ETUDE HISTOLOGIQUE DE LA BIGARRURE NERVALE, DE LA GRISELURE DU LIMBE ET DE LA MEDIANE NOIRE, TROIS DESORDRES DU CHOU EN ENTREPOT

1987 ◽  
Vol 67 (1) ◽  
pp. 321-329
Author(s):  
L. S. BÉRARD ◽  
M. A. DUBUC-LEBREUX ◽  
J. VIETH
Keyword(s):  
Cell Wall ◽  
Chemical Composition ◽  
Phenolic Compounds ◽  
Brassica Oleracea ◽  
Similar Response ◽  
Physiological Disorder ◽  
Cytoplasmic Matrix ◽  
Parenchyma Cells ◽  
The Many

The evolution in storage of three physiological disorders of cabbage (Brassica oleracea var. capitata) has been studied by means of histological tests done in situ or after fixation and staining. The tissues tested were sampled on necrotic and healthy parts from the three outer-head leaves of the susceptible cv. Safekeeper and of the resistant cv. Hitoma. The tissues affected by vein streaking, grey speck disease or black midrib showed a similar response to the many tests: the absence of lipids, lignin and suberin in the necrotic cells, but the presence of unidentified phenolic compounds, concomitantly with a modification of birefringence of the cell wall and an alteration of the cytoplasmic matrix. Vein streaking is associated with creases on the adaxial epidermis of the midrib, grey speck disease with abundant wax on the abaxial blade, and black midrib with large vesicles in the necrotic parenchyma cells of the midrib.Key words: Brassica oleracea var. capitata, chemical composition, cytology, pepper spot, physiological disorder, storage

Influence of Structure and Chemical Composition on Thermal Softening of Palasan Canes (Calamus Merrillii)

IAWA Journal ◽  
2005 ◽  
Vol 26 (3) ◽  
pp. 363-374
Author(s):  
Willie P. Abasolo ◽  
Masato Yoshida ◽  
Hiroyuki Yamamoto ◽  
Takashi Okuyama
Keyword(s):  
Cell Wall ◽  
Chemical Composition ◽  
Creep Compliance ◽  
Thermal Response ◽  
Thermal Softening ◽  
Cellulose Content ◽  
Hemicellulose Content ◽  
Parenchyma Cells ◽  
Area Percentage ◽  
High Cellulose

The influence of structure on the thermal softening of Palasan canes was evaluated using the creep compliance test. The canes revealed compliance curves similar to wood. Correlating the average compliance per temperature to ground parenchyma and fiber area percentage showed that the former promoted thermal softening while the latter inhibited it. This thermal response was highly affected by the ratio between the heat resistant cellulose and heat sensitive hemicellulose components of the cell wall. Ground parenchyma cells with high hemicellulose content favored thermal softening, while fibers with high cellulose content inhibited it. Therefore, the degree of thermal softening is dependent on the proportion of ground parenchyma present within the region. If the ground parenchyma percentage is high it is expected that the amount of softening will be large and vice versa.

Structural Studies on Mitotic Spindle Fibres

1978 ◽  
Vol 36 (3) ◽  
pp. 615-626
Author(s):  
J.R. Mcintosh
Keyword(s):  
Chemical Composition ◽  
Mitotic Spindle ◽  
Structural Studies ◽  
Mitotic Apparatus ◽  
Chemical Studies ◽  
Medical Interest ◽  
Spindle Fibres

The mitotic apparatus is a structure of obvious biological and medical interest, but it has proved to be a difficult cellular machine to understand. The chemical composition of the spindle is only slightly elucidated, largely because of the difficulties in preparing useful isolates of the structure. Chemical studies of the mitotic spindle have been reviewed elsewhere (Mcintosh, 1977), and will not be discussed further here. One would think that structural studies on the mitotic apparatus (MA) in situ would be straightforward, but even with this approach there is some disagreement in the results obtained with various methods and by different investigators. In this paper I will review briefly the approaches which have been used in structural studies of the MA, pointing out the strengths and problems of each approach. I will summarize the principal findings of the different methods, and identify what seem to be fruitful avenues for further work.

