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Main Active Constituents (main + active_constituent)

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Chemistry	75%

Selected Abstracts

Analysis of sesquiterpene lactones in Eupatorium lindleyanum by HPLC-PDA-ESI-MS/MS

PHYTOCHEMICAL ANALYSIS, Issue 2 2010
Nian Yun Yang
Abstract Introduction , The aerial part Eupatorium lindleyanum is commonly used as an antipyretic and detoxicant clinically in traditional Chinese medicine. Our previous research showed that germacrane sesquiterpene lactones were its main active constituents, so the development of rapid and accurate methods for the identification of the sesquiterpene lactones is of great significance. Objective , To develop an HPLC-PDA-ESI-MS/MS method capable for simple and rapid analysis of germacrane sesquiterpene lactones in the aerial part E. lindleyanum. Methodology , High-performance liquid chromatography-photodiode array detection-electrospray ionization-tandem mass spectrometry was used to analyze germacrane sesquiterpene lactones of Eupatorium lindleyanum. The fragmentation behavior of germacrane sesquiterpene lactones in a Micromass Q/TOF Mass Spectrometer was discussed, and 9 germacrane sesquiterpene lactones were identified by comparison of their characteristic data of HPLC and MS analyses with those obtained from reference compounds. Results , The investigated germacrane sesquiterpene lactones were identified as eupalinolides C (1), 3,-acetoxy-8,-(4,-hydroxy-tigloyloxy)-14-hydroxy-costunolide (2), eupalinolides A (3), eupalinolides B (4), eupalinolides E (5), 3,-acetoxy-8,-(4,-oxo-tigloyloxy)-14-hydroxy-heliangolide (6), 3,-acetoxy-8,-(4,-oxo- tigloyloxy)-14-hydroxy-costunolide (7), hiyodorilactone B (8), and 3,-acetoxy-8,-(4,-hydroxy-tigloyloxy)- costunolide (9). Compounds 6, 7 and 9 were reported for the first time. Conclusion , HPLC-PDA-ESI-MS/MS provides a new powerful approach to identify germacrane sesquiterpene lactones in E. lindleyanum rapidly and accurately. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Gas chromatographic analysis of dimethyltryptamine and , -carboline alkaloids in ayahuasca, an amazonian psychoactive plant beverage

PHYTOCHEMICAL ANALYSIS, Issue 2 2009
Ana Paula Salum Pires
Abstract Introduction Ayahuasca is obtained by infusing the pounded stems of Banisteriopsis caapi in combination with the leaves of Psychotria viridis. P. viridis is rich in the psychedelic indole N,N -dimethyltryptamine, whereas B. caapi contains substantial amounts of , -carboline alkaloids, mainly harmine, harmaline and tetrahydroharmine, which are monoamine-oxidase inhibitors. Because of differences in composition in ayahuasca preparations, a method to measure their main active constituents is needed. Objective To develop a gas chromatographic method for the simultaneous determination of dimethyltryptamine and the main , -carbolines found in ayahuasca preparations. Methodology The alkaloids were extracted by means of solid phase extraction (C18) and detected by gas chromatography with nitrogen/phosphorous detector. Results The lower limit of quantification (LLOQ) was 0.02 mg/mL for all analytes. The calibration curves were linear over a concentration range of 0.02,4.0 mg/mL (r2 > 0.99). The method was also precise (RSD < 10%). Conclusion A simple gas chromatographic method to determine the main alkaloids found in ayahuasca was developed and validated. The method can be useful to estimate administered doses in animals and humans for further pharmacological and toxicological investigations of ayahuasca. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Identification and determination of major flavonoids in rat urine by HPLC-UV and HPLC-MS methods following oral administration of Dalbergia odorifera extract

BIOMEDICAL CHROMATOGRAPHY, Issue 1 2006
Rongxia Liu
Abstract Flavonoids are the main active constituents of Dalbergia odorifera. The excretion of the major flavonoids in rat urine after oral administration of D. odorifera extract was investigated by HPLC-UV and HPLC-MS methods. Utilizing the HPLC-MS technique, 18 flavonoids, including five isoflavones, four isoflavanones, four neoflavones, two flavanones, two chalcones and one isoflavanonol were identified in free form in a urine sample based on the direct comparison of the corresponding tR, UV maximum absorbance (,max) values and MS data with the authentic standards. The amounts of the prominent flavonoids, (3R)-4,-methoxy-2,,3,7-trihydroxyisoflavanone and vestitone, were determined by HPLC-UV with the internal standard method, and the validation procedure confirmed that it afforded reliable analysis of these two analytes in urine after oral administration of D. odorifera extract. Copyright © 2005 John Wiley & Sons, Ltd. [source]

Promotion of axonal maturation and prevention of memory loss in mice by extracts of Astragalus mongholicus

BRITISH JOURNAL OF PHARMACOLOGY, Issue 5 2006
C Tohda
Background and purpose: Neurons with atrophic neurites may remain alive and therefore may have the potential to regenerate even when neuronal death has occurred in some parts of the brain. This study aimed to explore effects of drugs that can facilitate the regeneration of neurites and the reconstruction of synapses even in severely damaged neurons. Experimental approach: We investigated the effects of extracts of Astragalus mongholicus on the cognitive defect in mice caused by injection with the amyloid peptide A,(25-35). We also examined the effect of the extract on the regeneration of neurites and the reconstruction of synapses in cultured neurons damaged by A,(25-35). Key results: A. mongholicus extract (1 g kg,1 day,1 for 15 days, p.o.) reversed A,(25-35)-induced memory loss and prevented the loss of axons and synapses in the cerebral cortex and hippocampus in mice. Treatment with A,(25-35) (10 ,M) induced axonal atrophy and synaptic loss in cultured rat cortical neurons. Subsequent treatment with A. mongholicus extract (100 ,g/ml) resulted in significant axonal regeneration, reconstruction of neuronal synapses, and prevention of A,(25-35)-induced neuronal death. Similar extracts of A. membranaceus had no effect on axonal atrophy, synaptic loss, or neuronal death. The major known components of the extracts (astragalosides I, II, and IV) reduced neurodegeneration, but the activity of the extracts did not correlate with their content of these three astragalosides. Conclusion and implications: A. mongholicus is an important candidate for the treatment of memory disorders and the main active constituents may not be the known astragalosides. British Journal of Pharmacology (2006) 149, 532,541. doi:10.1038/sj.bjp.0706865 [source]