 8-12 carbon atoms were investigated. The effects of structural variations on their physico-chemical and biological properties have been evaluated for a detailed understanding of their properties. Alkyl glycosides were tested on their toxicity against bacterial cells of the genus Pseudomonas (MTT assay), microbiological adhesion to hydrocarbons (MATH assay), cell surface hydrophobicity (Congo red assay), cell membrane permeability (crystal violet assay), and bacterial biofilm formation. Furthermore, their antifungal activity against two pathogenic microorganisms Candida albicans and Aspergillus niger was investigated using the disc diffusion method. Toxicological studies revealed that compounds could reduce the metabolic activity of bacterial cells only moderately but they increased the hydrophobicity of cell surface in Pseudomonas strains. In addition, alkyl glycosides changed the permeability of the cell membranes to the level of 30-40% for this strain. The compounds with an even number of carbon atoms in their alkyl chain promoted stronger bacterial biofilm formation on the glass surface. All studied derivatives demonstrated very strong antifungal activity against fungus A. niger but very small effect against C. albicans. Overall, the results showed that long-chain alkyl glycosides could be considered as inexpensive, biocompatible, nontoxic agents, and serve for the surface design to avoid bacterial adhesion as an alternative solution to antibiotic treatment.

Biobased Aldehydes from Fatty Epoxides through Thermal Cleavage of β-Hydroxy Hydroperoxides*

The ring-opening of epoxidized methyl oleate by aqueous H₂ O₂ has been studied using tungsten and molybdenum catalysts to form the corresponding fatty β-hydroxy hydroperoxides. It was found that tungstic acid and phosphotungstic acid gave the highest selectivities (92-93 %) towards the formation of the desired products, thus limiting the formation of the corresponding fatty 1,2-diols. The optimized conditions were applied to a range of fatty epoxides to give the corresponding fatty β-hydroxy hydroperoxides with 30-80 % isolated yields (8 examples). These species were fully characterized by ¹ H and ¹³ C NMR spectroscopy and HPLC-HRMS, and their stability was studied by differential scanning calorimetry. The thermal cleavage of the β-hydroxy hydroperoxide derived from methyl oleate was studied both in batch and flow conditions. It was found that the thermal cleavage in flow conditions gave the highest selectivity towards the formation of aldehydes with limited amounts of byproducts. The aldehydes were both formed with 68 % GC yield, and nonanal and methyl 9-oxononanoate were isolated with 57 and 55 % yield, respectively. Advantageously, the overall process does not require large excess of H₂ O₂ and only generates water as a byproduct.

Synthesis, Surface and Antimicrobial Activity of New Lactose-Based Surfactants

This work presents a synthesis method for new surfactants based on lactose. The compounds obtained belong to the homologous series of O-β-D-Galactopyranosyl-(1→4)-N-alkyl-(3-sulfopropyl)-D-glucosamine hydrochloride, containing 12 and 14 carbon atoms in the alkyl chain, and they may serve as an example of cationic surfactants. The newly synthesized compounds exhibit good surface properties, low value of CMC (Critical Micelle Concentration) and good wetting properties. These surfactants' ability to produce foam is considerably higher than in the commercial surfactants. Moreover, antibacterial and fungistatic activity was carried out by well diffusion assay against the selected bacteria (Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa), yeasts (Candida albicans) and filamentous fungi (Fusarium graminearum, F. avenaceum, F. oxysporum, F. culmorum, F. equiseti, Alternaria alternata and Botrytis cinerea). It was shown that the resulting quaternary salts significantly inhibit the growth of tested microorganisms. Antibacterial and fungistatic activity of the surfactant compounds varied depending on the species of bacteria or fungi. The results of antimicrobial activity of new lactose derivatives indicate that the compounds exhibit larger or similar antagonistic activity against tested bacteria and fungi than typical cationic surfactant cetylpyridinium chloride.

Biological impact of octyl d-glucopyranoside based surfactants

Development of many branches of industry has stimulated the search for new, effective surfactants with interesting properties. Potential use of alkyl glucose derivatives on a large scale, raises questions about the possible risks associated with their entry into the natural environment. To be able to evaluate this risk, the aim of the study was to determine the physicochemical properties of octyl d-glucopyranoside and its three derivatives: N-(octyl d-glucopyranosiduronyl)aspartic acid, N-(octyl d-glucopyranosiduronyl)glicyne and octyl d-glucopyranosiduronic acid. Moreover, their biodegradability by pure bacterial strains and biocenosis present in river water was examined. While descriptions of sugar-based surfactants on microbial cells are limited, the essential element of the study was to determine the effect of surfactants on cell surface properties of microorganisms isolated from activated sludge and compare it to the effects of the petroleum based surfactants and the surfactants produced from renewable materials. The results obtained indicate that physicochemical properties of surface active agents differ depending on the presence of functional groups in the surfactants molecules. What is more, the presence of amino acid substituent in the derivatives of octyl d-glucopyranoside resulted in a slight decrease in the surfactants biodegradation efficiency, in comparison to the compounds that did not contain such a substituent, prolonging this process from 5 to 10 days. Interestingly, even relatively slightly different derivatives modified the cell surface properties in a different way. Importantly, the surfactants based on octyl d-glucopyranoside have less negative impact on environmental microorganism and better biodegradability than the surfactant synthesized from petroleum products.

Design, synthesis, in silico and in vitro antimicrobial screenings of novel 1,2,4-triazoles carrying 1,2,3-triazole scaffold with lipophilic side chain tether

BACKGROUND

1,2,4-Triazoles and 1,2,3-triazoles have gained significant importance in medicinal chemistry.

RESULTS

This study describes a green, efficient and quick solvent free click synthesis of new 1,2,3-triazole-4,5-diesters carrying a lipophilic side chain via 1,3-dipolar cycloaddition of diethylacetylene dicarboxylate with different surfactant azides. Further structural modifications of the resulting 1,2,3-triazole diesters to their corresponding 1,2,4-triazole-3-thiones via multi-step synthesis has been also investigated. The structures of the newly designed triazoles have been elucidated based on their analytical and spectral data. These compounds were evaluated for their antimicrobial activities. Relative to the standard antimicrobial agents, derivatives of 1,2,3-triazole-bis-4-amino-1,2,4-triazole-3-thiones were the most potent antimicrobial agents with compound 7d demonstrating comparable antibacterial and antifungal activities against all tested microorganisms. Further, the selected compounds were studied for docking using the enzyme, Glucosamine-6-phosphate synthase.

CONCLUSIONS

The in silico study reveals that all the synthesized compounds had shown good binding energy toward the target protein ranging from - 10.49 to - 5.72 kJ mol-1 and have good affinity toward the active pocket, thus, they may be considered as good inhibitors of GlcN-6-P synthase.