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Optimization of the enzyme-catalyzed synthesis of amino acid-based surfactants from palm oil fractions

Soo EL, Salleh AB, Basri M, Zaliha Raja Abdul Rahman RN, Kamaruddin K

J Biosci Bioeng, 2003;95(4):361-7.
PMID: 16233420

The feasibility of using palm oil fractions as cheap and abundant sources of raw material for the synthesis of amino acid surfactants was investigated. Of a number of enzymes screened, the best results were obtained with the immobilized enzyme, Lipozyme. The effects of temperature, solvent, incubation period, fatty substrate/amino acid molar ratio, enzyme amount, and water removal on the reactions were analyzed and compared to those on reactions with free fatty acids and pure triglycerides as fatty substrates. All reactions were most efficient when carried out at high temperatures (70-80 degrees C) in hexane as a solvent. However, while reactions with free fatty acids proceeded better when a slight excess of the free fatty acids over the amino acids was used, reactions with triglycerides and palm oil fractions were best performed at equimolar ratios. Also, the addition of molecular sieves slightly enhanced reactions with free fatty acids but adversely affected reactions with triglycerides and palm oil fractions. Although reactions with palm oil fractions took longer (6 d) to reach equilibrium compared to reactions with free fatty acids (4 d) and pure triglycerides (4 d), better yields were obtained. Such lipase-catalyzed transacylation of palm oil fractions with amino acids is potentially useful in the production of mixed medium- to long-chain surfactants for specific applications.

Matched MeSH terms: Solvents
One pot synthesis, molecular structure and spectroscopic studies (X-ray, IR, NMR, UV-Vis) of novel 2-(4,6-dimethoxy-1,3,5-triazin-2-yl) amino acid ester derivatives

El-Faham A, Soliman SM, Osman SM, Ghabbour HA, Siddiqui MR, Fun HK, et al.

Spectrochim Acta A Mol Biomol Spectrosc, 2016 Apr 15;159:184-98.
PMID: 26845586 DOI: 10.1016/j.saa.2016.01.051

Novel series of 2-(4,6-dimethoxy,1,3,5-triazin-2-yl) amino acid ester derivatives were synthesized using simple one pot method in methanol. The products were obtained in high yields and purities as observed from their spectral data, elemental analyses, GC-MS and X-ray crystallographic analysis. The B3LYP/6-311G(d,p) calculated molecular structures are well correlated with the geometrical parameters obtained from the X-ray analyses. The spectroscopic properties such as IR vibrational modes, NMR chemical shifts and UV-Vis electronic transitions were discussed both experimentally and theoretically. The IR vibrational frequencies showed good correlations with the experimental data (R(2)=0.9961-0.9995). The electronic spectra were assigned based on the TD-DFT results. Intense electronic transition band is calculated at 198.1nm (f=0.1389), 204.2nm (f=0.2053), 205.0 (f=0.1704) and 205.7 (0.2971) for compounds 6a-i, respectively. The molecular orbital energy levels contributed in the longest wavelength transition band were explained. For all compounds, the experimental wavelengths showed red shifts compared to the calculations due to the solvent effect. The NMR chemical shifts were calculated using GIAO method. The NBO analyses were performed to predict the stabilization energies due to the electron delocalization processes occur in the studied systems.

Matched MeSH terms: Solvents
RETRACTED: Neoteric FT-IR investigation on the functional groups of phosphonium-based deep eutectic solvents

Aissaoui T, AlNashef IM, Hayyan M, Hashim MA

Spectrochim Acta A Mol Biomol Spectrosc, 2015 Oct 5;149:588-91.
PMID: 25985123 DOI: 10.1016/j.saa.2015.05.001

Deep eutectic solvents (DESs) are novel solvent media that are currently under investigation as an alternative to ionic liquids and conventional solvents. The physical properties of DESs as well as their mild environmental footprint and potentially critical industrial application necessitate understanding the interaction of functional groups on both the salt and hydrogen bond donor (HBD). In this study, four DESs were prepared by mixing triethylenglycol, diethylenglycol, ethylenglycol, and glycerol as HBDs with methyltriphenylphosphonium bromide as a salt at a molar ratio of 1:4. Fourier transform infrared spectroscopy was conducted to highlight the chemical structure and mechanism of the combination of the four DESs. New spectra illustrating the combination of the functional groups of the HBDs and salt were observed and interpreted. This study is the first to investigate the properties of neoteric phosphonium-based DESs.

