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Ambagaspitiya TD, Garza DJC, Skelton E, Kubacki E, Knight A, Bergmeier SC, Cimatu KLA. Using the pH sensitivity of switchable surfactants to understand the role of the alkyl tail conformation and hydrogen bonding at a molecular level in elucidating emulsion stability. J Colloid Interface Sci 2024; 678:164-175. [PMID: 39186896 DOI: 10.1016/j.jcis.2024.08.156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2024] [Revised: 08/17/2024] [Accepted: 08/19/2024] [Indexed: 08/28/2024]
Abstract
HYPOTHESIS The monoalkyl diamine surfactant, N-dodecylpropane-1,3-diamine (DPDA), is expected to exhibit a pH-dependent charge switchability. In response to pH changes, the interfacial self-assembly of DPDA becomes an intermediary constituent that can potentially modify the interfacial interactions and structural assembly of both the oil and water phases. Hence, we hypothesize that as we change the pH, DPDA will respond to it by changing its charge and alkyl tail conformation as well as the conformation of adjacent phases at the molecular level, consequently affecting emulsion formation and stability. A neutral pH, resulting in a mono-cationic dialkyl amine, affects the conformation, driving an ordered self-assembly and stable emulsion. EXPERIMENTS The pH-sensitivity and interfacial activity of DPDA were evaluated through pH titration and interfacial tension measurements. Subsequently, a molecular-level study of DPDA, as a pH-sensitive switchable surfactant, was performed at the dodecane-water interface using SFG spectroscopy. The interpretation of the vibrational spectra was further reinforced by determining the gauche defects in the interfacial alkyl chain organization and the extent of hydrogen (H) bonding between the interfacial water molecules. FINDINGS By adjusting the pH of water, the charge of the adsorbed DPDA molecules, their self-assembly, the organization of interfacial molecules, and ultimately the stability of the emulsion were tuned. At pH 7.0, the SFG spectra of DPDA showed that the interfacial alkyl chains were relatively well-ordered, while water molecules also had stronger H-bonding interactions. As a result, the oil-water emulsion showed improved stability. When water was at a high pH, the water molecules had fewer H-bonding interactions and relatively disordered alkyl chains at the interface, providing desirable conditions for demulsification. These observations were compatible with the observation in bulk emulsion preparation, confirming that alkyl chain packing and water H-bonding interactions at the interface contribute to overall emulsion stability.
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Affiliation(s)
- Tharushi D Ambagaspitiya
- Department of Chemistry and Biochemistry, Ohio University, 133 University Terrace, Chemistry Building, Athens, OH 45701-2979, United States.
| | - Danielle John C Garza
- Department of Chemistry and Biochemistry, Ohio University, 133 University Terrace, Chemistry Building, Athens, OH 45701-2979, United States.
| | - Eli Skelton
- Department of Chemistry and Biochemistry, Ohio University, 133 University Terrace, Chemistry Building, Athens, OH 45701-2979, United States.
| | - Emma Kubacki
- Department of Chemistry and Biochemistry, Ohio University, 133 University Terrace, Chemistry Building, Athens, OH 45701-2979, United States.
| | - Alanna Knight
- Department of Chemistry and Biochemistry, Ohio University, 133 University Terrace, Chemistry Building, Athens, OH 45701-2979, United States.
| | - Stephen C Bergmeier
- Department of Chemistry and Biochemistry, Ohio University, 133 University Terrace, Chemistry Building, Athens, OH 45701-2979, United States.
| | - Katherine Leslee Asetre Cimatu
- Department of Chemistry and Biochemistry, Ohio University, 133 University Terrace, Chemistry Building, Athens, OH 45701-2979, United States.
