Unique phase behaviour and self-assembly of a lysine derivative, Fmoc-homoarginine, in water-DMSO mixtures.

Ternary solutions of an amino acid derivative, Fmoc-homoarginine (Fmoc-hArg), dimethylsulfoxide (DMSO), and water exhibit unique phase behaviour. Fmoc-hArg is dissolved in DMSO to provide a clear solution, but the solution becomes turbid after aging (turn-over phase separation). The turbid DMSO solution of Fmoc-hArg becomes clear by addition of water at a volume fraction of water in the DMSO-water mixture from 0.2 to 0.4, and turbid again at . Concentrated-phase droplets in the turbid solutions at act as centers of spherulite and needle-like crystal formation. This unique phase behaviour is explained theoretically on the basis of the competition between the micellization and phase separation and the Flory-Huggins theory.

Effects of Free Linoleic Acid and Oleic Acid in Sesame Meal Extract as Pancreatic Lipase Inhibitors on Postprandial Triglyceridemia: A Randomized, Double-Blind, Placebo-Controlled, Crossover Study in Healthy Volunteers.

A great number of chemically diverse pancreatic lipase (PL) inhibitors have been identified to tackle obesity; however, very few of them have entered clinical studies. The ethanolic extract of sesame meal is a potent PL inhibitor, and its activity hinges exclusively on two free fatty acids: linoleic acid and oleic acid, which were proven to reduce postprandial triglyceride excursion in rats. Herein, to investigate the clinical efficacy of the sesame meal extract, in a crossover trial, 30 healthy volunteers were randomized to receive the sesame meal extract containing experimental food or placebo along with a high-fat meal. Treatment with the sesame meal extract significantly lowered the incremental postprandial serum triglyceride concentration and reduced the incremental area under the curve (iAUC) by 16.8% (p-value = 0.03) compared to placebo. Significant decreases in postprandial remnant-like lipoprotein particle cholesterol and low-density lipoprotein particles were also observed, whereas high-density lipoprotein cholesterol was increased. These results suggest that treatment with the sesame meal extract significantly reduced the postprandial excursion of triglycerides and improved the lipidemic profile after high dietary fat intake in healthy individuals, indicating the substantial potential of free linoleic acid and oleic acid and natural products rich in these compounds for the management of obesity and related conditions.

Interplay of Self-Assembling Aromatic Amino Acids and Functionalized Gold Nanoparticles Generating Supramolecular Structures.

In the recent years, protein metabolite-based self-assembled supramolecular structures have been linked to various pathological disorders. The self-assembly of protein over nanoparticle surfaces can lead to the formation of corona aggregates that have gained much attention owing to biomedical healthcare relevance. However, limited studies are available at the interface of amyloid formation and nanoparticle surfaces. In this context, the present study demonstrated the effect of specifically functionalized gold nanoparticles on the potential amyloid formation by self-assembled aromatic amino acids. The coassembly of aromatic amino acids and gold nanoparticles was utilized to gain mechanistic insight into altered intermolecular interactions between amino acid monomers. The polymorphism, thermal stability, and morphological pattern of coassembled aromatic amino acids and gold nanoparticle (Co-AA:AuNP) structures were analyzed using X-ray diffraction, thermogravimetric analysis, and field emission scanning electron microscopy, respectively. Finally, amyloid like aggregation of Co-AA:AuNP structures were evaluated using thioflavin T fluorescence assay in solution as well as the deposited phase. The present work is crucial for the design and usage of nanoparticles in biomedical applications, which may trigger amyloid-like metabolite aggregation leading to pathological disorders.

Self-assembly of aromatic α-amino acids into amyloid inspired nano/micro scaled architects.

In the pursuit for design of novel bio inspired materials, aromatic α-amino acids (phenylalanine, tyrosine, tryptophan and histidine) have been investigated for the generation of well-ordered self-assembled architects such as fibrils, rods, ribbons and twisted nanosheets in varying solvent systems. These nano/micro scaled architects were thoroughly characterized using FE-SEM, confocal microscopy, optical microscopy, 1H NMR, FTIR, XRD and TGA. These self-assembled architects were histologically stained with Congo red and thioflavin T dyes for investigation of amyloid morphology which revealed that the deposited state of ordered assemblies exhibit specific characteristic of amyloid deposits. The self-assembly of aromatic amino acids was observed to be driven by non-covalent forces such as π-π stacking, van der Waals and electrostatic interaction.