Differential metabolic and biological profiles of Lychnophora ericoides mart. (Asteraceae) from different localities in the Brazilian "campos rupestres"

This paper reports HPLC-DAD-MS/MS and HPLC-ECD characterisation of secondary metabolite profiles of Lychnophora ericoides Mart. leaf extracts from different provenances and their cytotoxic and antioxidant properties. Leaf extracts from populations representing seven different locations were evaluated for antioxidant activity by the DPPH radical scavenging system and activity towards cellular growth in three tumor cell lines. The extracts were electrochemically analysed by HPLC-ECD and their main secondary metabolites were identified by HPLC-DAD-MS and HPLC-DAD-MS/MS. An amplified defensive secondary chemistry, together with maximal cytotoxic and antioxidant bioactivities, were found for plants collected at the interface between two types of forest. These findings furnish additional support for the hypothesis that plants occurring at the interface between two forests ecosystems might be stimulated to amplify their own production and storage of defensive secondary metabolites due to the greater number of environmental influences

Metabolomic Fingerprinting of Salinispora From Atlantic Oceanic Islands

Salinispora (Micromonosporaceae) is an obligate marine bacterium genus consisting of three species that share over 99% 16S rRNA identity. The genome and biosynthetic pathways of the members of this genus have been widely investigated due to their production of species-specific metabolites. However, despite the species’ high genetic similarity, site-specific secondary metabolic gene clusters have been found in Salinispora strains collected at different locations. Therefore, exploring the metabolic expression of Salinispora recovered from different sites may furnish insights into their environmental adaptation or their chemical communication and, further, may lead to the discovery of new natural products. We describe the first occurrence of Salinispora strains in sediments from the Saint Peter and Saint Paul Archipelago (a collection of islets in Brazil) in the Atlantic Ocean, and we investigate the metabolic profiles of these strains by employing mass-spectrometry-based metabolomic approaches, including molecular networking from the Global Natural Products Social Molecular Networking platform. Furthermore, we analyze data from Salinispora strains recovered from sediments from the Madeira Archipelago (Portugal, Macaronesia) in order to provide a wider metabolomic investigation of Salinispora strains from the Atlantic Oceanic islands. Overall, our study evidences a broader geographic influence on the secondary metabolism of Salinispora than was previously proposed. Still, some biosynthetic gene clusters, such as those corresponding to typical chemical signatures of S. arenicola, like saliniketals and rifamycins, are highly conserved among the assessed strains

Sensitive method for determination of piplartine, an alkaloid amide from Piper species, in rat plasma samples by liquid chromatography-tandem mass spectrometry

Piplartine (PPTN) is an alkaloid amide found in Piper species that presents different activities. PPTN determination in rat plasma is necessary to better understand its biological effects. The aim of this study was to develop a sensitive LC-MS/MS method for the determination of PPTN in rat plasma. The performance criteria for linearity, sensitivity, precision, accuracy, recovery, and stability have been assessed and were within the recommended guidelines. The validated method proved to be suitable in a pilot study of PPTN kinetic disposition in rat plasma after a single intraperitoneal dose, and represents an appropriate tool to further pharmacokinetic studies

Novel 2-(R-phenyl)amino-3-(2-methylpropenyl)-[1,4]-naphthoquinones: synthesis, characterization, electrochemical behavior and antitumor activity

Novel 2-(R-phenyl)amino-3-(2-methyl-propenyl)-[1,4]-naphthoquinones (R = H, 4-OMe, 4-Ferrocenyl, 4-Me, 3-Me, 4-I, 3-I, 4-CN, 3-CN, 4-NO2 and 3-NO2) derived from nor-lapachol [2-hydroxy-3-(2-methylpropenyl)-1,4-naphthoquinone] were obtained in good yields. Their structures were proposed on the basis of a single crystal X-ray diffraction study (R = OMe, 2b), ¹H and 13C NMR studies and calculations using the B3LYP functional and the 6-311+G(2d,p) basis set. The half-wave potentials of the aminonaphthoquinones and ¹H NMR chemical shifts of the 3-propenyl hydrogen in 2a-k show good correlation with the substituent Hammett constants on the phenylamino ring. The antitumor assays showed promising activity for substrate methoxy-nor-lapachol 1 and the 4-ferrocenyl derivative 2c.Novas 2-(R-fenil)amino-3-(2-metilpropenil)-[1,4]-naftoquinonas (R = H, 4-OMe, 4-Ferrocenil, 4-Me, 3-Me, 4-I, 3-I, 4-CN, 3-CN, 4-NO2 e 3-NO2) derivadas do nor-lapachol [2-hidroxi-3-(2-metilpropenil)-1,4-naftoquinona] foram obtidas em bons rendimentos. A estrutura dos compostos foi proposta com base em estudos de difração de raios-X (R = OMe, 2b), dados de RMN de ¹H e 13C e cálculos teóricos utilizando o funcional B3LYP e a base 6-311+G(2d,p). Os potenciais de meia-onda das aminonaftoquinonas e o deslocamento químico do hidrogênio da cadeia 3-propenil dos compostos 2a-k mostraram boa correlação com as constantes de Hammett dos substituintes presentes no anel fenileno. A avaliação da citotoxicidade evidenciou atividade antitumoral promissora para o substrato metóxi-nor-lapachol 1 e o derivado 4-ferrocenil 2c.169178Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES