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Simultaneous Determination of the Saponification Value, Acid Value, Ester Value, and Iodine Value in Commercially Available Red Fruit Oil (Pandanus conoideus, Lam.) Using 1H qNMR Spectroscopy. FOOD ANAL METHOD 2022. [DOI: 10.1007/s12161-022-02401-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AbstractRed fruit oil (RFO) can be extracted from fruits of Pandanus conoideus, Lam., an endogenous plant of Papua, Indonesia. It is a commonly used essential original traditional medicine. By applying a newly developed quantitative 1H NMR (qNMR) spectroscopy method for quality assessment, a simultaneous determination of the saponification value (SV), acid value (AV), ester value (EV), and iodine value (IV) in RFO was possible. Dimethyl sulfone (DMSO2) was used as an internal standard. Optimization of NMR parameters, such as NMR pulse sequence, relaxation delay time, and receiver gain, finally established the 1H NMR-based quantification approach. Diagnostic signals of the internal standard at δ = 2.98 ppm, SV at δ = 2.37–2.20 ppm, AV at δ = 2.27–2.20 ppm, EV at δ = 2.37–2.27 ppm, and IV at δ = 5.37–5.27 ppm, respectively, were used for quantitative analysis. The method was validated concerning linearity (R2 = 0.999), precision (less than 0.83%), and repeatability in the range 99.17–101.17%. Furthermore, this method was successfully applied to crude RFO, crude RFO with palmitic and oleic acid addition, and nine commercial products. The qNMR results for the respective fat values are in accordance with the results of standard methods, as can be seen from the F- and t-test (< 1.65 and < 1.66, respectively). The fundamental advantages of qNMR, such as its rapidity and simplicity, make it a feasible and existing alternative to titration for the quality control of RFO.
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Mansour NM, El-Sherbiny DT, Ibrahim FA, El-Subbagh HI. Taguchi Approach for Optimization of a Green Quantitative 1H-NMR Practice for Characterization of Levetiracetam and Brivaracetam in Pharmaceuticals. J AOAC Int 2022; 105:1516-1527. [DOI: 10.1093/jaoacint/qsac077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 05/25/2022] [Accepted: 06/08/2022] [Indexed: 11/13/2022]
Abstract
Abstract
Background
Recently, quantitative nuclear magnetic resonance (qNMR) competes with separation techniques such as high performance liquid chromatography (HPLC) and capillary electrophoresis for quantification purposes when dealing with molecules that lack a chromophore.
Objective
The advantages of the proton nuclear magnetic resonance spectroscopy as a revolutionary quantitative analysis method were exploited aimed at simple and green assessment of two racetams, namely levetiracetam (LEV) and brivaracetam (BRV), as a new family of antiepileptic medications with a unique mechanism of action. The developed technique was effectively used to determine LEV in Keppra tablets and BRV in laboratory-prepared tablets without interfering with the ordinarily suspected excipients.
Method
A Taguchi approach was applied as a powerful and user-friendly statistical technique for optimization of the qH1NMR experimental design for both drugs. The optimum acquisition conditions were number of scans 32, pulse angle 20°, and relaxation delay of 40 s for LEV and number of scans 128, pulse angle 90°, and relaxation delay of 1 s for BRV. NMR spectra were obtained by means of phloroglucinol as an internal standard and dimethyl sulfoxide-d6 as a solvent.
Results
The diagnostic doublet of doublet quantitative signals at 4.3 and at 4.2 ppm were chosen to estimate LEV and BRV, respectively. The recovery of both drugs was quantified through the range of 0.1–12 mg/mL. The limits of detection were 0.013, 0.0013 and the limits of quantitation were 0.04, 0.0039 mg/mL for LEV and BRV correspondingly.
Conclusions
The suggested technique was fully validated according to ICH guidelines and proved to be an eco-friendly practice by means of three different assessment tools, including the green analytical procedures index, national environmental methods index, and analytical eco-scale. qH1NMR should be considered a green alternative for quantification and quality control assessment of pharmaceuticals.
