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Effect of monoethanolamine loading on the physicochemical properties of amine-functionalized Si-MCM-41

Anita Ramli, Sohail Ahmed, Suzana Yusup

Sains Malaysiana, 2014;43:253-259.

Siliceous mesoporous molecular sieve (Si-MCM-41) material with highly ordered hexagonal pore arrangement was synthesized at 373 K for 8-days duration by hydrothermal method, dried at 393 K and calcined at 823 K in N2 atmosphere. The calcined Si-MCM-41 was later functionalized with 10-50 wt. % monoethanolamine (MEA) by impregnation method and dried in vacuum at 343 K. The MEA-Si-MCM-41 samples were characterized for their physicochemical properties with FTIR, XRD, TGA, HRTEM, FESEM, BET and elemental analysis. XRD results showed that the intensity of the characteristic peaks of Si-MCM-41 reduces with increasing loading of MEA indicating that the MEA molecules are loaded in the pores as well as on the surface of Si-MCM-41. The appearance of FTIR peaks corresponding to N-H, C-N and C-H bonds suggested that Si-MCM-41 has been functionalized with MEA. The presence of Si-O-Si peaks in FTIR spectra of MEA-Si-MCM-41 samples indicates that the hexagonal pore arrangement remains intact and this is supported by HRTEM images. FESEM images show that MEA-Si-MCM-41 samples became agglomerated with increase loading of MEA. TGA analyses show that the MEA-Si-MCM-41 samples are thermally stable up to 528 K. N2 adsorption-desorption isotherms show that the textural properties of Si-MCM-41 material slowly change from a mesoporous material to non-porous material as the MEA loading increases due to pore filling effect during functionalization with MEA. Detection of N, C and H by elemental analysis confirms the presence of MEA in MEA-Si-MCM-41 samples.

Matched MeSH terms: Ethanolamine
Fulltext Sp1 and Sp3 Are the Transcription Activators of Human ek1 Promoter in TSA-Treated Human Colon Carcinoma Cells

Kuan CS, See Too WC, Few LL

PLoS One, 2016;11(1):e0147886.
PMID: 26807725 DOI: 10.1371/journal.pone.0147886

Ethanolamine kinase (EK) catalyzes the phosphorylation of ethanolamine, the first step in the CDP-ethanolamine pathway for the biosynthesis of phosphatidylethanolamine (PE). Human EK exists as EK1, EK2α and EK2β isoforms, encoded by two separate genes, named ek1 and ek2. EK activity is stimulated by carcinogens and oncogenes, suggesting the involvement of EK in carcinogenesis. Currently, little is known about EK transcriptional regulation by endogenous or exogenous signals, and the ek gene promoter has never been studied.

Matched MeSH terms: Ethanolamines; Phosphatidylethanolamines; Ethanolamine
Electrical and optical properties of nanostructured zinc oxide thin films influenced by annealing temperature

Shariffudin SS, Mamat MH, Rusop M

J Nanosci Nanotechnol, 2012 Oct;12(10):8165-8.
PMID: 23421195

Transparent nanostructured ZnO thin films were successfully deposited using sol-gel spin coating method on a quartz substrate. The 0.4 M ZnO solution gel was prepared using zinc acetate dihydrate (Zn(CH3COO)22H2O) as the precursor, 2-methoxyethanol as the solvent and monoethanolamine (MEA) as the stabilizer. The electrical and optical properties dependencies on the annealing temperature of the nanostructured ZnO thin films were investigated. It was found that as the annealing temperature increased, the particle size, conductivity and the peak of the UV emission also increased.

