scholarly journals METHOD FOR DETERMINING THE TOTAL CONTENT OF PHENOLIC COMPOUNDS IN PLANT EXTRACTS WITH FOLIN-DENIS REAGENT AND FOLIN-CHOCALTEU REAGENT: MODIFICATION AND COMPARISON

2021 ◽  
pp. 291-299
Author(s):  
Tat'yana Nikolayevna Nikolaeva ◽  
Petr Vladimirovich Lapshin ◽  
Natal'ya Viktorovna Zagoskina
Keyword(s):  
Phenolic Compounds ◽  
Gallic Acid ◽  
Absorption Spectra ◽  
Plant Extracts ◽  
Plant Tissue ◽  
Total Content ◽  
Linear Character ◽  
Tissue Extracts ◽  
Ethanol Extracts ◽  
Density Of Solutions

A modification of the method for determining the total content of phenolic compounds in plant tissue extracts with the Folin-Denis reagent and the Folin-Ciocalteu reagent has been carried out, allowing to establish the correspondence of the results obtained when using them. The method using the Folin-Denis reagent is adapted for conducting determinations in microvolumes. For the method using the Folin-Ciocalteu reagent, the concentration of the latter (0.4 N, a 5-fold dilution of the standard reagent) and the composition of the reaction mixture were selected, using which the optical densities of the reduction products of the Folin-Denis and Folin-Ciocalteu reagents containing polyphenols in ethanol extracts from wheat, buckwheat and calus tissue of tea were almost the same. The absorption spectra of the reduction products of these reagents by gallic acid, rutin, (-)-epicatechin, as well as ethanol extracts from wheat, buckwheat, and tea calus tissue, were located in the same region (680–770 nm) and had similar characteristics. Calibration graphs of the dependence of the optical density of solutions on the concentration of standard substances (gallic acid, (-)-epicatechin, rutin), constructed using the Folin-Denis and Folin-Ciocalteu reagents, had a linear character within the concentration range of 10–100 μg/ml and practically coincided. The results of determining the content of phenolic compounds in ethanol extracts of plants, differing in their ability to accumulate, showed very similar and statistically significant values when using these two reagents.

Total Soluble Sugar Quantification from Ethanolic Plant Extracts v1

2021 ◽  
Author(s):  
Lynn Doran ◽  
Amanda P. De Souza
Keyword(s):  
Plant Extracts ◽  
Plant Tissue ◽  
Soluble Sugar ◽  
Soluble Sugars ◽  
Total Soluble Sugars ◽  
Total Soluble Sugar ◽  
Tissue Extracts

Quantification of total soluble sugars (as glucose) in plant tissue extracts via the sulfuric phenol method adapted for 96 well plates.

Presence of spiroplasma-inhibitory substances in plant tissue extracts

1980 ◽  
Vol 26 (7) ◽  
pp. 807-811 ◽  
Author(s):  
C. H. Liao ◽  
T. A. Chen
Keyword(s):  
Plant Extracts ◽  
Plant Tissue ◽  
Cytoplasmic Membrane ◽  
Cynodon Dactylon ◽  
Culture Media ◽  
Cell Replication ◽  
Spiroplasma Citri ◽  
Tissue Extracts ◽  
Corn Stunt ◽  
Corn Stunt Spiroplasma

Plant tissue extracts prepared from corn, periwinkle, celery, and lettuce contain substance(s) which are inhibitory for spiroplasma growth in culture media. The inhibition titer, measured as the highest dilution of plant extracts which block spiroplasma growth, is inversely proportional to the spiroplasma concentration used for testing. At a concentration of 104 cells/mL, the growth of four spiroplasma isolates investigated (corn stunt spiroplasma, Spiroplasma citri, honey bee spiroplasma, and Bermuda grass (Cynodon dactylon) spiroplasma) was suppressed by the addition of corn and periwinkle extracts up to dilutions of 1/160 and 1/1280, respectively. Spiroplasmas remained viable in extract-supplemented media for at least 5 days and continued to multiply shortly after the plant extract was removed. These results suggest that (1) the inhibitory action of plant extracts is spiroplasmastatic, and (2) inhibitory factors may temporarily bind to cytoplasmic membrane and subsequently suppress the process of cell replication. The anti-mycoplasma activity was greatly reduced when the extract was placed in boiling water for 10 min or at 37 °C for 5 days. No loss of activity was detected when the extract was kept at −20 or 4 °C for 5 days.

