scholarly journals Natural Compounds as Sustainable Additives for Biopolymers

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 732 ◽  
Author(s):  
Nadka Tzankova Dintcheva ◽  
Giulia Infurna ◽  
Marilena Baiamonte ◽  
Francesca D’Anna
Keyword(s):  
Calcium Carbonate ◽  
Short Review ◽  
Natural Compounds ◽  
Natural Source ◽  
Vegetable Fibers ◽  
Naturally Occurring ◽  
Alumino Silicate ◽  
Sustainable Materials ◽  
Application Fields

In the last few decades, the interest towards natural compounds, coming from a natural source and biodegradable, for biopolymers is always increasing because of a public request for the formulation of safe, eco-friendly, and sustainable materials. The main classes of natural compounds for biopolymers are: (i) naturally occurring fillers (nFil), such as nano-/micro- sized layered alumino-silicate: halloysite, bentonite, montmorillonite, hydroxyapatite, calcium carbonate, etc.; (ii) naturally occurring fibers (nFib), such as wood and vegetable fibers; (iii) naturally occurring antioxidant molecules (nAO), such as phenols, polyphenols, vitamins, and carotenoids. However, in this short review, the advantages and drawbacks, considering naturally occurring compounds as safe, eco-friendly, and sustainable additives for biopolymers, have been focused and discussed briefly, even taking into account the requests and needs of different application fields.

scholarly journals Exploiting the Amazing Diversity of Natural Source-Derived Polysaccharides: Modern Procedures of Isolation, Engineering, and Optimization of Antiviral Activities

Polymers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 136
Author(s):  
Bimalendu Ray ◽  
Martin Schütz ◽  
Shuvam Mukherjee ◽  
Subrata Jana ◽  
Sayani Ray ◽  
...  
Keyword(s):  
Structural Characteristics ◽  
Antiviral Drug ◽  
Natural Source ◽  
Target Interaction ◽  
Charge Densities ◽  
Linkage Pattern ◽  
Naturally Occurring ◽  
Antiviral Activities ◽  
One Step

Naturally occurring polysaccharide sulfates are highly diverse, owning variations in the backbone structure, linkage pattern and stereochemistry, branching diversity, sulfate content and positions of sulfate group(s). These structural characteristics bring about diverse sulfated polymers with dissimilar negative charge densities and structure–activity relationships. Herein, we start with a short discussion of techniques needed for extraction, purification, chemical sulfation, and structural characterization of polysaccharides. Processes of isolation and sulfation of plant-derived polysaccharides are challenging and usually involve two steps. In this context, we describe an integrated extraction-sulfation procedure that produces polysaccharide sulfates from natural products in one step, thereby generating additional pharmacological activities. Finally, we provide examples of the spectrum of natural source-derived polysaccharides possessing specific features of bioactivity, in particular focusing on current aspects of antiviral drug development and drug–target interaction. Thus, the review presents a detailed view on chemically engineered polysaccharides, especially sulfated derivatives, and underlines their promising biomedical perspectives.

scholarly journals O-Annulation Leading to Five-, Six-, and Seven-Membered Cyclic Diaryl Ethers Involving C–H Cleavage

Synthesis ◽  
2019 ◽  
Vol 51 (19) ◽  
pp. 3588-3599 ◽  
Author(s):  
Alexandre Rossignon ◽  
Davide Bonifazi
Keyword(s):  
Organic Pollutants ◽  
Short Review ◽  
Natural Compounds ◽  
Molecular Materials ◽  
Diaryl Ethers ◽  
Ch Activation

Cyclic diaryl ethers are present in multiple natural compounds, organic pollutants as well as in π-conjugated organic molecular materials. This short review aims at overviewing the main synthetic advances in the O-annulation methods for preparing five-, six-, and seven-membered rings through C–H cleavage.1 Introduction2 Five-Membered Rings: The Dibenzofuran (DBF) Motif2.1 Palladium-Catalysed C–H Activation2.2 Copper-Catalysed C–H Activation2.3 Non-CH Activation Oxidant-Mediated Cyclisation2.4 Light-Mediated Cyclisation2.5 Acid-catalysed C–O Cleavage/C–O Formation3 Six-Membered Rings: DBX, PXX, Xanthone, and Their Derivatives3.1 Dibenzoxanthene (DBX)3.2 Peri-Xanthenoxanthene (PXX)3.3 Xanthones3.4 Miscellaneous4 Seven-Membered Rings: Cularine5 Conclusion

scholarly journals ANTIOXIDANT POTENTIAL OF PIPERIDINE CONTAINING COMPOUNDS-A SHORT REVIEW

