scholarly journals Formation of Amphiphilic Molecules from the Most Common Marine Polysaccharides, toward a Sustainable Alternative?

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4445
Author(s):  
Tiphaine Wong ◽  
Lorette Brault ◽  
Eric Gasparotto ◽  
Romuald Vallée ◽  
Pierre-Yves Morvan ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Carboxylic Acid ◽  
Bioactive Compounds ◽  
Biological Properties ◽  
Cross Linking ◽  
Structural Modifications ◽  
Chemical Structures ◽  
Amphiphilic Molecules

Marine polysaccharides are part of the huge seaweeds resources and present many applications for several industries. In order to widen their potential as additives or bioactive compounds, some structural modifications have been studied. Among them, simple hydrophobization reactions have been developed in order to yield to grafted polysaccharides bearing acyl-, aryl-, alkyl-, and alkenyl-groups or fatty acid chains. The resulting polymers are able to present modified physicochemical and/or biological properties of interest in the current pharmaceutical, cosmetics, or food fields. This review covers the chemical structures of the main marine polysaccharides, and then focuses on their structural modifications, and especially on hydrophobization reactions mainly esterification, acylation, alkylation, amidation, or even cross-linking reaction on native hydroxyl-, amine, or carboxylic acid functions. Finally, the question of the necessary requirement for more sustainable processes around these structural modulations of marine polysaccharides is addressed, considering the development of greener technologies applied to traditional polysaccharides.

Synthesis and Biological Properties of New Piperidine Substituted Benzothiazole Derivatives

2021 ◽  
Vol 6 (3) ◽  
pp. 181-185
Author(s):  
S. Syed Shafi ◽  
R. Rajesh ◽  
S. Senthilkumar
Keyword(s):  
Antibacterial Activity ◽  
Antifungal Activity ◽  
Carboxylic Acid ◽  
Biological Properties ◽  
The Novel ◽  
Photoluminescence Spectra ◽  
Benzothiazole Derivatives ◽  
Chemical Structures ◽  
Good Antibacterial Activity ◽  
Biological Studies

In present work, ethyl 2-aminobenzo[d]thiazole-6-carboxylate was reacted to piperidine using copper(II) bromide to get ethyl 2-(piperidin-1-yl)benzo[d]thiazole-6-carboxylate. The reaction of ethyl 2-(piperidin- 1-yl)benzo[d]thiazole-6-carboxylate with NaOH produces 2-(piperidin-1-yl)benzo[d]thiazole-6- carboxylic acid. The inter-mediate 2-(piperidin-1-yl)benzo[d]thiazole-6-carboxylic acid have been isolated as stable compounds. The chemical structures of synthesized compounds were established based on the 1H & 13C NMR and IR spectral data. The mass of the novel compounds was established with the help of the LC-MS technique. The photoluminescence spectra explain the optical property of the compound. The biological studies of synthesized compounds show that the compound 5e possesses good antibacterial activity and compound 5d has good antifungal activity.

scholarly journals Diversity in Chemical Structures and Biological Properties of Plant Alkaloids

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3374
Author(s):  
Sweta Bhambhani ◽  
Kirtikumar R. Kondhare ◽  
Ashok P. Giri
Keyword(s):  
Biological Activities ◽  
Biological Properties ◽  
Plant Metabolites ◽  
Diverse Range ◽  
Nitrogenous Compounds ◽  
Structural Modifications ◽  
Specialized Metabolites ◽  
Chemical Structures ◽  
Heterologous System ◽  
Plant Alkaloids

