In the present study, nine compounds (1-9) were isolated from Colletotrichum gloeosporioides (an endophytic fungus from Uncaria rhynchophylla) which was cultured in wheat bran medium. Their structures were elucidated as 4-Epi-14-hydroxy-10, 23-dihydro-24, 25-dehydroaflavinine (1), 10, 23-Dihydro-24,25 -dehydro-21-oxoaflavinine (2), Ergosterol (3), Ergosterol peroxide (4), Mellein (5), 4, 5-dihydroblumenol A (6), Colletotrichine A (7), Cyclo(L-leucyl-L-leucyl) (8), and Brevianamide F (9) based on NMR spectral data, as well as comparing with previous literature data. This is the first report about the isolation of compounds 1-2, 6, and 8-9 from Colletotrichum genus. All compounds were tested for their phosphoinositide 3-kinase (PI3Kα) inhibitory activity. Compounds 8 and 9 showed potent PI3K α inhibitory activity with IC50 values of 38.1 and 4.8 µM, respectively, while the other compounds showed very weak activity at a concentration of 20 µg/mL.
In the present study, nine compounds (1-9) were isolated from Colletotrichum gloeosporioides (an endophytic fungus from Uncaria rhynchophylla) which was cultured in wheat bran medium. Their structures were elucidated as 4-Epi-14-hydroxy-10, 23-dihydro-24, 25-dehydroaflavinine (1), 10, 23-Dihydro-24,25 -dehydro-21-oxoaflavinine (2), Ergosterol (3), Ergosterol peroxide (4), Mellein (5), 4, 5-dihydroblumenol A (6), Colletotrichine A (7), Cyclo(L-leucyl-L-leucyl) (8), and Brevianamide F (9) based on NMR spectral data, as well as comparing with previous literature data. This is the first report about the isolation of compounds 1-2, 6, and 8-9 from Colletotrichum genus. All compounds were tested for their phosphoinositide 3-kinase (PI3Kα) inhibitory activity. Compounds 8 and 9 showed potent PI3K α inhibitory activity with IC50 values of 38.1 and 4.8 µM, respectively, while the other compounds showed very weak activity at a concentration of 20 µg/mL.
Highland barley is one of the most important industrial crops in Tibetan plateau. Previous research indicated that highland barley has many medical functions. In this work, the antibacterial abilities of highland barley were investigated. The protein solutions hydrolyzed by trypsin for 4 h exhibited the highest antibacterial activity. An antibacterial peptide, barleycin, was screened and purified by magnetic liposome extraction combining with the protein profiles of reversed-phase high-performance liquid chromatography (RP-HPLC). Structure, characterization, and safety evaluation of barleycin were further investigated. Amino acids sequence was determined as Lys-Ile-Ile-Ile-Pro-Pro-Leu-Phe-His by N-sequencing. Circular dichroism spectra indicated the a-helix conformation of barleycin. The activity spectrum included <i>Bacillus subtilis, Staphylcoccus aureus, Listeria innocua and Escherichia coli</i> and the MICs were from 4 to 16 μg/mL. Safety evaluations with cytotoxicity and hemolytic suggested this antibacterial peptide could be considered as safe at MICs. Finally, mode of action of barleycin on sensitive cells was primarily studied. The results suggested the damage of cell membrane.
Recent researches shows that amino acids (AA) are not only cell signaling molecules but are also regulators of gene expression and the protein phosphorylation cascade. More precise analysis of AA composition is reckoned to be one of the most important applications in the biomedical and pharmaceutical fields. In this paper, we develop a sample, sensitive and mild method using 2-[2-(7H-dibenzo[a,g]carbazol-7-yl)-ethoxy]ethyl chloroformate (DBCEC) as A labeling reagent for AA determination by high-performance liquid chromatography (HPLC) with fluorescence detection (FLD) and identification with mass spectroscopy. The maximum excitation and emission wavelengths for DBCEC-AA derivatives were 300 and 395 nm, respectively. This method, in conjunction with a gradient elution, offered a baseline resolution of 20 AA on a reversed-phase Hypersil BDS C<sub>18</sub> column. LC separation for the derivatized AA showed good reproducibility, and all AA were found to give excellent linear responses with correlation coefficients > 0.9993. The calculated detection limits with a 25.0 fmol injection of each AA (at a signal-to-noise ratio of 3:1) ranged from 2.62 to 22.6 fmol. This method was applied to determine the AA composition in <i>Saussurea involucrate</i> and <i>Artemisia capillaris</i> Thunb. Meanwhile, this method exhibits a powerful potential for trace analysis of AA from biomedicine, foodstuff and other complex samples. Copyright © 2010 John Wiley & Sons, Ltd.
