scholarly journals Composition and Protein Precipitation Capacity of Condensed Tannins in Purple Prairie Clover (Dalea purpurea Vent.)

2021 ◽  
Vol 12 ◽  
Author(s):  
Qianqian Huang ◽  
Tianming Hu ◽  
Zhongjun Xu ◽  
Long Jin ◽  
Tim A. McAllister ◽  
...  
Keyword(s):  
Condensed Tannins ◽  
Quantum Coherence ◽  
High Performance ◽  
Degree Of Polymerization ◽  
Protein Precipitation ◽  
Early Flowering ◽  
Plant Tissues ◽  
Heteronuclear Single Quantum Coherence ◽  
The Mean ◽  
Different Tissues

This study aimed to determine the concentration and composition of condensed tannins (CT) in different tissues of purple prairie clover (PPC; Dalea purpurea Vent.) at different maturities and to determine their protein-precipitating capacity. The compositions of CT were elucidated after thiolysis with benzyl mercaptan followed by high-performance liquid-chromatography (HPLC) and 1H–13C heteronuclear single quantum coherence (HSQC) NMR spectroscopy. The results indicated that PPC flowering heads contained the highest CT concentration. Purple prairie clover CT consisted mainly of epicatechin (EC) and epigallocatechin (EGC) subunits. CT in the leaves were composed of more EC and less EGC than CT in stems and flowering heads at both the early flowering (EF) and late flowering (LF) head stages. The mean degree of polymerization was the highest for CT in stems and increased with maturity. CT isolated from PPC leaves at the early flowering head stage exhibited the greatest biological activity in terms of protein precipitation. Overall, the CT in PPC were predominantly procyanidins and the concentration and composition varied among the plant tissues and with maturity.

scholarly journals Adams-Harbertson Protein Precipitation-Based Wine Tannin Method Found Invalid

2008 ◽  
Vol 91 (5) ◽  
pp. 1090-1094 ◽  
Author(s):  
Larry Brooks ◽  
Leo McCloskey ◽  
Doug Mckesson ◽  
Marshall Sylvan
Keyword(s):  
High Performance ◽  
Protein Precipitation ◽  
Pinot Noir ◽  
Cabernet Sauvignon ◽  
Equivalence Point ◽  
Order Error ◽  
First Order ◽  
Percent Recovery ◽  
Standard Deviation Range ◽  
The Mean

Abstract The poor precision of the Adams-Harbertson wine tannin assay which was proposed for commercial winemaking, thereby creating the real possibility of quality control problems, is documented. The method is a version of the Hagerman and Butler protein precipitation-based tannin method. An extensive invalidation of the assay results with luxury wine data shows that the assay cannot distinguish bottled wine with reasonable accuracy. Five laboratories used Adams-Harbertson to assay 9 replicates each, of 3 bottled wines (n 135) found in California supermarkets, with tannin concentrations of nominally 500 and 1000 ppm by high-performance liquid chromatography (HPLC). Reliability exceeded the 5 industry requirement by nominally 5 times (z-score based on 5 distribution). Coefficient of variation was 27, making the standard deviation range 54 for Pinot Noir, 34 for Merlot, and 44 for Cabernet Sauvignon. Validity exceeded the 100 requirement. Intralaboratory validity recovery was 5563. Interwinery validity was 71178 of the mean for Pinot Noir, 81144 for Merlot, and 83164 for Cabernet Sauvignon. Range as a function of the mean was 89 for Pinot Noir, 55 for Merlot, and 67 for Cabernet Sauvignon. Expect intermethod validity to be nominally 50, i.e., percent recovery to HPLC. These statistically significant errors were predicted by the literature. First-order error is related to the tannin-protein equilibrium constant (Ka), as suggested by the original author, Hagerman, and the protein equivalence point error as suggested by Silber. This does not obviate second-order errors for tannin-protein analytical chemistry. Winemakers using the measurements risk making wines that are relatively more tannic than the measurements report.

scholarly journals Quantitative analysis of proanthocyanidins (tannins) from cardinal grape (Vitis vinifera) skin and seed by RP-HPLC

