An improved matrix deposition technique for thin layer chromatography coupled to MALDI-TOF mass spectrometry (TLC-MALDI).

Analytical thin layer chromatography (TLC) is a simple yet powerful chromatographic technique that is widely used for the qualitative characterization of complex mixtures such as plant extracts. For their qualitative and visual characterisation, a large number of more or less specific colour reactions are at hand and numerous reference substances are available as well. However, the identification of extract components by colour and the comparison of retention times is not straightforward.

Resolving phytosterols in microalgae using offline two-dimensional reversed phase liquid chromatography-supercritical fluid chromatography coupled with quadrupole time-of-flight mass spectrometry.

Sterols are unsaponifiable lipids resulting from plant metabolism that exhibit interesting bioactive properties. Microalgae are a major source of specific phytosterols, most of which are still not fully characterized. The similarity in sterol structures and the existence of positional isomers make the separation of phytosterols challenging.

Off-line two-dimensional liquid chromatography separation for the quality control of saponins samples from Quillaja Saponaria.

Quil-A is a purified extract of saponins with strong immunoadjuvant activity. While specific molecules have been identified and tested in clinical trials, Quil-A is mostly used as a totum of the Quillaja Saponaria bark extract. Quality control of the extract stability is usually based on the monitoring of specific saponins, whereas the comparison of samples with an initial chromatogram seems more appropriate.

Crystal structure of Dictyoglomus thermophilum β-d-xylosidase DtXyl unravels the structural determinants for efficient notoginsenoside R1 hydrolysis.

Dictyoglomus thermophilum β-d-xylosidase DtXyl is attractive as a potential thermostable biocatalyst able to produce biologically active ginsenosides intermediates from β-(1,2)-D-xylosylated compounds, including Notoginsenoside-R1. DtXyl was expressed as an active N-terminal His-tagged protein, and its crystal structure was solved in presence or absence of d-xylose product. Modelling of notoginsenoside R1 in DtXyl active site led to the identification of several hydrophobic residues interacting in close contact to the substrate hydrophobic core.

Biochemical Characterization of the α-l-Rhamnosidase Rha from : Application to the Selective Derhamnosylation of Natural Flavonoids.

α-l-Rhamnosidases are catalysts of industrial tremendous interest, but their uses are still somewhat limited by their poor thermal stabilities and selectivities. The thermophilic Rha from was cloned, and the recombinant protein was easily purified to homogeneity to afford 4.5 mg/L culture of biocatalyst.

Purification of two valepotriates from Centranthus ruber by centrifugal partition chromatography: From analytical to preparative scale.

Considering chemical complexity of plant crude extracts, purification of natural products is a rate limiting process to identify new compounds as well as to obtain standard references for quantitative or qualitative purposes. In the present work, a centrifugal partition chromatography (CPC) method was developed to isolate and produce high quality reference standards of valtrate and 7-homovaltrate from Centranthus ruber L. roots.

Two-dimensional multi-heart cutting centrifugal partition chromatography-liquid chromatography for the preparative isolation of antioxidants from Edelweiss plant.

The Edelweiss plant has been recognized as a very valuable source of anti-aging principles due to its composition of antioxidants compounds: leontopodic acid A and 3,5-dicaffeoylquinic acid. In this work, off-line multi-heart cutting CPC-LC separation was set up at industrial scale in order to isolate and produce new high quality reference material of these two antioxidants from Edelweiss. For this purpose, CPC and HPLC methods were developed and optimized at laboratory scale and a comprehensive CPCxHPLC analysis of the crude extract was established.

Semisynthetic and Natural Garcinoic Acid Isoforms as New mPGES-1 Inhibitors.

Over the last twenty years, tocotrienol analogues raised great interest because of their higher level and larger domain of biological activities when compared with tocopherols. Amongst the most promising therapeutic application, anti-inflammatory potency has been evaluated through the inhibition of various mediators of inflammation. Here, we worked on the isolation of two natural isoforms of garcinoic acid (i.