Five phenylethanoid glycosides (PhGs), forsythoside B, verbascoside, alyssonoside, isoverbascoside, and leucosceptoside B, were isolated and purified from Lamiophlomis rotata (Benth.) Kudo by high-speed counter-current chromatography (HSCCC) combined with macroporous resin (MR) column separation. In the present study, the two-phase solvent system composed of ethyl acetate/n-butanol/water (13:3:10, v/v/v) was used for HSCCC separation. A total of 27 mg of forsythoside B, 41 mg of verbascoside, 29 mg of alyssonoside, 23 mg of isoverbascoside, and 13 mg of leucosceptoside B with purities of 97.7, 99.2, 99.5, 99.3, and 97.3%, respectively, were obtained in a one-step separation within 4 h from 150 mg of crude extract. The recoveries of the five PhGs after MR-HSCCC separation were 74.5, 76.5, 72.5, 76.4, and 77.0%, respectively. The chemical structures of all five compounds were identified by (1) H and (13) C NMR spectroscopy.
A new flavonoid, along with 16 known ones, was separated from the aerial parts of Asterothamnus centrali-asiaticus. Their structures were elucidated by extensive spectroscopic methods, including 1D and 2D NMR techniques and HRESIMS. To confirm the structure of the new compound, computational prediction of its 13C chemical shifts was performed. All of the 17 flavonoids were reported from A. centrali-asiaticus for the first time. In addition, all flavonoids were evaluated for their antioxidant and α-glucosidase inhibitory activities. The results showed that 10 of them exhibited antioxidant activity. Meanwhile, four flavonoids displayed α-glucosidase inhibitory effect with IC50 values ranging from 38.9 to 299.7 μM.
Six compounds including two n-butyrophenone isomers and two stibene isomers were obtained from Rheum tanguticum Maxim. Two n-butyrophenone isomers with a separation factor of 1.14 were successfully separated by recycling high-speed counter-current chromatography after ten cycles. Two stibene isomers were successfully separated by preparative high-performance liquid chromatography. High-performance liquid chromatography analysis showed that the purities of the compounds were all over 98%. These compounds were identified as lindleyin, isolindleyin, resveratrol-4'-O-(2″-O-galloyl)-glucopyranoside, resveratrol-4'-O-(6''-O-galloyl)-glucopyranoside, emodin 1-O-β-d-glucoside, and 3,5-dihydroxy-4'-methoxystilbene-3-O-β-d-glucopyranoside. The results indicated that recycling high-speed counter-current chromatography and preparative high-performance liquid chromatography could be effective combination for the preparation of bioactive compounds from Rheum tanguticum Maxim.
Anthraquinone glycosides, such as chrysophanol 1-O-β-d-glucoside, chrysophanol 8-O-β-d-glucoside, and physion 8-O-β-d-glucoside, are the accepted important active components of Rheum tanguticum Maxim. ex Balf. due to their pharmacological properties: antifungal, antimicrobial, cytotoxic, and antioxidant activities. However, an effective method for the separation of the above-mentioned anthraquinone glycosides from this herb is not currently available. Especially, greater difficulty existed in the separation of the two isomers chrysophanol 1-O-β-d-glucoside and chrysophanol 8-O-β-d-glucoside. This study demonstrated an efficient strategy based on preparative high-performance liquid chromatography and high-speed countercurrent chromatography for the separation of the above-mentioned anthraquinone glycosides from Rheum tanguticum Maxim.ex Balf.
