Authors:P. Srivastava, H. Raut, H. Puntambekar and A. Desai
Storage of medicinal plants may cause deterioration of the active principles with time, thus, reducing the efficacy of plants. Therefore, quantification of the active principle is essential before using the crude drug. Phyllanthus amarus (PA) contains lignans, namely, phyllanthin and hypophyllanthin, which shows anti-hepatotoxic activity. In this paper, we highlight the effect of storage conditions on the quantification of bioactive markers by high-performance liquid chromatography (HPLC) analysis in the crude plant material of PA. HPLC analysis of crude PA samples stored for certain period at long-term study (LS, 30 °C and 65% RH), accelerated study (AS, 40°C and 75% RH), and real-time study (RT) conditions was carried out using the LiChroCART Purospher® STAR RP-18 endcapped (250 × 4.6 mm, 5 μm) column along with a Purospher STAR RP 18e (4.0 × 4.0 mm, 5 μm) guard column using methanol:water (70:30) at a flow rate of 0.7 mL min−1 with ultraviolet (UV) detection at 220 nm. The HPLC study indicated that PA samples kept under LS condition are rich in lignan contents as compared to the samples stored under AS and RT study conditions. Therefore, PA should be used fresh to get maximum concentration of active lignans or it should be stored under LS conditions up to 6 months.
Authors:F. Wang, H. Fan, D. Chen, H. Bai, Z. Chen and L. Xiao
Radiolabeled somatostatin analogue is a useful ligand for scintigraphic imaging of somatostatin receptor-bearing tumors. In
this study, we investigated the effects of different radiolabeling conditions on labeling yield and ratio between mono-iodinated
and di-iodinated125I-Tyr3-octreotide by HPLC analysis. In vitro and in vivo stabilities of125I-Tyr3-octreotide and111In-DTPA-D-Phe1-octreotide were also determined. Both radiolabeled compounds were relatively stable in vitro, but were decomposed to free125I− and111In-DTPA in vivo, respectively.
Plants have developed various mechanisms to protect themselves against oxidative stress. One of the most important non-enzymatic antioxidants is ascorbic acid. There is thus a need for a rapid, sensitive method for the analysis of the reduced and oxidised forms of ascorbic acid in crop plants. In this paper a simple, economic, selective, precise and stable HPLC method is presented for the detection of ascorbate in plant tissue. The sensitivity, the short retention time and the simple isocratic elution mean that the method is suitable for the routine quantification of ascorbate in a high daily sample number. The method has been found to be better than previously reported methods, because of the use of an economical, readily available mobile phase, UV detection and the lack of complicated extraction procedures. The method has been tested on Arabidopsis plants with different ascorbate levels and on wheat plants during Cd stress.
Authors:E.E. Sage, Y.X. Chang, R. Wickneswari and M.M. Mackeen
HPLC-UV system. The sample set was kept at -20 °C for 24 h and injected into the HPLC-UV system using the same method. 1.5 HPLCanalysis of HN labelled samples GABA standards and samples labelled with HN were analysed in triplicate using an Agilent 1100
Authors:M. Drobac, J. Arsenijević and N. Kovačević
reduced pressure (Rotavapor RII, Buchi) and redissolved in 5 ml of 80% (v/v) MeOH. Prior to injection, extracts were filtered through a 0.45 μm syringe filter (Captiva, Agilent Technologies). 1.3 HPLCanalysisHPLCanalysis was performed on an Agilent 1100
A novel method for separating and concentrating magnolol and honokiol from Magnoliae Cortex by solvent sublation and analysis of the compounds by high-performance liquid chromatography (HPLC) has been established. The optimum conditions for solvent sublation were use of n-butanol as sublation solvent, sample solution at pH 2, nitrogen flow 50 mL min–1, and sublation time 50 min. The floating product obtained under the optimum conditions was determined by HPLC analysis on a C18 reversed-phase column, with 22:78 (%, v/v) water-methanol as isocratic mobile phase at a flow rate of 1.00 mL min–1. When the method was used for quantification of magnolol and honokiol in Magnoliae Cortex recovery ranged from 98.1 to 106.1%, RSD was from 3.07 to 4.80%, and LOD for honokiol and magnolol were 0.94 and 1.14 ng mL–1, respectively.
