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Bioactive Constituents (bioactive + constituent)
Kinds of Bioactive Constituents Selected AbstractsVoltage-Dependent Block of N -Methyl- d -Aspartate Receptors by the Novel Anticonvulsant Dibenzylamine, a Bioactive Constituent of l -(+)-,-HydroxybutyrateEPILEPSIA, Issue 10 2003Sean D. Donevan Summary:,Purpose: Previously we demonstrated that l -(+)-,-hydroxybutyrate (L-BHB), acetoacetate (ACA), acetone, and dibenzylamine (DBA) were anticonvulsant in an audiogenic seizure,susceptible model, and that DBA was a bioactive contaminant identified in commercial lots of L-BHB. In the present study, we asked whether these effects could be mediated by ionotropic glutamate or ,-aminobutyric acidA (GABAA) receptors. Methods: We studied the effects of both stereoisomers of BHB (as well as the racemate), ACA, and DBA on N -methyl- d -aspartate (NMDA), ,-amino-3-hydroxy-5methyl-4-isoxazole-proprionic acid (AMPA), and GABAA receptors in cultured rodent neocortical neurons by using whole-cell voltage-clamp recording techniques. Results: Only L-BHB and DBA exerted a concentration- and voltage-dependent block of NMDA-evoked currents, whereas none of the tested substrates affected AMPA- or GABA-activated currents. The kinetics of whole-cell block by L-BHB and DBA were similar, providing additional evidence that DBA is responsible for the anticonvulsant activity of L-BHB. Conclusions: BHB and ACA do not exert direct actions on GABAA or ionotropic glutamate receptors in cultured neocortical neurons. In addition, we provide additional evidence that DBA is responsible for the anticonvulsant activity of L-BHB, and that this action may be mediated in part by voltage-dependent blockade of NMDA receptors. [source] ChemInform Abstract: Bioactive Constituents of Chinese Natural Medicines.CHEMINFORM, Issue 5 2001Part 5. Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] Bioactive Constituents from Turkish Pimpinella SpeciesCHEMISTRY & BIODIVERSITY, Issue 7 2006Nurhayat Tabanca No abstract is available for this article. [source] Isolation and identification of metabolites from dihydromyricetinMAGNETIC RESONANCE IN CHEMISTRY, Issue 11 2007Yansong Zhang Abstract Dihydromyricetin (DHM) is the major bioactive constituent of Rattan Tea, which is the tender stems and leaves of Ampelopsis grossendentata. Seven metabolites (2,8) of DHM (1) were obtained by the chromatographic method. The metabolites 2,5 were obtained from the urine of rats administered orally with DHM; and metabolites 6,8 were detected in the fecal specimens of rats, which were also produced by human intestinal bacteria (HIB) in vitro, and were separated from the cultured media of HIB containing DHM. Their structures were elucidated as 5,7,3,,5,-tetrahydroxyflavanonol (2); 5,7,3,,5,-tetrahydroxy-4,-methoxyflavanonol (3); 5,7,4,,5,-tetrahydroxy-3,-methoxyflavanonol (4); and dihydromyricetin- O -5-,- D -glucuronide (5); (2R,3S)-5,7,3,,4,,5,-pentahydroxyflavanonol (6); 3,4,5,7,3,,4,,5,-hepthydroxyflavan (7) and 5,7,3,,4,,5,-pentahydroxyflavanone (8) on the basis of UV, NMR and LC-MS/MS data. These seven metabolites were formed through familiar metabolic reactions. Dihydromyricetin- O -5-,- D -glucuronide (5) is a new compound. The 13C-NMR data of (2) and (4) are reported for the first time. Copyright © 2007 John Wiley & Sons, Ltd. [source] Quantitative LC/MS/MS method and in vivo pharmacokinetic studies of vitexin rhamnoside, a bioactive constituent on cardiovascular system from hawthornBIOMEDICAL CHROMATOGRAPHY, Issue 4 2007Mingjin Liang Abstract A simple and accurate liquid chromatography coupled with tandem mass spectrometry method was developed for determination and in vivo pharmacokinetic studies of vitexin rhamnoside in rat plasma. After protein precipitation using methanol, the analytes were separated by a Luna C18 column with an isocratic elution and analyzed by mass spectrometry in multiple reaction monitoring mode using the respective negative ion at m/z 577.2,293.0 for vitexin rhamnoside and m/z 593.2,413.0 for internal standard (IS) vitexin glucoside. The method was validated systematically within the concentration range 5,5000 µg/L (R > 0.996) and the lower limit of quantitation was 5 µg/L. Acceptable precision and accuracy were acquired for concentrations over the standard