This study presents an efficient strategy for separation of three phenolic compounds with high molecular weight from the crude extract of Terminalia chebula Retz. by ultrasound-assisted extraction and high-speed counter-current chromatography. The ultrasound-assisted extraction conditions were optimized by response surface methodology and the results showed the target compounds could be well enriched under the optimized extraction conditions. Then the crude extract was directly separated by high-speed counter-current chromatography without any pretreatment using n-hexane/ethyl acetate/methanol/water (1:7:0.5:3, v/v/v/v) as the solvent system. In 180 min, 13 mg of A, 18 mg of B, and 9 mg of C were obtained from 200 mg of crude sample. Their structures were identified as Chebulagic acid (A, 954 Da), Chebulinic acid (B, 956 Da), and Ellagic acid (C) by (1) H NMR spectroscopy.
The determination of trace plant growth regulator (PGR) has received more and more attentions in the field of phytophysiology and food safety. But the simple and sensitive method for simultaneously analysing multiple classes of PGR remains poorly investigated. In this study, a new pre-column fluorescence labelling method using 2-(11H-benzo[a]carbazol-11-yl)-ethyl-4-methylbenzenesulfonate (BCETS) as the labelling reagent has been developed for simultaneous determination of seven PGRs (i.e., indole-3-acetic acid, 3-indolybutyric acid, 3-indolepropionic acid, jasmonic acid, gibberellin A3, 1-naphthylacetic acid and 2-naphthaleneacetic acid) by HPLC with fluorescent detection (FLD). The proposed method offered the LOD of 0.34-0.73 ng/mL for seven PGRs, which were significantly lower than the reported methods. The crude extract without complex pre-treatments and purification was directly labelled by BCETS and analysed by HPLC-FLD, which facilitates the high-throughput sample screening. This method was proven to be inexpensive, simple, selective, sensitive, accurate and reliable for trace PGR determination.
A reversed-phase high-performance liquid chromatographic method with diode array detection was established to simultaneously determine the seven bioactive lignans in <i>Herpetospermum caudigerum</i>, namely ent-isolariciresinol (<b>1</b>), dehydrodiconiferyl alcohol (<b>2</b>), herpetrione (<b>3</b>), herpetin (<b>4</b>), herpetetrone (<b>5</b>), herpetotriol (<b>6</b>) amd herpetal (<b>7</b>). The HPLC assay was performed on a Restek Pinnacle DB C<sub>18</sub> column (250 × 4.6 mm, 5 µm) with gradient elution of acetonitrile and 0.1% phosphoric acid within 65 min. The detection wavelength was 240 nm. The flow-rate was 1.0 mL/min. All calibration curves showed good linearity (<i>r</i>² > 0.9998) within test ranges. The method was reproducible with intra- and inter-day variation of less than 1.98%. The method provided good accuracy with recoveries in the range 95.19-102.64% with RSDs less than 1.52%. The method was successfully applied to the quantification of seven constituents in 15 <i>H. caudigerum</i> samples collected from different cities. The results indicated that the developed assay could be considered as a suitable quality control method for <i>H. caudigerum</i>. Copyright © 2008 John Wiley & Sons, Ltd.
A simple, sensitive and selective method based on one-step fluorescence labeling and ultrasound-assisted dispersive liquid-liquid microextraction (UA-DLLME) was developed for the determination of biogenic amines (BAs) in foodstuff samples by high-performance liquid chromatography (HPLC) with fluorescence detection (FLD). In this work, fluorescence probe 2-(11H-benzo[a]carbazol-11-yl) ethyl carbonochloridate (BCEC-Cl) was applied to label BAs. What followed was the UA-DLLME procedure that was carried out using chloroform and acetone as extraction and disperser solvents, respectively. A response surface methodology (RSM) based on a Box-Behnken design (BBD) was employed to optimize the main parameters affecting the fluorescence labeling and DLLME efficiency. Under the optimal conditions, this method offered low limits of detection (LODs) of 1.1-7.8 ng/mL and limits of quantification (LOQs) of 3.5-26.1 ng/mL. Finally, the method was successfully used for the determination of trace BAs in real samples and exhibited powerful potential in the high-throughput sample screening.
