Eucommia Ulmodies Research Articles

Preparation and properties of NR/EUG composite film

Natural rubber latex (NRL) products have the following problems: poor dimensional stability caused by low modulus and difficulty in wearing caused by high surface adhesion. In order to solve the above problems, the present paper developed eucommia ulmodies latex (EUL), and successfully prepared natural rubber (NR)/ Eucommia ulmoides gum (EUG) composite film by blending EUL into NRL. The results showed that the appearance of EUL was milky white, which was similar to natural latex. The latex particles were regular spherical, and the particle sizes were in the range of 100 nm~2000 nm. Like the solid EUG, the EUG in latex particles kept crystalline state as well, which were α-form and β-form respectively. As the content of EUG increased from 0 % to 40 %, the crystallinity of the NR/EUG composite film gradually increased, which increased the highest modulus by 207 % and enhanced the dimensional stability of the film. At the same time, the crystallinity of EUG could effectively reduce the adhesion on the surface of the film, so it could improve the fitness of gloves and other latex products to human organs and facilitate wearing and taking off. At last, adding an appropriate amount of EUL could enhance the tear performance of the composite film. When the content of EUG was 20 %, the tear strength of the film increased by 19 %, which improved the cutting resistance of the latex product. So, the NR/EUG composite film could be used to develop high-modulus, low adhesive force of surface, high tear performance and super thin latex product. • EUG is made into latex by emulsion solvent evaporation technology. • NR/EUG composite film is first prepared. • The addition of EUL can increase the modulus of NR/EUG films. • The addition of EUL can increase the tear properties of NR/EUG films. • The addition of EUL can reduce adhesion of NR/EUG films.

Chlorogenic Acids in Cardiovascular Disease: A Review of Dietary Consumption, Pharmacology, and Pharmacokinetics.

Chlorogenic acids (CGAs) have gained considerable attention as pervasive human dietary constituents with potential cardiovascular-preserving effects. The main sources include coffee, yerba mate, Eucommia ulmodies leaves, and Lonicerae Japonicae Flos. CGA consumption can reduce the risks of hypertension, atherosclerosis, heart failure, myocardial infarction, and other factors associated with cardiovascular risk, such as obesity and type 2 diabetes. This review recapitulates recent advances of CGAs in the cardiovascular-preserving effects, pharmacokinetics, sources, and safety. Emerging evidence indicates that CGAs exhibit circulatory guarding properties through the suppression of oxidative stress, leukocyte infiltration, platelet aggregation, platelet-leukocyte interactions, vascular remodeling, and apoptosis as well as the regulation of glucose and lipid metabolism and vasodilatory action in the cardiovascular system. CGAs exert these effects by acting on complex signaling networks, but the global mechanisms are still not clear. The oral bioavailability of CGA is poor, and there is a potential sensitization concern about CGA. The bioactive metabolites, systematic toxicity, and optimized structure are needed for further identification.

Analysis of chemical constituents in an herbal formula Jitong Ning Tablet

Jitong Ning Tablet (JTNT), a traditional Chinese herbal formula, consists of Eucommia ulmodies oliv, Angelicae pubescentis radix, Aconiti radix cocta, Corydalis yanhusuo w.t. wang, Glycyrrhizae radix et rhizoma, Paeoniae radix rubra and Radix puerariae. It has been demonstrated to show protective effects on ankylosing spondylitis and anti-inflammatory effects. The chemical compositions of JTNT, playing a key role in quality control, remain unknown. In this study, an ultra-performance liquid chromatography combined with quadrupole time of flight mass spectrometry (UPLC-Q–TOF–MS) method in both positive and negative ion mode was established to investigate the chemical constituents of JTNT formula. In total, 162 compounds including flavonoids, triterpenoids, coumarins, alkaloids, phenylpropionic acids, lignans, terpenoids, and organic acids were detected, 152 of which were unambiguously or tentatively identified by comparing their retention times and accurate mass measurement with reference compounds and data in literatures. Our results would benefit quality control and chemical basis for JTNT.

