NP3 MS Workflow: An Open-Source Software System to Empower Natural Product-Based Drug Discovery Using Untargeted Metabolomics.

Natural products (or specialized metabolites) are historically the main source of new drugs. However, the current drug discovery pipelines require miniaturization and speeds that are incompatible with traditional natural product research methods, especially in the early stages of the research. This article introduces the NP3 MS Workflow, a robust open-source software system for liquid chromatography-tandem mass spectrometry (LC-MS/MS) untargeted metabolomic data processing and analysis, designed to rank bioactive natural products directly from complex mixtures of compounds, such as bioactive biota samples. NP3 MS Workflow allows minimal user intervention as well as customization of each step of LC-MS/MS data processing, with diagnostic statistics to allow interpretation and optimization of LC-MS/MS data processing by the user. NP3 MS Workflow adds improved computing of the MS2 spectra in an LC-MS/MS data set and provides tools for automatic [M + H]+ ion deconvolution using fragmentation rules; chemical structural annotation against MS2 databases; and relative quantification of the precursor ions for bioactivity correlation scoring. The software will be presented with case studies and comparisons with equivalent tools currently available. NP3 MS Workflow shows a robust and useful approach to select bioactive natural products from complex mixtures, improving the set of tools available for untargeted metabolomics. It can be easily integrated into natural product-based drug-discovery pipelines and to other fields of research at the interface of chemistry and biology.

Evaluation of Antioxidant Activity of Phytol Using Non- and Pre-Clinical Models.

BACKGROUND: Phytol (3,7,11,15-tetramethylhexadec-2-en-1-ol; PHY), the alcoholic diterpenoid is particularly interesting due to its diverse activities found in literature. This study evaluated in vitro and in vivo antioxidant capacity of PHY. METHODS: We conducted DPPH• (2,2-diphenyl-1-picrylhydrazyl) and ABTS•+ (2,2'-azino-bis(3- ethylbenzthiazoline-6-sulphonic acid)) radical scavenging tests as in vitro, while Saccharomyces cerevisiae test as in vivo. For in vitro tests, trolox and for in vivo test hydrogen peroxide (H2O2) were taken as standard and stressor, respectively. Additionally, we measured the superoxide dismutase (SOD), catalase (CAT), reduced glutathione (GSH), lipid peroxidation (LP) and nitrite (NO2 -) contents in mouse hippocampus taking 0.05% Tween 80 dissolved in 0.9% saline (0.25 ml) and ascorbic acid (250 mg/kg; AA) as vehicle and standard, respectively. PHY was administered at doses 25, 50 and 75 mg/kg. In the latter case, all the treatments were administered via intraperitoneal (i.p.) route. RESULTS: PHY at 7.2 µg/ml exhibited 59.89 ± 0.73% and 62.79 ± 1.99% scavenging capacity of DPPH• and ABTS•+, respectively. In S. cerevisiae strains, PHY showed prominent protective effects. Moreover, in Swiss mouse hippocampus; PHY reduced the LP and NO2 - contents, while increased in GSH, SOD and CAT activities. CONCLUSION: PHY exerted antioxidant potential in our current non- and preclinical test systems and can be a good candidate for the development of treatments of oxidative stress mediated diseases.

Condensation of Macrocyclic Polyketides Produced by Penicillium sp. DRF2 with Mercaptopyruvate Represents a New Fungal Detoxification Pathway.

Application of a refined procedure of experimental design and chemometric analysis to improve the production of curvularin-related polyketides by a marine-derived Penicillium sp. DRF2 resulted in the isolation and identification of cyclothiocurvularins 6-8 and cyclosulfoxicurvularins 10 and 11, novel curvularins condensed with a mercaptolactate residue. Two additional new curvularins, 3 and 4, are also reported. The structures of the sulfur-bearing curvularins were unambiguously established by analysis of spectroscopic data and by X-ray diffraction analysis. Analysis of stable isotope feeding experiments with [U-(13)C3(15)N]-l-cysteine confirmed the presence of the 2-hydroxy-3-mercaptopropanoic acid residue in 6-8 and the oxidized sulfoxide in 10 and 11. Cyclothiocurvularins A (6) and B (7) are formed by spontaneous reaction between 10,11-dehydrocurvularin (2) and mercaptopyruvate (12) obtained by transamination of cysteine. High ratios of [U-(13)C3(15)N]-l-cysteine incorporation into cyclothiocurvularin B (7), the isolation of two diastereomers of cyclothiocurvularins, the lack of cytotoxicity of cyclothiocurvularin B (7) and its methyl ester (8), and the spontaneous formation of cyclothiocurvularins from 10,11-dehydrocurvularin and mercaptopyruvate provide evidence that the formation of cyclothiocurvularins may well correspond to a 10,11-dehydrocurvularin detoxification process by Penicillium sp. DRF2.

Structure and Biogenesis of Roussoellatide, a Dichlorinated Polyketide from the Marine-Derived Fungus Roussoella sp. DLM33.

The structure of the fungal metabolite roussoellatide (1) has been established by spectroscopic and X-ray diffraction analyses. Results from feeding experiments with [1-(13)C]acetate, [2-(13)C]acetate, and [1,2-(13)C]acetate were consistent with a biosynthetic pathway to the unprecedented skeleton of 1 involving Favorskii rearrangements in separate pentaketides, subsequently joined via an intermolecular Diels-Alder reaction.

Chemical constituents of Lecythis pisonis and cytotoxic activity

The phytochemical investigation of the ethanol extract from leaves of Lecythis pisonis Cambess., Lecythidaceae, resulted in the isolation of seven triterpenes: α- and β-amyrin, uvaol and erythrodiol, ursolic and oleanolic acids and 3β-friedelinol, as well as a mixture of sitosterol and stigmasterol steroids and a diterpene (E)-phytol. The structures of these compounds were identified by¹H and 13C NMR spectral analysis and compared with literature data. The mixture of triterpenes ursolic and oleanolic acids isolated from the active ethereal fraction showed moderate cytotoxic activity. This paper describes for the first time the phytochemical and cytotoxic study of Lecythis pisonis' leaves.