<br>• A DLLME/HPLC-FLD method for triterpenic acid determination was developed. • DLLME was firstly used for preconcentration of triterpenic acids in medicinal herbs. • This method was sensitive and selective for triterpenic acid analysis. • A new derivatization reagent for triterpenic acid has been synthesized.<br>A novel analytical method was developed for simultaneous determination of six triterpenic acids using ultrasound-assisted dispersive liquid-liquid microextraction (UA-DLLME) follow by high-performance liquid chromatography (HPLC) with fluorescence detection. Six triterpenic acids (ursolic acid, oleanolic acid, betulinic acid, maslinic acid, betulonic acid and corosolic acid) were extracted by UA-DLLME using chloroform and acetone as the extraction and disperser solvents, respectively. After the extraction and nitrogen flushing, the extracts were rapidly derivatized with 2-(12,13-dihydro-7H-dibenzo[a,g]carbazol-7-yl)ethyl4-methylbenzenesulfonate. The main experimental parameters affecting extraction efficiency and derivatization yield were investigated and optimized by response surface methodology (RSM) combined with Box-Behnken design (BBD). The limits of detection (LODs) and the limits of quantification (LOQs) were in the range of 0.95-1.36 ng mL−1 and 3.17-4.55 ng mL−1, respectively. Under the optimum conditions, the method has been successfully applied for the analysis of triterpenic acids in six different traditional Chinese medicinal herbs.
Purpose: To develop an ultra-high performance liquid chromatography (UPLC) - photodiode array (PDA) method to compare the chemical composition of two different medicinal components of Pterocephalus hookeri. Methods: Samples were chromatographically separated in succession using Waters Acquity UPLCR BEH C18 column (2.1 × 100 mm, 1.7 µm) and gradient elution (0.2% phosphoric acid aqueous - acetonitrile). Using partial least squares discriminant analysis and one-way analysis of variance, attempts were made to distinguish different medicinal parts of P. hookeri. Results: Regression equation for 10 compounds showed good linear regression (R² > 0.9994). The relative standard deviations of precision, stability, repeatability and recovery were under 5%. Compared with the aerial plant part, the root had significantly higher levels of sylvestroside I (p < 0.01), cantleyoside (p < 0.001), dipsanosides B (p < 0.01) and dipsanosides A (p < 0.01), but significantly lower levels of loganic acid (p < 0.001), chlorogenic acid (p < 0.01), and isochlorogenic acid (p < 0.01). There were no significant differences between loganin, sweroside and isochlorogenic acid C. Conclusion: The described method is simple, accurate and reproducible, and can be used for the simultaneous determination of 10 major compounds of P. hookeri. The results demonstrate that there is variation in the chemical composition of the aerialpart and root of P. hookeri and that loganic acid and cantleyoside are the primary chemical biomarkers.
This study is to develop an UPLC-PDA method for determination of 10 major components in Pterocephalus. The UPLC-PDA assay was performed on a Waters Acquity UPLCR BEH C₁₈（2.1 mm ×100 mm,1.7 μm）, and the column temperature was at 30 ℃. The mobile phase consists of water containing 0.2% phosphoric acid (A) and acetonitrile (B) in gradient elution at a flow rate of 0.4 mL•min⁻¹. The detection wave length was set at 237 and 325 nm, and the injection volume was 1 μL in the UPLC system. The linear range of 10 detected compounds were good (r≥0.999 7), and the overall recoveries ranged from 96.30% to 103.0%, with the RSD ranging from 0.72% to 2.9%. The method was simple, accurate and reproducible, which can be used for the simultaneous determination of the content of ten major components in P. hookeri.
