scholarly journals Evaluation of precipitation and direct methods for HDL-cholesterol assay by HPLC

1997 ◽  
Vol 43 (10) ◽  
pp. 1885-1890 ◽  
Author(s):  
Mitsuyo Okazaki ◽  
Keiko Sasamoto ◽  
Toshio Muramatsu ◽  
Seijin Hosaki
Keyword(s):  
Direct Method ◽  
Direct Methods ◽  
Hdl Cholesterol ◽  
Hplc Method ◽  
Alternative Methods ◽  
Cholesterol Concentration ◽  
Precipitation Method ◽  
Qualitative Information ◽  
Quantitative Hplc Analysis ◽  
Quantitative Hplc

Abstract HDL-cholesterol (HDL-C) values measured by precipitation (sodium phosphotungstate–MgCl2) and direct methods were compared with those obtained by HPLC with a new column (TSKgel Lipopropak) and an eluent (TSKeluent LP-1). The HDL-C values determined by the precipitation method were significantly (P <0.001) lower than those by the HPLC method, whereas the HDL-C values by the direct method were slightly but significantly higher (P <0.02) than those by the HPLC method. A quantitative HPLC analysis of the cholesterol concentration in HDL and non-HDL fractions in the supernatant of serum separated by precipitation reagents with different MgCl2 concentrations ranging from 7.3 to 44 mmol/L revealed that reagents with >22 mmol/L MgCl2 precipitated part of HDL as well as non-HDL lipoproteins. The HPLC method providing quantitative and qualitative information with high precision was regarded as being a reliable approach for HDL-C assay. The HPLC can be also used to evaluate alternative methods for cholesterol assay.

scholarly journals CHEMOMETRICS ASSISTED VALIDATED HPLC METHOD DETECTING SEASONAL VARIANCES OF SECONDARY METABOLITES OF Camellia sinensis CONSIDERING THE ABIOTIC STRESSES

2019 ◽  
Vol 4 (2) ◽  
pp. 9
Author(s):  
Koushik Bhandari ◽  
Tridib Kumar Goswami ◽  
Baishakhi De
Keyword(s):  
Abiotic Stress ◽  
Secondary Metabolites ◽  
Black Tea ◽  
Hplc Method ◽  
Stress Factors ◽  
Tea Leaves ◽  
Abiotic Stress Factors ◽  
Quantitative Hplc Analysis ◽  
Experimental Findings ◽  
Quantitative Hplc

Climatic changes have great impact on the crops and agro-eco systems and such changes influences the concentration of secondary metabolites. IIT Kharagpur, India is a non-traditional tea growing zone where Tocklai Vegetative 25 variety was used as the research material. This study reports the development of a chemometrics assisted HPLC method validated as per ICH guidelines to explore the effect of seasonal variations in polyphenolics viz. catechins and methyl xanthenes like caffeine in fresh tea leaves and processed CTC black tea prepared from them. Further study was done on the variances amongst the concentration of secondary metabolites and abiotic stress factors. Good resolutions of secondary metabolites were obtained using 92% of 0.2% acetic acid and 8% of acetonitrile as the mobile phase, with a flow rate of 1 mL/ min, injection volume of 20 µl,  PDA detector was set at 200-600 nm and chromatograms were recorded at 274 nm. Results of quantitative HPLC analysis have clearly shown that highest yield of catechins and caffeine were observed in fresh tea leaves plucked during spring (24.3ºC temperature and average rainfall of 34 mm) and also the processed black tea made from it, followed by tea leaves plucked during monsoon (28.8 ºC temperature and 282 mm rainfall) and processed black tea prepared from it. The lowest concentrations of secondary metabolites were found in leaves plucked during autumn (26.2 °C temperature and 132 mm rainfall) and the processed tea prepared from it. The developed quantitative HPLC method showed an inter day precision of 0.3, intraday precision of 0.2, repeatability value of 0.31, ruggedness value of 0.33 and robustness value of 0.2. Considering temperature and rainfall as abiotic stress factors, highest total polyphenolic content was obtained during spring and lowest in autumn. From our experimental findings, the fresh tea leaves of spring season and also the processed black tea prepared from it showed higher yield of catechins.

scholarly journals Usefulness of apolipoprotein B-depleted serum in cholesterol efflux capacity assays using immobilized liposome-bound gel beads