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Wang Y, Han X, Wan X, Niu F, Zhou C. β-Escin: An Updated Review of Its Analysis, Pharmacology, Pharmacokinetics, and Toxicity. THE AMERICAN JOURNAL OF CHINESE MEDICINE 2023; 51:2095-2120. [PMID: 37865870 DOI: 10.1142/s0192415x23500908] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2023]
Abstract
[Formula: see text]-Escin is an oleanane-type pentacyclic triterpenoid saponin extracted from the seeds of Aesculus hippocastanum (AH), which is more widely distributed. [Formula: see text]-Escin sodium has been approved by the American FDA for clinical usage. This paper is intended to summarize an updated and comprehensive review of the pharmacological activities, pharmacokinetic properties, toxicity, and analytical methods of [Formula: see text]-escin. Studies have shown that [Formula: see text]-escin has significant antitumor, antiviral, anti-inflammatory, and other activities alongside less adverse effects and higher safety than other compounds. The review shows that the pharmacological effects of [Formula: see text]-escin involve mechanisms such as ATM/[Formula: see text]H2AX, RhoA/Rock, GSK-3[Formula: see text]/[Formula: see text]-Catenin, HER2/HER3/Akt, and PI3K/Akt signaling pathways, and Cyclin A, p21[Formula: see text], survivin, Bcl-2, Mcl-1, Caspases, TGF-[Formula: see text], MMPs, and TNF-[Formula: see text] among other inflammatory factors. [Formula: see text]-Escin has significant cytotoxicity; the use of the chitosan/xanthan gum-based polyelectrolyte complexes PA1 and PC-11 to modify it not only to reduces its toxicity, but also improves its drug efficacy. Because of this, these compounds may become a new research hotspot. [Formula: see text]-Escin in vivo metabolism can be converted by the CYP1A2 enzyme in the intestinal flora to produce [Formula: see text]-escin, deacylated, deglycosylated, and 21[Formula: see text]-[Formula: see text]-crotonoyl-protoescin, and the binding rate of the plasma proteins is higher than 90%. These are mainly metabolized by the liver, kidneys, and other organs, and excreted in the form of urine and feces. The number of reports on the specific mediators of the metabolism of [Formula: see text]-escin and their mechanisms and metabolites is relatively small; furthermore, the results are vague. Therefore, a complete and in-depth exploration of the pharmacokinetic characteristics of [Formula: see text]-escin is needed to provide a more complete and effective theoretical reference for the study of its pharmacodynamic activity.
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Affiliation(s)
- Yunyu Wang
- College of Pharmacy, Shandong University of Traditional Chinese Medicine, Shandong 250355, P. R. China
| | - Xiuwei Han
- Zhaoyuan Inspection and Testing Center, Shandong 265400, P. R. China
| | - Xinhuan Wan
- College of Pharmacy, Shandong University of Traditional Chinese Medicine, Shandong 250355, P. R. China
| | - Fengjv Niu
- College of Pharmacy, Shandong University of Traditional Chinese Medicine, Shandong 250355, P. R. China
| | - Changzheng Zhou
- College of Pharmacy, Shandong University of Traditional Chinese Medicine, Shandong 250355, P. R. China
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Ullah N, Haq F, Farid A, Kiran M, Al Othman ZA, Aljuwayid AM, Habila MA, Bokhari A, Rajendran S, Khoo KS. Coupling of carboxymethyl starch with 2-carboxyethyl acrylate: A new sorbent for the wastewater remediation of methylene blue. ENVIRONMENTAL RESEARCH 2023; 219:115091. [PMID: 36529323 DOI: 10.1016/j.envres.2022.115091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 11/20/2022] [Accepted: 12/15/2022] [Indexed: 06/17/2023]
Abstract
Textile and printing industries play a vital role in the economy of any country. But the effluents of these industries, which contain toxic Methylene Blue (MB) dye when mixed with fresh water, make it unfit for human health and aquatic life. For the removal of MB, different adsorbents were used, but they were expensive, non-biodegradable or less effective. In this research, novel carboxymethyl starch grafted poly 2-carboxyethyl acrylate (CM-St-g-P2CEtA) was synthesized by reacting carboxymethyl starch with 2-carboxyethyl acrylate. The reaction followed a free radical polymerization mechanism. The structure and properties of CM-St-g-P2CEtA were investigated by advanced analytical techniques. The CM-St-g-P2CEtA was employed for the remediation of Methylene Blue (MB) dye from wastewater. The removal percentage (%R) of MB was checked under different parameters, like different pH levels, different initial concentrations of dye, different adsorbent doses, and different contact times. The results obtained during the experiment were subjected to different adsorption and kinetic models. In the kinetic investigation, the experimental results were best represented by the pseudo-second-order kinetic model due to its high R2 value of 0.999. Similarly, with a regression coefficient (R2) value of 0.947, the Langmuir adsorption isotherm was best represented by the experimental results. The Langmuir adsorption model showed that MB dye was adsorbed on the surface of CM-St-g-P2CEtA in a monolayer pattern. The pseudo 2nd order kinetic model suggested that the adsorption process favored chemisorption mechanism. The CM-St-g-P2CEtA showed maximum percentage removal efficiency (%R) of 99.3% for MB dye.