curve range. It was further applied to assess pharmacokinetics and bioavailability of vitexin rhamnoside after intravenous and oral administration to rats. The oral bioavailability of vitexin rhamnoside was only 3.57%, which indicated that vitexin rhamnoside had poor absorption or underwent extensive first-pass metabolism. Practical utility of this new LC/MS/MS method was confirmed in pilot pharmacokinetic studies in rats following both intravenous and oral administration. Copyright © 2007 John Wiley & Sons, Ltd. [source] CHRACTERIZATION AND 1,1-DIPHENYL-2-PICRYLHYDRAZYL RADICAL SCAVENGING ACTIVITY OF METHANOL AND SUPERCRITICAL CARBON DIOXIDE EXTRACTS FROM LEAVES OF ADINANDRA NITIDAJOURNAL OF FOOD BIOCHEMISTRY, Issue 4 2008BENGUO LIU ABSTRACT Leaves of Adinandra nitida are consumed in southern China as health tea (Shiyacha) and as herbal medicine. In this study, the methanol and supercritical fluid extracts from leaves of A. nitida were obtained by traditional solvent extraction and supercritical carbon dioxide extraction, respectively. Both the extracts showed high 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity. By using ultraviolet-visible spectrometry (UV), infrared spectrometry (IR), nuclear magnetic resonance, electrospray ionization mass spectrometry (ESI-MS), high-performance liquid chromatography-ESI/MS, the main bioactive constituents in the methanol extract (ME) were identified as camellianin A, camellianin B, apigenin. By analysis of gas chromatography-mass spectrometry, a total of 16 compounds accounting for 98.79% of the supercritical fluid extract (SFE) were identified as ,-sitosterol, vitamin E, ,-tocopherol and so on. These compounds found in ME and SFE could contribute to the DPPH radical scavenging performance of the extracts in this study. PRACTICAL APPLICATION Adinandra nitida is a kind of particular wild plant in South China. Few reports have been published about it in the world. In this study, the methanol and supercritical fluid extracts from leaves of A. nitida were respectively obtained by two kinds of industrially significant methods, traditional solvent extraction and supercritical carbon dioxide extraction. By using ultraviolet-visible spectrometry (UV), infrared spectrometry (IR), nuclear magnetic resonance, electrospray ionization mass spectrometry (ESI-MS), high-performance liquid chromatography-ESI/MS, gas chromatography-MS, the main bioactive constituents in the two extracts were identified as flavonoids and plant sterols. Both the extracts showed high 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity and this activity of the flavonoid-rich methanol extract was 10 times more than that of butylated hydroxytoluene. These results showed that leaves of A. nitida is a new kind of natural antioxidant-rich, flavonoid-rich plant source with great commercial interest in the food and phytopharmaceutical market. [source] Permeation of bioactive constituents from Arnica montana preparations through human skin in-vitroJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 9 2006I. A. Tekko This study investigated and characterised transdermal permeation of bioactive agents from a topically applied Arnica montana tincture. Permeation experiments conducted over 48 h used polydimethylsiloxane (silastic) and human epidermal membranes mounted in Franz-type diffusion cells with a methanol-water (50:50 v/v) receptor fluid. A commercially available tincture of A. montana L. derived from dried Spanish flower heads was a donor solution. Further donor solutions prepared from this stock tincture concentrated the tincture constituents 1, 2 and 10 fold and its sesquiterpene lactones 10 fold. Permeants were assayed using a high-performance liquid chromatography method. Five components permeated through silastic membranes providing peaks with relative retention factors to an internal standard (santonin) of 0.28, 1.18, 1.45, 1.98 and 2.76, respectively. No permeant was detected within 12 h of applying the Arnica tincture onto human epidermal membranes. However, after 12 h, the first two of these components were detected. These were shown by Zimmermann reagent reaction to be sesquiterpene lactones and liquid chromatography/diode array detection/mass spectrometry indicated that these two permeants were 11,13-dihydrohelenalin (DH) analogues (methacrylate and tiglate esters). The same two components were also detected within 3 h of topical application of the 10-fold concentrated tincture and the concentrated sesquiterpene lactone extract. [source] Preparation of trypsin-immobilised chitosan beads and their application to the purification of soybean trypsin inhibitorJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 13 2008Li Zhang Abstract BACKGROUND: Trypsin inhibitors are among the most important antinutritional factors in legumes. Recent research has shown that soybean trypsin inhibitor (SBTI) exhibits multiple bioactivities, but very few studies on the purification of SBTI are available. Enzymes are commonly used as biospecific ligands in affinity purification of their substrates or inhibitors. The aim of the present study was to prepare trypsin (EC 3.4.21.4)-immobilised chitosan beads and use them to purify trypsin inhibitor from soybean whey. RESULTS: Compared with free trypsin, the immobilised trypsin had higher thermal and pH stability. The adsorption ratio of SBTI from crude SBTI aqueous solution by trypsin-immobilised chitosan beads was 33.3%. The purified SBTI obtained by affinity chromatography was characterised by sodium dodecyl sulfate polyacrylamide gel electrophoresis as a single polypeptide band with an Mr of 8.3 kDa belonging to the Bowman,Birk family. CONCLUSION: Trypsin-immobilised chitosan beads were effectively used in the affinity separation of trypsin inhibitor from soybean seeds, thus indicating that immobilised trypsin may have practical application in the soybean-processing industry. The results of this study provide a background for further investigation of potential applications of soybean bioactive constituents in the areas of agriculture and food. Copyright © 2008 Society of Chemical Industry [source] 1H and 13 C NMR assignments for two lignans from the heartwood of Streblus asperMAGNETIC RESONANCE IN CHEMISTRY, Issue 5 2008Jun Li Abstract In our ongoing investigation of the bioactive constituents from plants, two new lignans, magnolignan A-2- O -,- D -glucopyranoside and strebluslignanol were isolated from heartwood of Streblus asper, along with three known lignans, magnolignan A, magnolol, and magnaldehyde D. 1D and 2D NMR experiments, including COSY, HMQC, and HMBC, and other spectroscopic methods, including UV, IR, and MS were used for the determination of the structures and NMR assignments. Primary bioassays showed that magnolignan A-2- O -,- D -glucopyranoside and strebluslignanol have medium cytotoxic activity against HEp-2 and HepG2 cells, with IC50 of 13.3 µM, 46.4 µM and 10.1 µM, 21.7 µM, respectively. Copyright © 2008 John Wiley & Sons, Ltd. [source] New developments in the chemistry and biology of the bioactive constituents of tanshen,MEDICINAL RESEARCH REVIEWS, Issue 1 2007Xihong Wang Abstract Tanshen, the rhizome of Salvia miltiorrhiza Bunge, has been used in Chinese traditional medicine (TCM) for multiple therapeutic remedies. The major constituents of Tanshen include water-soluble phenolic acids and lipophilic tanshinones. Phenolic acids possess antioxidant and anticoagulant activities, whereas tanshinones show antibacterial, antioxidant, and antineoplastic activities. This review will focus on recent developments concerning the chemical constituents of Tanshen and their biological activities. These chemical and biological studies continue to increase our understanding about a scientific basis for the traditional clinical use of Tanshen and can also contribute to the development of new drug candidates. Recently, in the author's laboratory, a new compound, neo-tanshinlactone, was discovered to have potent selective antibreast cancer activity. This compound might serve as a lead for developing promising antibreast cancer clinical trials candidates. © 2006 Wiley Periodicals, Inc. Med Res Rev, 27, No. 1, 133,148, 2007 [source] The Effects of Nuts on Coronary Heart Disease RiskNUTRITION REVIEWS, Issue 4 2001Penny M. Kris-Etherton Ph.D. Epidemiologic studies have consistently demonstrated beneficial effects of nut consumption on coronary heart disease (CHD) morbidity and mortality in different population groups. Clinical studies have reported total and low-density lipoprotein cholesterol-lowering effects of heart-healthy diets that contain various nuts or legume