Phytochemicals belonging to the group of alkaloids are signature specialized metabolites endowed with countless biological activities. Plants are armored with these naturally produced nitrogenous compounds to combat numerous challenging environmental stress conditions. Traditional and modern healthcare systems have harnessed the potential of these organic compounds for the treatment of many ailments. Various chemical entities (functional groups) attached to the central moiety are responsible for their diverse range of biological properties. The development of the characterization of these plant metabolites and the enzymes involved in their biosynthesis is of an utmost priority to deliver enhanced advantages in terms of biological properties and productivity. Further, the incorporation of whole/partial metabolic pathways in the heterologous system and/or the overexpression of biosynthetic steps in homologous systems have both become alternative and lucrative methods over chemical synthesis in recent times. Moreover, in-depth research on alkaloid biosynthetic pathways has revealed numerous chemical modifications that occur during alkaloidal conversions. These chemical reactions involve glycosylation, acylation, reduction, oxidation, and methylation steps, and they are usually responsible for conferring the biological activities possessed by alkaloids. In this review, we aim to discuss the alkaloidal group of plant specialized metabolites and their brief classification covering major categories. We also emphasize the diversity in the basic structures of plant alkaloids arising through enzymatically catalyzed structural modifications in certain plant species, as well as their emerging diverse biological activities. The role of alkaloids in plant defense and their mechanisms of action are also briefly discussed. Moreover, the commercial utilization of plant alkaloids in the marketplace displaying various applications has been enumerated.

Synthesis, Characterization and Thermal Degradation of Some New 3,5-dimethyl Pyrazole Derivatives

2017 ◽  
Vol 68 (2) ◽  
pp. 317-322
Author(s):  
Anca Mihaela Mocanu ◽  
Constantin Luca ◽  
Alina Costina Luca
Keyword(s):  
Thermal Degradation ◽  
Degradation Mechanism ◽  
New Products ◽  
Analysis Data ◽  
Biological Properties ◽  
Elemental Analysis Data ◽  
Ftir Analysis ◽  
Spectral Measurements ◽  
Chemical Structures ◽  
And Storage

The purpose of this research is to synthetize, characterize and thermal degradation of new heterolytic derivates with potential biological properties. The derivates synthesis was done by obtaining new molecules with pyralozone structure which combine two pharmacophore entities: the amidosulfonyl-R1,R2 phenoxyacetil with the 3,5-dimethyl pyrazole which can have potential biological properties. The synthesis stages of the new products are presented as well as the elemental analysis data and IR, 1H-NMR spectral measurements made for elucidating the chemical structures and thermostability study which makes evident the temperature range proper for their use and storage. The obtained results were indicative of a good correlation of the structure with the thermal stability as estimated by means of the initial degradation temperatures as well as with the degradation mechanism by means of the TG-FTIR analysis.

Chitosan in Biomedical Engineering: A Critical Review

2019 ◽  
Vol 14 (2) ◽  
pp. 93-116 ◽  
Author(s):  
Shabnam Mohebbi ◽  
Mojtaba Nasiri Nezhad ◽  
Payam Zarrintaj ◽  
Seyed Hassan Jafari ◽  
Saman Seyed Gholizadeh ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Biomedical Engineering ◽  
Biological Properties ◽  
Advanced Materials ◽  
Comprehensive Overview ◽  
Chemical Structures ◽  
Bio Imaging ◽  
Significant Attention ◽  
Unique Chemical

Biomedical engineering seeks to enhance the quality of life by developing advanced materials and technologies. Chitosan-based biomaterials have attracted significant attention because of having unique chemical structures with desired biocompatibility and biodegradability, which play different roles in membranes, sponges and scaffolds, along with promising biological properties such as biocompatibility, biodegradability and non-toxicity. Therefore, chitosan derivatives have been widely used in a vast variety of uses, chiefly pharmaceuticals and biomedical engineering. It is attempted here to draw a comprehensive overview of chitosan emerging applications in medicine, tissue engineering, drug delivery, gene therapy, cancer therapy, ophthalmology, dentistry, bio-imaging, bio-sensing and diagnosis. The use of Stem Cells (SCs) has given an interesting feature to the use of chitosan so that regenerative medicine and therapeutic methods have benefited from chitosan-based platforms. Plenty of the most recent discussions with stimulating ideas in this field are covered that could hopefully serve as hints for more developed works in biomedical engineering.