Matched MeSH terms: Ethanolamine
Choline-Chloride-Based Eutectic Solvent for the Efficient Production of Docosahexaenoyl and Eicosapentaenoyl Ethanolamides via an Enzymatic Process

Liang H, Qin X, Tan CP, Li D, Wang Y

J Agric Food Chem, 2018 Nov 21;66(46):12361-12367.
PMID: 30394748 DOI: 10.1021/acs.jafc.8b04804

Docosahexaenoyl and eicosapentaenoyl ethanolamides (DHEA and EPEA) have physiological functions, including immunomodulation, brain development, and anti-inflammation, but their efficient production is still unresolved. In this study, choline-chloride-based natural deep eutectic solvents are used as media to improve the production of DHEA and EPEA. The water content showed a key effect on the reactant conversion. Adding water to choline chloride-glucose (CG, molar ratio of 5:2) led to a significant increase (13.03% for EPEA and 27.95% for DHEA) in the yields after 1 h. The high yields of EPEA (96.84%) and DHEA (90.06%) were obtained under the optimized conditions [fish oil ethyl esters/ethanolamine molar ratio of 1:2, temperature of 60 °C, 1 h, enzyme loading of 2195 units, and CG containing 8.50% water of 43.30% (w/w, relative to total reactants)]. The products could be easily separated using centrifugation. In summary, the research has the potential to produce fatty acyl ethanolamides.

Matched MeSH terms: Ethanolamine/chemistry*
Fulltext Hypothetical Protein BPSL3393 of Burkholderia pseudomallei is Involved in Ethanolamine Catabolism

Luan OG, Yam H, Samian R, Wajidi MFF, Mahadi NM, Mohamad S, et al.

Trop Life Sci Res, 2017 Jul;28(2):57-74.
PMID: 28890761 MyJurnal DOI: 10.21315/tlsr2017.28.2.5

Burkholderia pseudomallei is a soil-dwelling bacterium that causes a globally emerging disease called melioidosis. Approximately one third of the in silico annotated genes in its genome are classified as hypothetical genes. This group of genes is difficult to be functionally characterised partly due to the absence of noticeable phenotypes under conventional laboratory settings. A bioinformatic survey of hypothetical genes revealed a gene designated as BPSL3393 that putatively encodes a small protein of 11 kDA with a CoA binding domain. BPSL3393 is conserved in all the B. pseudomallei genomes as well as various in other species within the genus Burkholderia. Taking into consideration that CoA plays a ubiquitous metabolic role in all life forms, characterisation of BPSL3393 may uncover a previously over-looked metabolic feature of B. pseudomallei. The gene was deleted from the genome using a double homologous recombination approach yielding a null mutant. The BPSL3393 mutant showed no difference in growth rate with the wild type under rich and minimal growth conditions. An extensive metabolic phenotyping test was performed involving 95 metabolic substrates. The deletion mutant of BPSL3393 was severely impaired in its ethanolamine metabolism. The growth rate of the mutant was attenuated when ethanolamine was used as the sole carbon source. A transcriptional analysis of the ethanolamine metabolism genes showed that they were down-regulated in the BPSL3393 mutant. This seemed to suggest that BPSL3393 functions as a positive regulator for ethanolamine metabolism.

Matched MeSH terms: Ethanolamines; Ethanolamine
Guinea pig genital tract lipidome reveals in vivo and in vitro regulation of phosphatidylcholine 16:0/18:1 and contribution to Chlamydia trachomatis serovar D infectivity

Wali S, Gupta R, Yu JJ, Mfuh A, Gao X, Guentzel MN, et al.