In vitro and in vivo polysaccharides assembly: ultrastructural and cytochemical study of growing plant cell wall components.

1978 ◽  
Vol 36 (2) ◽  
pp. 434-435
Author(s):  
D. Reis ◽  
B. Vian ◽  
J. C. Roland
Keyword(s):  
Cell Wall ◽  
Self Assembly ◽  
Plant Cell Wall ◽  
Higher Plants ◽  
Three Dimensional ◽  
Cytochemical Study ◽  
Wall Components

Wall morphogenesis in higher plants is a problem still open to controversy. Until now the possibility of a transmembrane control and the involvement of microtubules were mostly envisaged. Self-assembly processes have been observed in the case of walls of Chlamydomonas and bacteria. Spontaneous gelling interactions between xanthan and galactomannan from Ceratonia have been analyzed very recently. The present work provides indications that some processes of spontaneous aggregation could occur in higher plants during the formation and expansion of cell wall.Observations were performed on hypocotyl of mung bean (Phaseolus aureus) for which growth characteristics and wall composition have been previously defined.In situ, the walls of actively growing cells (primary walls) show an ordered three-dimensional organization (fig. 1). The wall is typically polylamellate with multifibrillar layers alternately transverse and longitudinal. Between these layers intermediate strata exist in which the orientation of microfibrils progressively rotates. Thus a progressive change in the morphogenetic activity occurs.

Ultrastructure and Senescence in an Achloroplastic Mutant of Hordeum vulgare L. cv. Dyan

1992 ◽  
Vol 50 (1) ◽  
pp. 844-845
Author(s):  
R.H.M. Cross ◽  
C.E.J. Botha ◽  
A.K. Cowan ◽  
B.J. Hartley
Keyword(s):  
Cell Wall ◽  
Hordeum Vulgare ◽  
Leaf Tissue ◽  
Ultrastructural Changes ◽  
Hordeum Vulgare L ◽  
Mesophyll Cells ◽  
Lethal Mutant ◽  
Cytoplasmic Matrix ◽  
Close Proximity ◽  
Pinocytotic Vesicles

Senescence is an ordered degenerative process leading to death of individual cells, organs and organisms. The detection of a conditional lethal mutant (achloroplastic) of Hordeum vulgare has enabled us to investigate ultrastructural changes occurring in leaf tissue during foliar senescence.Examination of the tonoplast structure in six and 14 day-old mutant tissue revealed a progressive degeneration and disappearance of the membrane, apparently starting by day six in the vicinity of the mitochondria associated with the degenerating proplastid (Fig. 1.) where neither of the plastid membrane leaflets is evident (arrows, Fig. 1.). At this stage there was evidence that the mitochondrial membranes were undergoing retrogressive changes, coupled with disorganization of cristae (Fig. 2.). Proplastids (P) lack definitive prolamellar bodies. The cytoplasmic matrix is largely agranular, with few endoplasmic reticulum (ER) cisternae or polyribosomal aggregates. Interestingly, large numbers of actively-budding dictysomes, associated with pinocytotic vesicles, were observed in close proximity to the plasmalemma of mesophyll cells (Fig. 3.). By day 14 however, mesophyll cells showed almost complete breakdown of subcellular organelle structure (Fig. 4.), and further evidence for the breakdown of the tonoplast. The final stage of senescence is characterized by the solubilization of the cell wall due to expression and activity of polygalacturonase and/or cellulose. The presence of dictyosomes with associated pinocytotic vesicles formed from the mature face, in close proximity to both the plasmalemma and the cell wall, would appear to support the model proposed by Christopherson for the secretion of cellulase. This pathway of synthesis is typical for secretory glycoproteins.