peanuts. It is evident that the favorable fatty acid profile of nuts (high in unsaturated fatty acids and low in saturated fatty acids) contributes to cholesterol lowering and, hence, CHD risk reduction. Dietary fiber and other bioactive constituents in nuts may confer additional cardioprotective effects. [source] Application of Scion image software to the simultaneous determination of curcuminoids in turmeric (Curcuma longa)PHYTOCHEMICAL ANALYSIS, Issue 1 2009Uthai Sotanaphun Abstract Introduction Curcumin, desmethoxycurcumin and bisdesmethoxycurcumin are bioactive constituents of turmeric (Curcuma longa). Owing to their different potency, quality control of turmeric based on the content of each curcuminoid is more reliable than that based on total curcuminoids. However, to perform such an assay, high-cost instrument is needed. Objective To develop a simple and low-cost method for the simultaneous quantification of three curcuminoids in turmeric using TLC and the public-domain software Scion Image. Methodology The image of a TLC chromatogram of turmeric extract was recorded using a digital scanner. The density of the TLC spot of each curcuminoid was analysed by the Scion Image software. The density value was transformed to concentration by comparison with the calibration curve of standard curcuminoids developed on the same TLC plate. Results The polynomial regression data for all curcuminoids showed good linear relationship with R2 > 0.99 in the concentration range of 0.375,6 µg/spot. The limits of detection and quantitation were 43,73 and 143,242 ng/spot, respectively. The method gave adequate precision, accuracy and recovery. The contents of each curcuminoid determined using this method were not significantly different from those determined using the TLC densitometric method. Conclusion TLC image analysis using Scion Image is shown to be a reliable method for the simultaneous analysis of the content of each curcuminoid in turmeric. Copyright © 2008 John Wiley & Sons, Ltd. [source] Withanolide sulfoxide from Aswagandha roots inhibits nuclear transcription factor-kappa-B, cyclooxygenase and tumor cell proliferationPHYTOTHERAPY RESEARCH, Issue 7 2009Vanisree Mulabagal Abstract Investigation of the methanol extract of Aswagandha (Withania somnifera) roots for bioactive constituents yielded a novel withanolide sulfoxide compound (1) along with a known withanolide dimer ashwagandhanolide (2) with an S-linkage. The structure of compound 1 was established by extensive NMR and MS experiments. Compound 1 was highly selective in inhibiting cyclooxygenase-2 (COX-2) enzyme by 60% at 100 µm with no activity against COX-1 enzyme. The IC50 values of compound 1 against human gastric (AGS), breast (MCF-7), central nervous system (SF-268) and colon (HCT-116) cancer cell lines were in the range 0.74,3.63 µm. Both S-containing dimeric withanolides, 1 and 2, completely suppressed TNF-induced NF- ,B activation when tested at 100 µm. The isolation of a withanolide sulfoxide from W. somnifera roots and its ability to inhibit COX-2 enzyme and to suppress human tumor cell proliferation are reported here for the first time. In addition, this is the first report on the abrogation of TNF-induced NF- ,B activation for compounds 1 and 2. Copyright © 2009 John Wiley & Sons, Ltd. [source] Characterization of tanshinones in the roots of Salvia miltiorrhiza (Dan-shen) by high-performance liquid chromatography with electrospray ionization tandem mass spectrometryRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 8 2006Min Yang The qualitative analysis of tanshinones in the roots of Salvia miltiorrhiza (Dan-shen in Chinese) was performed using high-performance liquid chromatography with electrospray ionization tandem mass spectrometry (ESI-MSn). Tanshinones are the major bioactive constituents of Dan-shen, which is used in China for the treatment of haematological abnormalities and cardiovascular diseases. The ESI-MSn fragmentation behavior of tanshinones was investigated. For tanshinones with the tanshinone I nucleus, the fragmentation was triggered by loss of a molecule of CO except bearing a substituent at C17 or C18, followed by sequential eliminations of CO. If C15,16 was a saturated bond, the fragmentation was triggered by elimination of a molecule of H2O. For tanshinones with the tanshinone