2019 ◽  
Vol 3 (6) ◽  
pp. 201-205
Author(s):  
Farida Benmeziane ◽  
Yves Cadot
Keyword(s):  
High Performance ◽  
Biological Activities ◽  
Degree Of Polymerization ◽  
Bioactive Molecules ◽  
Grape Seeds ◽  
Epicatechin Gallate ◽  
Grape Skin ◽  
Rp Hplc ◽  
The Mean ◽  
Simple Molecules

Background: Grape phenolics are structurally diverse, from simple molecules to oligomers and polymers usually designated “tannins or proanthocyanidins (PAs)” referring to their ability to interact with proteins. Those compounds have been attributed to a great number of biological activities beneficial for human health as they act as antioxidant, anti-inflammatory, antitumor, etc. Aim: The objective of the current study was to quantify and to identify the PAs and determine the mean degree of polymerization (DPm) in seeds and skins of the grape cardinal variety cultivated in El-Tarf region, Algeria. Methods and Material: To determine PAs, Reverse Phase High-Performance Liquid Chromatography with Diode Array Detection (RP-HPLC-DAD) has been utilized. The DPm was determined after the reaction of thiolysis in the presence of toluene-α-thiol reagent. Results: HPLC-DAD analysis of Cardinal skin and seed extract showed that epicatechin gallate (ECG) and epigallocatechin (EGC) were the major constitutive units of grape skin tannins and the mean degree of polymerization (DPm) was lower for seed PAs than for skin. Conclusions: This study showed the richness of skin and grape seeds in polyphenolic compounds (PAs). Therefore, these parts of grape can be used as a potential source of bioactive molecules to promote the health of populations in this region in Algeria. Keywords: Grape, Skin, Seed, Proanthocyanidins, RP-HPLC-DAD.

scholarly journals Polyphenolic profile and stilbene content of Albanian “Kallmet” monovarietal wine

OENO One ◽  
2018 ◽  
Vol 52 (2) ◽  
pp. 135-144 ◽  
Author(s):  
Anisa Peçuli ◽  
Fabrice Lorenzini ◽  
Mariglen Angjellari ◽  
Sylvain Schnee ◽  
Katia Gindro ◽  
...  
Keyword(s):  
Condensed Tannins ◽  
Phenolic Content ◽  
Mean Value ◽  
Degree Of Polymerization ◽  
Anthocyanin Content ◽  
Red Wines ◽  
Grape Variety ◽  
The Mean ◽  
Red Grape ◽  
Polyphenolic Profile

Aim: The aim of this work was to characterize the phenolic content of wines from the most promising autochthonous red grape variety in Albania, the Kallmet.Methods and results: To make this first survey, 16 commercial monovarietal Kallmet wines were analyzed with special attention to proanthocyanidin (condensed tannins), anthocyanin and stilbene composition. The average content of total proanthocyanidins in these wines was 3877 mgL-1 and the anthocyanin content averaged 242 mgL-1. The mean degree of polymerization (mDP) varied from 8 subunits in young wine to 31 subunits in 6-year-old wine, with a mean value of 14.5 subunits. The total free anthocyanin content ranged from 85 mgL-1 in old wine to 609 mgL-1 in young wine, with a mean value of 242.5 mgL-1. Trans-piceid was the most abundant stilbene (11 mgL-1), followed by trans-resveratrol (1.8 mgL-1). It was evidenced that cis-forms of resveratrol and piceid presented a lower content than their trans-forms. The ratio between piceid (glycoside form) and resveratrol (aglycone form) was 8.2, showing a similar stilbene pattern as in Mediterranean wines.Conclusions: Kallmet wines show proanthocyanidin polymerization characteristics and stilbene profiles very similar to red wines deriving from other varieties grown under warm climates.Significance and impact of the study: In spite of the strong interest in Kallmet grape, there is still a need for detailed studies to know the range of the different components of interest found in the produced wine.