Synthesis and biological properties of cholecystokinin heptapeptide analogues containing D- and L-forms of tert-leucine or neopentylglycine in position 5

1991 ◽  
Vol 56 (10) ◽  
pp. 2209-2217 ◽  
Author(s):  
Jan Hlaváček ◽  
Jana Pírková ◽  
Jan Pospíšek ◽  
Jiřina Slaninová ◽  
Lenka Maletínská
Keyword(s):  
Gall Bladder ◽  
Solid Phase ◽  
Biological Activities ◽  
Biological Properties ◽  
Phase Synthesis ◽  
Structural Modifications ◽  
Bladder Contraction ◽  
Anorectic Effect ◽  
Carboxy Terminal ◽  
Anorectic Activity

Using solution or solid-phase synthesis we prepared the cholecystokinin fragment Boc-CCK-7 (Boc-Tyr-(SO3-.Na+)-Met-Gly-Trp-Met-Asp-PheNH2) and its four analogues in which the methionine moiety (Met) in the carboxy-terminal part is replaced by tert-leucine (Tle) or neopentylglycine (Neo) residue or D-enantiomers of these non-coded amino acids. These structural modifications led to reduction of the studied biological activities (gall bladder contraction, anorectic activity, analgetic and sedation activity) of all prepared analogues except Boc[Neo5]-CCK-7 which, being less analgetically active, retains full gall bladder and sedation activity of CCK-8. Moreover, its anorectic activity is substantially higher (400%). This analogue is very interesting particularly for its selectively increased (4x) anorectic effect compared with that of CCK-8.

scholarly journals Bioactive Compounds Obtained from Polish “Marynka” Hop Variety Using Efficient Two-Step Supercritical Fluid Extraction and Comparison of Their Antibacterial, Cytotoxic, and Anti-Proliferative Activities In Vitro

Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2366
Author(s):  
Katarzyna Klimek ◽  
Katarzyna Tyśkiewicz ◽  
Malgorzata Miazga-Karska ◽  
Agnieszka Dębczak ◽  
Edward Rój ◽  
...  
Keyword(s):  
Supercritical Fluid Extraction ◽  
Supercritical Fluid ◽  
Bioactive Compounds ◽  
Crude Extract ◽  
Normal Skin ◽  
Extraction Methods ◽  
Biological Properties ◽  
Added Value ◽  
Fluid Extraction

Given the health-beneficial properties of compounds from hop, there is still a growing trend towards developing successful extraction methods with the highest yield and also receiving the products with high added value. The aim of this study was to develop efficient extraction method for isolation of bioactive compounds from the Polish “Marynka” hop variety. The modified two-step supercritical fluid extraction allowed to obtain two hop samples, namely crude extract (E1), composed of α-acids, β-acids, and terpene derivatives, as well as pure xanthohumol with higher yield than that of other available methods. The post-extraction residues (R1) were re-extracted in order to obtain extract E2 enriched in xanthohumol. Then, both samples were subjected to investigation of their antibacterial (anti-acne, anti-caries), cytotoxic, and anti-proliferative activities in vitro. It was demonstrated that extract (E1) possessed more beneficial biological properties than xanthohumol. It exhibited not only better antibacterial activity against Gram-positive bacteria strains (MIC, MBC) but also possessed a higher synergistic effect with commercial antibiotics when compared to xanthohumol. Moreover, cell culture experiments revealed that crude extract neither inhibited viability nor divisions of normal skin fibroblasts as strongly as xanthohumol. In turn, calculated selectivity indexes showed that the crude extract had from slightly to significantly better selective anti-proliferative activity towards cancer cells in comparison with xanthohumol.

scholarly journals Bioactive potential of natural biomaterials: identification, retention and assessment of biological properties

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Kieran Joyce ◽  
Georgina Targa Fabra ◽  
Yagmur Bozkurt ◽  
Abhay Pandit
Keyword(s):  
Tissue Engineering ◽  
Therapeutic Potential ◽  
Biological Properties ◽  
Biological Assessment ◽  
Cross Linking ◽  
Natural Polymers ◽  
Drug Delivery Device ◽  
Biomedical Device ◽  
Wide Range ◽  
Bioactive Potential

AbstractBiomaterials have had an increasingly important role in recent decades, in biomedical device design and the development of tissue engineering solutions for cell delivery, drug delivery, device integration, tissue replacement, and more. There is an increasing trend in tissue engineering to use natural substrates, such as macromolecules native to plants and animals to improve the biocompatibility and biodegradability of delivered materials. At the same time, these materials have favourable mechanical properties and often considered to be biologically inert. More importantly, these macromolecules possess innate functions and properties due to their unique chemical composition and structure, which increase their bioactivity and therapeutic potential in a wide range of applications. While much focus has been on integrating these materials into these devices via a spectrum of cross-linking mechanisms, little attention is drawn to residual bioactivity that is often hampered during isolation, purification, and production processes. Herein, we discuss methods of initial material characterisation to determine innate bioactivity, means of material processing including cross-linking, decellularisation, and purification techniques and finally, a biological assessment of retained bioactivity of a final product. This review aims to address considerations for biomaterials design from natural polymers, through the optimisation and preservation of bioactive components that maximise the inherent bioactive potency of the substrate to promote tissue regeneration.