Metabolomics, 2016 Apr;12(4).
PMID: 27642272

INTRODUCTION: Chlamydia trachomatis (Ct), is the leading cause of sexually transmitted infections worldwide. Host transcriptomic- or proteomic profiling studies have identified key molecules involved in establishment of Ct infection or the generation of anti Ct-immunity. However, the contribution of the host metabolome is not known.
OBJECTIVES: The objective of this study was to determine the contribution of host metabolites in genital Ct infection.
METHODS: We used high-performance liquid chromatography-mass spectrometry, and mapped lipid profiles in genital swabs obtained from female guinea pigs at days 3, 9, 15, 30 and 65 post Ct serovar D intravaginal infection.
RESULTS: Across all time points assessed, 13 distinct lipid species including choline, ethanolamine and glycerol were detected. Amongst these metabolites, phosphatidylcholine (PC) was the predominant phospholipid detected from animals actively shedding bacteria i.e., at 3, 9, and 15 days post infection. However, at days 30 and 65 when the animals had cleared the infection, PC was observed to be decreased compared to previous time points. Mass spectrometry analyses of PC produced in guinea pigs (in vivo) and 104C1 guinea pig cell line (in vitro) revealed distinct PC species following Ct D infection. Amongst these, PC 16:0/18:1 was significantly upregulated following Ct D infection (p < 0.05, >twofold change) in vivo and in vitro infection models investigated in this report. Exogenous addition of PC 16:0/18:1 resulted in significant increase in Ct D in Hela 229 cells.
CONCLUSION: This study demonstrates a role for host metabolite, PC 16:0/18:1 in regulating genital Ct infection in vivo and in vitro.

Matched MeSH terms: Ethanolamines; Ethanolamine
Unusual metal ion cofactor requirement of Entamoeba histolytica choline and ethanolamine kinase isoforms

Chang CH, Few LL, Lim BH, Yvonne-Tee GB, Chew AL, See Too WC

Parasitol Res, 2023 Jul;122(7):1651-1661.
PMID: 37202563 DOI: 10.1007/s00436-023-07869-5

The de novo biosynthesis of phosphatidylcholine and phosphatidylethanolamine in Entamoeba histolytica is largely dependent on the CDP-choline and CDP-ethanolamine pathways. Although the first enzymes of these pathways, EhCK1 and EhCK2, have been previously characterized, their enzymatic activity was found to be low and undetectable, respectively. This study aimed to identify the unusual characteristics of these enzymes in this deadly parasite. The discovery that EhCKs prefer Mn2+ over the typical Mg2+ as a metal ion cofactor is intriguing for CK/EK family of enzymes. In the presence of Mn2+, the activity of EhCK1 increased by approximately 108-fold compared to that in Mg2+. Specifically, in Mg2+, EhCK1 exhibited a Vmax and K0.5 of 3.5 ± 0.1 U/mg and 13.9 ± 0.2 mM, respectively. However, in Mn2+, it displayed a Vmax of 149.1 ± 2.5 U/mg and a K0.5 of 9.5 ± 0.1 mM. Moreover, when Mg2+ was present at a constant concentration of 12 mM, the K0.5 value for Mn2+ was ~ 2.4-fold lower than that in Mn2+ alone, without affecting its Vmax. Although the enzyme efficiency of EhCK1 was significantly improved by about 25-fold in Mn2+, it is worth noting that its Km for choline and ATP were higher than in equimolar of Mg2+ in a previous study. In contrast, EhCK2 showed specific activity towards ethanolamine in Mn2+, exhibiting Michaelis-Menten kinetic with ethanolamine (Km = 312 ± 27 µM) and cooperativity with ATP (K0.5 = 2.1 ± 0.2 mM). Additionally, we investigated the effect of metal ions on the substrate recognition of human choline and ethanolamine kinase isoforms. Human choline kinase α2 was found to absolutely require Mg2+, while choline kinase β differentially recognized choline and ethanolamine in Mg2+ and Mn2+, respectively. Finally, mutagenesis studies revealed that EhCK1 Tyr129 was critical for Mn2+ binding, while Lys233 was essential for substrate catalysis but not metal ion binding. Overall, these findings provide insight into the unique characteristics of the EhCKs and highlight the potential for new approaches to treating amoebiasis. Amoebiasis is a challenging disease for clinicians to diagnose and treat, as many patients are asymptomatic. However, by studying the enzymes involved in the CDP-choline and CDP-ethanolamine pathways, which are crucial for de novo biosynthesis of phosphatidylcholine and phosphatidylethanolamine in Entamoeba histolytica, there is great potential to discover new therapeutic approaches to combat this disease.

Matched MeSH terms: Ethanolamines/metabolism; Phosphatidylethanolamines/metabolism; Ethanolamine