Highlights
This research represents the first simple, quick, and green alternative method for determination of both racetams in their pharmaceuticals.
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Affiliation(s)
- Noura M Mansour
- University of Mansoura, Faculty of Pharmacy, Department of Medicinal Chemistry , Mansoura 35516, Egypt
- Delta University for Science and Technology, Faculty of Pharmacy, Department of Pharmaceutical Chemistry , Gamasa 35712, Egypt
| | - Dina T El-Sherbiny
- University of Mansoura, Faculty of Pharmacy, Department of Medicinal Chemistry , Mansoura 35516, Egypt
- Delta University for Science and Technology, Faculty of Pharmacy, Department of Pharmaceutical Chemistry , Gamasa 35712, Egypt
| | - Fawzia A Ibrahim
- Mansoura University, Faculty of Pharmacy, Department of Analytical Chemistry , Mansoura 35516, Egypt
| | - Hussein I El-Subbagh
- University of Mansoura, Faculty of Pharmacy, Department of Medicinal Chemistry , Mansoura 35516, Egypt
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Yin T, Lu J, Liu Q, Zhu G, Zhang W, Jiang Z. Validated Quantitative 1H NMR Method for Simultaneous Quantification of Indole Alkaloids in Uncaria rhynchophylla. ACS OMEGA 2021; 6:31810-31817. [PMID: 34870003 PMCID: PMC8638010 DOI: 10.1021/acsomega.1c04464] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Accepted: 11/02/2021] [Indexed: 05/30/2023]
Abstract
Uncariae Ramulus Cum Uncis, known as "Gou-Teng" in Chinese, is derived mainly from the dried hook-bearing stems of Uncaria rhynchophylla. Quantitative determination of monoterpenoid indole alkaloids is critical for controlling its quality. In the present study, a rapid, accurate, and precise method was developed for the simultaneous quantitation of four characteristic components, namely, rhynchophylline (1), isorhynchophylline (2), corynoxeine (3), and isocorynoxeine (4), through 1H NMR spectrometry techniques. This method was performed on a 600 MHz NMR spectrometer with optimized acquisition parameters for performing quantitative experiments within 14 min. The highly deshielded signal of NH was at δH 10-11 in the aprotic solvent DMSO-d 6, which enables satisfactory separation of the signals to be integrated. Validation of the quantitative method was also performed in terms of specificity, linearity, sensitivity, accuracy, and precision. The method is linear in the concentration range of 25-400 μg/mL. The lower limit of quantification is 25 μg/mL. The intra- and interday relative standard deviation across three validation runs over the entire concentration range is less than 2.51%. The accuracy determined at three concentrations was within ±4.4% in terms of relative error. The proposed qNMR method was demonstrated to be a powerful tool for quantifying the alkaloids in traditional Chinese medicines (TCMs) due to its unique advantages of high precision, rapid analysis, and nonrequirement of standard compounds for calibration curve preparation. Moreover, qNMR represents a feasible alternative to high-performance liquid chromatography-based methods for the quality control of TCMs.
