Mass spectrometry as a tool for the dereplication of specialised metabolites from Pterocaulon angustifolium DC.

Pterocaulon genus comprises 26 species, half of them have been phytochemical investigations regarding the chemical composition, and coumarins have been considered the chemotaxonomic markers in the genus. Herein Pterocaulon angustifolium DC (Asteraceae), a native plant from Brazil, is investigated for the first time. Twenty-six compounds were isolated from aerial parts of P. angustifolium DC., being 5 triterpenes, 4 phytosterols, 9 flavonoids, 3 phenolic acids, and 5 coumarins. Moreover, a total of 177 compounds were putatively identified using the dereplication technique by UHPLC-HRMS/MS, more than 50% correspond to flavonoids and coumarins. Although 41 different coumarins have already been reported in Pterocaulon genus, 16 were identified for the first time in this study. Crude ethanolic extract and fractions of P. angustifolium were also biologically investigates, and dichloromethane fraction was the most active fraction in the evaluation of antiproliferative, antioxidant, antimicrobial and cholinesterase inhibitory activities.

TOCSY, hydrogen decoupling and computational calculations to an unequivocal structural elucidation of a new sesquiterpene derivative and identification of other constituents from Praxelis sanctopaulensis.

INTRODUCTION: Praxelis genus comprises 24 species, however, only two species of this genus have been chemically investigated. Here we investigated Praxelis sanctopaulensis, a native plant from Brazil, that occurs mainly in Cerrado regions. OBJECTIVE: The goal was to identify the specialised metabolites from P. sanctopaulensis, and compare with those described from Praxelis and Chromolaena species. METHODS: The phytochemical study of P. sanctopaulensis was performed through different chromatography techniques, including high-performance liquid chromatography (HPLC), gas chromatography flame ionisation detector (GC-FID), and ultra-high-performance liquid chromatography high-resolution tandem mass spectrometry (UHPLC-HRMS/MS). The structures of the compounds were established based on spectroscopic analysis, total correlated spectroscopy (TOCSY), hydrogen decoupling and computational calculations was used to an unequivocal structural elucidation of a new sesquiterpene. The antioxidant activity was evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP), and antimicrobial assay was performed by the microdilution method. Comparison of the flavonoids described P. sanctopaulensis was carried out using principal component analysis. RESULTS: The phytochemical investigation of P. sanctopaulensis led to the isolation of a pair of diastereomers, praxilone A and praxilone B. Seven known compounds were isolated from this species, another 14 fatty acids were detected in hexane fraction, and 26 compounds were identified from ethyl acetate fraction. All these compounds are being described for the first time in this species, with the exception of viridifloric acid. The ethyl acetate fraction showed potent antioxidant activity. CONCLUSIONS: Forty-seven compounds are described from P. sanctopaulensis. The combination of different techniques of nuclear magnetic resonance (NMR) spectroscopy and computational calculations allowed the unequivocal structure elucidation of a new cadinene. The clustering analysis showed similarities between the flavonoids identified in P. sanctopaulensis and in Chromolaena species.

Recent advances in leishmaniasis treatment.

About 1.5 million new cases of cutaneous leishmaniasis and 500,000 new cases of visceral leishmaniasis occur each year around the world. For over half a century, the clinical forms of the disease have been treated almost exclusively with pentavalent antimonial compounds. In this review, we describe the arsenal available for treating Leishmania infections, as well as recent advances from research on plants and synthetic compounds as source drugs for treating the disease. We also review some new drug-delivery systems for the development of novel chemotherapeutics. We observe that the pharmaceutical industry should employ its modern technologies, which could lead to better use of plants and their extracts, as well as to the development of synthetic and semi-synthetic compounds. New studies have highlighted some biopharmaceutical technologies in the design of the delivery strategy, such as nanoparticles, liposomes, cochleates, and non-specific lipid transfer proteins. These observations serve as a basis to indicate novel routes for the development and design of effective anti-Leishmania drugs.