The root endodermis in Ranunculus acris. II. Histochemistry of the endodermis and the synthesis of phenolic compounds in roots

1979 ◽  
Vol 57 (9) ◽  
pp. 1063-1077 ◽  
Author(s):  
M. G. Scott ◽  
R. L. Peterson
Keyword(s):  
Phenolic Compounds ◽  
Ultrastructural Level ◽  
Major Constituent ◽  
Hydroxyl Groups ◽  
Cortical Cells ◽  
Suberin Lamellae ◽  
Large Central Vacuole ◽  
Flocculent Material ◽  
Ranunculus Acris ◽  
Root Endodermis

Results of histochemical tests performed on fresh root tissue of Ranunculus acris provide the following information on the chemical nature of the root endodermis: (i) the Casparian strip is impregnated with lipid and possibly lignin, (ii) the suberin lamellae stain positively for lipid and phenols with free hydroxyl groups, and (iii) the tertiary wall contains alternating bands of lignin and cellulose.At the ultrastructural level, phenolic 'globules' present in vacuoles of adjacent cortical cells increase in size by accretion of flocculent material and the addition of dispersed granular material through the apparent fusion of smaller vacuoles with the large central vacuole. Globules adhering to fragments of the tonoplast membrane are clearly seen with the SEM.The ferric chloride test for catechol-type phenols at the TEM level proved useful in categorizing phenolic compounds present in intercellular spaces, in walls and vacuoles of cortical cells, surrounding starch grains in amyloplasts, and in the cytoplasm of endodermal cells. Prominent plastids containing large deposits of lipid, osmiophilic material, thylakoid membranes, and starch are seen to be a major constituent of cytoplasm in endodermal and cortical cells.

The root endodermis in Ranunculus acris. I. Structure and ontogeny

1979 ◽  
Vol 57 (9) ◽  
pp. 1040-1062 ◽  
Author(s):  
M. G. Scott ◽  
R. L. Peterson
Keyword(s):  
Plasma Membrane ◽  
Early Stage ◽  
Cellulose Microfibrils ◽  
Secondary Development ◽  
Wall Material ◽  
Casparian Strip ◽  
Suberin Lamellae ◽  
Ranunculus Acris ◽  
Endodermal Cells ◽  
Root Endodermis

The root endodermis in Ranunculus acris was investigated using light and transmission electron microscopy to obtain a more complete picture of endodermal development in a dicotyledonous species. Following the formation of a lateral bulge in anticlinal walls of proendodermal cells, portions of the plasma membrane became tenaciously associated with the primary wall material. The plasma membrane in the zone of the Casparian band appeared extremely electron dense and displayed a distinct tripartite organization. Cytoplasm of primary stage endodermal cells contained Golgi bodies with associated vesicles, lipid-like droplets, and multivesicular bodies containing membrane-enclosed vesicles. Cellulose microfibrils in the radial walls of endodermal cells became impregnated with an osmiophilic substance possibly through the incorporation of paramural bodies at a ledge-like invagination of the plasma membrane on either side of the Casparian strip. It is proposed that the intense organelle activity in the vicinity of the Casparian strip could signify an early stage of suberin lamellae synthesis. Between 8 and 10 suberin lamellae were laid down on radial and tangential walls of those endodermal cells which underwent secondary development, with the heaviest deposition occurring in the region of the Casparian strip. The parallel orientation of the suberin lamellae was frequently disrupted by electron-dense 'platelets' and small granules. A fibrillar suberin-like material was found in dilated cisternae of endoplasmic reticulum located adjacent to areas of deposition. Nuclei, membranous configurations, mitochondria, plastids, and other cytoplasmic organelles were found to persist in tertiary stage endodermal cells. Histochemistry and SEM showed that the mature endodermal wall complex of field-grown plants was comprised of alternating bands of cellulose, lignin, and possibly, suberin.

scholarly journals Advanced Analytical Methods for Phenolics in Fruits

2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Nesibe Ebru Kafkas ◽  
Müberra Kosar ◽  
Ayşe Tülin Öz ◽  
Alyson E. Mitchell
Keyword(s):  
Phenolic Compounds ◽  
Value Added ◽  
Biological Tissues ◽  
Carbon Chain ◽  
Polyphenolic Compounds ◽  
Hydroxyl Groups ◽  
Plant Metabolites ◽  
Secondary Plant Metabolites ◽  
Extraction Separation ◽  
Health Promoting