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Affiliation(s)
- Tianpeng Yin
- State
Key Laboratory of Quality Research in Chinese Medicines, Macau Institute
for Applied Research in Medicine and Health, Macau University of Science and Technology, Taipa 999078, Macau, China
- Faculty
of Bioengineering, Zunyi Medical University, Zhuhai Campus, Zhuhai 519041, China
| | - Jingguang Lu
- State
Key Laboratory of Quality Research in Chinese Medicines, Macau Institute
for Applied Research in Medicine and Health, Macau University of Science and Technology, Taipa 999078, Macau, China
| | - Qinghua Liu
- State
Key Laboratory of Quality Research in Chinese Medicines, Macau Institute
for Applied Research in Medicine and Health, Macau University of Science and Technology, Taipa 999078, Macau, China
| | - Guoyuan Zhu
- State
Key Laboratory of Quality Research in Chinese Medicines, Macau Institute
for Applied Research in Medicine and Health, Macau University of Science and Technology, Taipa 999078, Macau, China
| | - Wei Zhang
- State
Key Laboratory of Quality Research in Chinese Medicines, Macau Institute
for Applied Research in Medicine and Health, Macau University of Science and Technology, Taipa 999078, Macau, China
| | - Zhihong Jiang
- State
Key Laboratory of Quality Research in Chinese Medicines, Macau Institute
for Applied Research in Medicine and Health, Macau University of Science and Technology, Taipa 999078, Macau, China
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Khalil A, Kashif M. Use of Box-Behnken design for the nuclear magnetic resonance study of molecular complex of anticonvulsant drug with N,N-dimethylformamide and its application in quantitative analysis. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2021.115308] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Dong JW, Li XJ, Shi JY, Liu KQ. Application of a proton quantitative nuclear magnetic resonance spectroscopy method for the determination of actinodaphnine in Illigera aromatica and Illigera henryi. J Nat Med 2018; 73:312-317. [PMID: 30414014 DOI: 10.1007/s11418-018-1264-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 10/29/2018] [Indexed: 11/29/2022]
Abstract
Illigera aromatica S. Z. Huang et S. L. Mo and Illigera henryi W. W. Sm., belonging to the genus Illigera (Hernandiaceae), are used as herbal medicines for promoting blood circulation and treating tuberculosis. Actinodaphnine, the major bioactive alkaloid, plays an important role in the quality controls of the herbs. In the present study, a rapid, simple, accurate, and precise proton quantitative nuclear magnetic resonance (1H-qNMR) method was developed to determine the content of actinodaphnine in I. aromatica and I. henryi. DMSO-d6 enabled satisfactory separation of the signals to be integrated in 1H NMR spectrum. 1,4-Dinitrobenzene was selected as an internal standard. The limits of determination and quantitation were 0.005 and 0.038 mg/mL, respectively. This work implied that 1H-qNMR represents a feasible alternative to HPLC-based methods for quantitation of actinodaphnine in I. aromatica and I. henryi and is suitable for the quality control of I. aromatica and I. henryi.
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Affiliation(s)
- Jian-Wei Dong
- College of Chemistry and Environmental Science, Qujing Normal University, Qujing, 655011, People's Republic of China.
| | - Xue-Jiao Li
- College of Chemistry and Environmental Science, Qujing Normal University, Qujing, 655011, People's Republic of China
| | - Jun-You Shi
- College of Chemistry and Environmental Science, Qujing Normal University, Qujing, 655011, People's Republic of China
| | - Kai-Quan Liu
- College of Chemistry and Environmental Science, Qujing Normal University, Qujing, 655011, People's Republic of China
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Dong JW, Li XJ, Cai L, Shi JY, Li YF, Yang C, Li ZJ. Simultaneous determination of alkaloids dicentrine and sinomenine in Stephania epigeae by 1H NMR spectroscopy. J Pharm Biomed Anal 2018; 160:330-335. [PMID: 30114611 DOI: 10.1016/j.jpba.2018.08.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Revised: 07/30/2018] [Accepted: 08/04/2018] [Indexed: 02/06/2023]
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Kang E, Park HR, Yoon J, Yu HY, Chang SK, Kim B, Choi K, Ahn S. A simple method to determine the water content in organic solvents using the 1 H NMR chemical shifts differences between water and solvent. Microchem J 2018. [DOI: 10.1016/j.microc.2018.01.034] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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8
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Detection and quantification of phenethylamines in sports dietary supplements by NMR approach. J Pharm Biomed Anal 2018; 151:347-355. [DOI: 10.1016/j.jpba.2018.01.025] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Revised: 01/11/2018] [Accepted: 01/12/2018] [Indexed: 02/06/2023]