scholarly journals The Influence of the Extraction Conditions of Blackthorn (Prunus spinosa) Fruits and Leaves on the Yield of Phenolic Compounds

2021 ◽  
pp. 49-56
Author(s):  
Nino Gamkrelidze ◽  
◽  
Giorgi Kvartskava ◽  
Keyword(s):  
Chemical Composition ◽  
Phenolic Compounds ◽  
Plant Extracts ◽  
Food Production ◽  
Total Content ◽  
Dry Weight ◽  
Extraction Methods ◽  
Prunus Spinosa ◽  
Quality Of Food

Plant extracts used in food production significantly improve the quality of food. Chemical composition is the main prerequisites for the final use of plant extracts. The chemical composition of the extracts is affected by the extraction method and conditions - temperature, duration and solvent. On the basis of experimental data optimal conditions for the extraction of phenolic compounds from the fruits and leaves of blackthorn (Prunus spinosa) were selected. Among the extraction methods used in the experiment, the highest content of phenolic compounds in obtained extracts was observed during the ultrasonic extraction. A mixture of 0.25 parts of water and 0.75 parts of 96% ethanol showed best results from different volume ratios of water and ethanol. The optimal extraction time was 90 minutes. And the optimum temperature is 45°C. The total content of phenolic compounds in the extracts obtained by the abovementioned method amounted is 35.62±0.17 mgg -1(dry weight) for blackthorn fruits and 44,76 ± 0.08mgg -1(dry weight) for the leaves.

Estimation of nitric nitrogen and total nitrogen in plant tissue extracts

1923 ◽  
Vol 13 (1) ◽  
pp. 63-68 ◽  
Author(s):  
Patrick Hugh Gallagher
Keyword(s):  
Sulphuric Acid ◽  
Total Nitrogen ◽  
Plant Extracts ◽  
Plant Tissue ◽  
Nitrate Nitrogen ◽  
Reducing Agents ◽  
Amino Groups ◽  
Tissue Extracts ◽  
Colloidal Matter ◽  
Nitric Nitrogen

Several methods for estimating nitrates by reduction to ammonia were examined. The error involved in the use of acid reducing agents in presence of amino groups was emphasised.A method based on the use of Devarda's alloy and magnesia is recommended.In the estimation of nitrates in plant extracts, etc., by this method an equal volume of rectified spirit is first added to the solution to precipitate colloidal matter. The precipitate is filtered off and an aliquot part of the filtrate containing the equivalent in nitrate nitrogen of about 0.1 gm. of KNO3 is distilled with steam for 45 minutes with 1 gm. of Devarda's alloy and ½ gm. of freshly ignited magnesia. A blank determination is essential, in which the same volume of filtrate is distilled for the same length of time with ½ gm. of magnesia.In Kjeldahl estimations in presence of nitrates, where the separate estimation of nitrates is not required, 2 c.c. of 25 per cent. NaOH may be substituted for the magnesia. Relatively this is very much less soda than Devarda recommends. The mixture in this case may be distilled directly for half-an-hour. The nitrates are thus reduced and the ammonia produced is collected before beginning the digestion with sulphuric acid.This work was carried out under the supervision of Mr F. W. Foreman to whom the author's best thanks are due for much valuable criticism and advice.

scholarly journals PHENOLIC COMPOUNDS AGRIMONIA PILOSA DEPENDING ON THE PHASE OF PLANT DEVELOPMENT

2021 ◽  
pp. 151-158
Author(s):  
Tat'yana Mikhaylovna Shaldayeva ◽  
Vera Andreyevna Kostikova ◽  
Galina Ivanovna Vysochina
Keyword(s):  
Phenolic Compounds ◽  
Plant Development ◽  
Ellagic Acid ◽  
High Performance ◽  
Phenolic Content ◽  
Total Content ◽  
Reproductive Organs ◽  
Total Phenolic ◽  
Ethanol Extracts ◽  
Ground Part

