Geometry dependence of electron donating or accepting abilities of amine groups in 4,4′-disulfanediylbis(methylene)dithiazol-2-amine: Pyramidal versus planar

2017 ◽  
Vol 1141 ◽  
pp. 650-659 ◽  
Author(s):  
Hasan Karabıyık ◽  
Cumhur Kırılmış ◽  
Hande Karabıyık
Keyword(s):  
Geometry Dependence ◽  
Amine Groups

A greener and sustainable approach for converting polyurethane foam rejects into superior polyurethane coatings

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Mechanical Properties ◽  
Polyurethane Foam ◽  
Sebacic Acid ◽  
Polyurethane Foams ◽  
Hexamethylene Diisocyanate ◽  
Alkali Resistance ◽  
Microwave Reaction ◽  
P Recycling ◽  
Amine Groups ◽  
Green Polymer

Recycling is a crucial area of research in green polymer chemistry. Various developments in recycling are driven by Environmental concerns, interest in sustainability and desire to decrease the dependence on non-renewable petroleum based materials. Polyurethane foams [PUF] are widely used due to their light weight and superior heat insulation as well as good mechanical properties. As per survey carried Polyurethane Foam Association, 12 metric tonnes of polyurethane foam are discharged during manufacturing and/or processing and hence recycling of PUF is necessary for better economics and ecological reasons. In present study, rejects of PUF is subjected to reaction with a diethylene amine in presence of sodium hydroxide [NaOH] as catalyst, as a result depolymerised product containing hydroxyl and amine groups is obtained. Conventional and Microwave reaction for depolymerizing polyurethane foam have been carried, and best results are obtained by Microwave reaction. Further depolymerised product with hydroxyl and amine functionalities are reacted with bis (2-hydroxyethyl terephthalate) [BHET] obtained by recycling polyethylene terephthalate [PET] and sebacic acid, with stannous oxalate [FASCAT 2100 series] as catalyst to obtain Polyester amides. These Polyester amides having hydroxyl and amino groups in excess are cured with isocyanates-hexamethylene diisocyanate biuret [HDI biuret] and isophorone diisocyanate [IPDI] for coating applications. The coated films are characterized using physical, mechanical and chemical tests, which shows comparable physical, mechanical properties but alkali resistance is poor.

scholarly journals Biotin-Containing Third Generation Glucoheptoamidated Polyamidoamine Dendrimer for 5-Aminolevulinic Acid Delivery System

2021 ◽  
Vol 22 (4) ◽  
pp. 1982 ◽  
Author(s):  
Aleksandra Kaczorowska ◽  
Małgorzata Malinga-Drozd ◽  
Wojciech Kałas ◽  
Marta Kopaczyńska ◽  
Stanisław Wołowiec ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Aminolevulinic Acid ◽  
Reactive Oxygen ◽  
Pamam Dendrimer ◽  
Variable Number ◽  
Amide Bond ◽  
Oxygen Species ◽  
Nmr Spectrum ◽  
Guest Molecules ◽  
Amine Groups

Polyamidoamine PAMAM dendrimer generation 3 (G3) was modified by attachment of biotin via amide bond and glucoheptoamidated by addition of α-D-glucoheptono-1,4-lacton to obtain a series of conjugates with a variable number of biotin residues. The composition of conjugates was determined by detailed 1-D and 2-D NMR spectroscopy to reveal the number of biotin residues, which were 1, 2, 4, 6, or 8, while the number of glucoheptoamide residues substituted most of the remaining primary amine groups of PAMAM G3. The conjugates were then used as host molecules to encapsulate the 5-aminolevulinic acid. The solubility of 5-aminolevulinic acid increased twice in the presence of the 5-mM guest in water. The interaction between host and guest was accompanied by deprotonation of the carboxylic group of 5-aminolevulinic acid and proton transfer into internal ternary nitrogen atoms of the guest as evidenced by a characteristic chemical shift of resonances in the 1H NMR spectrum of associates. The guest molecules were most likely encapsulated inside inner shell voids of the host. The number of guest molecules depended on the number of biotin residues of the host, which was 15 for non-biotin-containing glucoheptoamidated G3 down to 6 for glucoheptoamidated G3 with 8 biotin residues on the host surface. The encapsulates were not cytotoxic against Caco-2 cells up to 200-µM concentration in the dark. All encapsulates were able to deliver 5-aminolevulinic acid to cells but aqueous encapsulates were more active in this regard. Simultaneously, the reactive oxygen species were detected by staining with H2DCFDA in Caco-2 cells incubated with encapsulates. The amount of PpIX was sufficient for induction of reactive oxygen species upon 30-s illumination with a 655-nm laser beam.