2019 ◽  
Vol 39 (4) ◽  
Author(s):  
Yuna Horiuchi ◽  
Ryunosuke Ohkawa ◽  
Shao-Jui Lai ◽  
Shitsuko Shimano ◽  
Michio Hagihara ◽  
...  
Keyword(s):  
Serum Protein ◽  
Cholesterol Efflux ◽  
Serum Proteins ◽  
Density Lipoprotein ◽  
Hdl Cholesterol ◽  
Cholesterol Concentration ◽  
Precipitation Method ◽  
Serum Samples ◽  
Apo B ◽  
Cholesterol Efflux Capacity

Abstract Cholesterol efflux capacity (CEC) in atherosclerotic lesions is the main anti-atherosclerotic function of high-density lipoprotein (HDL). In recent studies, apolipoprotein (apo) B-depleted serum (BDS) obtained with the polyethylene glycol (PEG) precipitation method is used as a cholesterol acceptor (CA) substitution for HDL isolated by ultracentrifugation. However, the suitability of BDS as a CA is controversial. In the present study, CEC obtained from BDS (BDS-CEC) was evaluated based on a parameter, defined as whole-CEC, which was calculated by multiplying CEC obtained using fixed amounts of HDL by cholesterol concentration to HDL-cholesterol (HDL-C) levels in the serum. Significant correlation (r = 0.633) was observed between both CECs. To eliminate systematic errors from possible contamination with serum proteins and low-density lipoprotein (LDL) or very-LDL (VLDL) in BDS-CEC, the deviation of each CEC-BDS from the regression equation was compared with serum protein, LDL, and triglyceride (TG) levels. No correlation was observed between the deviation and the levels of each of these serum components, indicating that the deviations do not derive from systematic error. Further, to evaluate the effects of serum protein on the results, we measured BDS-CEC of reconstituted serum samples prepared using combinations of five levels of serum proteins with five levels of HDL-C. No significant change in BDS-CEC was observed in any combination. These results indicate that BDS-CEC reflects not only the function of HDL but also its concentration in serum.

scholarly journals Analysis of Homoisoflavonoids in Caesalpinia digyna by HPLC-ESI-MS, HPLC and Method Validation

2012 ◽  
Vol 7 (9) ◽  
pp. 1934578X1200700 ◽  
Author(s):  
Somendu K. Roy ◽  
Amit Srivastava ◽  
Sanjay M. Jachak
Keyword(s):  
Method Validation ◽  
Mobile Phase ◽  
Hplc Method ◽  
Good Recovery ◽  
Esi Ms ◽  
Validation Parameters ◽  
Quantitative Hplc Analysis ◽  
Quantitative Hplc ◽  
Hplc Analyses

The roots of Caesalpinia digyna have been reported to contain gallic acid derivatives and minor homoisoflavonoids, but HPLC-ESI-MS and HPLC analyses of the homoisoflavonoids were challenging due to their low concentration in the roots. Separation and identification was accomplished by HPLC-ESI-MS and further elaborated for quantification using a C18 column with detection at 330 nm. A gradient mobile phase consisting of methanol and water (0.1% acetic acid) was used. The developed HPLC method showed good linearity (r2≥0.998), high precision (RSD<5%) and a good recovery (99.3-104.5%) of the compounds. The lowest detection limit was 0.75 ng and the method was found to be robust. All the validation parameters were found to be within the permissible limits and, therefore, the developed method is accurate and reliable for the quality control of C. digyna and other Caesalpinia species. This is the first report of sample preparation on Diaion HP-20 resin and characterization of homoisoflavonoids by HPLC-ESI-MS, extended by extensive quantitative HPLC analysis of homoisoflavonoids in C. digyna roots and method validation.

Use of a dual-precipitation procedure for measuring high-density lipoprotein 3 (HDL3) in normolipidemic serum.

1989 ◽  
Vol 35 (7) ◽  
pp. 1390-1393 ◽  
Author(s):  
T A Cloey ◽  
P S Bachorik
Keyword(s):  
High Density Lipoprotein ◽  
Density Lipoprotein ◽  
Hdl Cholesterol ◽  
High Density ◽  
Cholesterol Concentration ◽  
Precipitation Method ◽  
Serum Samples ◽  
Precipitation Procedure ◽  
The Difference ◽  
Hdl2 Cholesterol