scholarly journals Bioactive Compounds in Salicornia patula Duval-Jouve: A Mediterranean Edible Euhalophyte

Foods ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 410
Author(s):  
Irene Sánchez-Gavilán ◽  
Esteban Ramírez ◽  
Vicenta de la Fuente
Keyword(s):  
Fatty Acids ◽  
Bioactive Compounds ◽  
Mediterranean Area ◽  
Biological Properties ◽  
Total Phenolic ◽  
Tinto River ◽  
New Findings ◽  
High Concentrations ◽  
Salicornia Patula ◽  
First Time

Many halophytes have great nutritional and functional potential, providing chemical compounds with biological properties. Salicornia patula Duval-Jouve is a common euhalophyte from saline Mediterranean territories (Spain, Portugal, France, and Italy). In the present work we quantified for the first time the bioactive compounds in S. patula (total phenolic compounds and fatty acids), from Iberian Peninsula localities: littoral-coastal Tinto River basin areas (southwest Spain, the Huelva province), and mainland continental territories (northwest and central Spain, the Valladolid and Madrid provinces). Five phenolic acids including caffeic, coumaric, veratric, salicylic, and transcinnamic have been found with differences between mainland and coastal saltmarshes. S. patula contain four flavonoids: quercetin-3-O-rutinoside, kaempferol/luteolin, apigenin 7-glucoside, and pelargonidin-3-O-rutinoside. These last two glycosylated compounds are described for the first time in this genus of Chenopodiaceae. The fatty acid profile described in S. patula stems contains palmitic, oleic, and linoleic acids in high concentrations, while stearic and long-chain fatty acids were detected in low amounts. These new findings confirm that S. patula is a valuable source of bioactive compounds from Mediterranean area.

scholarly journals On-surface activation of benzylic C-H bonds for the synthesis of pentagon-fused graphene nanoribbons

Nano Research ◽  
2021 ◽  
Author(s):  
Xiushang Xu ◽  
Marco Di Giovannantonio ◽  
José I. Urgel ◽  
Carlo A. Pignedoli ◽  
Pascal Ruffieux ◽  
...  
Keyword(s):  
Carbon Nanomaterials ◽  
Graphene Nanoribbons ◽  
Gold Surface ◽  
Fine Tuning ◽  
Uniform Structure ◽  
Methyl Groups ◽  
Structural Modifications ◽  
Force Microscopy ◽  
Chemical Structures ◽  
Atomic Force

AbstractGraphene nanoribbons (GNRs) have potential for applications in electronic devices. A key issue, thereby, is the fine-tuning of their electronic characteristics, which can be achieved through subtle structural modifications. These are not limited to the conventional armchair, zigzag, and cove edges, but also possible through incorporation of non-hexagonal rings. On-surface synthesis enables the fabrication and visualization of GNRs with atomically precise chemical structures, but strategies for the incorporation of non-hexagonal rings have been underexplored. Herein, we describe the on-surface synthesis of armchair-edged GNRs with incorporated five-membered rings through the C-H activation and cyclization of benzylic methyl groups. Ortho-Tolyl-substituted dibromobianthryl was employed as the precursor monomer, and visualization of the resulting structures after annealing at 300 °C on a gold surface by high-resolution noncontact atomic force microscopy clearly revealed the formation of methylene-bridged pentagons at the GNR edges. These persisted after annealing at 340 °C, along with a few fully conjugated pentagons having singly-hydrogenated apexes. The benzylic methyl groups could also migrate or cleave-off, resulting in defects lacking the five-membered rings. Moreover, unexpected and unique structural rearrangements, including the formation of embedded heptagons, were observed. Despite the coexistence of different reaction pathways that hamper selective synthesis of a uniform structure, our results provide novel insights into on-surface reactions en route to functional, non-benzenoid carbon nanomaterials.

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