Estimation of the Mean Degree of Polymerization of Condensed Tannins from the Kernel and Shell of Carya illinoinensis by HPLC/MS and Spectrophotometric Methods

2017 ◽  
Vol 10 (9) ◽  
pp. 3023-3031 ◽  
Author(s):  
M. A. Lerma-Herrera ◽  
J. A. Núñez-Gastélum ◽  
J. Ascacio-Valdés ◽  
C. N. Aguilar ◽  
J. Rodrigo-García ◽  
...  
Keyword(s):  
Condensed Tannins ◽  
Degree Of Polymerization ◽  
Carya Illinoinensis ◽  
Spectrophotometric Methods ◽  
The Mean

scholarly journals Structural features of condensed tannins affectin vitroruminal methane production and fermentation characteristics

2016 ◽  
Vol 154 (8) ◽  
pp. 1474-1487 ◽  
Author(s):  
N. T. HUYEN ◽  
C. FRYGANAS ◽  
G. UITTENBOGAARD ◽  
I. MUELLER-HARVEY ◽  
M. W. A. VERSTEGEN ◽  
...  
Keyword(s):  
Condensed Tannins ◽  
High Performance ◽  
Rumen Fluid ◽  
Condensed Tannin ◽  
Structural Features ◽  
Degree Of Polymerization ◽  
Gas Production ◽  
Peg Treatment ◽  
Polymer Size

SUMMARYAnin vitrostudy was conducted to investigate the effects of condensed tannin (CT) structural properties, i.e. average polymer size (or mean degree of polymerization), percentage ofcisflavan-3-ols and percentage of prodelphinidins in CT extracts on methane (CH4) production and fermentation characteristics. Condensed tannins were extracted from eight plants in order to obtain different CT types: blackcurrant leaves, goat willow leaves, goat willow twigs, pine bark, redcurrant leaves, sainfoin plants, weeping willow catkins and white clover flowers. They were analysed for CT content and CT composition by thiolytic degradation, followed by high performance liquid chromatography (HPLC) analysis. Grass silage was used as a control substrate. Condensed tannins were added to the substrate at a concentration of 40 g/kg, with or without polyethylene glycol (+ or −PEG 6000 treatment) to inactivate tannins, then incubated for 72 h in mixed buffered rumen fluid from three different lactating dairy cows per run. Total cumulative gas production (GP) was measured by an automated GP system. During the incubation, 12 gas samples (10µl) were collected from each bottle headspace at 0, 2, 4, 6, 8, 12, 24, 30, 36, 48, 56 and 72 h of incubation and analysed for CH4. A modified Michaelis-Menten model was fitted to the CH4concentration patterns and model estimates were used to calculate total cumulative CH4production (GPCH4). Total cumulative GP and GPCH4curves were fitted using biphasic and monophasic modified Michaelis-Menten models, respectively. Addition of PEG increased GP, GPCH4, and CH4concentration compared with the −PEG treatment. All CT types reduced GPCH4and CH4concentration. All CT increased the half time of GP and GPCH4. Moreover, all CT decreased the maximum rate of fermentation for GPCH4and rate of substrate degradation. The correlation between CT structure and GPCH4and fermentation characteristics showed that the proportion of prodelphinidins within CT had the largest effect on fermentation characteristics, followed by average polymer size and percentage ofcisflavan-3-ols.

Placental Transfer of Vitamin K1 and Its Implications in Fetal Hemostasis

1988 ◽  
Vol 60 (01) ◽  
pp. 039-043 ◽  
Author(s):  
L Mandelbrot ◽  
M Guillaumont ◽  
M Leclercq ◽  
J J Lefrère ◽  
D Gozin ◽  
...  
Keyword(s):  
Vitamin K ◽  
High Performance ◽  
Ultrasound Guidance ◽  
Placental Transfer ◽  
Vitamin K1 ◽  
Vitamin K Deficiency ◽  
Prothrombin Activity ◽  
Oral Supplementation ◽  
K Deficiency ◽  
The Mean

