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Chemical Markers (chemical + marker)
Selected AbstractsFragrant Volatile Compounds in the Liverwort Drepanolejeunea madagascariensis (Steph.) Grolle: Approach by the HS-SPME TechniqueCHEMISTRY & BIODIVERSITY, Issue 3 2010Anne Gauvin-Bialecki Abstract Three populations of the epiphyllous liverwort Drepanolejeunea madagascariensis collected in the cloud forests of Reunion Island (Mascarene Archipelago) were investigated for their volatile compounds, because of the pleasant, sweet, warm, woody-spicy, and herbaceous fragrance, slightly reminiscent of dill, of this species. By applying the headspace solid-phase microextraction (HS-SPME) technique coupled to GC/MS analysis, 34 compounds were detected in total, with p -menth-1-en-9-ol (28.8,43.5%), limonene (10.5,14.7%), , -phellandrene (8.8,11.6%), and the so-called dill ether (8.5,16.6%) as the main components. The presence of 1-epi- , -pinguisene confirms the possible use of pinguisane-type sesquiterpenoids as a characteristic chemical marker for the order Jungermanniales. [source] Determination of multicomponent contents in Calculus bovis by ultra-performance liquid chromatography,evaporative light scattering detection and its application for quality controlJOURNAL OF SEPARATION SCIENCE, JSS, Issue 10 2010Weijun Kong Abstract A fast ultra-performance liquid chromatography,evaporative light scattering detection (UPLC-ELSD) method was established for simultaneous quantification of seven components in natural Calculus bovis (C. bovis) and its substitutes or spurious breeds. On a Waters Acquity UPLC® BEH C18 column, seven analytes were efficiently separated using 0.2% aqueous formic acid,acetonitrile as the mobile phase in a gradient program. The evaporator tube temperature of ELSD was set at 100°C with the nebulizing gas flow-rate of 1.9,L/min. The results showed that this established UPLC-ELSD method was validated to be sensitive, precise and accurate with the LODs of seven analytes at 2,11,ng, and the overall intra-day and inter-day variations less than 3.0%. The recovery of the method was in the range of 97.8,101.6%, with RSD less than 3.0%. Further results of PCA on the contents of seven investigated analytes suggested that compounds of cholic acid, deoxycholic acid and chenodeoxycholic acid or cholesterol should be added as chemical markers to UPLC analysis of C. bovis samples for quality control and to discriminate natural C. bovis sample and its substitutes or some spurious breeds, then normalize the use of natural C. bovis and ensure its clinical efficacy. [source] Simultaneous qualification and quantification of eight triterpenoids in Radix Achyranthis Bidentatae by high-performance liquid chromatography with evaporative light scattering detection and mass spectrometric detectionJOURNAL OF SEPARATION SCIENCE, JSS, Issue 6 2007Juan Li Abstract An HPLC with evaporative light scattering detection (ELSD) and ESI-MS was established for the simultaneous determination of eight triterpenoids in Radix Achyranthis Bidentatae. The optimal chromatographic conditions were achieved on a Zorbax C18 column by linear gradient elution with 0.08% v/v aqueous formic acid and ACN as the mobile phase at the flow rate of 0.8 mL/min. Temperature for the detector drift tube was set at 101°C and the nitrogen flow rate was 2.8 L/min. The identities of the analytes were accomplished by comparing retention times and mass data with those of reference compounds. The validation of the method included tests of linearity, sensitivity, repeatability, recovery, and stability. All the calibration curves of the eight triterpenoids showed good linear regression (R2 >0.997) within the test ranges. The method provides desirable repeatability with overall intra- and interday variations of less than 4.9%. The obtained recoveries varied between 93.6 and 98.1% while the RSDs were below 3.9% (n = 3). The analysis results indicate that the content of investigated triterpenoids in Radix Achyranthis Bidentatae from different locations was greatly diverse, and the triterpenoids could be used as chemical markers for the discrimination of genuine and ungenuine crude drugs. [source] Characterisation of varnishes used in violins by pyrolysis-gas chromatography/mass spectrometryRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 23 2008Giuseppe Chiavari The correct characterisation and a detailed knowledge of the materials originally used in violin varnishes, like natural resins, is crucial for the conservation in museums and for a suitable restoration technique. The study presented here reports on the potential of