scholarly journals Cocrystals versus Salts of Fluorescein

Crystals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1217
Author(s):  
Mihai Răducă ◽  
Augustin M. Mădălan
Keyword(s):  
Hydrogen Bond ◽  
Optical Properties ◽  
Organic Molecules ◽  
Amino Nitrogen ◽  
Amino Groups ◽  
Organic Salts

A series of nitrogen-containing organic molecules (4,4’-bipyridyl; trans-1,2-bis(4-pyridyl)ethylene; 1,2-bis(4-pyridyl)ethane; 4-aminopyridine and trans-1,4-diaminocyclohexane) was envisaged for cocrystallization experiments together with fluorescein. These compounds, containing pyridyl or/and amino nitrogen atoms, can act either as hydrogen bond acceptors for the phenol groups of fluorescein-generating cocrystals or as proton acceptors forming organic salts. Five cocrystals were obtained with the partners containing only pyridyl groups: {(H2Fl)2(bipy)} (1); {(H2Fl)2(bipy)(MeOH)2} (2); {(H2Fl)2(bpete)(EtOH)2} (3); {(H2Fl)(bpete)} (4); {(H2Fl)(bpeta)} (5). The compounds bearing amino groups deprotonate fluorescein producing salts: [(HFl)(Hampy)]∙2H2O (6); [(HFl)(Hampy)] (7); [(Fl)(H2diach)]∙3H2O (8); [(HFl)2(H2diach)]∙2H2O∙EtOH (9); and [(HFl)2(Fl)2(H2diach)3]∙4H2O (10). Optical properties of the cocrystals and salts were investigated.

On the potential role of the amino nitrogen atom as a hydrogen bond acceptor in macromolecules

1998 ◽  
Vol 279 (5) ◽  
pp. 1123-1136 ◽  
Author(s):  
Ben Luisi ◽  
Modesto Orozco ◽  
Jiri Sponer ◽  
Francisco J Luque ◽  
Zippora Shakked
Keyword(s):  
Hydrogen Bond ◽  
Nitrogen Atom ◽  
Potential Role ◽  
Amino Nitrogen ◽  
Hydrogen Bond Acceptor ◽  
Amino Nitrogen Atom

Crystal structure of osimertinib mesylate Form B (Tagrisso), (C28H34N7O2)(CH3O3S)

2021 ◽  
pp. 1-9
Author(s):  
James A. Kaduk ◽  
Nicholas C. Boaz ◽  
Emma L. Markun ◽  
Amy M. Gindhart ◽  
Thomas N. Blanton
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Powder Diffraction ◽  
Density Functional ◽  
Amino Nitrogen ◽  
Strong Hydrogen Bond ◽  
Powder Diffraction File ◽  
Dimethylamino Group ◽  
Intramolecular Hydrogen

The crystal structure of osimertinib mesylate Form B has been solved and refined using synchrotron X-ray powder diffraction data and optimized using density functional techniques. Osimertinib mesylate Form B crystallizes in space group P-1 (#2) with a = 11.42912(17), b = 11.72274(24), c = 13.32213(22) Å, α = 69.0265(5), β = 74.5914(4), γ = 66.4007(4)°, V = 1511.557(12) Å3, and Z = 2. The crystal structure is characterized by alternating layers of cation–anion and parallel stacking interactions parallel to the ab-planes. The cation is protonated at the nitrogen atom of the dimethylamino group, which forms a strong hydrogen bond between the cation and the anion. That hydrogen atom also participates in a weaker intramolecular hydrogen bond to an amino nitrogen. There are two additional N–H⋅⋅⋅O hydrogen bonds between the cation and the anion. Several C–H⋅⋅⋅O hydrogen bonds also link the cations and anions. The powder pattern has been submitted to ICDD® for inclusion in the Powder Diffraction File™.

scholarly journals Physicochemical properties of three food proteins treated with transglutaminase