Phenolic compounds are a group of secondary plant metabolites, many with health-promoting properties that are present in all parts of plants. They have an aromatic structure, including either one or more hydroxyl groups giving them the ability to stabilize free radicals and protect biological tissues against damage related to reactive oxygen species. Phenolic compounds are concentrated in the fruit of plants, and therefore, the fruit can be an important dietary source of these phytochemicals, which exist as monomers, or bound to one another. Polyphenolic compounds are classified into different subclasses based upon the number of phenol ring systems that they contain, saturation, and length of the carbon chain that bind the rings to one another. The phenolic acids present in fruit tissues protect the plant against disease, infections, UV radiation, and insect damage. For this reason, the beneficiary effects of phenolic compounds are continually being investigated for their health-promoting properties and for meeting increased consumer demand for healthy nutritious food. Due to the functional properties of polyphenolic compounds, there is increased interest on improving extraction, separation, and quantification techniques of these valuable bioactive compounds, so they can be used as value-added ingredients in foods, pharmaceuticals, and cosmetics. This review provides information on the most advanced methods available for the analysis of phenolics in fruits.

scholarly journals Phenolic Compounds Content and Genetic Diversity at Population Level across the Natural Distribution Range of Bearberry (Arctostaphylos uva-ursi, Ericaceae) in the Iberian Peninsula

Plants ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1250
Author(s):  
Esther Asensio ◽  
Daniel Vitales ◽  
Iván Pérez ◽  
Laia Peralba ◽  
Juan Viruel ◽  
...  
Keyword(s):  
Phenolic Compounds ◽  
Iberian Peninsula ◽  
Climatic Factors ◽  
Population Level ◽  
Plastid Dna ◽  
Major Constituent ◽  
Natural Distribution ◽  
Antioxidant Additive ◽  
Wide Range ◽  
Tract Infections

Bearberry (Arctostaphylos uva-ursi) is a medicinal plant traditionally employed for the treatment of urinary tract infections due to high contents of arbutin (hydroquinone β-D-glucoside), which is now mainly used as a natural skin-whitening agent in cosmetics. Bearberry has also been proposed as a natural antioxidant additive due to the high contents of phenolic compounds in leaves. We studied the variation on phenolic compounds in 42 wild populations of bearberry, aiming to elucidate if intrinsic biological, climatic, and/or geographic factors affect phenolic contents across its natural distribution in the Iberian Peninsula. Bearberry leaves were collected during autumn over a three-year period (2014–2016) in populations across a latitude and altitude gradient. Methanolic extracts showed a wide range of variation in total phenols content, and different phenolic profiles regarding arbutin (levels of this major constituent varied from 87 to 232 mg/g dr wt), but also catechin and myricetin contents, which were affected by geographic and climatic factors. Moderate levels of variation on genome size—assessed by flow cytometry—and on two plastid DNA regions were also detected among populations. Genetic and cytogenetic differentiation of populations was weakly but significantly associated to phytochemical diversity. Elite bearberry genotypes with higher antioxidant capacity were subsequently identified.

Synthesis of disaccharide congeners of the Trichinella spiralis glycan and binding site mapping of two monoclonal antibodies

2002 ◽  
Vol 80 (8) ◽  
pp. 1141-1161 ◽  
Author(s):  
Ping Zhang ◽  
Judith Appleton ◽  
Chang-Chun Ling ◽  
David R Bundle
Keyword(s):  
Monoclonal Antibodies ◽  
Binding Sites ◽  
Functional Group ◽  
Trichinella Spiralis ◽  
Carbohydrate Antigen ◽  
Major Constituent ◽  
Hydroxyl Groups ◽  
Site Mapping ◽  
Polar Interactions ◽  
Antigen Antibody

The tetrasaccharide epitope, β-D-Tyvp(1[Formula: see text]3)β-D-GalNAcp(1[Formula: see text]4)[α-L-Fucp(1[Formula: see text]3)]β-D-GlcNAcp (1) is the major constituent of the N-glycan expressed on the cell surface of the parasite Trichinella spiralis. Two monoclonal antibodies (Mabs 9D4 and 18H1) that protect rats against infection by T. spiralis bind the terminal disaccharide epitope β-D-Tyvp(1[Formula: see text]3)β-D-GalNAcp conjugated to BSA. The syntheses of disaccharide congeners containing mono-deoxy, mono-methyl, as well as modifications to replace the acetamido group are reported. These target disaccharides were assayed for binding to the protective MAbs. For each antibody different clusters of three hydroxyl groups, that include C-2 and C-4 of tyvelose and for 18H1, the GalNAc acetamido group, provide the key polar interactions with the antibody binding sites. Mapping of the sites by functional group replacement revealed a similar pattern of recognition for the dideoxyhexose by the two MAbs while each recognizes distinct surfaces of the GalNAc residue. Consequently although both antibodies bury the 4-OH of tyvelose, the principal contact surface occurs on opposite sides of the 3,6-dideoxyhexose.Key words: β-tyveloside, 3,6-dideoxy-D-arabino-hexose, Trichinella carbohydrate antigen, antibody mapping, Trichinella spiralis, N-glycans, molecular recognition of carbohydrates, antigen topology, functional group replacement.