SummaryVitamin K status was evaluated using coagulation studies and/ or vitamin IQ assays in a total of 53 normal fetuses and 47 neonates. Second trimester fetal blood samples were obtained for prenatal diagnosis under ultrasound guidance. Endogenous vitamin K1 concentrations (determined by high performance liquid chromatography) were substantially lower than maternal levels. The mean maternal-fetal gradient was 14-fold at mid trimester and 18-fold at birth. Despite low vitamin K levels, descarboxy prothrombin, detected by a staphylocoagulase assay, was elevated in only a single fetus and a single neonate.After maternal oral supplementation with vitamin K1, cord vitamin K1 levels were boosted 30-fold at mid trimester and 60 fold at term, demonstrating placental transfer. However, these levels were substantially lower than corresponding supplemented maternal levels. Despite elevated vitamin K1 concentrations, supplemented fetuses and neonates showed no increase in total or coagulant prothrombin activity. These results suggest that the low prothrombin levels found during intrauterine life are not due to vitamin K deficiency.

scholarly journals N-[7-Chloro-4-[4-(phenoxymethyl)-1H-1,2,3-triazol-1-yl] quinoline]-acetamide

Molbank ◽  
10.3390/m1213 ◽  
2021 ◽  
Vol 2021 (2) ◽  
pp. M1213
Author(s):  
Paolo Coghi ◽  
Jerome P. L. Ng ◽  
Ali Adnan Nasim ◽  
Vincent Kam Wai Wong
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Quantum Coherence ◽  
Biologically Active ◽  
Proton Nuclear Magnetic Resonance ◽  
Dipolar Cycloaddition ◽  
Heteronuclear Single Quantum Coherence ◽  
Pharmacokinetic Properties ◽  
Nuclear Magnetic

The 1,2,3-triazole is a well-known biologically active pharmacophore constructed by the copper-catalyzed azide–alkyne cycloaddition. We herein reported the synthesis of 4-amino-7-chloro-based [1,2,3]-triazole hybrids via Cu(I)-catalyzed Huisgen 1,3-dipolar cycloaddition of 4-azido-7-chloroquinoline with an alkyne derivative of acetaminophen. The compound was fully characterized by Fourier-transform infrared (FTIR), proton nuclear magnetic resonance (1H-NMR), carbon-13 nuclear magnetic resonance (13C-NMR), heteronuclear single quantum coherence (HSQC), ultraviolet (UV) and high-resolution mass spectroscopies (HRMS). This compound was screened in vitro with different normal and cancer cell lines. The drug likeness of the compound was also investigated by predicting its pharmacokinetic properties.

scholarly journals Plunging Airfoil: Reynolds Number and Angle of Attack Effects

Aerospace ◽  
2021 ◽  
Vol 8 (8) ◽  
pp. 216
Author(s):  
Emanuel A. R. Camacho ◽  
Fernando M. S. P. Neves ◽  
André R. R. Silva ◽  
Jorge M. M. Barata
Keyword(s):  
Reynolds Number ◽  
High Performance ◽  
Angle Of Attack ◽  
Systems Design ◽  
Reynolds Numbers ◽  
Navier Stokes ◽  
Low Reynolds Numbers ◽  
Operational Conditions ◽  
Naca0012 Airfoil ◽  
The Mean

Natural flight has consistently been the wellspring of many creative minds, yet recreating the propulsive systems of natural flyers is quite hard and challenging. Regarding propulsive systems design, biomimetics offers a wide variety of solutions that can be applied at low Reynolds numbers, achieving high performance and maneuverability systems. The main goal of the current work is to computationally investigate the thrust-power intricacies while operating at different Reynolds numbers, reduced frequencies, nondimensional amplitudes, and mean angles of attack of the oscillatory motion of a NACA0012 airfoil. Simulations are performed utilizing a RANS (Reynolds Averaged Navier-Stokes) approach for a Reynolds number between 8.5×103 and 3.4×104, reduced frequencies within 1 and 5, and Strouhal numbers from 0.1 to 0.4. The influence of the mean angle-of-attack is also studied in the range of 0∘ to 10∘. The outcomes show ideal operational conditions for the diverse Reynolds numbers, and results regarding thrust-power correlations and the influence of the mean angle-of-attack on the aerodynamic coefficients and the propulsive efficiency are widely explored.

