14130-06-4Relevant academic research and scientific papers
Gelation properties of various long chain amidoamines: Prediction of solvent gelation via machine learning using Hansen solubility parameters
Adenier, Guillaume,Delbecq, Frederic,Kawai, Takeshi,Ogue, Yuki
, (2020)
Four new amphiphilic long chain amidoamine derivatives displaying different structure variations are synthesized and tested in 27 liquids and compared to the study of two similar molecules already reported in the literature. In many cases, these compounds can act as low molecular weight gelators to form a three-dimensional network in organic liquids or water, which can be confirmed by FE-SEM observations and rheology measurements. For each sample, XRD diffraction of the corresponding xerogel and FT-IR analysis of native supramolecular gels reveal that they can self-assemble into lamellar-like aggregates or in pseudo-cubic structures, depending on the alkyl chain length and the steric hindrance of the polar head. The number of amide bonds and their positions inside gelator structures are determinant for the nature of the packing. For each gelator, we perform a series of gelation tests in each of the solvents and show that Hansen parameters, which are known characteristics of each liquid, can be used to successfully predict their gelation properties via machine learning in the vast majority of liquids at a concentration of 4 wt%.
Effects of Alkyl Chain Length and Hydrogen Bonds on the Cooperative Self-Assembly of 2-Thienyl-Type Diarylethenes at a Liquid/Highly Oriented Pyrolytic Graphite (HOPG) Interface
Yokoyama, Soichi,Hirose, Takashi,Matsuda, Kenji
, p. 13569 - 13576 (2015/09/22)
An appropriate understanding of the process of self-assembly is of critical importance to tailor nanostructured order on 2D surfaces with functional molecules. Photochromic compounds are promising candidates for building blocks of advanced photoresponsive surfaces. To investigate the relationship between molecular structure and the mechanism of ordering formation, 2-thienyl-type diarylethenes with various lengths of alkyl side chains linked through an amide or ester group were synthesized. Their self-assemblies at a liquid/solid interface were investigated by scanning tunneling microscopy (STM). The concentration dependence of the surface coverage was analyzed by using a cooperative model for a 2D surface based on two characteristic parameters: the nucleation equilibrium constant (Kn) and the elongation equilibrium constant (Ke). The following conclusions can be drawn. 1)The concentration at which a stable 2D molecular ordering is observed by STM exponentially decreases with increasing length of the alkyl chain. 2)Compounds bearing amide groups have higher degrees of cooperativity in self-assembly on 2D surfaces (i.e., σ, which is defined as Kn/Ke) than compounds with ester groups. 3)The self-assembly process of the open-ring isomer of an ester derivative is close to isodesmic, whereas that of the closed-ring isomer is cooperative because of the difference in equilibrium constants for the nucleation step (i.e., Kn) between the two isomers. Getting along: A scanning tunneling microscopy (STM) investigation revealed a cooperative self-assembly process for photochromic 2-thienyl-type diarylethenes. The lengths of the alkyl chains, hydrogen bonds, and photoisomerization have a significant effect on the adsorption parameters at a liquid/highly oriented pyrolytic graphite (HOPG) interface (see figure).
Synthesis, critical micelle concentrations, and antimycobacterial properties of homologous, dendritic amphiphiles. Probing intrinsic activity and the "cutoff" effect
Sugandhi, Eko W.,Macri, Richard V.,Williams, André A.,Kite, Brett L.,Slebodnick, Carla,Falkinham III, Joseph O.,Esker, Alan R.,Gandour, Richard D.
, p. 1645 - 1650 (2008/02/01)
Newkome-type, 1→3 C-branched dendrons make an excellent headgroup for amphiphiles with ultralong, saturated, linear alkyl chains. Synthesis of a homologous series of five such amphiphiles from 14 to 22 carbons- RNHCONHC(CH2CH2CO2H)3, R = n-C nH2n+1, n = 14, 16, 18, 20, 22-proceeds readily. These amphiphiles are soluble in aqueous solutions of triethanolamine. Surface-tension measurements on this homologous series reveal an unusually gradual decrease in log critical micelle concentration (CMC) as the chain length increases. In fact, the tetradecyl homologue does not appear to form micelles. Further, measurements of minimal inhibitory concentration (MIC) by broth microdilution against Mycobacterium smegmatis as a function of the initial cell density provide a direct measure of the intrinsic activity (MIC0) of each homologue. The hexadecyl homologue is the most active at inhibiting growth with an MIC0 equal to 3.5 × 10-5 M, which is 100-fold below the CMC.
Synthesis of 4-Alkylcytosine Nucleosides and Evaluation of Cytostatic Activity in the L1210 Murine Leukemia
Schott, Herbert,Haeussler, Markus P.,Schwendener, Reto A.
, p. 465 - 470 (2007/10/02)
4-Alkylcytosine nucleosides 2 were prepared by nucleophilic substitution of the 4-(1,2,4-triazol-1-yl) residue of uracil nucleoside derivatives 1 using different amino compounds.The antitumor activity against L1210 murine leukemia of fifteen 4-alkylcytosine nucleosides dissolved in buffer or incorporated into liposomes was tested.Liposomal 1-(β-D-arabinofuranosyl)-4-octadecylamino-2(1H)-pyrimidinone (2d) having the highest activity gave an increase of life span (ILS) of 706percent and 6/6 survivors at 400 μmol/kg.The structurally related and well-known antitumor drug 1-(β-D-arabinofuranosyl)cytosine (araC) dissolved in buffer gave only 179percent ILS and 0/6 survivors under corresponding conditions.Derivatives 2a-c and 2e-f having shorter or longer alkyl chains were less active.All the other derivatives showed no antitumor effect.The activity of the 4-alkylcytosine nucleoside was also lost, when the arabinose residue was replaced by ribose or deoxyribose. - Key Words: Nucleosides / Murine leukemia / Liposomes / Leukemia / Cytosine / Antitumor agents / Carbohydrates