The composition and content of phenolic compounds in the organs of the above-ground part of Agrimonia pilosa Ledeb. depending on the phase of plant development were studied by high performance liquid chromatography (HPLC). Fourteen compounds found in water-ethanol extracts from organs of A. pilosa. Flavonols (kaempferol, astragalin, kaempferol-3-O-β-rutinoside, quercetin, hyperoside and rutin), flavones (apigenin, vitexin, luteolin and luteolin-7-glucoside) and phenolic acids (chlorogenic, caffeic, vanillic and ellagic acids) have been identified. Hyperoside, rutin, and ellagic acid were the major constituents in the extracts from the leaves and the reproductive organs of the species. The highest content of rutin were found in the leaves during vegetative growth and in the inflorescences (2.75 and 2.67 mg/g, respectively). The highest content of hyperoside were observed in leaves in the phase of budding and fruiting (2.02 and 2.25 mg/g). The highest content of ellagic acid were revealed in leaves in the fruiting phase and in buds (3.49 and 2.09 mg/g). The highest total phenolic content was found in the leaves during the fruiting (21.1 mg/g). Unidentified flavonols number 12 and 13 (1.62 and 2.76 mg/g, respectively) were the domi-nant components in the leaves in the growing phase. The total content of phenolic compounds in buds (9.52 mg/g) and in inflorescences (9.80 mg/g) was the same. The total content of phenolic compounds in fruits was two times less (4.24 mg/g) than in buds and inflorescences.

scholarly journals Comparison of the phenolic content and total antioxidant activity in wines as determined by spectrophotometric methods

2008 ◽  
Vol 26 (No. 4) ◽  
pp. 242-253 ◽  
Author(s):  
P. Stratil ◽  
V. Kubáň ◽  
J. Fojtová
Keyword(s):  
Phenolic Compounds ◽  
Gallic Acid ◽  
Antioxidant Activities ◽  
Total Content ◽  
Trolox Equivalent Antioxidant Capacity ◽  
Hydroxyl Groups ◽  
Red Wines ◽  
Antioxidant Power ◽  
Spectrophotometric Methods ◽  
Total Antioxidant

Folin-Ciocalteu reagent (FCM) and Price and Butler method (PBM) were used for spectrophotometric determination of the total content of phenolic compounds in 29 wines (8 white, 21 red). The average contents of phenolic compounds determined by FCM and PBM were 108 (90–119) and 105 (90–129) for white wines, and 1545 (874–2262) and 547 (306–816) mg/l of gallic acid equivalents (GAE) for red wines, respectively. The reason for the lower PBM values in red wines is the higher reactivity in PBM of phenolic compounds, especially of gallic acid generally used as a standard in the above methods. The higher reactivity of the standard means that the measured absorbance of the sample responds to a lower concentration. The average total antioxidant activities determined by TEAC (Trolox Equivalent Antioxidant Capacity), FRAP (Ferric Reducing Antioxidant Power), and DPPH (using diphenyl-<I>p</I>-picrylhydrazyl radical) were 5.14 (4.30–6.14), 1.43 (0.86–2.14), and 0.71 (0.61–0.81) of Trolox equivalents (TE) and 26.44 (13. 9–34.4), 9.43 (4.92–13.9), and 5.52 (2.91–8.62) mmol/l TE for white and red wines, respectively. Almost the same molar absorptivities with TEAC and DPPH methods were found while with FRAP method it was somewhat higher (about 1.56-times). The ratio of the values determined by FRAP and DPPH methods for white and red wines were 2.0 and 1.7, respectively. The TEAC values were 2.8- and 4.8-fold higher than those determined by FRAP and DPPH methods, respectively. The radical ABTS•+ used in TEAC method is therefore the most reactive and responds to the highest number of hydroxyl groups of the phenolic compounds of wines.

scholarly journals Relationships Between the Content of Phenolic Compounds and the Antioxidant Activity of Polish Honey Varieties as a Tool for Botanical Discrimination