2004 ◽  
Vol 34 (4) ◽  
pp. 1219-1223 ◽  
Author(s):  
Luís Henrique de Barros Soares ◽  
Patrícia Melchionna Albuquerque ◽  
Francine Assmann ◽  
Marco Antônio Záchia Ayub
Keyword(s):  
Physicochemical Properties ◽  
Nitrogen Content ◽  
Soy Protein ◽  
Free Amino ◽  
Amino Nitrogen ◽  
Emulsifying Properties ◽  
Amino Groups ◽  
Emulsifying Activity ◽  
Food Proteins ◽  
Isolated Soy Protein

Three sources of food proteins were treated with microbial transglutaminase (EC 2.3.2.13) in order to assess changes in the physicochemical properties of reactivity, solubility, emulsification, and free amino groups of the formed polymers. Samples of lactic casein (LC), isolated soy protein (ISP), and hydrolysed animal protein (HAP), were incubated with the enzyme for one or two hours. LC and ISP showed a reduced solubility of 15% and 24% respectively, with HAP showing no alteration on solubility. Amino nitrogen content was 7%, 3% and 2% reduced for HAP, LC and ISP respectively. LC and ISP demonstrated lower emulsifying activity when they were enzymatically treated but the formed emulsions were stable, contrasting with HAP, which exhibited no changes in emulsifying properties.

Optical properties of hemicyanines with terminal amino groups and their applications in near-infrared fluorescent imaging of nucleoli

2014 ◽  
Vol 2 (40) ◽  
pp. 7065-7072 ◽  
Author(s):  
Jia-Tao Miao ◽  
Chen Fan ◽  
Ru Sun ◽  
Yu-Jie Xu ◽  
Jian-Feng Ge
Keyword(s):  
Optical Properties ◽  
Near Infrared ◽  
Water Solubility ◽  
Stokes Shift ◽  
Fluorescent Imaging ◽  
Amino Groups ◽  
Long Wave ◽  
Terminal Amino ◽  
Wave Emission ◽  
Low Cytotoxicity

A cellular dye with properties of long-wave emission, large Stokes shift, water solubility, low cytotoxicity, and good photostability is reported.

scholarly journals THE PARTIAL REACTIVATION OF FORMOLIZED TOBACCO MOSAIC VIRUS PROTEIN

1938 ◽  
Vol 22 (2) ◽  
pp. 165-191 ◽  
Author(s):  
A. Frank Ross ◽  
W. M. Stanley
Keyword(s):  
Tobacco Mosaic Virus ◽  
Mosaic Virus ◽  
Amino Nitrogen ◽  
Specific Property ◽  
Virus Protein ◽  
Amino Groups ◽  
Reactivation Process ◽  
Virus Activity ◽  
Simultaneous Decrease ◽  
Phenol Reagent

A marked reactivation of tobacco mosaic virus protein that has been partially or completely inactivated by formaldehyde was obtained by dialysis at pH 3. The activity of partially inactivated virus proteins was generally increased about 10-fold by the reactivation process. It was also found possible to reactivate completely inactive preparations to an appreciable extent. It was shown that the inactivation and the subsequent reactivation cannot be explained by the toxicity of the formaldehyde or of the formolized protein or by aggregation. Inactivation was accompanied by a decrease in amino groups as indicated by Van Slyke gasometric determinations and by colorimetric estimations using ninhydrin. Inactivation also causes a decrease in the number of groups that react with Folin's reagent at pH 7.7. The latter are probably the indole nuclei of tryptophane, for it was demonstrated that tryptophane, glycyltryptophane, and indole propionic acid react with formaldehyde in a similar manner, while tyrosine and glycyltyrosine do not. Evidence that reactivation is accompanied by an increase in amino nitrogen and in groups that react with Folin's reagent was obtained by colorimetric estimation. The demonstration that the addition of formaldehyde to the virus protein results in a simultaneous decrease of activity, of amino groups, and of groups that react with Folin's phenol reagent, and that under conditions favorable for the removal of formaldehyde the virus activity is regained and the number of such groups increases, indicates that certain of these groups play at least a partial role in the structure necessary for virus activity. These changes can best be interpreted on the basis of known chemical reactions and are considered as evidence that virus activity is a specific property of the protein.

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