The thioamidation of gem-dibromoalkenes in an aqueous medium

2021 ◽  
Vol 19 (11) ◽  
pp. 2473-2480
Author(s):  
Jigarkumar K. Vankar ◽  
Ankush Gupta ◽  
Jaydeepbhai P. Jadav ◽  
Shankara H. Nanjegowda ◽  
Guddeangadi N. Gururaja
Keyword(s):  
Aqueous Medium ◽  
Direct Integration ◽  
Amine Groups

The direct integration of sulphur and amine groups with 1,1-dibromoalkenes for thioamide synthesis has been achieved in an aqueous medium.

scholarly journals Effect of H2O-Based Low-Pressure Plasma (LPP) Treatment on the Germination of Bambara Groundnut Seeds

Agronomy ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 338
Author(s):  
Naeem Ahmed ◽  
Asad Masood ◽  
Kim S. Siow ◽  
M. F. Mohd Razip Wee ◽  
Rahmat Zaki Auliya ◽  
...  
Keyword(s):  
Food Security ◽  
Seed Germination ◽  
Chemical Modification ◽  
Low Pressure ◽  
Germination Percentage ◽  
Bambara Groundnut ◽  
Pressure Plasma ◽  
Low Pressure Plasma ◽  
Amine Groups

In general, seed germination is improved by low-pressure plasma (LPP) treatment using precursors such as air, nitrogen, argon, or water (H2O). Here, H2O-based LPP treatment using the optimized parameters of 10 W and 10 s improves the germination of Bambara groundnut seeds by 22%. LPP increases the wettability and roughness of the seed hilum while oxidizing the surface with carboxyl and amine groups. In this H2O-based treatment of Bambara groundnut seeds, combinatory etching and chemical modification facilitated the imbibition process and increased the germination percentage. The success of this method has the potential to be scaled up to solve food security with seeds otherwise facing germination-related issues.

scholarly journals Amine-Grafted Mesoporous Carbons as Benzocaine-Delivery Platforms

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2188
Author(s):  
Joanna Goscianska ◽  
Aleksander Ejsmont ◽  
Anita Kubiak ◽  
Dominika Ludowicz ◽  
Anna Stasiłowicz ◽  
...  
Keyword(s):  
Release Kinetics ◽  
The Body ◽  
Therapeutic Drug ◽  
Mesoporous Carbons ◽  
Precise Control ◽  
Pharmaceutical Ingredients ◽  
Sorption Ability ◽  
Porous Carriers ◽  
Textural Parameters ◽  
Amine Groups

Smart porous carriers with defined structure and physicochemical properties are required for releasing the therapeutic drug with precise control of delivery time and location in the body. Due to their non-toxicity, ordered structure, and chemical and thermal stability, mesoporous carbons can be considered modern carriers for active pharmaceutical ingredients whose effectiveness needs frequent dosing algorithms. Here, the novel benzocaine delivery systems based on ordered mesoporous carbons of the cubic structure were obtained with the use of a hard template method and functionalization with amine groups at 40 °C for 8 h. It has been shown that amine grafting strongly modifies the surface chemistry and textural parameters of carbons. All samples indicated good sorption ability towards benzocaine, with evident improvement following the functionalization with the amine groups. The sorption capacity and drug release kinetics were strongly affected by the porosity of carbon carriers and the surface functional groups. The smallest amount of benzocaine (~12%) was released from pristine mesoporous carbon, which could be correlated with strong API–carrier interactions. Faster and more efficient release of the drug was observed in the case of triethylenetetramine modified carbon (~62%). All benzocaine delivery platforms based on amine-grafted mesoporous carbons revealed high permeability through the artificial membrane.

