A series of amide quaternary ammonium surfactants with the formula C HCONH(CH)N(CH)·CHCO ( = 9, 11, 13, 15) were synthesized using a fatty acid, ,-dimethylethylenediamine, and a green reagent dimethyl carbonate. A comparative study of the four surfactants in terms of surface activity, aggregation characteristics, and foam properties was conducted. The results show that these amide quaternary ammonium surfactants reduce the surface tension of water to a minimum value of 23.69 mN·m at a concentration of 1.55 × 10 mol·L and self-assemble spontaneously into aggregates, which are mostly vesicles. Furthermore, with increasing the alkyl chain length, their critical micelle concentration (CMC) values and surface tension values at the CMC (γ) decrease and then increase, and the degree of counterion binding (β) decreases. It is also found that these amide quaternary ammonium surfactants exhibit excellent foam ability and foam stability.
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http://dx.doi.org/10.1021/acsomega.2c06353 | DOI Listing |
Org Biomol Chem
January 2025
College of Chemical Engineering, Zhejiang University of Technology, Hangzhou, 310014, P. R. China.
Succinyldiamide derivatives are important structural motifs in various natural products, pharmaceuticals, and functional materials. Herein, a novel, mild, and environmentally friendly method was developed for synthesizing functionalized succinyldiamides each containing a quaternary carbon center. This strategy was designed to involve photocatalytic decarboxylation of readily available oxalic monoamide using a non-precious metal photocatalyst, 4CzIPN, followed by a free-radical addition/Smiles rearrangement cascade reaction of -aryl--(arylsulfonyl)acrylamides.
View Article and Find Full Text PDFOrg Lett
December 2024
Department of Chemistry, Graduate School of Science, Tohoku University, 6-3 Aramaki Aza-Aoba, Aoba-ku, Sendai, Miyagi 980-8578, Japan.
Consecutive all-carbon quaternary centers were synthesized in three steps from the corresponding ketones. The three reactions were (1) Knoevenagel condensation of ketone and malononitrile to afford dicyanoalkene, (2) 1,4-addition reaction of a Grignard reagent to dicyanoalkene, and (3) oxidative transformation of a malononitrile moiety to an ester, thioester, amide, and α-nitroketone. This method was applied to the synthesis of 17α-methyl steroids with a good yield and excellent diastereoselectivity.
View Article and Find Full Text PDFFuture Med Chem
December 2024
Department of Medicinal Chemistry, Third Military Medical University, Chongqing, China.
Tetrandrine (Tet), a bisbenzylisoquinoline alkaloid from , is noted for its diverse pharmacological effects but faces limitations in clinical use due to toxicity, poor solubility, and low bioavailability. Researchers are working to address these issues by developing Tet derivatives with greater therapeutic potential through structural modification. Generally, key modifications include: 1) introducing an aromatic heterocycle or a hydrophobic alkyne unit at the -5 position can enhance its antitumor activity; 2) adding an amide, sulfonamide, or electron-withdrawing group at the -14 position can enhance its antitumor activity; 3) changing its structure to a quaternary ammonium salt can alter its solubility and greatly boost its antibacterial activity; 4) structural modification of the -12-methoxybenzyl motif can enhance its metabolic stability and thus change the activity of the analogs; 5) Tet structural simplification may result in the identification of anticancer lead compounds with novel mechanisms of action.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
Institute of Preventive Medicine, National Defense Medical Center, New Taipei City 23742, Taiwan, ROC; Graduate Institute of Medical Science, National Defense Medical Center, Taipei 11490, Taiwan, ROC; Graduate Institute of Biodefense, National Defense Medical Center, Taipei 11490, Taiwan, ROC. Electronic address:
This study introduced a novel antiviral approach by combining three substances with different antiviral mechanisms: N-(2-hydroxy)propyl-3-trimethylammoniumchitosan (HTC), silver nanoparticles (AgNPs), and oseltamivir. First, positively surface-charged AgNPs were prepared using an environmentally friendly method. The surfaces of these AgNPs were capped with cationic quaternary chitosan HTC.
View Article and Find Full Text PDFChem Sci
December 2024
Leibniz-Institut für Katalyse e.V. Albert-Einstein-Straße 29a 18059 Rostock Germany
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