Microwave Pretreatment of Vegetable Materials to Increase the Extraction Yield of Natural Products

2018 ◽  
Vol 69 (8) ◽  
pp. 1976-1979
Author(s):  
Ioana Asofiei ◽  
Ioan Calinescu ◽  
Adina Ionuta Gavrila ◽  
Daniel Ighigeanu ◽  
Diana Martin
Keyword(s):  
Natural Products ◽  
Chemical Composition ◽  
Phenolic Compounds ◽  
Total Phenolic Content ◽  
Phenolic Content ◽  
Extraction Yield ◽  
Total Phenolic ◽  
Microwave Pretreatment ◽  
Pretreatment Time ◽  
Conventional Extraction

It was designed and built a laboratory experimental installation (LEI) for the microwave pretreatment of vegetable materials. To study the influence of microwave pretreatment on the total phenolic content (TPC), a conventional extraction of polyphenols from treated and untreated fresh sea buckthorn leaves was performed. For short extraction times, the amount of phenolic compounds was higher for the extracts obtained from treated leaves, but a long pretreatment time (28 s) led to a decrease in TPC. The qualitative analysis showed that the chemical composition is not affected by the microwave pretreatment.

scholarly journals By-Products of Camu-Camu [Myrciaria dubia (Kunth) McVaugh] as Promising Sources of Bioactive High Added-Value Food Ingredients: Functionalization of Yogurts

Molecules ◽  
2019 ◽  
Vol 25 (1) ◽  
pp. 70 ◽  
Author(s):  
Natália Conceição ◽  
Bianca R. Albuquerque ◽  
Carla Pereira ◽  
Rúbia C. G. Corrêa ◽  
Camila B. Lopes ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Phenolic Compounds ◽  
Food System ◽  
Food Additives ◽  
Added Value ◽  
Phenolic Profile ◽  
Food Ingredients ◽  
Myrciaria Dubia ◽  
By Products ◽  
Fruit Part

Camu-camu (Myrciaria dubia (Kunth) McVaugh) is a fruit economically relevant to the Amazon region, mostly consumed in the form of processed pulp. Our aim was to perform an unprecedented comparative study on the chemical composition and bioactivities of the camu-camu pulp and industrial bio-residues (peel and seed), and then the most promising fruit part was further explored as a functionalized ingredient in yogurt. A total of twenty-three phenolic compounds were identified, with myricetin-O-pentoside and cyanindin-3-O-glucoside being the main compounds in peels, followed by p-coumaroyl hexoside in the pulp, and ellagic acid in the seeds. The peel displayed the richest phenolic profile among samples, as well as the most significant antibacterial (MICs = 0.625–10 mg/mL) and anti-proliferative (GI50 = 180 µg/mL against HeLa cells) activities. For this reason, it was selected to be introduced in a food system (yogurt). Taken together, our results suggest the possibility of using the camu-camu peel as a source of food additives.

scholarly journals Comparative Evaluation of Chemical Composition, Phenolic Compounds, and Antioxidant and Antimicrobial Activities of Tropical Black Bolete Mushroom Using Different Preservation Methods

Foods ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 781
Author(s):  
Jaturong Kumla ◽  
Nakarin Suwannarach ◽  
Keerati Tanruean ◽  
Saisamorn Lumyong
Keyword(s):  
Chemical Composition ◽  
Phenolic Compounds ◽  
Natural Antioxidants ◽  
Antimicrobial Activities ◽  
Fresh Sample ◽  
Antioxidant Power ◽  
Preservation Methods ◽  
Ferric Reducing Antioxidant Power ◽  
Nutritional Benefits ◽  
Antioxidant And Antimicrobial Activities

Tropical black bolete, Phlebopus portentosus, provides various nutritional benefits and natural antioxidants to humans. In this study, the chemical composition, phenolic compounds, and antioxidant and antimicrobial activities of fresh mushroom samples and samples stored for a period of one year using different preservation methods (drying, brining, and frozen) were investigated. The results indicated that the brining method significantly reduced the protein and fat contents of the mushrooms. The polyphenol and flavonoid contents of the frozen sample were not significantly different from that of the fresh sample. The results revealed that an inhibition value of 50% (IC50) for the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay of the extract of the dried and frozen samples was not statistically different from that of the fresh sample. The IC50 value of 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) assay and ferric reducing antioxidant power (FRAP) value in the extract of the frozen sample were not found to be significantly different from those of the fresh sample. Furthermore, the lowest degree of antioxidant activity was found in the extract of the brined sample. Additionally, the antimicrobial activities of the extracts of the fresh and frozen samples were not significantly different and both extracts could have inhibited the growth of all tested Gram-positive bacteria and Pseudomonas aeruginosa.