Matched MeSH terms: Solvents
Vortex-assisted liquid-liquid-liquid microextraction (VALLLME) technique: A new microextraction approach for direct liquid chromatography and capillary electrophoresis analysis

Makahleh A, Yap HF, Saad B

Talanta, 2015 Oct 01;143:394-401.
PMID: 26078176 DOI: 10.1016/j.talanta.2015.05.011

A new, rapid and sensitive microextraction technique named vortex-assisted liquid-liquid-liquid microextraction (VALLLME) is proposed. The complete extraction process involves two steps. First, a vortex-assisted liquid-liquid microextraction (VALLME) procedure was used to extract the analytes from a relatively large volume of sample (donor phase) to a small volume of organic solvent (intermediate phase). Next, a micro-vortex-assisted liquid-liquid extraction (µ-VALLE) was used to extract the target analytes from the intermediate phase to a smaller volume of aqueous solution (acceptor phase). The final extract (acceptor phase) can be directly injected into the high performance liquid chromatography or capillary electrophoresis units without any further treatments. The selection of the intermediate phase and the manipulation of pH are key parameters that ensure good extraction efficiency of the technique. The proposed technique has been successfully applied for the determination of carvedilol (used as model analyte) in biological fluid samples. The optimum extraction conditions were: toluene as intermediate phase (150 μL); pH of the donor phase, 9.5; vortex time of the VALLME, 45 s (maximum speed, 2500 rpm); 0.1M HCl (15 μL) as acceptor phase; vortexing time of the µ-VALLME, 75 s (maximum stirring speed, 2500 rpm) and salt concentration in the donor phase, 5% (w/v). Under these conditions, enrichment factors of 51- and 418-fold for VALLME step and VALLLME procedure, respectively, were achieved.

Matched MeSH terms: Solvents
Fulltext Evaluation of in-vitro antioxidant and antibacterial properties of Commelina nudiflora L. extracts prepared by different polar solvents

Kuppusamy P, Yusoff MM, Parine NR, Govindan N

Saudi J Biol Sci, 2015 May;22(3):293-301.
PMID: 25972750 DOI: 10.1016/j.sjbs.2014.09.016

The study explored on the commonly available weed plant Commelina nudiflora which has potential in-vitro antioxidant and antimicrobial activity. The different polar solvents such as ethanol, chloroform, dichloromethane, hexane and aqueous were used for the soxhlet extraction. The extracts were identified pharmacologically as important bioactive compounds and their potential free radical scavenging activities, and antimicrobial properties were studied. C. nudiflora extracts were monitored on their in-vitro antioxidant ability by DPPH and ABTS radical scavenging assay. Aqueous extract shows significant free radical scavenging activity of 63.4 mg/GAE and 49.10 mg/g in DPPH and ABTS respectively. Furthermore, the aqueous crude extract was used in antibacterial studies, which shows the highest inhibitory activity against Pseudomonas aeruginosa, Escherichia coli and Salmonella typhi. Among all the extracts, aqueous extract of C. nudiflora has significant control over free radical scavenging activity and inhibition of the growth of food pathogenic bacteria. Also, the aqueous extract contains abundance of phenolics and flavonoids higher than other extracts. This study explored weed plant C. nudiflora as a potential source of antioxidant and antibacterial efficacy and identified various therapeutic value bioactive compounds from GC-MS analysis.

Matched MeSH terms: Solvents
Fulltext Reverse engineering of Ayurvedic lipid based formulation, ghrita by combined column chromatography, normal and reverse phase HPTLC analysis

Duraipandi S, Selvakumar V, Er NY

BMC Complement Altern Med, 2015;15:62.
PMID: 25885542 DOI: 10.1186/s12906-015-0568-9

Ghritas are ayurvedic lipid based preparations in which oil or ghee is boiled with prescribed kasaya (polyherbal decoction) and kalka (fine paste of herbs) until the evaporation of aqueous phase transfers the contents into oily phase. The polyherbal decoction used in the preparation predominantly contains water soluble Active Botanical Ingredients (ABIs).

