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OBJECTIVE@#The present study aimed to quantify and identify the bioactive compounds of the Arbutus unedo L. leaves in order to evaluate both their antioxidant properties and litholytic activities against calcium oxalate stones.@*METHODS@#This survey was carried out using hydroalcoholic extract (E.FA) and infusion (I.FA) of A. unedo leaves. The quantification of phenolic compounds, flavonoids, flavonols and anthocyanins was done by spectrophotometric methods and identification of chemical components was performed by ultra-performance liquid chromatography with photodiode array and electrospray ionization tandem mass spectrometry. Antioxidant activity was measured using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) method and by the ferric reducing/antioxidant power (FRAP) assay. Litholytic activity of E.FA and I.FA was studied using a special model that resembles circuitry of the urinary system.@*RESULTS@#E.FA showed greater antioxidant efficacy than I.FA (P < 0.05). Its higher efficiency was shown via the values of median inhibitory concentration, which was close to (76.14 ± 0.91) µg/mL for E.FA versus (202.64 ± 5.77) μg/mL for I.FA using the DPPH method, and (53.77 ± 0.81) μg/mL for E.FA versus (236.86 ± 31.90) μg/mL for I.FA, using FRAP method. I.FA exhibited significantly higher litholytic activity compared to E.FA (P < 0.05), with dissolution values of 31.03% ± 0.63% versus 14.55% ± 0.65%, respectively.@*CONCLUSION@#Overall, the results suggest that the A. unedo is rich in bioactive compounds, and possesses antioxidant and litholitic abilities that are worthy of further study.
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A method has been developed by solid phase extraction-high performance liquid chromatography coupled with photodiode array detector for simultaneous determination of 10 kinds of cyanotoxins in lake water, including microcystin-RR (MC-RR), MC-YR, MC-HtyR, MC-LR, MC-WR, MC-LA, MC-LY, MC-LW, MC-LF and nodularin ( NOD ).The samples were enriched and purified by a HLB solid phase extraction column.The separation was performed on a Waters C18 column (250 mm×4.6 mm, 5 μm) with the gradient elution of acetonitrile and water containing 0.05% trifluoroacetic acid.The flow rate of the mobile phase was 0.8 mL/min.The column temperature was 30℃ and the injection volume was 20 μL.The photodiode array detector was scanned from 190 nm to 300 nm and the detection wavelength was 238 nm.Multiple qualitative analyses were completed according to retention time, full scanning spectrum of photodiode array detector and purity analysis of chromatographic peak.Good linearity was observed in the cyanotoxin concentration range of 0.05 mg/L-2.0 mg/L with correlation coefficients ( R) from 0.9998 to 0.9999.The limits of detection for 10 cyanotoxins were in the range of 0.005 μg/L-0.020 μg/L.The recoveries were in the range of 85.1%-105.3% at the three spiked levels of 0.1 mg/L, 1.0 mg/L and 1.8 mg/L with the relative standard deviations ( RSD ) of 0.8% -9.2%.The method was characteriZed by wide applicability, convenient operation, quick analytical rate, high sensitivity, good accuracy and high recovery.The qualitative accuracy was improved by using multiple qualitative analyses.This method was successfully applied to determination of 10 kinds of cyanotoxins in lake water.
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A novel stability-indicating Reverse Phase High Pressure Liquid Chromatography (RP-HPLC-PDA) method was developed and validated for quantitative determination of Camptothecin (CPT) in bulk, formulation and in dissolution samples using Inertsil-C18 (250mm x 4.6mm, 5μm) column with mobile phase combination of 15mM Ammonium acetate and acetonitrile (60:40) at a flow rate of 1mL/min. Eluents were monitored at a wavelength of 254 nm with an injection volume of 20µL. CPT was completely degraded in oxidative and base hydrolysis conditions and around 37% in acidic conditions and no degradation of CPT was observed with thermal, thermal/humidity and photo conditions. CPT showed linearity over a concentration range of 2-10μg/mL with a regression coefficient (R2) of 0.994 and correlation coefficient (R) of 0.999. The limit of detection (LOD) and limit of quantification (LOQ) values for CPT were 0.025μg/mL and 0.077μg/mL respectively. The developed method was validated as per ICH guidelines. The method was also successfully applied to dissolution testing of controlled release formulation.
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An ultra high performance liquid chromatography-photodiode array detection-tandem quadrupole mass spectrometry ( UPLC-PAD-MS/MS) method was developed for the determination of total 13 flavonols and flavonol glycosides in red onion which including 6 quercetin and its glycosides, 4 isorhamnetin and its glycosides, 3 Kaempferol and its glycosides. The chromatographic separation was carried out by used a UPLC HSS T3 column and eluted under gradient with mobile phases of acetonitrile and water both contained 0 . 1%formic acid at a flow rate of 0. 3 mL/min. The results showed that the major flavonols and flavonol glycosides in red onion were quercetin-4’-glucoside, quercetin-3, 4’-diglucoside, quercetin and Isorhamnetin-4’-glucoside. The amounts and distributions of flavonols and flavonol glycosides among different parts of red onion were different. For the same amount of dry materials, the content ratio of total flavonols and flavonol glycosides in the outer two layers, the third layer and the inner layer was 60. 3:33. 0:6. 7, the amount of quercitin and its glycosides accounts above 92. 1% of total flavonols and flavonol glycosides for each part. In the outer two layers, the amount of flavonol monoglycosides are the highest, in the third layer, the amount of flavonol aglycones were the highest, but in the inner layer, the amount of flavonol diglycosides were the highest. Small amounts of Kaempferol and its glycosides were found in red onion, and mostly were found in outer layers. This method is simple, fast, accurate and convenient, and can be used to analyze flavonols and flavonol glycosides in onion product.
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Aim: To investigate the chemical components in Zhizidahuang decoction( ZZDHD) to reveal the possible material therapeutic basis. Methods: High performance liquid chromatography coupled with photodiode array detector and tandem mass spectrometry ( HPLC-PDA-MS/MS) was applied to simultaneously characterize the chemical components and their structures in ZZDHD. The analysis was preformed on a Lichrospher C_(18) column using a binary eluent of 0. 1% acetic acid( A) and methanol( B) mixed under the gradient mode; UV spectra were scaned from 210 nm to 480 nm; negative ESI experiments in data-dependent scan mode were performed. Results: HPLC-PDA-MS/MS chromatogram of ZZDHD was achieved. Based on UV spectral data, information of molecular weight and mass fragmentation behaviors connected with extracted ion current( EIC) chromatogram, twenty kinds of components were detected and identified, including flavonoids, anthraquinones, iridoids and other constituents. Conclusion: The method presented in this study, which combined HPLC with UV and MS, allowes the characterization of compounds in the complex herbal system even without the reference standards.