2018 ◽  
Vol 11 (8) ◽  
pp. 66
Author(s):  
Manjusha R K ◽  
Shaheen Begum ◽  
Arifa Begum ◽  
Bharathi K
Keyword(s):  
Biological Activities ◽  
Short Review ◽  
Heterocyclic Ring ◽  
Antioxidant Potential ◽  
Naturally Occurring ◽  
Antioxidant Profile ◽  
Antioxidant Agents ◽  
Wide Range ◽  
Privileged Scaffold ◽  
Candidate Molecule

Piperidine is a saturated heterocyclic ring, considered as a privileged scaffold in view of its role in wide range of biological activities. Piperidine is good candidate molecule for obtaining potent antioxidant agents. The planar nature of this heterocyclic nucleus allows the introduction of substituent groups at different positions on the ring. In the present review, the antioxidant profile of piperidine containing compounds has been focused. The compounds were classified into naturally occurring piperidines, unsaturated piperidines, N-substituted piperidines, piperamides, piperanols, piperidine oximes, and hydrazides.

Short Review: The Effect of Reaction Conditions on Plant-Mediated Synthesis of Silver Nanoparticles

2018 ◽  
Vol 917 ◽  
pp. 145-151 ◽  
Author(s):  
Nur Syazana Jalani ◽  
Sharifah Zati-Hanani ◽  
Yi Peng Teoh ◽  
Rozaini Abdullah
Keyword(s):  
Silver Nanoparticles ◽  
Bioactive Compounds ◽  
Short Review ◽  
Natural Source ◽  
Hazardous Chemicals ◽  
Reaction Conditions ◽  
Physical Methods ◽  
Stabilizing Agents ◽  
Environmental Friendly ◽  
Source Plant

Recently, interest in plant-mediated synthesis of the silver nanoparticles (AgNPs) is growing among researchers and till now the potential of different plants is still further explored to synthesize nanoparticles. Conventionally, AgNPs are synthesized using chemical and physical methods. However, these methods involve use of toxic and hazardous chemicals which are harmful to health and environment. Therefore, plant-mediated synthesis has been used as environmental friendly alternative to overcome the limitation of conventional methods. The bioactive compounds in plant acts as natural reducing and stabilizing agents which help to increase the rate of synthesis and stabilization of synthesized nanoparticles. Besides, the nanoparticles synthesized using plants are reported to be more stable and the rate of synthesis is much faster compared to other methods. This review focuses on the biosynthesis of AgNPs using plant as natural source plant and the effect of reaction conditions are summarised and discussed.

Studies of the Uroporphyrins

1960 ◽  
Vol 6 (2) ◽  
pp. 71-97 ◽  
Author(s):  
C J Watson ◽  
M H Berg ◽  
V E Hawkinson ◽  
Irene Bossenmaier
Keyword(s):  
Calcium Carbonate ◽  
Ethyl Acetate ◽  
Extraction Procedure ◽  
Type I ◽  
Acute Porphyria ◽  
Preliminary Heating ◽  
Type Iii ◽  
Naturally Occurring ◽  
Isomer Composition ◽  
Metabolic Significance