A chemometrics-assisted excitation-emission matrix (EEM) fluorescence method is presented for simultaneous determination of umbelliferone and scopoletin in Tibetan medicine Saussurea laniceps (SL) and traditional Chinese medicine Radix angelicae pubescentis (RAP). Using the strategy of combining EEM fluorescence data with second-order calibration method based on the alternating trilinear decomposition (ATLD) algorithm, the simultaneous quantification of umbelliferone and scopoletin in the two different complex systems was achieved successfully, even in the presence of potential interferents. The pretreatment is simple due to the "second-order advantage" and the use of "mathematical separation" instead of awkward "physical or chemical separation". Satisfactory results have been achieved with the limits of detection (LODs) of umbelliferone and scopoletin being 0.06ngmL(-1) and 0.16ngmL(-1), respectively. The average spike recoveries of umbelliferone and scopoletin are 98.8±4.3% and 102.5±3.3%, respectively. Besides, HPLC-DAD method was used to further validate the presented strategy, and t-test indicates that prediction results of the two methods have no significant differences. Satisfactory experimental results imply that our method is fast, low-cost and sensitive when compared with HPLC-DAD method.
• A simultaneous microwave/ultrasonic-assisted enzymatic extraction method was established for the first time. • Simultaneous microwave/ultrasonic-assisted enzymatic process can improve antioxidant capacity of juice by-product extract. • Simultaneous microwave/ultrasonic-assisted enzymatic process can increase the extraction efficiency of antioxidant ingredients. • <b>Nitraria tangutorun</b> Bobr. juice by-products extract exhibited excellent cell protection effect from oxidative injury.<br>By-products originating from food processing are a considerable disposal problem for the food industry. Because of the absence of specifically effective processing technology, huge quantities of by-products are often abandoned as rubbish and prone to microbial spoilage. Given this, a simultaneous microwave/ultrasonic assisted enzymatic extraction (SMU-AEE) method was established for the first time, and performed for antioxidant ingredients extraction from <b>Nitraria tangutorum</b> juice by-products (NJB) in the present study. Its experimental conditions were optimized by single factor test and response surface methodology (RSM), and gave the corresponding response values for antioxidant capacity of NJB extract (NJBE) of 219.73 ± 7.03 mg TE/g, which was 27.62%-190.23% higher than those obtained by traditional extraction methods. Chemical composition assay suggested that the increasing of antioxidant capacity of NJBE by SMU-AEE was because of the improvement of extraction efficiency of antioxidant ingredients from NJB, including phenols, flavonoids and anthocyanins. Furthermore, oxidative injury protection ability assay showed that NJBE was good at protecting cells from UVB-oxidative phototoxicity and doxorubicin-oxidative cardiotoxicity, and its protecting ability surpasses or approaches to that of grape seed extract (GSE, the positive control drug), indicating its good potential to be a natural antioxidant in food and pharmaceutical industries.
<p>Contains a Tibetan-Chinese vocabulary. The terms found here come from Asanga's <em>Yogācāryabhūmiśāstra</em>. (Michael Walter and Manfred Taube 2006-05-15, revised by Bill McGrath 2008-01-03)</p>
Background. Xiaotong Tiegao (XTT) is an ancient topical Tibetan medicine plaster which is widely used in China. Irritant contact dermatitis (ICD) caused by XTT is very common. It is still unclear why some people are more prone to develop ICD. The aim of this study is to study the baseline skin biophysical parameters and patch test results in individuals predisposing to XTT induced ICD. Methods. During a four-month period, 149 healthy volunteers with ICD and 50 volunteers without ICD after applying XTT were recruited. The skin biophysical parameters were measured, and contact allergy to 20 common allergens was patch tested, at two weeks after the ICD was recovered. Results. There were no significant differences in age and sex between ICD and control groups. It was found that skin median melanin value (176.50 vs 189.50, P < 0.05, Mann-Whitney U-test) and erythema value (319.90 ± 70.49 vs 347.93 ± 84.55, P < 0.05, Independent-Samples T test) were much lower in ICD than control group. Overall patch test results were not different, but the positivity rate of nickel sulfate (15.44% vs 4.00%, P < 0.05, Fisher's exact test) was significantly higher in ICD group. Conclusions. In conclusion, people with nickel allergy, lower values of skin melanin, and erythema are predisposing to develop ICD. [ABSTRACT FROM AUTHOR]