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Deng Y, Li M, Chen LX, Chen XQ, Lu JH, Zhao J, Li SP. Chemical characterization and immunomodulatory activity of acetylated polysaccharides from Dendrobium devonianum. Carbohydr Polym 2018; 180:238-245. [DOI: 10.1016/j.carbpol.2017.10.026] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Revised: 10/03/2017] [Accepted: 10/05/2017] [Indexed: 11/25/2022]
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Yu C, Zhang Q, Xu PY, Bai Y, Shen WB, Di B, Su MX. Quantitative determination and validation of octreotide acetate using 1 H-NMR spectroscopy with internal standard method. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2018; 56:37-45. [PMID: 28921691 DOI: 10.1002/mrc.4665] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Revised: 09/04/2017] [Accepted: 09/09/2017] [Indexed: 06/07/2023]
Abstract
Quantitative nuclear magnetic resonance (qNMR) is a well-established technique in quantitative analysis. We presented a validated 1 H-qNMR method for assay of octreotide acetate, a kind of cyclic octopeptide. Deuterium oxide was used to remove the undesired exchangeable peaks, which was referred to as proton exchange, in order to make the quantitative signals isolated in the crowded spectrum of the peptide and ensure precise quantitative analysis. Gemcitabine hydrochloride was chosen as the suitable internal standard. Experimental conditions, including relaxation delay time, the numbers of scans, and pulse angle, were optimized first. Then method validation was carried out in terms of selectivity, stability, linearity, precision, and robustness. The assay result was compared with that by means of high performance liquid chromatography, which is provided by Chinese Pharmacopoeia. The statistical F test, Student's t test, and nonparametric test at 95% confidence level indicate that there was no significant difference between these two methods. qNMR is a simple and accurate quantitative tool with no need for specific corresponding reference standards. It has the potential of the quantitative analysis of other peptide drugs and standardization of the corresponding reference standards.
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Affiliation(s)
- Chen Yu
- Department of Pharmaceutical Analysis, China Pharmaceutical University, Nanjing, 210009, China
| | - Qian Zhang
- Department of Pharmaceutical Analysis, China Pharmaceutical University, Nanjing, 210009, China
| | - Peng-Yao Xu
- Department of Pharmaceutical Analysis, China Pharmaceutical University, Nanjing, 210009, China
| | - Yin Bai
- Department of Pharmaceutical Analysis, China Pharmaceutical University, Nanjing, 210009, China
| | - Wen-Bin Shen
- Center for Instrumental Analysis, China Pharmaceutical University, Nanjing, 210009, China
| | - Bin Di
- Department of Pharmaceutical Analysis, China Pharmaceutical University, Nanjing, 210009, China
- Key Laboratory on Protein Chemistry and Structural Biology, China Pharmaceutical University, Nanjing, 210009, China
| | - Meng-Xiang Su
- Department of Pharmaceutical Analysis, China Pharmaceutical University, Nanjing, 210009, China
- Key Laboratory on Protein Chemistry and Structural Biology, China Pharmaceutical University, Nanjing, 210009, China
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11
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Impact of synthesized amino alcohol plasticizer on the morphology and hydrophilicity of polysulfone ultrafiltration membrane. J Memb Sci 2017. [DOI: 10.1016/j.memsci.2016.08.068] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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12
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Sudan dyes in adulterated saffron (Crocus sativus L.): Identification and quantification by (1)H NMR. Food Chem 2016; 217:418-424. [PMID: 27664653 DOI: 10.1016/j.foodchem.2016.08.078] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Revised: 02/01/2016] [Accepted: 08/23/2016] [Indexed: 11/21/2022]
Abstract
Saffron, the dried red stigmas of Crocus sativus L., is considered as one of the most expensive spices worldwide, and as such, it is prone to adulteration. This study introduces an NMR-based approach to identify and determine the adulteration of saffron with Sudan I-IV dyes. A complete (1)H and (13)C resonance assignment for Sudan I-IV, achieved by two-dimensional homonuclear and heteronuclear NMR experiments, is reported for the first time. Specific different proton signals for the identification of each Sudan dye in adulterated saffron can be utilised for quantitative (1)H NMR (qHNMR), a well-established method for quantitative analysis. The quantification of Sudan III, as a paradigm, was performed in varying levels (0.14-7.1g/kg) by considering the NMR signal occurring at 8.064ppm. The high linearity, accuracy and rapidity of investigation enable high resolution (1)H NMR spectroscopy to be used for evaluation of saffron adulteration with Sudan dyes.