Molecularly imprinted polymer for caffeic acid by precipitation polymerization and its application to extraction of caffeic acid and chlorogenic acid from Eucommia ulmodies leaves

Molecularly imprinted polymers (MIPs) for caffeic acid (CA) were prepared using 4-vinylpyridine and methacrylamide (MAM) as functional monomers, divinylbenzene as a crosslinker and acetonitrile–toluene (3:1, v/v) as a porogen by precipitation polymerization. The use of MAM as the co-monomer resulted in the formation of microsphere MIPs and non-imprinted polymers (NIPs) with ca. 3- and 5-μm particle diameters, respectively. Binding experiments and Scatchard analyses revealed that the binding capacity and affinity of the MIP to CA are higher than those of the NIP. The retention and molecular-recognition properties of the prepared MIPs were evaluated using water–acetonitrile and sodium phosphate buffer–acetonitrile as mobile phases in hydrophilic interaction chromatography (HILIC) and reversed-phase chromatography, respectively. In HILIC mode, the MIP showed higher molecular-recognition ability for CA than in reversed-phase mode. In addition to shape recognition, hydrophilic interactions seem to work for the recognition of CA on the MIP in HILIC mode, while hydrogen bonding and hydrophobic interactions seem to work for the recognition of CA in reversed-phase mode. The MIP had a specific molecular-recognition ability for CA in HILIC mode, while other structurally related compounds, such as chlorogenic acid （CGA), gallic acid, protocatechuic acid and vanillic acid, could not be recognized by the MIP. Furthermore, the MIP was successfully applied for extraction of CA and CGA in the leaves of Eucommia ulmodies in HILIC mode.

Molecularly imprinted polymer for chlorogenic acid by modified precipitation polymerization and its application to extraction of chlorogenic acid from Eucommia ulmodies leaves

Molecularly imprinted polymers (MIPs) for chlorogenic acid (CGA) were prepared by modified precipitation polymerization using methacrylic acid as a functional monomer, divinylbenzene as a crosslinker and methanol or dimethylsulfoxide as a co-solvent. The prepared MIPs were microspheres with a narrow particle size distribution. Binding experiments and Scatchard analyses revealed that two classes of binding sites, high and low affinity sites, were formed on the MIP. The retention and molecular-recognition properties of the prepared MIP were evaluated using a mixture of water and acetonitrile as a mobile phase in hydrophilic interaction chromatography. With an increase of acetonitrile content, the retention factor of CGA was increased on the MIP. In addition to shape recognition, hydrophilic interactions seem to work for the recognition of CGA on the MIP. The MIP had a specific molecular-recognition ability for CGA, while other related compounds, such as caffeic acid, gallic acid, protocatechuic acid and vanillic acid, could not be recognized by the MIP. Furthermore, the MIP for CGA was successfully applied for extraction of CGA in the leaves of Eucommia ulmodies.

An Outlook on Chlorogenic Acids—Occurrence, Chemistry, Technology, and Biological Activities

Phenolics are widespread dietary antioxidants. Among these, chlorogenic acids (CGAs) received considerable attention for their wide distribution and part of human diet with potential biological effects. CGAs (71 compounds), being esters of derivatives of cinnamic acids with quinic acid are widely distributed in plant materials. Coffee is among the highest found in plants, ranging from 4 to 14%. Besides, these are reported in plant foods such as apples, pears, carrot, tomato, sweet potato, Phyllostachys edulis, oilseeds, Prunus domestica L, cherries, and eggplant. The traditional Chinese medicinal plants such as flowers and buds of Lonicera japonica Thunb and the leaves of Eucommia ulmodies contained CGAs as bioactive compound. These play an important role in the formation of roasted coffee flavor and have a marked influence on coffee cup quality. CGAs are considered as main precursors of coffee flavor and pigments. Recent technological advancements in the separation and purification of CGAs such as molecular-imprinted polymer technique; microwave-assisted extraction; pH gradient counter current chromatography has also been described. The consumption of coffee correlated to several health benefits such as reducing the risk of human chronic diseases such as inflammation, diabetes, and cardiovascular disease owing to its antioxidant potential.