Abstract We compared results by a dual-precipitation method (J Lipid Res 1982;23:1206-23) for measuring high-density lipoprotein 3 (HDL3) cholesterol with those by ultracentrifugation at d 1.125, using 56 fresh and 105 frozen-stored serum samples. For both methods, HDL2-cholesterol was calculated as the difference between total HDL-cholesterol and HDL3-cholesterol. In general, for pooled serum samples, agreement was closest with ultracentrifugation when we used a dextran sulfate concentration of 5.0 mg/L to precipitate the HDL2-rich fraction, although the optimal concentration varied from 3.0 to 6.8 mg/L for different pools. For individual samples, the values for HDL3 by dual precipitation averaged 12.8% lower than by ultracentrifugation. The coefficients of correlation between the two methods were HDL3, r = 0.70; and HDL2, r = 0.92. The dual-precipitation method reflected the expected sex-related differences in HDL2-cholesterol concentration and inverse relationship with triglyceride concentration.

scholarly journals Seven Direct Methods for Measuring HDL and LDL Cholesterol Compared with Ultracentrifugation Reference Measurement Procedures

2010 ◽  
Vol 56 (6) ◽  
pp. 977-986 ◽  
Author(s):  
W Greg Miller ◽  
Gary L Myers ◽  
Ikunosuke Sakurabayashi ◽  
Lorin M Bachmann ◽  
Samuel P Caudill ◽  
...  
Keyword(s):  
National Cholesterol Education Program ◽  
Ldl Cholesterol ◽  
Direct Method ◽  
Total Error ◽  
Direct Methods ◽  
Hdl Cholesterol ◽  
Individual Sample ◽  
Serum Samples ◽  
Reference Measurement ◽  
The Difference

Abstract Background: Methods from 7 manufacturers and 1 distributor for directly measuring HDL cholesterol (C) and LDL-C were evaluated for imprecision, trueness, total error, and specificity in nonfrozen serum samples. Methods: We performed each direct method according to the manufacturer’s instructions, using a Roche/Hitachi 917 analyzer, and compared the results with those obtained with reference measurement procedures for HDL-C and LDL-C. Imprecision was estimated for 35 runs performed with frozen pooled serum specimens and triplicate measurements on each individual sample. Sera from 37 individuals without disease and 138 with disease (primarily dyslipidemic and cardiovascular) were measured by each method. Trueness and total error were evaluated from the difference between the direct methods and reference measurement procedures. Specificity was evaluated from the dispersion in differences observed. Results: Imprecision data based on 4 frozen serum pools showed total CVs &lt;3.7% for HDL-C and &lt;4.4% for LDL-C. Bias for the nondiseased group ranged from −5.4% to 4.8% for HDL-C and from −6.8% to 1.1% for LDL-C, and for the diseased group from −8.6% to 8.8% for HDL-C and from −11.8% to 4.1% for LDL-C. Total error for the nondiseased group ranged from −13.4% to 13.6% for HDL-C and from −13.3% to 13.5% for LDL-C, and for the diseased group from −19.8% to 36.3% for HDL-C and from −26.6% to 31.9% for LDL-C. Conclusions: Six of 8 HDL-C and 5 of 8 LDL-C direct methods met the National Cholesterol Education Program total error goals for nondiseased individuals. All the methods failed to meet these goals for diseased individuals, however, because of lack of specificity toward abnormal lipoproteins.

scholarly journals Quantification and Comparison of Extraction Methods for Alkaloids in Aegle marmelos Leaves by HPLC

2014 ◽  
Vol 9 (7) ◽  
pp. 1934578X1400900
Author(s):  
Aniket Karmase ◽  
K Prasanna ◽  
Sruti Rasabattula ◽  
Kamlesh K Bhutani
Keyword(s):  
Hplc Analysis ◽  
Extraction Methods ◽  
Hplc Method ◽  
Good Recovery ◽  
Aegle Marmelos ◽  
Low Concentrations ◽  
Validation Parameters ◽  
Marker Compounds ◽  
Quantitative Hplc Analysis ◽  
Quantitative Hplc

The leaves of Aegle marmelos are reported to contain multi-bioactive classes of compounds including coumarins, furanocoumarins and alkaloids. HPLC analysis of the crude extract was challenging due to low concentrations of the compounds in the leaves. Five compounds visible in the HPLC chromatogram were separated and identified by HPLC and further elaborated for quantification as marker compounds of A. marmelos leaves using a C18 column with detection at 275 nm. A gradient mobile phase consisting of acetonitrile and water was used. The developed HPLC method showed good linearity (r2≥0.994), high precision (RSD<5%), and good recovery (99.27–99.98%) of the compounds. The lowest detection limit was 5 ng and the method was found to be robust. All the validation parameters were within the permissible limits. Therefore, the developed method is accurate and reliable for the quality control of A. marmelos. This is the first report of extensive quantitative HPLC analysis of marker compounds in A. marmelos leaves and method validation.

