High-Resolution Magic Angle Spinning (HR-MAS) NMR-Based Fingerprints Determination in the Medicinal Plant Berberis laurina.

Berberis laurina (Berberidaceae) is a well-known medicinal plant used in traditional medicine since ancient times; however, it is scarcely studied to a large-scale fingerprint. This work presents a broad-range fingerprints determination through high-resolution magical angle spinning (HR-MAS) nuclear magnetic resonance (NMR) spectroscopy, a well-established flexible analytical method and one of most powerful "omics" platforms. It had been intended to describe a large range of chemical compositions in all plant parts. Beyond that, HR-MAS NMR allowed the direct investigation of botanical material (leaves, stems, and roots) in their natural, unaltered states, preventing molecular changes. The study revealed 17 metabolites, including caffeic acid, and berberine, a remarkable alkaloid from the genus Berberis L. The metabolic pattern changes of the leaves in the course of time were found to be seasonally dependent, probably due to the variability of seasonal and environmental trends. This metabolites overview is of great importance in understanding plant (bio)chemistry and mediating plant survival and is influenceable by interacting environmental means. Moreover, the study will be helpful in medicinal purposes, health sciences, crop evaluations, and genetic and biotechnological research.

Supramolecular polyelectrolyte complexes based on cyclodextrin-grafted chitosan and carrageenan for controlled drug release.

In the present study, supramolecular polyelectrolyte complexes (SPEC) based on a cyclodextrin-grafted chitosan derivative and carrageenan were prepared and evaluated for controlled drug release. Samples were characterized by FTIR, SEM, and ζ-potential measurements, which confirmed the formation of the polymeric complex. The phenolphthalein test confirmed the presence and availability of inclusion sites from the attached ßCD. Silver sulfadiazine was used as the model drug and the association with the SPEC was studied by FTIR and computational molecular modeling, using a semi-empirical method. DRS and TEM analyses have shown that Ag+ ions from the drug were reduced to form metallic silver nanostructures. In vitro tests have shown a clear bacterial activity toward Gram-positive bacteria Staphylococcus aureus and Enterococcus durans/hirae and Gram-negative bacteria Klebsiella pneumoniae and Escherichia coli. Finally, this work shows that ßCD-chitosan/carrageenan supramolecular polyelectrolyte complexes hold an expressive potential to be applied as a polymer-based system for controlled drug release.

Evaluation of the antioxidant activities of fatty polyhydroquinolines synthesized by Hantzsch multicomponent reactions.

Polyhydroquinolines (PHQs) are the unsymmetrical Hantzsch derivatives of 1,4-dihydropyridines with several biological applications. In this work, new fatty 2- and 3-substituted PHQ derivatives from different fatty acids and fatty alcohol feedstocks were synthesized at good yields via a four-component reaction (4CR). The antioxidant activities of fatty PHQs were investigated using three different antioxidant methods. The experiments showed that the compounds derived from 2-nitrobenzaldehyde and fatty palmitic (C16:0) and oleic (C18:1) chains showed better antioxidant activity. This revealed that combining the ortho NO2 group in the aromatic ring with the insertion of fatty chains in the PHQ core contributed to the antioxidant activity. However, among all the fatty PHQs tested, the fatty 2-substituted compound derived from oleyl alcohol and 2-nitrobenzaldehyde showed the highest antioxidant activity (EC50, 2.11-4.69 µM), which was similar to those of the antioxidant standards butylated hydroxytoluene (EC50, 1.98-6.47 µM) and vitamin E (EC50, 1.19-5.88 µM). In addition, this lipophilic compound showed higher antioxidant activity than the antihypertensive drug nifedipine (EC50, 49.25-126.86 µM). These results indicate that the new fatty PHQs may find novel applications as antioxidant additives.