Screening, Identification, and Potential Interaction of Active Compounds from Eucommia ulmodies Leaves Binding with Bovine Serum Albumin

The aqueous extract of Eucommia ulmoides leaves has been commonly known as Du-zhong tea as a functional health food for the treatment of hypertension, hypercholesterolemia, and fatty liver. This study developed a centrifugal ultrafiltration-high-performance liquid chromatography (HPLC) method for screening and identification of bioactive compounds in E. ulmoides leaves binding with bovine serum albumin (BSA). Six active compounds were screened, isolated, and elucidated by their ultraviolet (UV), electrospray ionization-mass spectrometry (ESI-MS), and nuclear magnetic resonance (NMR) data as geniposidic acid (1), caffeic acid (2), chlorogenic acid (3), quercetin-3-O-sambubioside (4), rutin (5), and isoquercitrin (6). The interaction between active compounds and BSA was investigated in the absence and presence of other compounds by quenching the intrinsic BSA fluorescence. The results indicated that the structures significantly affected the binding process. The values of binding constants for compounds 2-6 were in the range of 10(5)-10(6) mol L(-1), while geniposidic acid (1) hardly quenching the BSA intrinsic fluorescence. However, the quenching process of geniposidic acid was easily affected in the presence of other active compounds. The formation of the geniposidic acid-phenylpropanoid (flavonoid) complex could increase the binding affinity of geniposidic acid with BSA; however, the increased steric hindrance of the complex may make phenylpropanoid or flavonoid dissociate from BSA and then decrease their affinities.

A rapid ultra performance liquid chromatography–tandem mass spectrometric method for the qualitative and quantitative analysis of ten compounds in Eucommia ulmodies Oliv.

A rapid method for qualitative and quantitative analysis of constituents in Eucommia ulmoides Oliv. was developed by ultra performance liquid chromatography with electrospray ionization–tandem mass spectrometry (UPLC–ESI-MS). Ten compounds including iridoids, phenylpropanoids, and flavonoids were identified and further quantified as marker substances by UPLC-UV using switching UV wavelength within 16 min. The separation was carried out on an Acquity UPLC BEH C 18 column with 0.1% formic acid aqueous solution and acetonitrile as the mobile phase under gradient conditions. The developed method was applied to the quality assessment of various E. ulmoides samples, including different medicinal parts, differently processed bark and bark from different habitats. The results showed that the branches of E. ulmoides were not suitable for medicinal use. The process of carbonizing led to significant loss of major components, whereas the process of stir-frying with salt-water enhanced the extraction of chlorogenic acid with negligible loss of the other components. The contents of the investigated compounds varied very remarkably for the bark of E. ulmoides collected from different habitats. This study might provide a comprehensive method for the quality assessment of E. ulmoides.

Selection and fingerprints of the control substances for plant drug Eucommia ulmodies Oliver by HPLC and LC–MS

Eucommia ulmodies Oliver ( E. ulmodies) has been used as herbal medicine for thousands years in China. The selection of the control substances and their fingerprints of this plant medicine were investigated by using high performance liquid chromatography (HPLC) and liquid chromatography–mass spectrometry (LC–MS). The gradient elution mode was applied in chromatographic separation, and the data was analyzed by “Computer Aided Similarity Evaluation” software to compare the similarity of the E. ulmodies from different habitats. Low similarity was found in the samples from nonadjacent provinces, while high similarity was obtained in those from the adjacent provinces. The LC–MS fingerprints of E. ulmodies showed the main active constituents and could be used for its original identification and quality evaluation.

