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AbstractA multiple columns and detections liquid chromatography system, including size exclusion chromatography (SEC) and reversed phase liquid chromatography (RPLC), for the analysis of macromolecules and micromolecules in ginseng root and leaf was developed. The columns were connected by two switching valves. Macromolecules were separated on a SEC column (TSK gel SuperMultipore PW-H column, 6?mm× 150?mm, 8?μm) by isocratic elution of 50?mM ammonium acetate aqueous solution, 0.3?mL/min of flow rate and detected by evaporative light scattering detection (ELSD). Micromolecules were analyzed on a Poroshell RP column (Agilent Poroshell 120?SB-Aq column, 4.6?mm × 50?mm, 2.7 µm) with gradient elution of water and acetonitrile, 0.6?mL/min of flow rate and detected by ultraviolet detection (UV). As a result, in the macromolecules chromatogram of ginseng root sample showed two main peaks while only one major peak for ginseng leaf. For micromolecules analysis, 17 compounds (3 nucleosides + 14 saponins) and 17 compounds (3 nucleosides + 1 flavonoid + 13 saponins) were found in ginseng root and leaf, respectively. The developed method is helpful for the quality evaluation of ginseng root and leaf. 相似文献
33.
Marta Klimek-Szczykutowicz Micha Dziurka Ivica Blaevi Azra ulovi Sebastian Granica Izabela Korona-Glowniak Halina Ekiert Agnieszka Szopa 《Molecules (Basel, Switzerland)》2020,25(22)
The main compounds in both extracts were gluconasturtiin, 4-methoxyglucobrassicin and rutoside, the amounts of which were, respectively, determined as 182.93, 58.86 and 23.24 mg/100 g dry weight (DW) in biomass extracts and 640.94, 23.47 and 7.20 mg/100 g DW in plant herb extracts. The antioxidant potential of all the studied extracts evaluated using CUPRAC (CUPric Reducing Antioxidant Activity), FRAP (Ferric Reducing Ability of Plasma), and DPPH (1,1-diphenyl-2-picrylhydrazyl) assays was comparable. The anti-inflammatory activity of the extracts was tested based on the inhibition of 15-lipoxygenase, cyclooxygenase-1, cyclooxygenase-2 (COX-2), and phospholipase A2. The results demonstrate significantly higher inhibition of COX-2 for in vitro cultured biomass compared with the herb extracts (75.4 and 41.1%, respectively). Moreover, all the studied extracts showed almost similar antibacterial and antifungal potential. Based on these findings, and due to the fact that the growth of in vitro microshoots is independent of environmental conditions and unaffected by environmental pollution, we propose that biomass that can be rapidly grown in RITA® bioreactors can serve as an alternative source of bioactive compounds with valuable biological properties. 相似文献
34.
35.
《Molecules (Basel, Switzerland)》2020,25(24)
The main challenge of plant chemical diversity exploration is how to develop tools to study exhaustively plant tissues. Their sustainable sourcing is a limitation as bioguided strategies and dereplication need quite large amounts of plant material. We examine if alternative solutions could overcome these difficulties by obtaining a secure, sustainable, and scalable source of tissues able to biosynthesize an array of metabolites. As this approach would be as independent of the botanical origin as possible, we chose eight plant species from different families. We applied a four steps culture establishment procedure, monitoring targeted compounds through mass spectrometry-based analytical methods. We also characterized the capacities of leaf explants in culture to produce diverse secondary metabolites. In vitro cultures were successfully established for six species with leaf explants still producing a diversity of compounds after the culture establishment procedure. Furthermore, explants from leaves of axenic plantlets were also analyzed. The detection of marker compounds was confirmed after six days in culture for all tested species. Our results show that the first stage of this approach aiming at easing exploration of plant chemodiversity was completed, and leaf tissues could offer an interesting alternative providing a constant source of natural compounds. 相似文献
36.
Yiyuan Han Zhixing Lin Jiajing Zhou Gyeongwon Yun Rui Guo Joseph J. Richardson Frank Caruso 《Angewandte Chemie (International ed. in English)》2020,59(36):15618-15625
Functional materials composed of proteins have attracted much interest owing to the inherent and diverse functionality of proteins. However, establishing general techniques for assembling proteins into nanomaterials is challenging owing to the complex physicochemical nature and potential denaturation of proteins. Here, a simple, versatile strategy is introduced to fabricate functional protein assemblies through the interfacial assembly of proteins and polyphenols (e.g., tannic acid) on various substrates (organic, inorganic, and biological). The dominant interactions (hydrogen‐bonding, hydrophobic, and ionic) between the proteins and tannic acid were elucidated; most proteins undergo multiple noncovalent stabilizing interactions with polyphenols, which can be used to engineer responsiveness into the assemblies. The proteins retain their structure and function within the assemblies, thereby enabling their use in various applications (e.g., catalysis, fluorescence imaging, and cell targeting). 相似文献
37.
