HPLC-DAD-MS Fingerprint of Andrographis Paniculata (Burn. f.) Nees (Acanthaceae)

An HPLC-UV fingerprint analysis was developed for the quality evaluation of Andrographis paniculata aerial parts. HPLC-DAD-MS experiments allowed the identification of eleven diterpenes and five flavonoids. Plant material of Indian and Chinese origin was evaluated employing the developed method. The chemical fingerprints of the plant material of different origins do not show significant differences

Development of an innovative maceration technique to optimize extraction and phase partition of natural products

The extraction of active components from plants is the first crucial step in the field of natural product research. In the case of non-targeted extraction with an objective to isolate and characterize as many compounds as possible, the most classical technique, and the simplest to implement, is the Soxhlet extraction (SE). However, this method does not allow to extract all the compounds from the plant. Indeed, the use of several solvents allowing a variation of polarity is especially suitable since natural products are so diverse with various physicochemical properties (e.g. polarity, solubility…). Thus the second most used technique is the extraction by successive macerations using solvents of increasing polarity. If this method is frequently used, very few studies are available to rationalize and optimize it. Furthermore, this extraction technique still requires some enhancement mainly for efficiency, economic, environmental and time constraint reasons. In this work, we present an innovative method of successive macerations using a mixture of solvents with the aim of simultaneously improving the yield, the partition of the compounds between the different phases and reducing the volume of solvent. Triphasic systems were prepared by mixing five different solvents (n-heptane, ethyl acetate, acetonitrile, butan-1-ol and water) in various proportions. Seven natural compounds of different polarity were then dissolved in these mixtures. After decantation, an apolar, an intermediate and a polar phase were obtained and analyzed to evaluate the partition of each compound. The best triphasic system showed a very performant phase partition. Indeed, the majority of the relevant secondary metabolites are found in the intermediate phase while primary metabolites were recovered in apolar and polar phases. This triphasic system was subsequently used to perform three successive macerations with a polarity gradient on aerial parts of a model plant, Anthyllis vulneraria L. Our results showed an overall good yield compared to conventional maceration techniques, while reducing time of extractions and volume of solvents

Development of an innovative maceration technique to optimize extraction and phase partition of natural products

The extraction of active components from plants is the first crucial step in the field of natural product research. In the case of non-targeted extraction with an objective to isolate and characterize as many compounds as possible, the most classical technique, and the simplest to implement, is the Soxhlet extraction (SE). However, this method does not allow to extract all the compounds from the plant. Indeed, the use of several solvents allowing a variation of polarity is especially suitable since natural products are so diverse with various physicochemical properties (e.g. polarity, solubility…). Thus the second most used technique is the extraction by successive macerations using solvents of increasing polarity. If this method is frequently used, very few studies are available to rationalize and optimize it. Furthermore, this extraction technique still requires some enhancement mainly for efficiency, economic, environmental and time constraint reasons. In this work, we present an innovative method of successive macerations using a mixture of solvents with the aim of simultaneously improving the yield, the partition of the compounds between the different phases and reducing the volume of solvent. Triphasic systems were prepared by mixing five different solvents (n-heptane, ethyl acetate, acetonitrile, butan-1-ol and water) in various proportions. Seven natural compounds of different polarity were then dissolved in these mixtures. After decantation, an apolar, an intermediate and a polar phase were obtained and analyzed to evaluate the partition of each compound. The best triphasic system showed a very performant phase partition. Indeed, the majority of the relevant secondary metabolites are found in the intermediate phase while primary metabolites were recovered in apolar and polar phases. This triphasic system was subsequently used to perform three successive macerations with a polarity gradient on aerial parts of a model plant, Anthyllis vulneraria L. Our results showed an overall good yield compared to conventional maceration techniques, while reducing time of extractions and volume of solvents

Antimycobacterial Coumarins from the Sardinian Giant Fennel (Ferula communis)

The structure of a new prenylated coumarin (E-ω-benzoyloxyferulenol, 1b) from the Sardinian giant fennel (Ferula communis) has been confirmed by synthesis. The parent compound ferulenol (1a) showed sub-micromolar antimycobacterial activity, which was partly retained in 1b and in the simplified synthetic analogue 3, but diminished in its ω-hydroxy and ω-acetoxy derivatives (1c and 1d, respectively). The outstanding activity of 1a, its low toxicity, and the evidence for definite structure−activity relationships make this prenylated 4-hydroxycoumarin an interesting antibacterial chemotype worth further investigation

Global computing in a dynamic network of tuple spaces

We present tKlaim (TopologicalKlaim), a process description language that retains the main features of Klaim (process distribution and mobility, remote and asynchronous communication through distributed data spaces), but extends it with new constructs to flexibly model the interconnection structure underlying a network and its evolution in time. We show how tKlaim can be used to model a number of interesting distributed applications and how systems correctness can be guaranteed, also in the presence of failures, by exploiting observational equivalences to study the relationships between descriptions of systems at different levels of abstraction

Marine versus Non-Marine Bacterial Exopolysaccharides and Their Skincare Applications

Bacteria are well-known to synthesize high molecular weight polysaccharides excreted in extracellular domain, which constitute their protective microenvironment. Several bacterial exopolysaccharides (EPS) are commercially available for skincare applications in cosmetic products due to their unique structural features, conferring valuable biological and/or textural properties. This review aims to give an overview of bacterial EPS, an important group of macromolecules used in cosmetics as actives and functional ingredients. For this purpose, the main chemical characteristics of EPS are firstly described, followed by the basics of the development of cosmetic ingredients. Then, a focus on EPS production, including upstream and downstream processes, is provided. The diversity of EPS used in the cosmetic industry, and more specifically of marine-derived EPS is highlighted. Marine bacteria isolated from extreme environments are known to produce EPS. However, their production processes are highly challenging due to high or low temperatures; yield must be improved to reach economically viable ingredients. The biological properties of marine-derived EPS are then reviewed, resulting in the highlight of the challenges in this field