Separation and purification of chlorogenic acid by molecularly imprinted polymer monolithic stationary phase

Separation and purification of chlorogenic acid by removal of the impurities compounds co-existed in the product using molecular imprinting technique was firstly reported. In this work, an in situ synthesis method was utilized for the preparation of molecularly imprinted polymer monolithic stationary phase using the impurity molecule (caffeic acid) as template, the mixture of tetrahydrofuran and isooctane as solvent, and methacrylic acid and ethyl glycol dimethacrylate as functional monomer and cross-linker, respectively. The retention behavior of the monolithic polymer to chlorogenic acid molecule, the template and several main impurities compounds in the product was studied and the adsorption capacity of compounds on the stationary phase determined by frontal chromatographic technique. A relatively weak retention of the target product molecule (chlorogenic acid) on the polymer and a strong adsorption capability of the monolith to the template and several main impurities were observed. This might mainly result from the ‘shape’ difference of chlorogenic acid molecule with the impurities compounds molecules. This approach was shown to be successful for the separation and purification of chlorogenic acid from the extract of Eucommia ulmodies leaves.

Solvent effects on focused microwave assisted extraction of polyphenolic acids from Eucommia ulmodies

An open microwave-assisted extraction system was used to extract gallic acid, protocatechuic acid, chlorogenic acid and caffeic acid from Eucommia ulmodies. The effect of extraction variables, especially solvent, on the recoveries of these polyphenolic compounds was investigated using factorial design. As extracting solvent for these compounds, methanol produced a higher recovery than pure water. For straight chain alcohol solvents, the lower the carbon number, the higher the recoveries of the polyphenolic acids. The optimal ratio of methanol:water:glacial acetic acid in the solvent mixture used in microwave-assisted extraction was 2:8:0.3 (v/v) and this solvent could be directly used as the mobile phase in HPLC separation without additional intermittent treatment as reported in literature. The extraction under the condition of 50% microwave power and 30 s irradiation at a solvent:sample ratio of 10 (mL/g) was found to be the most advantageous. The repeatability test of extraction and chromatographic analysis was satisfactory for the analysis of these polyphenolic compounds.

Application of ultrasonic technique for extracting chlorogenic acid from Eucommia ulmodies Oliv. ( E. ulmodies)

An ultrasonic method for the extraction of chlorogenic acid from fresh leaves of Eucommia ulmodies Oliv. was investigated and optimized. The influence of four extraction variables on extraction efficiency of chlorogenic acid was investigated. The optimum extraction conditions found were: 70% aqueous methanol; solvent: sample ratio=20:1 (v/w); extraction time 3 × 30 min. The recovery of chlorogenic acid was studied (HPLC) and the reproducibility of the extraction method was determined. The optimized ultrasonic extraction conditions were applied to extract chlorogenic acid from fresh leaves, fresh bark and dried bark of E. ulmodies and four traditional Chinese medicines. The application of sonication method was shown to be highly efficient in the extraction of chlorogenic acid from E. ulmodies and other Chinese medicines compared with classical methods.

Focused microwave-assisted solvent extraction and HPLC determination of effective constituents in Eucommia ulmodies Oliv. (E. ulmodies)

A new focused microwave-assisted solvent extraction method using water as solvent has been developed for leaching geniposidic and chlorogenic acids from Eucommia ulmodies Oliv. The extraction procedures were optimized using a two indexes orthogonal experimental design and graphical analysis, by varying irradiation time, solvent volume, solvent composition and microwave power. The optimum extraction conditions were obtained: for geniposidic acid, 50% micorwave power, 40s irradiation, and 80% (v/v) aqueous methanol as extraction solvent (20mlg−1 sample); and for chlorogenic acid, 50% micorwave power, 30s irradiation, and 20% aqueous methanol (20mlg−1 sample). The composition of the extraction solvent was optimized and can be directly used as the mobile phase in the HPLC separation. Quantification of organic acids was done by HPLC at room temperature using Spherigel C18 chromatographic column (250mm×4.6mm, i.d. 5μm), the methanol:water:acetic acid (20:80:1.0, v/v) mobile phase and UV detection at 240nm. The R.S.D. of the extraction process for geniposidic and chlorogenic acid were 3.8 and 4.1%, respectively.