scholarly journals Physico-chemical characterization of chitosan-based edible films incorporating bioactive compounds of different molecular weight

2011 ◽  
Vol 106 (2) ◽  
pp. 111-118 ◽  
Author(s):  
Ana I. Bourbon ◽  
Ana C. Pinheiro ◽  
Miguel A. Cerqueira ◽  
Cristina M.R. Rocha ◽  
Maria C. Avides ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Bioactive Compounds ◽  
Chemical Characterization ◽  
Edible Films ◽  
Physico Chemical ◽  
Different Molecular Weight

Atmospheric Acetic Acid Pulping of Rice Straw IV: Physico-Chemical Characterization of Acetic Acid Lignins from Rice Straw and Woods. Part 1. Physical Characteristics

Holzforschung ◽  
1999 ◽  
Vol 53 (5) ◽  
pp. 511-518 ◽  
Author(s):  
Xue-Jun Pan ◽  
Yoshihiro Sano
Keyword(s):  
Molecular Weight ◽  
Acetic Acid ◽  
Hydrochloric Acid ◽  
Rice Straw ◽  
Chemical Characterization ◽  
Thermomechanical Analysis ◽  
Considerable Effect ◽  
Physico Chemical ◽  
C Nmr

Summary Lignins obtained by atmospheric acetic acid delignification of rice straw, birch and fir were characterized by molecular weight, solubility and thermomechanical analysis, and by ultraviolet (UV), Fourier transform infra-red (FTIR) and 13C-NMR spectroscopy. Rice straw lignins (rice lignins) were very different from birch and fir lignins. The former was difficult to dissolve in most tested solvents and infusible on heating, while the latter had a good solubility and fusibility. FTIR spectra indicated that the rice lignins had more conjugated and fewer unconjugated carbonyl groups than the wood lignins. 13C-NMR spectra showed that rice lignins had more polysaccharides associated to the lignin and more p-coumaric and ferulic acid than the wood lignins. Concentrations of acetic acid and choice of catalyst (sulfuric or hydrochloric acid) had a considerable effect on the characteristics of rice lignins. Rice lignin obtained with 90% acetic acid than that obtained with 80% acetic acid, and the lignin obtained with sulfuric acid as catalyst than that obtained with hydrochloric acid, had lower molecular weight, better solubility, lower glass-transition temperature and lower UV absorptivity. 80% acetic acid delignified rice straw less effectively than 90% acetic acid.

scholarly journals Physico-chemical characterization of the pulp and peel of Brazilian Pitomba (Talisia esculenta (A. St.-Hill.) Radlk)

2020 ◽  
Vol 9 (1) ◽  
pp. e122911774
Author(s):  
Layanne Nascimento Fraga ◽  
Anne Karoline de Souza Oliveira ◽  
Bruna Pinheiro Aragão ◽  
Ana Mara de Oliveira e Silva ◽  
Elma Regina Silva de Andrade Wartha ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Vitamin C ◽  
Bioactive Compounds ◽  
Mineral Content ◽  
Chemical Characterization ◽  
The State ◽  
High Income ◽  
Fresh Sample ◽  
Physico Chemical

This study aimed to evaluate the physico-chemical composition and bioactive compounds of pulp and the peel of the pitomba arising from the state of Sergipe/Brazil. The income, the physico-chemical characterization, mineral content, vitamin C and carotenoids of pulp and pitomba peel were determined. The peel presented high income (44,60% of the fruit). A significant amount of vitamin C (20,68 ± 2,93 mg/100g of fresh sample) and carotenoids (43,56 ± 2,04 μg/mL of the extract) were observed in the pulp, while the peel had a high mineral content, mainly potassium (223,00 ± 2,00 mg/100g), calcium (78,90 ± 0,40 mg/100g) and magnesium (47,50 ± 0,90 mg/100g). The constituents’ knowledge of the peel and pulp of the pitomba in natura adds value to the fruit, since it allows a better use of it, considering that the peel is discarded and only its pulp is consumed.