Matched MeSH terms: Solvents
Ultrasonic extraction of anthocyanin from Clitoria ternatea flowers using response surface methodology

Chong FC, Gwee XF

Nat Prod Res, 2015;29(15):1485-7.
PMID: 25836369 DOI: 10.1080/14786419.2015.1027892

The ultrasonic extraction (UE) method of anthocyanin from Clitoria ternatea flowers using response surface methodology (RSM) was performed in this study. By using RSM, the objective is to optimise the extraction yield of anthocyanin from C. ternatea which is influenced by various factors, including the extraction temperature, time, ratio of solvent to solid and ultrasonic power. The empirical model was investigated by performing first-level optimisation in a two-level factorial design with Design Expert 7 software. In comparison with the conventional solvent extraction, UE showed a 246.48% better extraction yield and produced an anthocyanin extract with a radical scavenging activity of 68.48% at the optimised factors of 50°C, 150 min, 15 mL/g and 240 W.

Matched MeSH terms: Solvents
Fatty acid compositions in local sea cucumber, Stichopus chloronotus, for wound healing

Fredalina BD, Ridzwan BH, Abidin AA, Kaswandi MA, Zaiton H, Zali I, et al.

Gen. Pharmacol., 1999 Oct;33(4):337-40.
PMID: 10523072

Fatty acid profile from crude extracts of local sea cucumber Stichopus chloronotus was determined using gas chromatography (GC) technique. The extracts were prepared separately in methanol, ethanol, phosphate buffer saline (PBS), and distilled water as part of our study to look at the affinity of these solvents in extracting the lipid from sea cucumber. The PBS and distilled water extractions indicate water-soluble components, while the organic fractions are extracted in methanol and ethanol as organic solvents. Furthermore, water extraction is the conventional method practiced in Malaysia. In our analysis the C14:0 (myristic), C16:0 (palmitic), C18:0 (stearic), C18:2 (linoleic), C20:0 (arachidic), and C20:5 (eicosapentaenoic, EPA) were significantly different (p < 0.01) in the four solvent extractions. However, the PBS extraction contained a much higher percentage of EPA (25.69%) compared to 18.89% in ethanol, 7.84% in distilled water, and only 5.83% in methanol, and variances were significantly different (p < 0.01 ). On the other hand, C22:6 (docosahexaenoic acid or DHA) is much higher in water extraction (57.55%), in comparison to the others where only 3.63% in PBS and 1.20% in methanol, and this difference is significant at p < 0.01. No DHA was detected in ethanol extractions. Subsequently, C18:1 (oleic acid) was only detected in PBS (21.98%) and water extraction (7.50%). It is interesting that palmitic acid, C16:() was higher in methanol (20.82%) and ethanol (2.18%), while 12.55% was detected in PBS and only 2.20% in water extraction: and again this was significantly different at p < 0.01. Although our results have shown that all four solvents were different in terms of their ability to extract fatty acids, the major component for tissue repair was well preserved. Probably this is one of the important precocious steps when working with a delicate sea cucumber, in both experimental and/or at the preparative stages. Freshness of the sea cucumber samples is important when undertaking this type of experiment. Finally, we believe that the local sea cucumber S. chloronotus contains all the fatty acids required to play a potential active role in tissue repair.

Matched MeSH terms: Solvents
Comparison of solvent extraction and solid-phase extraction for the determination of organochlorine pesticide residues in water

Tan GH

Analyst, 1992 Jul;117(7):1129-32.
PMID: 1524230

Solid-phase extraction (SPE) of organochlorine pesticide residues from environmental water samples was evaluated using octadecyl (C18)-bonded porous silica. The efficiency of SPE of these pesticide residues from reagent water samples at 1-5 micrograms dm-3 levels was compared with those obtained by solvent extraction with hexane and Freon TF (trichlorotrifluoroethane). Average recoveries exceeding 80% for these organochlorine pesticides were obtained via the SPE method using small cartridges containing 100 mg of 40 microns C18-bonded porous silica. The average recovery by solvent extraction with hexane and Freon TF exceeded 90% in both instances. It was concluded that the recoveries and precision for the SPE of organochlorine pesticides were poorer than those for the solvent extraction method. Organochlorine pesticide residue levels in environmental water samples from two major rivers flowing through predominantly rice-growing areas were monitored by gas chromatography using the solvent extraction method with hexane. Exceptionally high levels of organochlorine pesticide residues such as BHC, DDT, heptachlor, endosulfan and dieldrin were found in these water samples.

