ABSTRACT
The Terminalia catappa L. tree is an ornamental and shade tree producter of a large amount of biological waste sent to landfills. Therefore, this plant constitutes so-called municipal solid wood waste (MSWW), which causes undesirable impacts on the environment, such as the generation of methane through the action of microorganisms. Sustainable solutions for the proper use and disposal of MSWW are a topic that has assumed great relevance at present due to the high quantities of MSWW generated worldwide. Pyrolysis constitutes an attractive alternative for the sustainable use of MSWW to produce higher value-added products. This study investigated the slow pyrolysis of Terminalia catappa L. fruit and the use of the aqueous fraction produced for bovine mastitis control. We obtained four fractions from the pyrolysis process, with average yields of the aqueous phase (36.22 ± 2.0 %), bio-oil (5.52 ± 0.4 %), biochar (37.55 ± 2.8 %) and gas (20.71 ± 2.0 %). The aqueous fraction was extracted with organic solvents and analyzed by gas chromatography coupled to mass spectrometry (GCâMS). The extracts were composed mainly of phenols (50 %), furan derivatives, cyclic ketones, and others with lower contents, such as alcohols and esters. The aqueous fraction had bactericidal activity against Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa and Escherichia coli, which are responsible for bovine mastitis. In addition, the fraction showed low cytotoxicity against a murine melanoma cell line from a C57BL/6J mouse, B16F10 cells and mouse peritoneal cells.
ABSTRACT
In Leishmania donovani, the causative protozoan of visceral leishmaniasis, nucleoside hydrolase enzyme (NH) is fundamental for the biosynthesis of its DNA and RNA. Therefore, LdNH is considered a potential target for the development of new leishmaniasis chemotherapy. Moringa oleifera Lamarck is a medicinal plant native to northeastern India with numerous pharmacological properties, including antileishmanial activity. Thus, this study aimed to explore the inhibitory activity of different extracts from M. oleifera leaves and flowers on LdNH. Using LdNH covalently immobilized on magnetic particles (LdNH-MPs), a novel activity assay was developed based on the direct quantification of the formed product by HPLC-DAD. This study screened 12 extracts from leaves and flowers of M. oleifera using different extraction methods. The hydroethanolic (70% ethanol) extract from flowers, obtained by infusion (FIEH) or ultrasound-assisted extraction (FUEH), exhibited respectively IC50 values of 26.2 ± 4.63 µg/mL and 4.96 ± 0.52 µg/mL. The most promising extract (FUEH) was investigated by high-resolution LdNH inhibition profiling, which showed different regions of inhibition in the biochromatogram. A ligand fishing assay was attempted to pinpoint the bioactive compounds. Experimental conditions employed in the elution step of the ligand fishing assay did not result in ligands isolation. However, the analyses of the crude extract solution and the supernatants after the incubation with the active and inactive LdNH-MPs indicated missing peaks referring to compounds selectively retained in the active LdNH-MPs incubation. The missing peaks eluted in the same region that exhibits inhibition in the high-resolution LdNH inhibition profiling. The ligands were identified by UHPLC-MS/MS as palatinose, adenosine, 3-p-coumaroylquinic acid, 4-p-coumaroylquinic acid, hyperoside, quercetin-3-O-malonyl glycoside, and kaempferol-3-O-galactoside.