Background: Xiaotong Tiegao (XTT) is an ancient topical Tibetan medicine plaster which is widely used in China. Irritant contact dermatitis (ICD) caused by XTT is very common. It is still unclear why some people are more prone to develop ICD. The aim of this study is to study the baseline skin biophysical parameters and patch test results in individuals predisposing to XTT induced ICD. Methods: During a four-month period, 149 healthy volunteers with ICD and 50 volunteers without ICD after applying XTT were recruited. The skin biophysical parameters were measured, and contact allergy to 20 common allergens was patch tested, at two weeks after the ICD was recovered. Results: There were no significant differences in age and sex between ICD and control groups. It was found that skin median melanin value (176.50 vs 189.50, P < 0.05, Mann-Whitney U-test) and erythema value (319.90 ± 70.49 vs 347.93 ± 84.55, P < 0.05, Independent-Samples T test) were much lower in ICD than control group. Overall patch test results were not different, but the positivity rate of nickel sulfate (15.44% vs 4.00%, P < 0.05, Fisher's exact test) was significantly higher in ICD group. Conclusions: In conclusion, people with nickel allergy, lower values of skin melanin, and erythema are predisposing to develop ICD.
Emissions of nitrous oxide (N₂O) contribute to global warming and stratospheric ozone depletion. Anthropogenic N₂O emissions predominately result from the addition of synthetic nitrogen (N) fertilizers to terrestrial ecosystems. Usually, an exponential increase in N₂O emissions occurs as N addition rates increase to exceed plant demands. However, most evidence to date is from temperate areas, with little information available for alpine ecosystems. Here we examined the changes in N₂O flux under eight N addition levels and the mechanisms regulating these changes in a Tibetan alpine steppe. Our results showed that N₂O emission rate increased linearly with increasing N additions. Even when soil N availability exceeded plant N uptake, no sharp N₂O emissions were observed. The likely explanation was that decreased soil temperature limited the growth of nitrification-related microorganisms, mainly ammonia-oxidizing archaea, which further attenuated the positive response of N₂O emissions to excess N supply. These findings suggest that the N-induced changes in soil temperature regulate the growth of nitrifying microorganisms and the subsequent N₂O fluxes in this alpine steppe, and the exponential N₂O emission-N rate relationship observed in warm regions may not be simply extrapolated to alpine ecosystems.<br>N₂O emission exhibited a linear, rather than an exponential, response to increasing N additionsN₂O flux was explained by the changes in AOA along this N addition gradientDecreased soil temperature limited the growth of AOA, weakening the positive response of N₂O flux to excess N supplies
In order to investigate the embryological characteristics of <i>Delavaya toxocarpa</i> Franch. and provide a basis for further understanding the phylogeny within Sapindaceae s.l., we studied the sporogenesis and gametogenesis of <i>D. toxocarpa</i> using the conventional paraffin section method. The results were as follows: anthers are tetrasporangium; tapetum is typically secretory type; cytokinesis in the microsporecyte meiosis is of the simultaneous type and microspore tetrads are tetrahedral; mature pollen contains two cells; the ovary is bilocular with two ovules per locule; placentation is axial; the ovule is amphitropous, bitegmic, and crassinucellate; the chalazal megaspore in a linear tetrad becomes functional; and the development of megaspore is of the polygonum type. Most similarities shared by the species observed suggest that the species and genera of Sapindaceae s.l. have phylogenetic consistency. The distinctive trait, lacking hypostase, indicates <i>Delavaya</i> (and <i>Handeliodendron</i>) might be more primitive than other genera in Sapindaceae. Moreover, some characters, such as opposite palmate compound leaf, apical thyrse, rounded seed without wing, 2 hemitropous ovules per locule, and lacking aril, indicate the close relationship between <i>Delavaya</i>, Aceraceae, and Hippocastanaceae. The preliminary data about the embryological and morphological characteristics in <i>Delavaya</i> might justify the basic systematic position of this genus in the family Sapindaceae s.s.
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