Matched MeSH terms: Solvents
The effect of water activity on modified lipase during esterification

Salleh AB, Taib M, Basri M, Ampon K, Yunus WM, Razak CN

Ann N Y Acad Sci, 1996 Oct 12;799:328-31.
PMID: 8958097
Matched MeSH terms: Solvents
Chloroquine polymeric membrane electrodes: Development and applications

Saad B, Kanapathy K, Ahmad MN, Hussin AH, Ismail Z

Talanta, 1991 Dec;38(12):1399-402.
PMID: 18965315

Three main types of PVC solvent polymeric membrane ion-selective electrodes for chloroquine are described. They are based on three ion-pairing agents namely dipicrylamine (DPA), tetraphenylborate (TPB) or tetrakis(4-chlorophenyl)borate (TCPB) with either dioctylphenyl phosphonate (DOPP) or trioctyl phosphate (TOP) solvent mediator. All electrodes exhibit Nernstian responses, fast dynamic response times and a wide useful pH range. The best all-round electrode is based on TPB and TOP plasticizing solvent mediators with a limit of detection of 7.1 x 10(-6)M and was utilized for the assay of chloroquine in tablets. Direct potentiometric determinations with either the analyte addition method or the normal calibration method gave results comparable to the official method.

Matched MeSH terms: Solvents
Fulltext Reinventing nano drug delivery systems for hydrophilic active ingredients in Ayurvedic lipid based formulations containing poly herbal decoction

Duraipandi S, Selvakumar V

J Ayurveda Integr Med, 2019 01 08;11(3):224-227.
PMID: 30635246 DOI: 10.1016/j.jaim.2018.01.008

BACKGROUND: Anu Tailam, an Ayurvedic medicated oil where 'anu' meant for atom and 'tailam' meant for oil and virtually meant for 'oil of subtle or atomic size particles'. Since the major active ingredients in this formulation are incorporated from the polyherbal decoction, it is expected to contain predominantly water soluble ingredients.
OBJECTIVES: It is hypothesized that these polar active botanical ingredients are present in the formulation should be either suspended in the form of submicron particles or entrapped in the submicron vesicular structures since the formulation did not show any precipitation or phase separation instead showed a monophasic oily liquid with very little moisture.
MATERIALS AND METHODS: In the present investigation, the micro architecture of the anu tailam is studied via column chromatography and high performance thin layer chromatography to prove the contents are polar hydrophilic compounds followed by optical microscopy, photon correlation Spectroscopy (PCS) and environmental scanning electron microscope (ESEM) to study the particle/vesicle size of the formulation.
RESULTS: In this study, it was proved that the formulation contained only polar ingredients and can be extracted in polar solvents like methanol and ethanol. It was also found that the formulation taken for study contained nano particles of the active botanical ingredients embedded in a network of vesicular structures of the lipid base.
CONCLUSION: The selected Ayurvedic formulation 'anutailam' found to contain novel nano drug delivery system to deliver water soluble ingredients across barriers.

Matched MeSH terms: Solvents
Acetic acid buffer as extraction medium for free and bound phenolics from dried blackcurrant (Ribes nigrum L.) skins

Azman EM, Charalampopoulos D, Chatzifragkou A

J Food Sci, 2020 Nov;85(11):3745-3755.
PMID: 32990367 DOI: 10.1111/1750-3841.15466

The aim of this study was to investigate the effects of different solvent and extraction temperatures on the free and bound phenolic compounds and antioxidant activity of dried blackcurrant skins (DBS). Apart from acetic acid buffer solution, different solvent systems, including water, methanol, and mixtures of methanol/water, were also employed and the effects of solvent and temperature (30 and 50 °C) on the free and bound forms of anthocyanins, hydroxycinnamic acids, and flavonols yield were assessed. The results showed that among all solvents, acetic acid buffer resulted in the highest free anthocyanin content (1,712.3 ± 56.1 mg/100 g) (P