IIA nucleus, the fragmentation was triggered by loss of a molecule of H2O, followed by successive eliminations of CO. Ions corresponding to loss of a molecule of propylene (,m,=,42) were also observed. Moreover, when C15,16 was a saturated bond, ions corresponding to losses of CH3, H2O and propylene were more abundant. If no D-ring existed, the presence of isopropyl resulted in an elimination of a molecule of H2O with an adjacent CO or OH. In addition, the extension of the , -conjugation in the A-ring (especially at C1,2) induced the fragmentation by loss of a molecule of CO. These fragmentation rules were applied to the identification of tanshinones in a chloroform/methanol (3:7) extract of Dan-shen, which was separated on a C18 column with gradient elution. A total of 27 tanshinones were identified, including five new constituents. The established method could be used for the sensitive and rapid identification of tanshinones in the Dan-shen drug and its pharmaceutical preparations. Copyright © 2006 John Wiley & Sons, Ltd. [source] Analysis of bufadienolides in the Chinese drug ChanSu by high-performance liquid chromatography with atmospheric pressure chemical ionization tandem mass spectrometryRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 13 2005Min Ye The qualitative analysis of bufadienolides in the Chinese drug ChanSu was performed using high-performance liquid chromatography with atmospheric pressure chemical ionization tandem mass spectrometry (APCI-MS/MS). Bufadienolides are the major bioactive constituents of ChanSu, which is used to treat heart failure and cancer in traditional Chinese medicine. The APCI-MS fragmentation behavior of bufadienolides was studied. For bufadienolides with only hydroxyl substituents, the fragmentation was characterized by successive eliminations of H2O and CO molecules, and the profile of MS/MS product ions was correlated with the number of hydroxyl groups. If a C-16 acetoxyl group was present, the fragmentation of [M+H]+ ions was triggered by initial loss of 60,Da (HOAc). The elimination of CO was significant for bufadienolides with a 19-formyl group, and the 19-hydroxyl group could be characterized by the loss of 30,Da (HCHO). These fragmentation rules were applied to the identification of bufadienolides in a methanolic extract of ChanSu, which was separated on a C18 column with gradient elution. A total of 35 bufadienolides were identified, including four new constituents. The method established here facilitated the convenient and rapid quality control of ChanSu crude drug and its pharmaceutical preparations. Copyright © 2005 John Wiley & Sons, Ltd. [source] Characterization of phenolic compounds in the Chinese herbal drug Tu-Si-Zi by liquid chromatography coupled to electrospray ionization mass spectrometry,RAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 11 2005Min Ye Phenolic compounds are the major bioactive constituents of the Chinese herbal drug Tu-Si-Zi, which is prepared from the seeds of Cuscuta chinensis. However, seeds of C. australis also are offered under the name of this drug in the herb market. In order to make a comparison of their chemical constituents, the phenolic compounds of these two Cuscuta species were analyzed by high-performance liquid chromatography/diode-array detection/electrospray ion trap tandem mass spectrometry (HPLC/DAD/ESI-MSn). A total of 50 compounds were observed in the methanol extracts, including 23 flavonoids, 20 lignans and 7 quinic acid derivatives. These compounds were separated on a C18 column and identified or tentatively characterized based on UV spectra and MS fragmentation behavior. In contrast to previous reports, the phenolic patterns of these two Cuscuta species were found to be very different. Kaempferol and astragalin were the predominant constituents of C. australis, while hyperoside was the major compound in C. chinensis. Most of the identified compounds, especially the acylated flavonoid glycosides, have not previously been reported from Cuscuta species. In addition, a 30,Da neutral loss observed for flavonols was investigated and could be used to differentiate flavonoid isomers such as kaempferol and luteolin. The ESI-MS fragmentation behavior of furofuran lignans was also investigated, and a characteristic pathway is proposed. The large differences