Abstract 1. Seventeen cases of hepatic porphyria have been studied with respect to variations in isomer composition of the urinary Waldenström uroporphyrin complex. 2. Comparison was made of the effect of various isolation procedures on the isomer composition of the uroporphyrin complex, with special reference to the effect of preliminary heating of the urine. 3. Methods not employing heat, including the ethyl acetate extraction procedure of Waldenström, the talc adsorption of Grinstein et al., and a number of modifications, usually yielded relatively small amounts of a uroporphyrin complex, preponderantly Type I isomer. In two instances, however, the complex contained 60-70 per cent Type III. When separable on calcium carbonate, the Type III component was again shown to consist in the main of a 7-COOH porphyrin. Preheating of the urine regularly produced much larger amounts of a Waldenström type porphyrin, and larger proportions of Type III isomer in the complex. 4. The Waldenström porphyrin isolated following conversion of naturally occurring porphyrinogen, by irradiation with ultraviolet light, usually contained a marked preponderance of uroporphyrin I. In certain instances, however, the porphyrinogen was entirely that of the "208" Type III porphyrin. 5. While the large amount of Type III porphyrin found after heating the urine undoubtedly represents nonenzymatic conversion of porphobilinogen, the smaller amount of Type I isomer usually present in major proportion in the preformed uroporphyrin complex or its porphyrinogen may have intrinsic metabolic significance. In exceptional cases of acute porphyria, the uroporphyrin of the unheated urine is preponderantly the Type III isomer.

scholarly journals NARINGIN REVEALS AMELIORATIVE PROPERTY OVER ELEVATED OXIDATIVE STRESS LEVELS IN ANIMAL MODELS

2018 ◽  
Vol 11 (12) ◽  
pp. 46
Author(s):  
Zorawar Singh ◽  
Adeshwinder Kaur ◽  
Shivam Sharma
Keyword(s):  
Oxidative Stress ◽  
Free Radicals ◽  
Animal Models ◽  
Grapefruit Juice ◽  
Cardiac Fibrosis ◽  
Review Paper ◽  
Short Review ◽  
Protective Role ◽  
Naturally Occurring ◽  
Cell Components

Oxidative stress (OxiS) has been implicated in the pathogenesis of many diseases. Free radicals interact with different cell components including DNA, proteins, and lipids to become stable. In this process, these free radicals damage the integrity of these biological moieties and result in various health implications. Naringin (NG), a naturally occurring phytochemical commonly found in grapefruit juice has been explored for its protective role against OxiS. In this short review paper, an attempt has been made to compile the study reports revealing the antioxidative nature of NG in different animal models. Studies have reported NG as a potential antioxidant in various health ailments including diabetes, cardiac fibrosis, cognitive dysfunction, and neurodegeneration.

The synthesis of copper/zinc solid solutions of hydroxyl carbonates, sulphates, nitrates, chlorides and bromides

2011 ◽  
Vol 75 (5) ◽  
pp. 2573-2582 ◽  
Author(s):  
C. H. Yoder ◽  
R. W. Schaeffer ◽  
P. McWilliams ◽  
A. Rowand ◽  
X. Liu ◽  
...  
Keyword(s):  
Calcium Carbonate ◽  
Solid Solutions ◽  
Copper Nitrate ◽  
Zinc Nitrate ◽  
Cell Parameters ◽  
Naturally Occurring ◽  
Jahn Teller ◽  
Jahn Teller Effect ◽  
Copper Zinc ◽  
Temperature Preparation

AbstractThe relative stabilities of the copper/zinc solid solutions of hydroxyl sulphates, carbonates, nitrates, chlorides and bromides were studied by attempting their preparation using a variety of methods. All of the naturally occurring solid solutions except rosasite were obtained as single phases. Rosasite crystallized in a mixture with malachite and calcium carbonate during a room temperature preparation from calcium carbonate, copper nitrate and zinc nitrate. The solid solution with the antlerite stoichiometry [endmember Cu3SO4(OH)4] as well as the nitrates were not produced by the methods employed. All of the natural polymorphs of Cu2(OH)3Cl were obtained and a new method for the preparation of botallackite is reported. Botallackite was found to be stable in solution for over a year, contrary to previous reports. A bromine-bearing analogue of botallackite was prepared. Compounds were characterized by X-ray diffractometry, which was used to determine the unit-cell parameters, and by atomic absorption spectroscopy. The relative instability of solid solutions with certain stoichiometries is discussed in terms of the Jahn-Teller effect and relative solubilities.

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