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1810
Author(s):  
Monika Kędzierska-Matysek ◽  
Małgorzata Stryjecka ◽  
Anna Teter ◽  
Piotr Skałecki ◽  
Piotr Domaradzki ◽  
...  
Keyword(s):  
Principal Component Analysis ◽  
Antioxidant Activity ◽  
Phenolic Compounds ◽  
Caffeic Acid ◽  
Principal Component ◽  
Total Content ◽  
Component Analysis ◽  
Total Phenolic ◽  
Hydroxybenzoic Acid ◽  
Coumaric Acid

The study compared the content of eight phenolic acids and four flavonoids and the antioxidant activity of six Polish varietal honeys. An attempt was also made to determine the correlations between the antioxidant parameters of the honeys and their polyphenol profile using principal component analysis. Total phenolic content (TPC), total flavonoid content (TFC), antioxidant activity (ABTS) and reduction capacity (FRAP) were determined spectrophotometrically, and the phenolic compounds were determined using high-performance liquid chromatography (HPLC). The buckwheat honeys showed the strongest antioxidant activity, most likely because they had the highest concentrations of total phenols, total flavonoids, p-hydroxybenzoic acid, caffeic acid, p-coumaric acid, vanillic acid and chrysin. The principal component analysis (PCA) of the data showed significant relationships between the botanic origin of the honey, the total content of phenolic compounds and flavonoids and the antioxidant activity of the six Polish varietal honeys. The strongest, significant correlations were shown for parameters of antioxidant activity and TPC, TFC, p-hydroxybenzoic acid, caffeic acid and p-coumaric acid. Analysis of four principal components (explaining 86.9% of the total variance), as a classification tool, confirmed the distinctiveness of the Polish honeys in terms of their antioxidant activity and content of phenolic compounds.

scholarly journals 1H nuclear magnetic resonance-based metabolite profiling of guava leaf extract: an attempt to develop a prototype for standardization of plant extracts

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Manasi S. Gholkar ◽  
Jia V. Li ◽  
Poonam G. Daswani ◽  
P. Tetali ◽  
Tannaz J. Birdi
Keyword(s):  
Ferulic Acid ◽  
Gallic Acid ◽  
Plant Extracts ◽  
Nmr Spectra ◽  
Leaf Extract ◽  
Partial Least Square ◽  
Least Square ◽  
E Coli ◽  
H Nmr ◽  
Guava Leaf

Abstract Background Herbal medicines are fast gaining popularity. However, their acceptability by modern practitioners is low which is often due to lack of standardization. Several approaches towards standardization of herbals have been employed. The current study attempted to recognize key peaks from 1H NMR spectra which together would comprise of a spectral fingerprint relating to efficacy of Psidium guajava (guava) leaf extract as an antidiarrhoeal when a number of unidentified active principles are involved. Methods Ninety samples of guava leaves were collected from three locations over three seasons. Hydroalcoholic (water and ethanol, 50:50) extracts of these samples were prepared and their 1H NMR spectra were acquired. Spectra were also obtained for quercetin, ferulic acid and gallic acid as standards. Eight bioassays reflecting different stages of diarrhoeal pathogenesis were undertaken and based on pre-decided cut-offs, the extracts were classified as ‘good’ or ‘poor’ extracts. The bioactivity data was then correlated with the 1H NMR profiles using Regression or Orthogonal Partial Least Square-Discriminant Analysis (OPLS-DA). Results OPLS-DA showed seasonal and regional segregation of extracts. Significant models were established for seven bioassays, namely those for anti-bacterial activity against Shigella flexneri and Vibrio cholerae, adherence of E. coli, invasion of E. coli and S. flexneri and production and binding of toxin produced by V. cholerae. It was observed that none of the extracts were good or bad across all the bioassays. The spectral analysis showed multiple peaks correlating with a particular activity. Based on NMR and LC-MS/MS, it was noted that the extracts contained quercetin, ferulic acid and gallic acid. However, they did not correlate with the peaks that segregated extracts with good and poor activity. Conclusions The current study identified key peaks in 1H NMR spectra contributing to the anti-diarrhoeal activity of guava leaf extracts. The approach of using spectral fingerprinting employed in the present study can thus be used as a prototype towards standardization of plant extracts with respect to efficacy.

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