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Affiliation(s)
- Naveed Ullah
- Institute of Chemical Sciences, Gomal University, D.I.Khan, 29050, KPK, Pakistan.
| | - Fazal Haq
- Institute of Chemical Sciences, Gomal University, D.I.Khan, 29050, KPK, Pakistan.
| | - Arshad Farid
- Gomal Center of Biochemistry and Biotechnology, Gomal University, D.I.Khan, 29050, KPK, Pakistan.
| | - Mehwish Kiran
- Department of Horticulture, Gomal University, D.I.Khan, 29050, KPK, Pakistan.
| | - Zeid A Al Othman
- Department of Chemistry, College of Science, King Saud University, P. O. Box 2455, Riyadh, 11451, Saudi Arabia
| | - Ahmed Muteb Aljuwayid
- Department of Chemistry, College of Science, King Saud University, P. O. Box 2455, Riyadh, 11451, Saudi Arabia
| | - Mohamed A Habila
- Department of Chemistry, College of Science, King Saud University, P. O. Box 2455, Riyadh, 11451, Saudi Arabia
| | - Awais Bokhari
- Sustainable Process Integration Laboratory, SPIL, NETME Centre, Faculty of Mechanical Engineering, Brno University of Technology, VUT Brno, Technická 2896/2, 616 00, Brno, Czech Republic.
| | - Saravanan Rajendran
- Departamento de Ingeniería Mec ́anica, Facultad de Ingeniería, Universidad de Tarapac ́a, Avda. General Vel ́asquez, 1775, Arica, Chile.
| | - Kuan Shiong Khoo
- Department of Chemical Engineering and Materials Science, Yuan Ze University, Taiwan.
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Krzan M, Rey NG, Jarek E, Czakaj A, Santini E, Ravera F, Liggieri L, Warszynski P, Braunschweig B. Surface Properties of Saponin-Chitosan Mixtures. Molecules 2022; 27:7505. [PMID: 36364333 PMCID: PMC9658537 DOI: 10.3390/molecules27217505] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 10/25/2022] [Accepted: 10/26/2022] [Indexed: 08/03/2024] Open
Abstract
The surface properties of saponin and saponin-chitosan mixtures were analysed as a function of their bulk mixing ratio using vibrational sum-frequency generation (SFG), surface tensiometry and dilational rheology measurements. Our experiments show that saponin-chitosan mixtures present some remarkable properties, such as a strong amphiphilicity of the saponin and high dilational viscoelasticity. We believe this points to the presence of chitosan in the adsorption layer, despite its complete lack of surface activity. We explain this phenomenon by electrostatic interactions between the saponin as an anionic surfactant and chitosan as a polycation, leading to surface-active saponin-chitosan complexes and aggregates. Analysing the SFG intensity of the O-H stretching bands from interfacial water molecules, we found that in the case of pH 3.4 for a mixture consisting of 0.1 g/L saponin and 0.001 g/L chitosan, the adsorption layer was electrically neutral. This conclusion from SFG spectra is corroborated by results from surface tensiometry showing a significant reduction in surface tension and effects on the dilational surface elasticity strictly at saponin/chitosan ratios, where SFG spectra indicate zero net charge at the air-water interface.
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Affiliation(s)
- Marcel Krzan
- Jerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, ul. Niezapominajek 8, 30-239 Krakow, Poland
| | - Natalia García Rey
- Institute of Physical Chemistry and Center for Soft Nanoscience, Westfälische Wilhelms-Universität Münster, Corrensstraße 28/30, 48149 Münster, Germany
| | - Ewelina Jarek
- Jerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, ul. Niezapominajek 8, 30-239 Krakow, Poland
| | - Agnieszka Czakaj
- Jerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, ul. Niezapominajek 8, 30-239 Krakow, Poland
| | - Eva Santini
- Institute of Condensed Matter and Technologies for Energy, Consiglio Nazionale delle Ricerche, Via Marini 6, 16149 Genova, Italy
| | - Francesca Ravera
- Institute of Condensed Matter and Technologies for Energy, Consiglio Nazionale delle Ricerche, Via Marini 6, 16149 Genova, Italy
| | - Libero Liggieri
- Institute of Condensed Matter and Technologies for Energy, Consiglio Nazionale delle Ricerche, Via Marini 6, 16149 Genova, Italy
| | - Piotr Warszynski
- Jerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, ul. Niezapominajek 8, 30-239 Krakow, Poland
| | - Björn Braunschweig
- Institute of Physical Chemistry and Center for Soft Nanoscience, Westfälische Wilhelms-Universität Münster, Corrensstraße 28/30, 48149 Münster, Germany
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