Qi‐Zhi Zhong Joseph J. Richardson Shiyao Li Wenjie Zhang Yi Ju Jianhua Li Shuaijun Pan Jingqu Chen Frank Caruso 《Angewandte Chemie (International ed. in English)》2020,59(4):1711-1717
Functional coatings are of considerable interest because of their fundamental implications for interfacial assembly and promise for numerous applications. Universally adherent materials have recently emerged as versatile functional coatings; however, such coatings are generally limited to catechol, (ortho‐diphenol)‐containing molecules, as building blocks. Here, we report a facile, biofriendly enzyme‐mediated strategy for assembling a wide range of molecules (e.g., 14 representative molecules in this study) that do not natively have catechol moieties, including small molecules, peptides, and proteins, on various surfaces, while preserving the molecule's inherent function, such as catalysis (≈80 % retention of enzymatic activity for trypsin). Assembly is achieved by in situ conversion of monophenols into catechols via tyrosinase, where films form on surfaces via covalent and coordination cross‐linking. The resulting coatings are robust, functional (e.g., in protective coatings, biological imaging, and enzymatic catalysis), and versatile for diverse secondary surface‐confined reactions (e.g., biomineralization, metal ion chelation, and N‐hydroxysuccinimide conjugation). 相似文献
38.
Nine glycosides ( 1–9 ) were characterized from the n‐butanol‐soluble fraction of the ethanolic extract of the leaves of Sageretia thea by the general approach. Among these, Compounds 6 and 7 were identified as a mixture. Application of HPLC‐SPE‐NMR in two selected fractions led to the separation of this mixture and the characterization of three additional minors ( 10–12 ). Among these, 7‐O‐methylmyricetin 3‐O‐α‐l ‐arabinofuranoside ( 8 ) is a new natural product and eight compounds, i.e. glucofragulin A ( 1 ), quercetin‐3‐O‐α‐l ‐arabinopyranoside ( 5 ), 3‐O‐β‐d ‐galactopyranoside ( 6 ), 3‐O‐β‐d ‐glucopyranoside ( 7 ), and 3‐O‐α‐l ‐arabinofuranoside ( 11 ), myricetin‐3‐O‐α‐l ‐arabinofuranoside ( 9 ) and 3‐O‐β‐d‐glucopyranoside ( 10 ), and quercetrin ( 12 ), are found for the first time from the title plant. 相似文献
39.
This study reports the catalytic oxidation and detection of tea polyphenols (TPs) at glassy‐carbon electrode modified with multiwalled carbon nanotubes‐chitosan (MWCNTs‐CS) film. The adsorption of TPs at the surface of the MWCNTs through π–π conjugation prevents the aggregation of nanotubes and induces a stable MWCNTs suspension in water over 30 days. Based on the adsorptive accumulation of polyphenols at MWCNTs, TPs is sensitively and selectively detected by adsorptive stripping voltammetry. The accumulation conditions and pH effect on the adsorptive stripping detection were examined. The linear range was found to be 100 to 1000 mg L?1 with a detection limit of 10 mg L?1 (S/N=3) for 2.5 min accumulation. Additionally, the MWCNTs‐CS electrode is easily renewed by applying positive potential to remove the adsorbed TPs. This method was successfully applied to determine TPs in commercially available teas with satisfied result compared with that of conventional spectrometric analysis. 相似文献
40.
Dmytro Neshchadin Dr. Rebecca Levinn Georg Gescheidt Prof. Dr. Stephen N. Batchelor Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(23):7008-7016
Polyphenols occur naturally in a vast variety of plants. One of their predominant properties is their antioxidant activity. To provide a deeper understanding of the antioxidant mechanism, 1H CIDNP spectroscopy (CIDNP=chemically induced dynamic nuclear polarization) is used to study model hydrogen abstraction reactions with four catechin‐based polyphenols: catechin (CA), gallocatechin (GC), epigallocatechin (EGC), and epigallocatechin gallate (EGCG). The experiments involve photoinduced hydrogen‐atom transfer to a hydrogen abstractor (e.g., excited isopropylthioxanthone) followed under steady‐state conditions and in a time‐resolved fashion (resolution 500 ns–1 ms). It is found that hydrogen abstraction is an essentially stochastic process with a slight preference for the B rings in the catechin‐based polyphenols. Remarkably, analogous reactivity patterns could be followed in the “real systems”, green tea and red wine. We also show that CIDNP can be used as a semiquantitative tool to assess chemical reactivity. 相似文献