Laboratory Methods for the Physico-Chemical Characterization of Recombinant Allergens as Reference Standards

Alergologia ◽  
2020 ◽  
Vol 1 (4) ◽  
pp. 7
Author(s):  
Mariana Vieru ◽  
Florin-Dan Popescu ◽  
Laura Haidar ◽  
Carmen Bunu-Panaitescu
Keyword(s):  
Chemical Characterization ◽  
Reference Standards ◽  
Recombinant Allergens ◽  
Laboratory Methods ◽  
Physico Chemical

Mineralogical and physico-chemical characterization of a sintered feldspathic sand

2010 ◽  
Vol 35 (5) ◽  
pp. 261-267 ◽  
Author(s):  
Wissemn Gallala ◽  
Mohamed Essghaier Gaied ◽  
Borhen Kchaou
Keyword(s):  
Chemical Characterization ◽  
Physico Chemical

Physical - Chemical Issues of Cephalosporin Intercalated Nanoparticles for Life - Threatening Infections Treatment

2001 ◽  
Vol 71 (3) ◽  
pp. 342-349
Author(s):  
Lucian Eva ◽  
Letitia Doina Duceac ◽  
Liviu Stafie ◽  
Constantin Marcu ◽  
Geta Mitrea ◽  
...  
Keyword(s):  
Chemical Characterization ◽  
Advanced Characterization ◽  
Generation Cephalosporin ◽  
Fourth Generation ◽  
Exchange Method ◽  
Physico Chemical ◽  
Life Threatening ◽  
Double Hydroxide ◽  
Double Hydroxides

The fourth generation cephalosporin antibacterial agent, cefepime, was loaded into layered double hydroxides for enhancing antibiotic efficiency, reducing side effects, as well as achieving the sustained release property. The intercalation of antibiotic into the inter-gallery of ZnAl-layered double hydroxide (LDH) was carried out using ion exchange method, by this constituting a nano-sized organic-inorganic hybrid material for a controlled release novel formulation. Although cefepime is a broad spectrum antibiotic, it has various adverse effects and a significant degradation rate. Thus, the preparation and physico-chemical characterization of nanomaterials able to intercalate this drug is an important study for medical and pharmaceutical field. The antibiotic inclusion into LDHs nanostructure was confirmed by advanced characterization techniques and the release profile of cefepime was analysed with the respect to pH of the simulated media.

scholarly journals Nano-Assemblies from Amphiphilic PnBA-b-POEGA Copolymers as Drug Nanocarriers

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1164
Author(s):  
Angeliki Chroni ◽  
Thomas Mavromoustakos ◽  
Stergios Pispas
Keyword(s):  
Molecular Weight ◽  
Chain Transfer ◽  
Raft Polymerization ◽  
Polymeric Nanocarriers ◽  
Reversible Addition ◽  
2D Noesy ◽  
Drug Nanocarriers ◽  
Glycol Methyl Ether ◽  
Different Molecular Weight

The focus of this study is the development of highly stable losartan potassium (LSR) polymeric nanocarriers. Two novel amphiphilic poly(n-butyl acrylate)-block-poly(oligo(ethylene glycol) methyl ether acrylate) (PnBA-b-POEGA) copolymers with different molecular weight (Mw) of PnBA are synthesized via reversible addition fragmentation chain transfer (RAFT) polymerization, followed by the encapsulation of LSR into both PnBA-b-POEGA micelles. Based on dynamic light scattering (DLS), the PnBA30-b-POEGA70 and PnBA27-b-POEGA73 (where the subscripts denote wt.% composition of the components) copolymers formed micelles of 10 nm and 24 nm in water. The LSR-loaded PnBA-b-POEGA nanocarriers presented increased size and greater mass nanostructures compared to empty micelles, implying the successful loading of LSR into the inner hydrophobic domains. A thorough NMR (nuclear magnetic resonance) characterization of the LSR-loaded PnBA-b-POEGA nanocarriers was conducted. Strong intermolecular interactions between the biphenyl ring and the butyl chain of LSR with the methylene signals of PnBA were evidenced by 2D-NOESY experiments. The highest hydrophobicity of the PnBA27-b-POEGA73 micelles contributed to an efficient encapsulation of LSR into the micelles exhibiting a greater value of %EE compared to PnBA30-b-POEGA70 + 50% LSR nanocarriers. Ultrasound release profiles of LSR signified that a great amount of the encapsulated LSR is strongly attached to both PnBA30-b-POEGA70 and PnBA27-b-POEGA73 micelles.

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