Matched MeSH terms: Solvents
Fulltext Antibacterial activity of Spilanthes acmella flower extracts (SAFE) against Streptococcus mutans

Siti Aisyah Abd Ghafar, Muhammad Fikhry Mohd Salehuddin,, Nur Syamimi Syuhada Che Awang, Rohazila Mohamad Hanafiah

Malaysian Journal of Medicine and Health Sciences, 2019;15(108):42-42.
MyJurnal

Introduction:Spilanthes acmella, also known as “subang nenek’, has been used traditionally in Malaysia to treat toothache. A previous study has shown Spilanthes acmella leaves extracts (SALE) inhibit Streptococcus mutans growth. Streptococcus mutans is commonly found in the human oral cavity and is the main contributor to tooth de-cay. There is no study on the antibacterial effects of Spilanthes acmella flower extracts (SAFE) against Streptococcus mutans reported to date. Therefore, the objective of this study is to investigate antibacterial properties of SAFE against S. mutans. Methods:S. mutans was subcultured in Muller Hinton (MH) broth and agar. Sequential extractions of S. acmella flowers were conducted using four different solvents with increasing polarity, [n- hexane, dichloromethane (DCM), acetone, methanol (MeoH)] and tested with different concentrations against S. mutans via the disc diffusion assay, minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC). Sodium fluoride (NaF) was used as a positive control while DMSO was used as a negative control. Results: The disc diffusion assay shows SAFE inhibited Streptococcus mutans growth. SAFE-DCM shows the greatest inhibition properties (12.33±2.30 mm) followed by SAFE-n-hexane (11.33±0.57 mm). Meanwhile, SAFE-Meoh and SAFE-acetone show no inhibition zone (6.00±0.001 mm). MIC value for SAFE-DCM and SAFE-n-hexane is 12.5 mg/mL respectively. Whereas, MBC value SAFE-DCM and SAFE-n-hexane is 50.0 mg/mL respectively. Conclusion: It can be concluded SAFE-DCM and SAFE-n-hexane possesses bactericidal properties against Streptococcus mutans.

Matched MeSH terms: Solvents
Fulltext Development of Polyvinylidene Fluoride Membrane by Incorporating Bio-Based Ginger Extract as Additive

Fahrina A, Arahman N, Mulyati S, Aprilia S, Mat Nawi NI, Aqsha A, et al.

Polymers (Basel), 2020 Sep 03;12(9).
PMID: 32899138 DOI: 10.3390/polym12092003

Biofouling on the membrane surface leads to performance deficiencies in membrane filtration. In this study, the application of ginger extract as a bio-based additive to enhance membrane antibiofouling properties was investigated. The extract was dispersed in a dimethyl acetamide (DMAc) solvent together with polyvinylidene fluoride (PVDF) to enhance biofouling resistance of the resulting membrane due to its antibiotic property. The concentrations of the ginger extract in the dope solution were varied in the range of 0-0.1 wt %. The antibacterial property of the resulting membranes was assessed using the Kirby Bauer disc diffusion method. The results show an inhibition zone formed around the PVDF/ginger membrane against Escherichia coli and Staphylococcus aureus demonstrating the efficacy of the residual ginger extract in the membrane matrix to impose the antibiofouling property. The addition of the ginger extract also enhanced the hydrophilicity in the membrane surface by lowering the contact angle from 93° to 85°, which was in good agreement with the increase in the pure water flux of up to 62%.

Matched MeSH terms: Solvents
Fulltext Docetaxel-Loaded Poly(3HB-co-4HB) Biodegradable Nanoparticles: Impact of Copolymer Composition

Faisalina AF, Sonvico F, Colombo P, Amirul AA, Wahab HA, Majid MIA

Nanomaterials (Basel), 2020 Oct 26;10(11).
PMID: 33114572 DOI: 10.3390/nano10112123