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Monakhova YB, Kuballa T, Löbell-Behrends S, Hengen J, Maixner S, Kohl-Himmelseher M, Ruge W, Lachenmeier DW. 1H NMR screening of pharmacologically active substances in weight-loss supplements being sold online. ACTA ACUST UNITED AC 2012. [DOI: 10.1002/lemi.201290115] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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14
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Monakhova YB, Kuballa T, Löbell-Behrends S, Maixner S, Kohl-Himmelseher M, Ruge W, Lachenmeier DW. Standardless 1H NMR determination of pharmacologically active substances in dietary supplements and medicines that have been illegally traded over the internet. Drug Test Anal 2012; 5:400-11. [PMID: 22550015 DOI: 10.1002/dta.1367] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2012] [Revised: 03/30/2012] [Accepted: 03/30/2012] [Indexed: 11/06/2022]
Abstract
Dietary supplements and medicines are widely marketed over the Internet. Such products may be counterfeited and lack some or all of the labelled ingredients, or, in the case of lifestyle supplements, illegally contain pharmacologically active substances, such as anorectic or androgenic compounds. The market control - especially in the case of customs seizures - is complex, as reference substances necessary for identification and calibration in traditional high performance liquid chromatography (HPLC) or gas chromatography-mass spectrometry (GC-MS) analysis are often unavailable, or extremely expensive. In this study, we introduce a 400 MHz (1) H NMR methodology, which allows identification and quantitative estimation even without such pure compound standards. The identification can be based on literature spectra, or if these data are unavailable, by applying computational NMR spectra prediction. For standardless NMR determination, simple peak-area comparison of the target compound with the TSP reference was used. The applicability was demonstrated for a wide range of compounds, such as mesterolone, oxymetholone, sibutramine, monacolin K, vinpocetine, evodiamine, caffeine, kavain, and dehydroepiandrosterone. The average relative standard deviations were 5.0% for peak area comparison, and 3.3% for external calibration with standard substance. The method uncertainty is therefore higher in standardless determination, but acceptable for the purpose of proving the presence or absence of pharmacologically active substances. The limit of detection of 0.5-2 mg/kg is sufficient for the purpose. NMR is ideally suited to controlling dietary supplements or illegal medicines as it provides qualitative and at least semi-quantitative information more rapidly (measurement time 20 min) than with any other currently available spectroscopic or chromatographic method.
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Affiliation(s)
- Yulia B Monakhova
- Chemisches und Veterinäruntersuchungsamt (CVUA) Karlsruhe, Karlsruhe, Germany
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Chantarudee A, Phuwapraisirisan P, Kimura K, Okuyama M, Mori H, Kimura A, Chanchao C. Chemical constituents and free radical scavenging activity of corn pollen collected from Apis mellifera hives compared to floral corn pollen at Nan, Thailand. BMC COMPLEMENTARY AND ALTERNATIVE MEDICINE 2012; 12:45. [PMID: 22513008 PMCID: PMC3488964 DOI: 10.1186/1472-6882-12-45] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/30/2011] [Accepted: 04/18/2012] [Indexed: 01/14/2023]
Abstract
BACKGROUND Bee pollen is composed of floral pollen mixed with nectar and bee secretion that is collected by foraging honey (Apis sp.) and stingless bees. It is rich in nutrients, such as sugars, proteins, lipids, vitamins and flavonoids, and has been ascribed antiproliferative, anti-allergenic, anti-angiogenic and free radical scavenging activities. This research aimed at a preliminary investigation of the chemical constituents and free radical scavenging activity in A. mellifera bee pollen. METHODS Bee pollen was directly collected from A. mellifera colonies in Nan province, Thailand, in June, 2010, whilst floral corn (Zea mays L.) pollen was collected from the nearby corn fields. The pollen was then sequentially extracted with methanol, dichloromethane (DCM) and hexane, and each crude extract was tested for free radical scavenging activity using the DPPH assay, evaluating the percentage scavenging activity and the effective concentration at 50% (EC50). The