scholarly journals Establishing pinostrobin reference standard for quantitative analysis of the rhizomes of Boesenbergia pandurata

2020 ◽  
Vol 4 (4) ◽  
pp. first
Author(s):  
Nhan Trung Nguyen ◽  
Truong Nhat Van Do ◽  
An Phu Thi Do ◽  
Mai Thanh Thi Nguyen
Keyword(s):  
Food Processing ◽  
Quality Evaluation ◽  
Biological Activities ◽  
Hplc Method ◽  
Viet Nam ◽  
Reference Standard ◽  
Main Ingredient ◽  
System Suitability ◽  
Quantitative Hplc Analysis ◽  
Quantitative Hplc

Boesenbergia pandurata Roxb. Schlecht. (Zingiberaceae), called ``Ngai bun'' in Viet Nam, is one of the Southeast Asian medicinal plants and its rhizomes are used primarily as a spice. This is a perennial, short-stemmed plant, formed by leaf sheaths and can grow up to 50 cm. The leaves are 7-11 cm wide and 25-50 cm long. Its rhizome surfaces are light brown in color, the inner rhizome is yellow, oval-shaped, and has a very aromatic odor. In folklore, Boesenbergia pandurata rhizomes are used as a spice for food processing. This plant contains pinostrobin as the major constituents. Previously showed that pinostrobin compound is the main ingredient together with a variety of biological activities such as antibacterial, inhibition of free radicals, ... Pinostrobin is necessary composition for the screening, testing, and quality evaluation of the rhizomes of B. pandurata species and others in the Zingiberaceae family. This research had conducted a reference standard of pinostrobin isolated from the rhizomes of B. pandurata had 99.26 % purity, which is reliable in medicinal testing. An HPLC method for pinostrobin determination was conducted and The quantitative HPLC analysis was validated for system suitability, selectivity, linearity ranges, and precision. Application of the process to investigate the preparation of extract shown that reflux extraction with ethanol obtained the highest pinostrobin content with 22.05 % in extracts and 2.89 % in dried rhizomes of B. pandurata.

Quantitative HPLC analysis of chamuangone in Garcinia cowa leaf extracts

Planta Medica ◽  
2013 ◽  
Vol 79 (13) ◽  
Author(s):  
P Panichayupakaranant ◽  
A Sakunpak
Keyword(s):  
Hplc Analysis ◽  
Leaf Extracts ◽  
Garcinia Cowa ◽  
Quantitative Hplc Analysis ◽  
Quantitative Hplc

Platelet Aggregation and Plasma Lipoproteins in Alcoholics During Alcohol Withdrawal

1986 ◽  
Vol 55 (02) ◽  
pp. 173-177 ◽  
Author(s):  
K Desai ◽  
J S Owen ◽  
D T Wilson ◽  
R A Hutton
Keyword(s):  
Platelet Aggregation ◽  
Alcohol Withdrawal ◽  
Ldl Cholesterol ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Hdl Cholesterol ◽  
Plasma Lipoprotein ◽  
Cholesterol Concentration ◽  
Arachidonic Acid Content ◽  
Low Density

SummaryPlatelet aggregation, platelet lipid composition and plasma lipoprotein concentrations were measured each week in a group of seventeen alcoholics, without overt liver disease, for one month, following acute, total alcohol withdrawal. The platelets were initially hypoaggregable but, within 1-2 weeks of cessation of drinking, they became hyperaggregable and then gradually returned towards normal values. Hyperaggregability could not be explained by increases in either the cholesterol or the arachidonic acid content of the platelets. Plasma very-low-density lipoprotein cholesterol levels remained high throughout the study, but the initially raised levels of high-density lipoprotein (HDL) cholesterol fell by 26%. Low-density lipoprotein (LDL) cholesterol concentration rose by 10% after two weeks of withdrawal but then returned to about the starting level. The resulting changes in the plasma LDL-cholesterol: HDL-cholesterol ratio, which had increased by more than 50% after two weeks of abstinence, essentially paralleled the time course of enhanced platelet reactivity in all but four of the alcoholics. These findings suggest that alterations in plasma lipoprotein concentrations during acute alcohol withdrawal may be a contributory factor to the haemostatic disorders present in such patients.

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