validation of hyaluronic acid - drug conjugates based targeted drug delivery for the treatment of COVID-19.

The impact of COVID-19 urges scientists to develop targeted drug delivery to manage Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) viral infections with a fast recovery rate. The aim of the study is to develop Hyaluronic Acid (HA) drug conjugates of viral drugs to target two important enzymes (Mpro and PLpro) of SARS-CoV-2. Three antiviral drugs, namely Dexamethasone (DEX), Favipiravir (FAV), and Remdesivir (REM), were chosen for HA conjugation due to their reactive functional groups.

Herbicide activity of extracts from Ailanthus altissima (Simaroubaceae).

The purpose of the present study was to isolate and characterize ailanthone-rich materials from the bark of the deciduous tree Ailanthus altissima (Mill.) Swingle and to assess their herbicide activity on selected herbaceous species. Ailanthone-rich fractions were obtained from A.

Two-dimensional diffusion-ordered NMR spectroscopy as a tool for monitoring functionalized carbon nanotube purification and composition.

Functionalized carbon nanotube (CNT) derivatives are currently under thorough investigation in different biomedical investigations. In this field of research, the composition of sample either in terms of covalently attached or physisorbed moieties can greatly affect the observed results and hamper the comparison between different studies. Therefore, the availability of a fast and reliable analytical technique to assess both the type of interaction (covalent vs noncovalent) and the composition of CNT conjugates is of great importance.

Synthesis and characterization of novel cardanol based benzoxazines.

Benzoxazines are a class of phenolic compounds extensively studied in polymer science because of their properties as fiber reinforcements, fire-retardants and curing agents. In this article is described a solvent-less process, based on a Mannich reaction involving a primary amine and an aldehyde, for the preparation of new benzoxazines deriving from cardanol (a well known phenol obtained as a renewable organic resource and harmful by-product of the cashew industry). Particular attention is given to the synthesis and chemical characterization (both by 1H NMR spectroscopy and HPLC), while the thermal polymerization process has been monitored by differential scanning calorimetry.

Diffusion-ordered NMR spectroscopy in the structural characterization of functionalized carbon nanotubes.

The emerging applications of functionalized carbon nanotubes (CNTs) in various research domains necessitate the use of many different analytical techniques to confirm their structural modifications in a fast and reliable manner. Thus far, NMR spectroscopy has not been among the main tools for characterization of organically modified carbon nanostructures. (1)H analysis is limited because the signals in these derivatives are typically weak and broad, resulting in uncertainties of a few parts per million, and because of the strong interference of residual solvent signals.

Hydration and self-association of caffeine molecules in aqueous solution: comparative effects of sucrose and beta-cyclodextrin.

The UV-spectra of pure caffeine were measured and two quite differentiated hyper- or hypo-chromic effects were observed as concentration was increased. The first one was explained as due to caffeine-water molecule interaction and the second as originating from dimer formation and staking of caffeine molecules. The effects of sucrose and beta-cyclodextrin on the hydration and the self-association of caffeine were also examined by UV spectroscopy.

Synthesis of 6-amino-6-deoxyhyaluronan as an intermediate for conjugation with carboxylate-containing compounds: application to hyaluronan-camptothecin conjugates.

A novel methodology for making drug conjugates using hyaluronan as a carrier was developed. This strategy involves a completely regioselective two-step synthesis of 6-amino-6-deoxyhyaluronan, which is then easily functionalized with drugs through a suitable linker. The case of hyaluronan-camptothecin conjugates is described, making use of a simple succinate linker.

Synthesis of 6-O-methotrexylhyaluronan as a drug delivery system.

Selective halogenation of hyaluronan and partial halogen substitution by methotrexate led to 6-chloro-6-deoxy-6-O-methotrexylhyaluronan, a potential antitumor drug. The remaining halogen could be further substituted by a second organic carboxylate, leading to mixed esters. 6-O-Acetyl-6-O-methotrexylhyaluronan and 6-O-butyryl-6-O-methotrexylhyaluronan were thus synthesized and characterized by NMR spectroscopy.