observed between the phenolic constituents of C. chinensis and C. australis strongly encouraged further comparison of the bioactivities of these two species. Copyright © 2005 John Wiley & Sons, Ltd. [source] A simple RP-HPLC method for quantification of columbianadin in rat plasma and its application to pharmacokinetic studyBIOMEDICAL CHROMATOGRAPHY, Issue 4 2010You-Bo Zhang Abstract A rapid and sensitive reversed-phase high-performance liquid chromatographic (RP-HPLC) method was developed to investigate pharmacokinetics of columbianadin, one of the main bioactive constituents in the roots of Angelica pubescens f. biserrata, in rat plasma after intravenous administration to rats at two doses of 10 and 20,mg/kg. The method involves a plasma clean-up step using liquid,liquid extraction by diethyl ether, followed by RP-HPLC separation and detection. Separation of columbianadin was performed on an analytical DiamonsilÔ ODS C18 column, with a mobile phase of MeOH,H2O (85,:,15, v/v) at a flow-rate of 1.0,mL/min, and UV detection was set at 325,nm. The retention time of columbianadin and scoparone (internal standard) was 6.7 and 3.5,min, respectively. The calibration curve was linear over the range of 0.2,20.0,,g/mL (r2 = 0.9986) in rat plasma. The lower limits of detection and quantification were 0.05 and 0.1,,g/mL, respectively. The extraction recovery from plasma was in the range of 81.61,89.93%. The intra- and inter-day precisions (relative standard deviation) were between 1.01 and 9.33%, with accuracies ranging from 89.76 to 109.22%. The results indicated that the method established was suitable for the determination and pharmacokinetic study of columbianadin in rat plasma. Copyright © 2009 John Wiley & Sons, Ltd. [source] Simultaneous determination of twelve bioactive constituents in Buyang Huanwu decoction by HPLC-DAD-ELSD and HPLC-TOF/MSBIOMEDICAL CHROMATOGRAPHY, Issue 2 2010E-Hu Liu Abstract Buyang Huanwu Decoction (BYHYD) is a classical traditional Chinese medicinal prescription that has been widely used for treating cerebrovascular illnesses for hundreds of years. In this study, a comprehensive analytical method has been developed for quantitative analysis of the major constituents in BYHWD. This method was based on high-performance liquid chromatography coupled to a diode array and evaporative light scattering detectors (HPLC-DAD-ELSD) on a common reverse-phase C18 column. HPLC coupled with on-line time-of-flight mass spectrometry (HPLC-TOF/MS) was additionally adopted to provide further validation for the constituents. It was found that 0.3% aqueous formic acid and acetonitrile was the optimum mobile phase for gradient elution. This method, which showed excellent precision and accuracy, was successfully applied to quantify the bioactive constituents in six BYHWD products. The validated HPLC-DAD-ELSD method, together with the HPLC-TOF/MS analysis, provided a new basis for assessing the quality of traditional Chinese medicinal prescription consisting of many bioactive components. Copyright © 2009 John Wiley & Sons, Ltd. [source] Determination and pharmacokinetic study of tussilagone in rat plasma by RP-HPLC methodBIOMEDICAL CHROMATOGRAPHY, Issue 11 2008Yu-Feng Liu Abstract A simple and rapid high-performance liquid chromatographic method was used to study the pharmacokinetics of tussilagone, one of the main bioactive constituents in the flower buds of Tussilago farfara L. of traditional Chinese medicines, in rat plasma. Plasma was deproteinized by ethyl acetate for sample clean-up. The drugs were separated on a Dikma DiamonsilÔ C18 column (4.6 × 250 mm, 5.0 µm), and detected by UV absorption at 220 nm. Methanol,water (75:25, v/v) was used as the mobile phase. It was applied to the pharmacokinetic study of tussilagone in rats after a dose of 5 mg/kg by intravenous administration and a dose of 200 mg/kg by intragastrical administration. A biphasic phenomenon with a rapid distribution followed by a slower elimination phase was observed from the plasma concentration,time curve by intravenous administration, while the plasma concentration,time curve of tussilagone conformed to a one-compartment model by intragastrical administration. The absolute bioavailability of tussilagone is about 1.31%. Copyright © 2008 John Wiley & Sons, Ltd. [source] | ||||||||||||||||||||||