| 1. |
- Liu, Xiaojie, et al.
(författare)
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Broad range chemical profiling of natural deep eutectic solvent extracts using a high performance thin layer chromatography-based method
- 2018
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Ingår i: Journal of Chromatography A. - : ELSEVIER SCIENCE BV. - 0021-9673 .- 1873-3778. ; 1532, s. 198-207
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Tidskriftsartikel (refereegranskat)abstract
- Natural deep eutectic solvents (NADES) made mainly with abundant primary metabolites are being increasingly applied in green chemistry. The advantages of NADES as green solvents have led to their use in novel green products for the food, cosmetics and pharma markets. However, one of the main difficulties encountered in the development of novel products and their quality control arises from their low vapour pressure and high viscosity. These features create the need for the development of new analytical methods suited to this type of sample. In this study, such a method was developed and applied to analyse the efficiency of a diverse set of NADES for the extraction of compounds of interest from two model plants, Ginkgo biloba and Panax ginseng. The method uses high-performance thin-layer chromatography (HPTLC) coupled with multivariate data analysis (MVDA). It was successfully applied to the comparative quali- and quantitative analysis of very chemically diverse metabolites (e.g., phenolics, terpenoids, phenolic acids and saponins) that are present in the extracts obtained from the plants using six different NADES. The composition of each NADES was a combination of two or three compounds mixed in defined molar ratios; malic acid-choline chloride (1:1), malic acid-glucose (1:1), choline chloride-glucose (5:2), malic acid-proline (1:1), glucose-fructose-sucrose (1:1:1) and glycerol-proline-sucrose (9:4:1). Of these mixtures, malic acid-choline chloride (1:1) and glycerol-proline-sucrose (1:1:1) for G. biloba leaves, and malic acid-choline chloride (1:1) and malic acid-glucose (1:1) for P. ginseng leaves and stems showed the highest yields of the target compounds. Interestingly, none of the NADES extracted ginkgolic acids as much as the conventional organic solvents. As these compounds are considered to be toxic, the fact that these NADES produce virtually ginkgolic acid-free extracts is extremely useful. The effect of adding different volumes of water to the most efficient NADES was also evaluated and the results revealed that there is a great influence exerted by the water content, with maximum yields of ginkgolides, phenolics and ginsenosides being obtained with approximately 20% water (w/w).
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| 2. |
- Pettersson, Jenny, et al.
(författare)
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NMR metabolomic analysis of fecal water from subjects on a vegetarian diet
- 2008
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Ingår i: Biological and Pharmaceutical Bulletin. - : Pharmaceutical Society of Japan. - 0918-6158 .- 1347-5215. ; 31:6, s. 1192-1198
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Tidskriftsartikel (refereegranskat)abstract
- A vegetarian diet rich in phytochemicals may prevent colon carcinogenesis by affecting biochemical processes in the colonic mucosa. Compounds passing the digestive system reaching the colon could potentially be detected in fecal water. We previously reported that intact fecal water samples from human volunteers significantly decreased prostaglandin production and COX-2 protein expression in colonic cells. The aim with the present study was to further study the composition of the fecal waters, using NMR spectroscopy and multivariate data analysis, and to trace the COX-2 inhibiting activity. Intact fecal water samples and fractions thereof were analyzed for their ability to inhibit prostaglandin E2 production in the human colon cell line HT-29. The majority of the tested aqueous phases derived from intact fecal water showed ability to inhibit prostaglandin production in cells (13.8+/-1.34% inhibition, p=0.01). NMR analysis indicated the presence of significant quantities of amino acids and fatty acids. Major metabolites included; acetic acid, butanoic acid, propanoic acid, glutamic acid and alanine. Smaller amounts of glycine and fumaric acid, which are known to have anti-inflammatory and anti-tumorigenic properties, were also detected. This study describes for the first time NMR metabolomic analysis of fecal water from subjects on a vegetarian diet.
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| 3. |
- Rosén, Josefin, 1978-
(författare)
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ChemGPS-NP and the Exploration of Biologically Relevant Chemical Space
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Chemical space is basically infinite, and comprises all molecules that could possibly exist. Intelligent ways to efficiently navigate through chemical space and to select promising compounds in drug discovery are important tasks, and the focus of this thesis. In this work a new model for chemical space navigation, ChemGPS-NP, was developed. This model is based on a methodology where a global chemical space map is defined through principal component analysis of physico-chemical properties of a reference set of compounds. Through interpolation from the reference set, positions of novel compounds can be defined on this map and interpreted as chemical properties. ChemGPS-NP was demonstrated to be able to chart the entire biologically relevant chemical space, including both drug-like and natural compounds. This is an important improvement considering the present interest in natural products (NPs) in the pharmaceutical industry, as well as the track record of NPs to serve as basis for more than 50% of all marketed drugs. ChemGPS-NP proved able to handle and process large data sets, to aid in efficient selection of test objects, and to extract useful information from the results of high-throughput screening campaigns. Using ChemGPS-NP, it was shown that NPs occupy unique regions of chemical property space in comparison to drug-like compounds, and a number of features distinguishing NPs from medicinal chemistry compounds were identified. ChemGPS-NP was also shown to be able to reliably predict mode of action of anticancer agents based on chemical structure, a finding that has potential to improve cancer research efficiency. Applying a property based similarity search based on calculated eight dimensional Euclidean distances from ChemGPS-NP rendered a tool to identify NP inspired potential leads for drug discovery. Furthermore, ChemGPS-NPWeb, an online version of ChemGPS-NP, was developed, which provides scientists with open access to the tool via http://chemgps.bmc.uu.se/.
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| 4. |
- Ruhaak, Lucia Renee, et al.
(författare)
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Evaluation of the Cyclooxygenase Inhibiting Effects of Six Major Cannabinoids Isolated from Cannabis sativa
- 2011
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Ingår i: Biological and Pharmaceutical Bulletin. - : Pharmaceutical Society of Japan. - 0918-6158 .- 1347-5215. ; 34:5, s. 774-778
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Tidskriftsartikel (refereegranskat)abstract
- Cyclooxygenase enzymes (COX-1 and COX-2) catalyse the production of prostaglandins from arachidonic acid. Prostaglandins are important mediators in the inflammatory process and their production can be reduced by COX-inhibitors. Endocannabinoids, endogenous analogues of the plant derived cannabinoids, occur normally in the human body. The Endocannabinoids are structurally similar to arachidonic acid and have been suggested to interfere with the inflammatory process. They have also been shown to inhibit cancer cell proliferation. Anti-inflammatory effects of cannabinoids and endocannabinoids have been observed, however the mode of action is not yet clarified. Anti-inflammatory activity (i.e., inhibition of COX-2) is proposed to play an important role in the development of colon cancer, which makes this subject interesting to study further. In the present work, the six cannabinoids tetrahydrocannabinol (Delta(9)-THC), tetrahydrocannabinolic acid (Delta(9)-THC-A), cannabidiol (CBD), cannabidiolic acid (CBDA), cannabigerol (CBG) and cannabigerolic acid (CBGA), isolated from Cannabis sativa, were evaluated for their effects on prostaglandin production. For this purpose an in vitro enzyme based COX-1/COX-2 inhibition assay and a cell based prostaglandin production radioimmunoassay were used. Cannabinoids inhibited cyclooxygenase enzyme activity with IC50 values ranging from 1.7.10(-3) to 2.0.10(-4) M.
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