pyrolysis (Py) coupled with gas chromatography (GC) and mass spectrometry (MS) for the identification of chemical markers of each resin; this tecnique is very sensitive and selective, it needs a small quantity of sample and does not require chemical treatments. To improve the chromatographic behaviour of polar compounds the derivatising agent tetramethylammonium hydroxide (TMAH) in combination with pyrolysis has been used, in the so-called TMAH thermochemolysis or thermally assisted hydrolysis and methylation (THM), or more simply pyrolysis-methylation. The natural resins studied were colophony, sandarac, manila copal, elemi, amber and benzoin, mainly composed of terpenic compounds, with the exception of the latter, composed of aromatic compounds. Many compounds were identified; in particular, methyl esters of resinous acids that, individually or in a group, can be used as chemical markers. However, through this technique it was not possible to distinguish between the sandarac and manila copal resins because their chromatographic behaviour is very similar. Finally, the procedure applied has been employed in the characterisation of original varnish samples. Copyright © 2008 John Wiley & Sons, Ltd. [source] Secondary metabolite production by the fungal pathogen Eutypa lata: Analysis of extracts from grapevine cultures and detection of those metabolites in plantaAUSTRALIAN JOURNAL OF GRAPE AND WINE RESEARCH, Issue 2 2006RICHARD LARDNER Eutypa dieback of grapevines is caused by the fungal pathogen Eutypa lata and reduces vineyard longevity worldwide. Early detection could reduce losses due to this disease, so our aim was to identify acetylenic phenol metabolites of E. lata that could prove suitable as chemical markers in an early diagnostic test for the pathogen. Accordingly, secondary metabolite production by 30 isolates of E. lata grown on media derived from canes of three grapevine cultivars was analysed using HPLC. Six metabolites, namely eutypinol, methyl eutypinol, eulatachromene, eutypine, 2- iso -propenyl-5-formylbenzofuran and eulatinol, were detected in culture filtrates. Most abundant were eutypinol and methyl eutypinol, produced by 97 and 83% of isolates, respectively. There was no apparent correlation between secondary metabolite production on media containing milled canes from the three cultivars of grapevine, and the field tolerance of these same cultivars to Eutypa dieback. When various other fungi commonly isolated from grapevine trunks in Australia were grown on milled cane, no secondary metabolites characteristic of E. lata were detected, suggesting such compounds are specific to E. lata. To examine the detection of secondary metabolites in planta, micropropagated grapevine plantlets were treated with purified or crude culture filtrates from nine isolates of E. lata grown on malt yeast broth. Various secondary metabolites were identified in treated plantlets, however, no single compound was detected consistently. Eutypinol was detected in micropropagated grapevine plantlets inoculated with mycelium of E. lata, however, no metabolites were detected in the sap of vines which had been artificially inoculated with the pathogen. [source] Improved chromatographic fingerprints for facile differentiation of two Ganoderma spp.BIOMEDICAL CHROMATOGRAPHY, Issue 3 2009Chun-Mei Fu Abstract This paper addresses a comprehensive and comparative study of six phytochemical extraction methods for triterpenes from the fruiting body of Ganoderma spp. Quantitative analysis of extracts was performed by HPLC with photodiode array detection. In general, pressurized liquid extraction and microwave-assisted extraction under optimized conditions produce better yields, and the former also significantly reduces the total time of extraction and manipulation of a sample, as well as the amount of solvent used in comparison with conventional soxhlet, reflux, ultrasonic, and methanol,CO2 supercritical fluid extractions. Based on the improved extraction protocol, the fingerprinting profiles for two species of Lingzhi were established using the consistent chromatographic features of 12 authentic samples. Eleven common peaks of ganoderic/ganoderenic acids were identified using LC-ESI-MS-MS. These specific triterpene groups were adopted as chemical markers for Lingzhi. Using chemometric analysis, the developed fingerprinting was successfully applied to differentiate between the two species under the Ganoderma genus and is applicable as a method for quality evaluation of this valuable medicinal fungus and its related proprietary products. Copyright © 2008 John Wiley & Sons, Ltd. [source] | ||||||||||