scholarly journals Studies on Computational Molecular Interaction Between SARS-CoV-2 Main Protease and Natural Products

2020 ◽  
Author(s):  
Manish Manish
Keyword(s):  
Natural Products ◽  
Molecular Interaction ◽  
Scientific Literature ◽  
Dynamics Simulation ◽  
Major Constituent ◽  
Literature Mining ◽  
Hydroxyl Groups ◽  
Scoring Functions ◽  
Protease Inhibition ◽  
Main Protease

A combination of docking approaches, scoring functions, molecular dynamic simulation, and literature mining have been employed to screen readily available natural products (unique 27256 chemical entities, 598435 unique compounds), which can inhibit the SARS-CoV-2 main protease. Theaflavin digallate, a major constituent of black tea, has been observed to be as three top hits after the virtual screening of 598435 unique compounds. The main protease-theaflavin digallate complex appeared to be in the metastable stage and interact with critical active site residues of the main protease during molecular dynamics simulation for 200 ns. <i>Invitro</i> evidence on main protease inhibition of 2003 SARS-CoV by theaflavin digallate is available in the scientific literature. As evident by the dynamics of intermolecular interactions, theaflavin digallate, forms approximately three hydrogen bonds with Glu166 of main protease, mostly through hydroxyl groups in the benzene ring of benzo(7) annulen-6-one. Glu166 is the most critical amino acid for main protease dimerization, which in turn, is necessary for catalytic activity.<i> </i>We have employed chloroquine and epigallocatechin gallate (green tea component) as a control set. Based on computational molecular interaction and data available in scientific literature, theaflavin digallate can inhibit the main protease of SARS-CoV-2.

scholarly journals The structure of the endodermis during the development of pea (Pisum sativum L.) roots

2014 ◽  
Vol 56 (1) ◽  
pp. 11-18 ◽  
Author(s):  
Joanna Kopcińska ◽  
Władysław Golinowski
Keyword(s):  
Cell Wall ◽  
Pisum Sativum ◽  
Cell Walls ◽  
Secondary Cell Wall ◽  
Pisum Sativum L ◽  
Pea Root ◽  
Suberin Lamellae ◽  
Cell Components ◽  
Casparian Strips ◽  
Root Endodermis

It is shown on the basis of cytological studies that during the development of the pea root endodermis, the following structures were formed (in order of appearance): proendodermis, Casparian strips, suberin lamellae and secondary cell walls. The proendodermis cells had, in addition to the commonly occurring cell components, small vacuoles filled with phenols. The Casparian strips developed in the radial walls and accounted for no more than 1/3 of their length. The suberin layer, found on all of the endodermis walls, was deposited last over the Casparian strips. The secondary cell wall was formed only in the cells located over the phloem bundles. Its thickness was uniform over the entire circumference of the cell.

scholarly journals Studies on Computational Molecular Interaction Between SARS-CoV-2 Main Protease and Natural Products

2020 ◽  
Author(s):  
Manish Manish
Keyword(s):  
Natural Products ◽  
Molecular Interaction ◽  
Scientific Literature ◽  
Dynamics Simulation ◽  
Major Constituent ◽  
Literature Mining ◽  
Hydroxyl Groups ◽  
Scoring Functions ◽  
Protease Inhibition ◽  
Main Protease

A combination of docking approaches, scoring functions, molecular dynamic simulation, and literature mining have been employed to screen readily available natural products (unique 27256 chemical entities, 598435 unique compounds), which can inhibit the SARS-CoV-2 main protease. Theaflavin digallate, a major constituent of black tea, has been observed to be as three top hits after the virtual screening of 598435 unique compounds. The main protease-theaflavin digallate complex appeared to be in the metastable stage and interact with critical active site residues of the main protease during molecular dynamics simulation for 200 ns. <i>Invitro</i> evidence on main protease inhibition of 2003 SARS-CoV by theaflavin digallate is available in the scientific literature. As evident by the dynamics of intermolecular interactions, theaflavin digallate, forms approximately three hydrogen bonds with Glu166 of main protease, mostly through hydroxyl groups in the benzene ring of benzo(7) annulen-6-one. Glu166 is the most critical amino acid for main protease dimerization, which in turn, is necessary for catalytic activity.<i> </i>We have employed chloroquine and epigallocatechin gallate (green tea component) as a control set. Based on computational molecular interaction and data available in scientific literature, theaflavin digallate can inhibit the main protease of SARS-CoV-2.