Polyhydroxyalkanoate (PHA) copolymers show a relatively higher in vivo degradation rate compared to other PHAs, thus, they receive a great deal of attention for a wide range of medical applications. Nanoparticles (NPs) loaded with poorly water-soluble anticancer drug docetaxel (DCX) were produced using poly(3-hydroxybutyrate-co-4-hydroxybutyrate), P(3HB-co-4HB), copolymers biosynthesised from Cupriavidus malaysiensis USMAA1020 isolated from the Malaysian environment. Three copolymers with different molar proportions of 4-hydroxybutirate (4HB) were used: 16% (PHB16), 30% (PHB30) and 70% (PHB70) 4HB-containing P(3HB-co-4HB). Blank and DCX-loaded nanoparticles were then characterized for their size and size distribution, surface charge, encapsulation efficiency and drug release. Preformulation studies showed that an optimised formulation could be achieved through the emulsification/solvent evaporation method using PHB70 with the addition of 1.0% PVA, as stabilizer and 0.03% VitE-TPGS, as surfactant. DCX-loaded PHB70 nanoparticles (DCX-PHB70) gave the desired particle size distribution in terms of average particle size around 150 nm and narrow particle size distribution (polydispersity index (PDI) below 0.100). The encapsulation efficiency result showed that at 30% w/w drug-to-polymer ratio: DCX- PHB16 NPs were able to encapsulate up to 42% of DCX; DCX-PHB30 NPs encapsulated up to 46% of DCX and DCX-PHB70 NPs encapsulated up to 50% of DCX within the nanoparticle system. Approximately 60% of DCX was released from the DCX-PHB70 NPs within 7 days for 5%, 10% and 20% of drug-to-polymer ratio while for the 30% and 40% drug-to-polymer ratios, an almost complete drug release (98%) after 7 days of incubation was observed.

Matched MeSH terms: Solvents
Self-assembly of a robust hydrogen-bonded octylphosphonate network on cesium lead bromide perovskite nanocrystals for light-emitting diodes

Brown AAM, Hooper TJN, Veldhuis SA, Chin XY, Bruno A, Vashishtha P, et al.

Nanoscale, 2019 Jul 07;11(25):12370-12380.
PMID: 31215940 DOI: 10.1039/c9nr02566a

We report the self-assembly of an extensive inter-ligand hydrogen-bonding network of octylphosphonates on the surface of cesium lead bromide nanocrystals (CsPbBr3 NCs). The post-synthetic addition of octylphosphonic acid to oleic acid/oleylamine-capped CsPbBr3 NCs promoted the attachment of octylphosphonate to the NC surface, while the remaining oleylammonium ligands maintained the high dispersability of the NCs in non-polar solvent. Through powerful 2D solid-state 31P-1H NMR, we demonstrated that an ethyl acetate/acetonitrile purification regime was crucial for initiating the self-assembly of extensive octylphosphonate chains. Octylphosphonate ligands were found to preferentially bind in a monodentate mode through P-O-, leaving polar P[double bond, length as m-dash]O and P-OH groups free to form inter-ligand hydrogen bonds. The octylphosphonate ligand network strongly passivated the nanocrystal surface, yielding a fully-purified CsPbBr3 NC ink with PLQY of 62%, over 3 times higher than untreated NCs. We translated this to LED devices, achieving maximum external quantum efficiency and luminance of 7.74% and 1022 cd m-2 with OPA treatment, as opposed to 3.59% and 229 cd m-2 for untreated CsPbBr3 NCs. This represents one of the highest efficiency LEDs obtained for all-inorganic CsPbBr3 NCs, accomplished through simple, effective passivation and purification processes. The robust binding of octylphosphonates to the perovskite lattice, and specifically their ability to interlink through hydrogen bonding, offers a promising passivation approach which could potentially be beneficial across a breadth of halide perovskite optoelectronic applications.

Matched MeSH terms: Solvents
Fulltext Dry Thermotropic Glycolipid Self-Assembly:A Review