scholarly journals Application of Artificial Intelligence (AI) for Sustainable Highway and Road System

Symmetry ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 60
Author(s):  
Md Arifuzzaman ◽  
Muhammad Aniq Gul ◽  
Kaffayatullah Khan ◽  
S. M. Zakir Hossain
Keyword(s):  
Experimental Data ◽  
High Performance ◽  
Adhesion Force ◽  
Model Development ◽  
Real Life ◽  
Bayesian Optimization ◽  
Support Vector ◽  
Adhesive Properties ◽  
Bayesian Optimization Algorithm ◽  
The Mean

There are several environmental factors such as temperature differential, moisture, oxidation, etc. that affect the extended life of the modified asphalt influencing its desired adhesive properties. Knowledge of the properties of asphalt adhesives can help to provide a more resilient and durable asphalt surface. In this study, a hybrid of Bayesian optimization algorithm and support vector regression approach is recommended to predict the adhesion force of asphalt. The effects of three important variables viz., conditions (fresh, wet and aged), binder types (base, 4% SB, 5% SB, 4% SBS and 5% SBS), and Carbon Nano Tube doses (0.5%, 1.0% and 1.5%) on adhesive force are taken into consideration. Real-life experimental data (405 specimens) are considered for model development. Using atomic force microscopy, the adhesive strength of nanoscales of test specimens is determined according to functional groups on the asphalt. It is found that the model predictions overlap with the experimental data with a high R2 of 90.5% and relative deviation are scattered around zero line. Besides, the mean, median and standard deviations of experimental and the predicted values are very close. In addition, the mean absolute Error, root mean square error and fractional bias values were found to be low, indicating the high performance of the developed model.

scholarly journals An HPLC-automated Derivatization for Glutathione and Related Thiols Analysis in Brassica rapa L.

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1157
Author(s):  
Francesco Nacca ◽  
Concetta Cozzolino ◽  
Petronia Carillo ◽  
Pasqualina Woodrow ◽  
Amodio Fuggi ◽  
...  
Keyword(s):  
Brassica Rapa ◽  
High Performance ◽  
Internal Standard ◽  
Plant Tissues ◽  
Cellular Functions ◽  
Sulphur Compounds ◽  
Stress Protection ◽  
Automated Method ◽  
Reduced Forms

The high content of glucosinolates and glutathione makes the Brassicaceae an important healthy food. Thiols and especially glutathione and γ-Glu-Cys-Gly tripeptide are involved in many fundamental cellular functions such as oxidative stress protection. Although several methods for sulphur compounds analysis in biological samples are actually used, the determination of glutathione and other sulphur derivatives in plant tissues is rather problematic due to their extreme susceptibility to oxidation, which can lead to their overestimation. The aim of this work was the improvement and validation of an automated method for determination of reduced and oxidised glutathione, cysteine and γ-glutamylcysteine in plant tissues. The method consists of a fully automated pre-column derivatization of thiols based on monobromobimane reagent, a high-performance liquid chromatography derivatives separation, and a fluorimetric detection and quantification. The method was successfully applied for determination of the oxidized and reduced forms of Cys, γ-GC and GSH content in leaves, petioles, inflorescences and roots of Brassica rapa L. subsp. Sylvestris. At harvest, in freshly cut plants, the average contents of GSH/2GSSG were 840/45, 345/70 and 150/70 nmol g−1 FW for the florets, leaf blades and stems, respectively; those of Cys/2Cys were 80/12, 29/12 and 24/6 nmol g-1 FW; while those of γ-GC/γ-GCCG-γ were 8.0/4.0, and 6.0/3.0, 3.0/2.0 nmol g−1 FW, respectively. Such amounts were lower in low-sulphur-grown plants at harvest. The very low coefficient of variation between repeated tests (maximum 1.6%), the high recovery of internal standard (>96%) and the linear correlation coefficient of the calibration (R2 > 0.99) support the efficiency of this method that allowed analysing about 50 samples/die in a totally automated manner with no operator intervention. Our results show that the reported method integrations can significantly improve thiols detection via HPLC.

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