scholarly journals Studies on Computational Molecular Interaction Between SARS-CoV-2 Main Protease and Natural Products

2020 ◽  
Author(s):  
Manish Manish
Keyword(s):  
Natural Products ◽  
Molecular Interaction ◽  
Scientific Literature ◽  
Dynamics Simulation ◽  
Major Constituent ◽  
Literature Mining ◽  
Hydroxyl Groups ◽  
Scoring Functions ◽  
Protease Inhibition ◽  
Main Protease

A combination of docking approaches, scoring functions, molecular dynamic simulation, and literature mining have been employed to screen readily available natural products (unique 27256 chemical entities, 598435 unique compounds), which can inhibit the SARS-CoV-2 main protease. Theaflavin digallate, a major constituent of black tea, has been observed to be as three top hits after the virtual screening of 598435 unique compounds. The main protease-theaflavin digallate complex appeared to be in the metastable stage and interact with critical active site residues of the main protease during molecular dynamics simulation for 200 ns. <i>Invitro</i> evidence on main protease inhibition of 2003 SARS-CoV by theaflavin digallate is available in the scientific literature. As evident by the dynamics of intermolecular interactions, theaflavin digallate, forms approximately three hydrogen bonds with Glu166 of main protease, mostly through hydroxyl groups in the benzene ring of benzo(7) annulen-6-one. Glu166 is the most critical amino acid for main protease dimerization, which in turn, is necessary for catalytic activity.<i> </i>We have employed chloroquine and epigallocatechin gallate (green tea component) as a control set. Based on computational molecular interaction and data available in scientific literature, theaflavin digallate can inhibit the main protease of SARS-CoV-2.

scholarly journals An Effective Approach to Improve the Photocatalytic Activity of Graphitic Carbon Nitride via Hydroxyl Surface Modification

Catalysts ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 17 ◽  
Author(s):  
Zizhen Li ◽  
Xiangchao Meng ◽  
Zisheng Zhang
Keyword(s):  
Photocatalytic Activity ◽  
Surface Modification ◽  
Water Treatment ◽  
Phenolic Compounds ◽  
Visible Light ◽  
Adsorption Energy ◽  
Carbon Nitride ◽  
Hydrophobic Surface ◽  
Hydroxyl Groups ◽  
Photocatalytic Activities

In this work, we have developed a hydrothermal method to modify g-C3N4 with hydroxyl surface modification. Modified g-C3N4 has exhibited higher photocatalytic activity in the removal of phenolic compounds under visible light. The improvement may be due to the following merits: (1) Tuning of the hydrophobic surface of g-C3N4 to be hydrophilic; (2) improved adsorption energy, and (3) narrowed band gap for g-C3N4 after hydroxyl surface modification. This method is easy-to-operate, very effective in adding hydroxyl groups on the surface of C3N4, and may be extended to other systems to promote their photocatalytic activities in water treatment.

scholarly journals Insights into the Binding of Dietary Phenolic Compounds to Human Serum Albumin and Food-Drug Interactions

Pharmaceutics ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 1123
Author(s):  
Anallely López-Yerena ◽  
Maria Perez ◽  
Anna Vallverdú-Queralt ◽  
Elvira Escribano-Ferrer
Keyword(s):  
Phenolic Compounds ◽  
Human Serum Albumin ◽  
Serum Albumin ◽  
Drug Interactions ◽  
Human Serum ◽  
Herbal Medicines ◽  
Drug Binding ◽  
Hydroxyl Groups ◽  
Binding Affinities ◽  
Native Form

The distribution of drugs and dietary phenolic compounds in the systemic circulation de-pends on, among other factors, unspecific/specific reversible binding to plasma proteins such as human serum albumin (HSA). Phenolic substances, present in plant-derived feeds, foods, beverages, herbal medicines, and dietary supplements, are of great interest due to their biological activity. Recently, considerable research has been directed at the formation of phenol–HSA complexes, focusing above all on structure–affinity relationships. The nucleophilicity and planarity of molecules can be altered by the number and position of hydroxyl groups on the aromatic ring and by hydrogenation. Binding affinities towards HSA may also differ between phenolic compounds in their native form and conjugates derived from phase II reactions. On the other hand, food–drug interactions may increase the concentration of free drugs in the blood, affecting their transport and/or disposition and in some cases provoking adverse or toxic effects. This is caused mainly by a decrease in drug binding affinities for HSA in the presence of flavonoids. Accordingly, to avoid the side effects arising from changes in plasma protein binding, the intake of flavonoid-rich food and beverages should be taken into consideration when treating certain pathologies.

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