Introduction.

The direct interaction of molecules, extracts and medicines with tissues or living organisms it is essential and unavoidable knowledge in the actual commercial therapy. Studies achieve during the preclinical and clinical stages of drug development and that are very useful to reveal the pharmacological profile of drugs.

Methods.

In previous years, we have presented the results obtained from the study of a hydro-ethanolic extract of Stevia rebaudiana Bertoni (Asteraceae) through a novel system that allows the on-line detection of pharmacologically active substances, based on liquid chromatography (through MPLC or HPLC techniques) coupled to biological detection using perifused or perfused organs.¹

In this communication we describe uses and perspectives in Bioorganic Chemistry of coupling MPLC and HPLC to studies of living tissues or organs in the pre-characterization processes of new bioactive compounds present in mixtures derived from chemical synthesis (for example, combinatorial chemistry) or from extracts of natural origin.

Results.

These techniques enabled us to easily identify the fractions that showed contractile activity and according to its mass spectrum we identified the active compound as rebaudioside N from one extract of Stevia rebaudiana Bertoni.¹

This type of methodology reduced the number of animals slaughtered, investigation time and the expenses associated with such studies.

Conclusions.

The results show that a direct combination of liquid chromatography with perfusion systems of isolated organs may be a powerful tool to facilite the pharmacological characterization of active compounds in mixtures.

References.

¹ Campuzano-Bublitz et al., Naunyn-Schmiedeberg's Arch Pharmacol. 2018, 391, 9–16.

Bacterial and fungal infections, among which urinary tract infections (UTI) and vulvovaginal candidiasis (VVC) stand out, have a high prevalence among young, healthy women, affecting 75% of them of childbearing age. The main causative agent of UTIs is Escherichia coli, while Candida albicans mainly cause VVC. Strategies for the treatment of these infections generate the appearance of microorganisms resistant to commonly used antibiotics and antifungals In this work, the antimicrobial potential of ethyl acetate and methanol extracts from agroindustrial waste from the Maule region, Chile (Chilean papaya, blueberry, and grape) was evaluated against the pathogens that cause UTIs and VVC by measuring the halo of inhibition. The extracts were chemically characterized by analysis of total phenolics and the antioxidant capacity was determined by DPPH^· and ABTS^·+ radical scavenging assays. Extracts from Chilean papaya, blueberry, and grape residues showed a total phenolic content ranging from 4.91 to 17.22 g GAE/100 g of extract. The antioxidant capacity of the extracts varied between 21.6 and 101.2 µg/mL. According to the inhibition zone observed, the antimicrobial activity of the extracts was classified as moderate to good. The results suggest that the proposed agroindustrial waste extracts could potentially be used as functional ingredients to treat CVV and UTIs caused by E. coli, providing added value to the residues.

The acidic condensation of 3-coumaranone (benzofuran-2(3H)-one ) with aromatic carbonyl compounds (aldehydes, diones) conduct to different products depending of the acidity of the catalyst.

With poorly Bronsted acid such as acidic clay (K10, KSF), aurons (3- benzylidenebenzofuran-2(3H)-one and (or) 3-(hydroxyl(phenyl) methyl)benzofuran-2(3H)-on were formed according the microwave activation.

We reported herein that double condensation of 3-coumaranone with aromatic carbonyl compounds (aldehydes or polyones) take place with Brønsted hyperacids. The condensation under microwave irradiation of 3-coumaranone and 8-hydroxy-3- coumaranone with benzaldehydes or polyones (ninhydrin, isatin, phenanthraquinone, acenaphthoquinone) were studied in dimethylsulfoxide with pentafluoroanilinium triflate (PFAT) or without solvent with triflic acid as catalyst.

The 3,3’-(phenylmethylene)bis(benzofuran-2(3H)-ones were identified by HPLC coupled with mass spectroscopy and by NMR and then separated by preparative thin layer chromatography.

A reaction mechanism for this double condensation of 3-coumaranone with aromatic carbonyl compounds is proposed involving the addition of a carbocation to an enolic form of 3-coumaranone. This proposed mechanism is very close to the known reaction mechanism for the condensation of aldehyde with two molecules of 4- hydroxycoumarone to form dicoumarols in presence of acidic catalysts.

Aurones are known for their numerous biological properties, it is likely that these 3,3’- (phenylmethylene)bis(benzofuran-2(3H)-ones have interesting biological properties which will be studied in the near future.

In the microwave-assisted pyrolysis (MAP) process, acid-pretreated cocoa pod husk (CPH) was placed in a microwave at 600 W for 15 minutes, resulting in biochar production (BCCPH). This was followed by a doping process with iron salts (+2, +3) to obtain BCCPH-Fe. Characterization of BCCPH-Fe was carried out using surface analysis (BET), thermogravimetric analysis (TGA), particle size distribution, and Fourier Transform Infrared Spectroscopy (FTIR). Subsequently, the photodegradation process was performed using three different light sources, with tartrazine as the adsorbate. The effect of pH on photodegradation was studied, and the percentage of degradation was evaluated through equilibrium and kinetic studies. The amount of BCCPH-Fe, tartrazine concentration, and exposure time to the light source were also evaluated. The best conditions for the photodegradation process were: 254 nm light source, pH of 5, 1 g/100 mL BCCPH-Fe, 25 ppm tartrazine concentration, and 40 h exposure time. Under these conditions, a 93.45% removal of tartrazine was achieved. The experimental data of the adsorption equilibrium best fit the Langmuir-Hinshelwood model, while the adsorption kinetics best fit the pseudo-first-order model. The apparent kinetic constant was 0.04053 [h-1], and the correlation coefficient was 0.98667. In conclusion, photodegradation using BCCPH-Fe can be an effective method for the removal of tartrazine from wastewater, offering a sustainable alternative to traditional methods.