Qualitative and quantitative analysis of Radix Astragali products by fast high-performance liquid chromatography-diode array detection coupled with time-of-flight mass spectrometry through dynamic adjustment of fragmentor voltage.
ABSTRACT A novel fast high-performance liquid chromatography (HPLC) method coupled with diode array detection (DAD) and time-of-flight mass spectrometry (TOF/MS) was developed for qualitative and quantitative analysis of Radix Astragali products. The potential of fast HPLC on 1.8-microm particles was compared with the performance of HPLC on conventional 5-microm particles columns. Significant advantages of fast HPLC include high-speed chromatographic separation, four times faster than HPLC with conventional columns, and great enhancement in sensitivity with limits of detection low to 0.001 ng. With dynamic adjustment of fragmentor voltage in TOF/MS, an efficient transmission of the ions was achieved to obtain the best sensitivity and abundant fragmentation. By accurate mass measurements within 5 ppm error for each molecular ion and subsequent fragment ions, a reliable identification and differentiation of six major saponins including two groups of isomers and twelve main isoflavonoids was described here for the first time. For quantitative analysis by fast HPLC-TOF/MS, linearity of response over two orders of magnitude was demonstrated (r(2)>0.99) for all analytes. Intra-day reproducibility was below 3% RSD and inter-day values were below 5% RSD. A good correlation (slope=1.1108, r(2)=0.9853) was observed for accuracy test. It is concluded that the fast and sensitive HPLC-DAD-TOF/MS is powerful in qualitative and quantitative analysis of complex herbal medicines in terms of time savings, sensitivity, selectivity, precision, accuracy as well as increasing sample throughout and lowering solvent consumption.
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ABSTRACT: A novel method has been developed for rapid analysis of the major constituents in Radix Astragali and honey-processed Astragalus within 23 minutes using ultra-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight mass spectrometry (UPLC/ESI-Q-TOF-MS). Separation analysis was performed on HSS T3 columns with gradient elution of acetonitrile-water containing 0.1% formic acid at a flow rate of 0.3 mL/min. Methodology validation showed that the established method had good repeatability (RSD<8.07%), intra-day precisions (RSD<4.20%), and stability (RSD<7.78%). Accurate molecular weight and characteristic fragment ions obtained from Q-TOF-MS provided a reliable criterion for structural characterization of the major compounds in raw and honey-processed Astragalus. 35 major constituents, including flavonoids, isoflavan, pterocarpan, and saponins, were identified or tentatively characterized by comparing their retention time and MS spectra with those of authentic standards and literature data. Further quantitative analysis revealed that the content changes of chemical compositions could cause the tonic effect differences between raw and honey-processed Astragalus. The established method is rapid and reliable for simultaneous analysis of constituents in an extract of Radix Astragali, and this method will simplify further studies of metabolism and pharmacodynamics and will encourage the use of HSS T3 columns in similar traditional Chinese medicine research.Analytical methods 08/2014; 6(19). DOI:10.1039/C4AY01098A · 1.94 Impact Factor
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ABSTRACT: A rapid and high-sensitive ultra-fast liquid chromatography coupled with a diode-array detector and a quadrupole/time-of-flight mass spectrometry (MS) method was established and validated for the chemical profiling of Nao-shuan-tong capsule (NSTC) and simultaneous quantification of five major constituents. A total of 59 components including monoterpene glycosides, flavonoids, sesquiterpenoids, ketosteroids, thiophenes, organic acids and alkaloids were identified or tentatively characterized in NSTC based on the accurate mass and tandem MS behavior. Five major bioactive constituents were chosen as the chemical indexes of holistic quality evaluation and quantified simultaneously. All calibration curves showed good linear regression (r(2) > 0.9991) in the range 25.2-510, 145-2,900, 1.84-36.8, 2.61-52.2 and 3.25-26.2 μg/mL for gastrodin, paeoniflorin, typhaneoside, β-ecdysterone and isorhamnetin-3-O-neohesperidoside, respectively. It also showed good precision, stability and accuracy for quantification of these five compounds. The limit of detections and limit of quantitations for the analytes ranged from 0.14 to 1.09 μg/mL and from 0.47 to 3.63 μg/mL, respectively. The validated quantification method was applied to analyze 10 batches of commercial NSTC. These results will provide a basis for quality control of the production process and the further pharmacological study in vivo of NSTC.Journal of chromatographic science 10/2014; DOI:10.1093/chromsci/bmu137 · 1.03 Impact Factor
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ABSTRACT: Danggui Buxue Tang (DBT) is a Traditional Chinese Medicine (TCM) formula primarily used to treat symptoms associated with menopause in women. Usually, DBT is composed of one portion of Radix Angelicae Sinensis (RAS) and five portions of Radix Astragali (RA). Clinically, Radix Hedysari (RH) is sometimes used by TCM physicians to replace RA in DBT. In order to verity whether the chemical constituents of the DBT1 (RA:RAS = 5:1, w/w) and DBT2 (RH:RAS = 5:1, w/w) share similarities the chemical profiles of the two DBTs crude extracts and urine samples were analyzed and compared with the aid of HPLC-DAD-ESI-IT-TOF-MSn, which determines the total ion chromatogram (TIC) and multi-stage mass spectra (MSn). Then, the DBT1 and DBT2 were identified and compared on the basis of the TIC and the MSn. In the first experiment (with crude extracts), 69 compounds (C1-C69) were identified from the DBT1; 46 compounds (c1-c46) were identified from the DBT2. In the second experiment(with urine samples), 44 compounds (M1-M44) were identified from the urine samples of rats that had been administered DBT1, and 34 compounds (m1-m34) were identified from the urine samples of rats that had been administered DBT2. Identification and comparison of the chemical compositions were carried out between the DBT1 and DBT2 of the crude extracts and urine samples respectively. Our results showed that the two crude extracts of the DBTs have quite different chemical profiles. The reasons for their differences were that the special astragalosides in DBT1 and the isoflavonoid glycosides formed the malonic acid esters undergo single esterification and acetyl esters undergo acetylation in DBT1. In contrast, the urine from DBT1-treated rats strongly resembled that of DBT2-treated rats. These metabolites originate mainly from formononetin, calycosin and their related glycosides, and they were formed mainly by the metabolic process of reduction, deglycosylation, demethylation, hydrogenation and sulfation. The HPLC-DAD-ESI-IT-TOF-MSn method was successfully applied for the rapid chemical profiles evaluation of two DBTs and their related urine samples.Molecules 05/2014; 19(5):5650-5673. DOI:10.3390/molecules19055650 · 2.10 Impact Factor