Hashim R, Zahid NI, Velayutham TS, Aripin NFK, Ogawa S, Sugimura A

J Oleo Sci, 2018 Jun 01;67(6):651-668.
PMID: 29760332 DOI: 10.5650/jos.ess17261

Also recognized as carbohydrate liquid crystals, glycolipids are amphiphiles whose basic unit comprises of a sugar group attached to an alkyl chain. Glycolipids are amphitropic, which means these materials form liquid crystal self-assemblies when dry (thermotropic) as well as when dissolved in solvents (lyotropic/surfactants) such as water. Many glycolipids are also naturally derived since these can be found in cell membranes. Their membrane and surfactant functions are largely understood through their lyotropic properties. While glycolipids are expected to play major roles as eco-friendly surfactants in the global surfactant market, their usefulness as thermotropic liquid crystal material is, to date, unknown, due to relatively lack of research performed and data reported in the literature. Understandably since glycolipids are hygroscopic with many hydroxy groups, removing the last trace water is very challenging. In recent time, with careful lyophilization and more consistent characterization technique, some researchers have attempted serious studies into "dry" or anhydrous glycolipids. Motivated by possible developments of novel thermotropic applications, some results from these studies also provide surprising new understanding to support conventional wisdom of the lyotropic systems. Here we review the dry state of glycosides, a family of glycolipids whose sugar headgroup is linked to the lipid chain via a glycosidic oxygen linker. The structure property relationship of both linear and anhydrous Guerbet glycosides will be examined. In particular, how the variation of sugar stereochemistry (e.g. anomer vs. epimer), the chain length and chain branching affect the formation of thermotropic liquid crystals phases, which not only located under equilibrium but also far from equilibrium conditions (glassy phase) are scrutinized. The dry glycolipid assembly has been subjected to electric and magnetic fields and the results show interesting behaviors including a possible transient current generation.

Matched MeSH terms: Solvents
Fulltext Changes in chemical composition and amino acid content of Soy Protein Isolate (SPI) from tempeh

Wan Saidatul Syida, W.K., Normah, I., Noriham, A., Mohd Yusuf, M.

International Food Research Journal, 2018;25(4):1528-1533.
MyJurnal

Processing of soybeans to other products and consumption of soy products is increasing worldwide mainly due to acclaimed health benefits. Processing can alter soybean sensory appeal, nutritive value and potentially affect consumer health. Rhizopus oligosporus was used to ferment soybean for 3 days. The tempeh flour (TF) was produced form tempeh while defatted tempeh flour (DTF) was then produced from TF by immersing in hexane solvent while soy protein isolate (SPI) was prepared from DTF by using alkali and acid followed by neutralization treatment. In this study, nutritional properties and amino acid content of tempeh, TF, DTF and SPI were determined. Therefore, the objective of this study is was to evaluate the effect of each treatment on the chemical composition and amino acid content for all the samples. The results showed that the nutritional properties (total ash, moisture, crude fat, total carbohydrate and crude fibre) were reduced significantly (p < 0.05) except for protein content. Protein content was significantly (p < 0.05) increased by 50.5% in SPI. For amino acid content, the results obtained showed that SPI contain highest amount of essential and non-essential amino acid followed by DTF, Tempeh and TF. Glutamic acid was found to be the highest amino acid component in all samples. The evaluation from the results showed that SPI can be considered as potential functional food ingredients.

Matched MeSH terms: Solvents
Fulltext Antifouling Properties of PES Membranes by Blending with ZnO Nanoparticles and NMP⁻Acetone Mixture as Solvent

Ahmad AL, Sugumaran J, Shoparwe NF

Membranes (Basel), 2018 Dec 14;8(4).
PMID: 30558199 DOI: 10.3390/membranes8040131

In this study, the antifouling properties of polyethersulfone (PES) membranes blended with different amounts of ZnO nanoparticles and a fixed ratio of N-methyl-2-pyrrolidone (NMP)-acetone mixture as a solvent were investigated. The properties and performance of the fabricated membranes were examined in terms of hydrophilicity, porosity, pore size, surface and cross-section image using scanning electron microscopy (SEM), surface roughness using atomic force microscopy (AFM), pure water flux, and humic acid filtration. Addition of ZnO as expected was found to improve the hydrophilicity as well as to encourage pore formation. However, the agglomeration of ZnO at a higher concentration cannot be avoided even when dissolved in a mixed solvent. The presence of highly volatile acetone contributed to the tight skin layer of the membrane which shows remarkable antifouling ability with the highest flux recovery ratio and negligible irreversible fouling. ZnO NPs in acetone/NMP mixed solvent shows an improvement in flux and rejection, but, the fouling resistance was moderate compared to the pristine membrane.

Matched MeSH terms: Solvents

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