scholarly journals Phytochemical and Psychotropic Research of Motherwort (Leonurus cardiaca L.) Modified Dry Extracts

Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 230
Author(s):  
Oleh Koshovyi ◽  
Ain Raal ◽  
Igor Kireyev ◽  
Nadiya Tryshchuk ◽  
Tetiana Ilina ◽  
...  
Keyword(s):  
Amino Acids ◽  
Chemical Composition ◽  
Phenolic Compounds ◽  
Pharmacological Activity ◽  
Ellagic Acid ◽  
Hydroxycinnamic Acids ◽  
Psychotropic Activity ◽  
Phytochemical Analysis ◽  
Phenolic Substances ◽  
Leonurus Cardiaca

The prospect of creating a new medicine with psychotropic activity is shown as a result of studying the chemical composition and pharmacological activity of modified dry extracts of motherwort (Leonurus cardiaca L.) tincture. The most promising substances were the dry extracts, modified by adding small amounts of arginine, valine, phenylalanine, glycine, lysine, and alanine. A total of 15 main phenolic substances were found in the extracts, and eight of them were identified. There were also 10 hydroxycinnamic acids in these extracts, three of which were identified (chlorogenic, caffeic, and rosmarinic acids). The dominant hydroxycinnamic acids were chlorogenic and caffeic acids. Among flavonoids, catechin, hyperoside, and rutin were identified. It should be noted that the extracts had a significant content of ellagic acid. On the basis of the results of the phytochemical analysis of the extracts, it can be concluded that the composition of phenolic compounds does not differ significantly, and the main differences are related to amino acids, which obviously have an impact on the overall pharmacological effect. The results obtained indicate the presence of anxiolytic activity in the motherwort extracts studied in complex with amino acids. The extracts with glycine, valine, and arginine were more effective in reducing anxiety in animals.

Chemical Composition, Morphological Characteristics, and Cell Wall Structure of Malaysian Oil Palm Fibers

2008 ◽  
Vol 47 (3) ◽  
pp. 273-280 ◽  
Author(s):  
H. P. S. Abdul Khalil ◽  
M. Siti Alwani ◽  
R. Ridzuan ◽  
H. Kamarudin ◽  
A. Khairul
Keyword(s):  
Cell Wall ◽  
Chemical Composition ◽  
Oil Palm ◽  
Morphological Characteristics ◽  
Cell Wall Structure ◽  
Wall Structure

scholarly journals An Atmospheric Origin for HCN-Derived Polymers on Titan

Processes ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 965
Author(s):  
Zoé Perrin ◽  
Nathalie Carrasco ◽  
Audrey Chatain ◽  
Lora Jovanovic ◽  
Ludovic Vettier ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Gas Phase ◽  
Formation Process ◽  
Upper Atmosphere ◽  
Gas Mixture ◽  
Space Probe ◽  
Atmospheric Haze ◽  
Formation And Evolution ◽  
Haze Formation

Titan’s haze is strongly suspected to be an HCN-derived polymer, but despite the first in situ measurements by the ESA-Huygens space probe, its chemical composition and formation process remain largely unknown. To investigate this question, we simulated the atmospheric haze formation process, experimentally. We synthesized analogues of Titan’s haze, named Titan tholins, in an irradiated N2–CH4 gas mixture, mimicking Titan’s upper atmosphere chemistry. HCN was monitored in situ in the gas phase simultaneously with the formation and evolution of the haze particles. We show that HCN is produced as long as the particles are absent, and is then progressively consumed when the particles appear and grow. This work highlights HCN as an effective precursor of Titan’s haze and confirms the HCN-derived polymer nature of the haze.

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