Organic cathode interfacial materials for non-fullerene organic solar cells

2021 ◽  
Author(s):  
Minkyu Kyeong ◽  
Jinho Lee ◽  
Matyas Daboczi ◽  
Katherine Stewart ◽  
Huifeng Yao ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Solar Cells ◽  
Power Conversion Efficiency ◽  
Conversion Efficiency ◽  
High Power ◽  
Organic Solar Cells ◽  
Power Conversion ◽  
High Power Conversion Efficiency ◽  
Amine Groups

Functionalized polyethyleneimines that are compatible with non-fullerene acceptors have been developed by protecting the reactive amine groups, leading to non-fullerene solar cells with high power conversion efficiency and enhanced thermal stability.

Modification of zeolitic imidazolate framework-8 with amine groups for improved antibacterial activity

2021 ◽  
Author(s):  
Nazerah Ahmad ◽  
Nik Abdul Hadi Md Nordin ◽  
Juhana Jaafar ◽  
Nik Ahmad Nizam Nik Malek ◽  
Ahmad Fauzi Ismail ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Zeolitic Imidazolate Framework ◽  
Amine Groups

scholarly journals Calcium phosphate phase transition in the presence of Aminosilane

2014 ◽  
Vol 70 (a1) ◽  
pp. C67-C67
Author(s):  
Babak Mostaghaci ◽  
Brigitta Loretz ◽  
Robert Haberkorn ◽  
Guido Kickelbick ◽  
Claus-Michael Lehr
Keyword(s):  
Phase Transition ◽  
Calcium Phosphate ◽  
Blood Compatibility ◽  
Transfection Efficiency ◽  
Hek293 Cells ◽  
Step Method ◽  
Calcium Phosphate Nanoparticles ◽  
Amine Groups ◽  
The Impact

Calcium phosphate has been the point of interest for in vitro gene delivery for many years because of its biocompatibility and straight forward application. However, there are some limitations regarding in vivo administration of these particles mostly because of vast agglomeration of the particles and lack of strong bond between the particles and pDNA. We introduced a simple single step method to functionalize calcium phosphate nanoparticles with Aminosilanes having a different number of amine groups. The nanoparticles were characterized chemically and structurally and their toxicity and interaction with pDNA were studied as well. Results revealed that different crystalline phase of calcium phosphate nanoparticles (Brushite and Hydroxyapatite) with a size below 150 nm were prepared, depending on conditions of synthesis and phase, each with a narrow size distribution. The aminosilane agents caused oriented nucleation and growth of crystallites and can decrease the pH for producing hydroxyapatite phase. The phenomenon could be revealed with the presence of anisotropy in the structure of synthesized hydroxyapatite. The number of amine groups in the Aminosilane agent could change the phase transition pH. Brushite particles revealed to have stronger interaction with pDNA mostly because of their higher positive surface charge. Both particles showed blood compatibility and negligible toxicity. Transfection experiment revealed the capability of both brushite and hydroxyapatite particles to transfect A549 and HEK293 cells. The new modified nanoparticles can be stored in a dried state and re-dispersed easily at the time of administration. Moreover, the transfection efficiency is higher in comparison with conventional calcium phosphate. This study showed the impact of presence and type of the modifying agent on the crystal structure and the amount of surface functionalization of nanoparticles, which in consequence influenced their interaction with cells.

Sign in / Sign up

Export Citation Format

Share Document