Detailed phenolic characterization of Protea pure and hybrid cultivars by liquid chromatography–ion mobility–high resolution mass spectrometry (LC-IM-HR-MS)

In this study we report a detailed investigation of the polyphenol composition of pure ( and ) and hybrid cultivars (Black beauty and Limelight). Aqueous methanol extracts of leaf and bract tissues were analyzed by ultrahigh pressure liquid chromatography hyphenated to photodiode array and ion mobility-high resolution mass spectrometric (UHPLC-PDA-IM-HR-MS) detection. A total of 67 metabolites were characterized based on their relative reversed phase (RP) retention, UV-vis spectra, low and high collision energy HR-MS data, and collisional cross section (CCS) values. These metabolites included 41 phenolic acid esters and 25 flavonoid derivatives, including 5 anthocyanins. In addition, an undescribed hydroxycinnamic acid-polygalatol ester, caffeoyl--polygalatol (1,5-anhydro-[6--caffeoyl]-sorbitol(glucitol)) was isolated and characterized by 1D and 2D NMR for the first time. This compound and its isomer are shown to be potential chemo-taxonomic markers

Estimating the Rotational Synchronous Component from Instantaneous Angular Speed Signals in Variable Speed Conditions

International audienceCondition monitoring performed directly from the estimated instantaneous angular speed has found some interesting applications in industrial environments, going from bearing monitoring to gear failure detection. One common way to estimate the angular speed makes use of angular encoders linked to a rotating shaft. At the opposite of traditional time-sampled signals, encoders describe purely angular phenomena often encountered in rotating machines. However, rotating encoders suffer from various geometric defects, corrupting the measurement with an angular periodic signature. The angular synchronous average is a very popular tool to estimate this systematic error, but is only adapted to constant speed conditions, which is rarely the case in real applications. We propose here two different estimators to compute a robust estimation of the synchronous component in variable speed conditions. The former, as a data-driven approach, is based on a local weighted least squares method, while the latter is a model-based approach. We study the behaviour of our estimators with both simulations and experimental signals, and show the relevance of the proposed method in an industrial context

A cytotoxic bis(1,2,3-triazol-5-ylidene)carbazolide gold(III) complex targets DNA by partial intercalation

Abstract The syntheses of bis(triazolium)carbazole precursors and their corresponding coinage metal (Au, Ag) complexes are reported. For alkylated triazolium salts, di- or tetranuclear complexes with bridging ligands were isolated, while the bis(aryl) analogue afforded a bis(carbene) AuI-CNC pincer complex suitable for oxidation to the redox-stable [AuIII(CNC)Cl]⁺ cation. Although the ligand salt and the [AuIII(CNC)Cl]⁺ complex were both notably cytotoxic toward the breast cancer cell line MDA-MB-231, the AuIII complex was somewhat more selective. Electrophoresis, viscometry, UV-vis, CD and LD spectroscopy suggest the cytotoxic [AuIII(CNC)Cl]⁺ complex behaves as a partial DNA intercalator. In silico screening indicated that the [AuIII(CNC)Cl]⁺ complex can target DNA three-way junctions with good specificity, several other regular B-DNA forms, and Z-DNA. Multiple hydrophobic π-type interactions involving T and A bases appear to be important for B-form DNA binding, while phosphate O⋅⋅⋅Au interactions evidently underpin Z-DNA binding. The CNC ligand effectively stabilizes the AuIII ion, preventing reduction in the presence of glutathione. Both the redox stability and DNA affinity of the hit compound might be key factors underpinning its cytotoxicity in vitro