Authors:M. Szaufer-Hajdrych, W. Bylka, I. MatłAwska, M. Wójciak-Kosior, G. Matysik and J. Jodynis-Liebert
Densitometric HPTLC and HPLC have been used for quantification of p-coumaric and protocatechuic acids in an ethereal fraction from a methanolic extract of Aquilegia vulgaris L. HPLC analysis was performed on an RP-18 column with methanol-water-formic acid 25:75:0.5 (υ/υ) as mobile phase. Thin layer chromatography was performed on Si60 F254 HPTLC plates with mixtures of heptane, dichloromethane, diisopropyl ether, formic acid, and water as mobile phases. Satisfactory separation of the phenolic acids was achieved by use of the multiple gradient development technique. The quantities of p-coumaric and protocatechuic acids determined by HPLC were 0.374 and 2.283 mg g−1 dry plant material, respectively; HPTLC results were somewhat higher — 0.396 and 2.584 mg g−1, respectively. The precision of both methods, expressed as relative standard deviation, was satisfactory. The methods are useful for quality control of Aquilegia vulgaris extracts.
The fruits of Cucurbita pepo L. var. melopepo Alef. are very much appreciated in low calory human diets, mainly for their delicate taste. Their carotenoid pattern has not yet been established, as both the epicarp and the mesocarp are white, suggesting that they contain no carotenoids. HPLC analysis of carotenoids from these fruits revealed a chromatographic pattern very similar to that of other fruits belonging to different varieties of Cucurbita pepo L. - a fact with great chemotaxonomic importance. The main carotenoids are lutein and ß-carotene; traces of violaxanthin, lactucaxanthin, ß-cryptoxanthin, 9Z-ß-carotene and 15Z-ß-carotene are also present. HPLC separation was achieved on a Nucleosil 120 - 5 C18 column, using the following mobile phases: A - acetonitrile : water (9 : 1) and B - ethyl acetate. The flow rate was 1 ml/min and the solvent gradient was as follows: from 0 to 16 min - 10 to 70% B, then from 16 to 25 min - 70 to 10% B. Quantification of the carotenoids was achieved by the internal standard method, using echinenone as internal standard. The total carotenoid content was found to be 1.12 µg carotenoids/g dry weight for the mesocarp and 3.62 µg carotenoids/g dry weight for the epicarp.
Authors:F.-Y. Du, X.-H. Xiao, P.-P. Xu and G.-K. Li
An efficient ionic liquid-based microwave-assisted (IL-MAE) method has been developed for extraction of dehydrocavidine from Corydalis saxicola Bunting (C. saxicola) for subsequent rapid analysis by high-performance liquid chromatography (HPLC). The yield of dehydrocavidine reached 9.446 mg g−1 within 10 min under the optimum IL-MAE conditions (1.5 mol L−1 [hmim]Br as extraction solvent, liquid-to-solid ratio 20:1 (mL:g), and extraction temperature 70°C). Compared with conventional procedures, the proposed IL-MAE method has many advantages, for example high extraction yield, short extraction time, low solvent consumption, no use of volatile organic solvents, and no further sample clean-up before HPLC analysis. The method was validated for limit of detection (LOD) and quantification (LOQ), linearity, precision, recovery, and reproducibility. The calibration range was 5.0–200 mg L−1 and the correlation coefficient, r, was 0.9996. The LOD and LOQ were 0.035 and 0.12 mg L−1, respectively. The relative standard deviations of intra-day and inter-day assays were below 2.6% and 6.5%, respectively. Recovery was between 93.8% and 109.3% with RSD values below 5.0%. The method can be used for rapid and effective extraction and analysis of active components from medicinal plants.
Authors:T. Sivakumar, R. Manavalan and K. Valliappan
This paper deals with optimization of a liquid-liquid extraction procedure for simultaneous HPLC analysis of domperidone and pantoprazole in human plasma. Central composite design and Derringer's desirability function were used to optimize the concentration of KOH and the volume of ethyl acetate as the main factors affecting the liquid-liquid extraction procedure. After extraction, the analytes were separated quantitatively on a C18 column with 10 mM pH 7.0 phosphate buffer-methanol-acetonitrile 48.46:20:31.54 (υ/υ) as mobile phase at a flow rate of 1.20 mL min−1 and with UV detection at 285 nm. It was concluded that extraction recovery of both the analytes was affected by KOH concentration and that recovery of pantoprazole was affected by ethyl acetate (extraction solvent) volume. Extraction recovery under optimum extraction conditions was 93.52% for domperidone and 92.72% for pantoprazole. The optimized extraction method was validated. Linearity was established for six levels in the ranges 10–1000 ng mL−1 for pantoprazole and 15–1000 ng mL−1 for domperidone. The lower limit of quantitation (LLOQ) and detection (LOD) were estimated as 9.84 and 5.91 ng mL−1, respectively, for pantoprazole and 14.56 and 8.79 ng mL−1 for domperidone. The optimized method was linear, specific, accurate, and precise; the high recovery (>92%) and low relative standard deviation (<2.5%) enable reliable quantification of these analytes in spiked human plasma.