most active crude fraction from the bee pollen was then further enriched for bioactive components by silica gel 60 quick and adsorption or Sephadex LH-20 size exclusion chromatography. The purity of all fractions in each step was observed by thin layer chromatography and the bioactivity assessed by the DPPH assay. The chemical structures of the most active fractions were analyzed by nuclear magnetic resonance. RESULTS The crude DCM extract of both the bee corn pollen and floral corn pollen provided the highest active free radical scavenging activity of the three solvent extracts, but it was significantly (over 28-fold) higher in the bee corn pollen (EC(50) = 7.42 ± 0.12 μg/ml), than the floral corn pollen (EC(50) = 212 ± 13.6% μg/ml). After fractionation to homogeneity, the phenolic hydroquinone and the flavone 7-O-R-apigenin were found as the minor and major bioactive compounds, respectively. Bee corn pollen contained a reasonably diverse array of nutritional components, including biotin (56.7 μg/100 g), invert sugar (19.9 g/100 g), vitamin A and β carotene (1.53 mg/100 g). CONCLUSIONS Bee pollen derived from corn (Z. mays), a non-toxic or edible plant, provided a better free radical scavenging activity than floral corn pollen.
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Analytical challenges in drug counterfeiting and falsification—The NMR approach. J Pharm Biomed Anal 2011; 55:679-87. [DOI: 10.1016/j.jpba.2010.12.017] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2010] [Revised: 12/09/2010] [Accepted: 12/11/2010] [Indexed: 11/18/2022]
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17
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Pieri V, Belancic A, Morales S, Stuppner H. Identification and quantification of major steviol glycosides in Stevia rebaudiana purified extracts by 1H NMR spectroscopy. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2011; 59:4378-4384. [PMID: 21417451 DOI: 10.1021/jf104922q] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The use of (1)H NMR spectroscopy for the characterization of Stevia rebaudiana extracts is presented. The developed method allows qualitative and quantitative determination of the major steviol glycosides in purified extracts and fractions obtained from various stages of the purification process. Moreover, it proved to be a powerful tool to differentiate between glycosides which are naturally occurring in the stevia plant and artifacts formed in the course of the manufacturing process. Identification of steviol glycosides was achieved by the use of 2D NMR techniques, whereas quantification is based on qHNMR using anthracene as internal standard. The solvent mixture pyridine-d(5)-DMSO-d(6) (6:1) enabled satisfactory separation of the signals to be integrated. Validation of the method was performed in terms of specificity, precision, accuracy, linearity, robustness, and stability. Quantitative results were compared to those obtained with the JECFA HPLC-UV method and were found to be in reasonable agreement. NMR analysis does not rely on the use of reference compounds and enables significantly faster analysis compared to HPLC-UV. Thus, NMR represents a feasible alternative to HPLC-based methods for the quality control of Stevia rebaudiana extracts.
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Affiliation(s)
- Valerio Pieri
- Institute of Pharmacy/Pharmacognosy, Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innsbruck, Austria
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18
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NMR techniques in biomedical and pharmaceutical analysis. J Pharm Biomed Anal 2011; 55:1-15. [DOI: 10.1016/j.jpba.2010.12.023] [Citation(s) in RCA: 97] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2010] [Revised: 12/12/2010] [Accepted: 12/15/2010] [Indexed: 01/04/2023]
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20
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Holzgrabe U. Quantitative NMR spectroscopy in pharmaceutical applications. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2010; 57:229-40. [PMID: 20633364 DOI: 10.1016/j.pnmrs.2010.05.001] [Citation(s) in RCA: 212] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2010] [Accepted: 04/29/2010] [Indexed: 05/12/2023]
Affiliation(s)
- Ulrike Holzgrabe
- Institute of Pharmacy and Food Chemistry, University of Würzburg, Am Hubland, 97074 Würzburg, Germany.
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