The seeds (6.9±0.2% by weight of fruit) of the red-skin rambutan (Nephelium lappaceum L.) contain a considerable amount of crude fat (38.0±4.36%) and thus, the aim of the study was to determine the physico-chemical properties of this fat for potential applications. The iodine and saponification values, and unsaponifiable matter and free fatty acid contents of the seed fat were 50.27 g I2/100g fat, 182.1 mg KOH/g fat, 0.8% and 2.1%, respectively. The fat is pale yellow with a Lovibond color index of 3.1Y+1.1R. The fatty acid profile indicates an almost equal proportion of saturated (49.1%) and unsaturated (50.9%) fatty acids, where oleic (42.0%) and arachidic (34.3%) acids were the most dominant fatty acids. It also contained small amounts of stearic (8.0%), palmitic (4.6%), gadoleic (5.9%), linoleic (2.2%), behenic (2.1%) palmitoleic (0.7%) myristic (0.1%) and erucic (0.1%) acids. HPLC analysis showed that the fat comprised mainly unknown triacylglycerols (TAG) with high retention times indicating they have higher carbon numbers compared with many vegetable oils. The fat has melting and cooling points of 44.2°C and –42.5°C, respectively, making it a semi-solid at room temperature. The solid content at 0°C was 53.5% and the fat melted completely at 40°C. z-Nose analysis showed that the presence of high levels of volatile compounds in red-skin rambutan seed and seed fat.
In the development of solvent-free offset ink, the roles of resin molecular weight and used solvent on the ink performance were evaluated by examining the relationship between the various properties of resin and solvent and print quality. To find the best performing resin, the soy-oil fatty acid methyl ester (FAME) was applied to the five modified-phenolic resins having different molecular weights. It is found from the experimental results that the ink made of higher molecular weight and better solubility resin gives better printability and print quality. It is because larger molecular weight resin with better solubility gives higher rate of ink transfer. From the ink application of different esters to high molecular weight resin, the best printing performance was yielded from the soy-oil fatty acid butyl ester (FABE). It is due to its high kinematic viscosity resulting in the smallest change of ink transfer weight upon multiple number of printing, which improves the stability of ink quality.
A sugar-based gemini surfactant N,N’-dialkyl-N,N’-dilactobionamideethylenediamine (2CnLac, where n represents alkyl chain lengths of 8, 10, 12, and 14) was synthesized by reacting N,N’-dialkylethylenediamine with lactobionic acid. The adsorption properties of 2CnLac were characterized by equilibrium and dynamic surface tension measurements. Their micellization properties were investigated by steady-state fluorescence using pyrene as a probe and dynamic light scattering (DLS) techniques. The dependence of these properties on the alkyl chain length and the number of sugars was determined through a comparison with the corresponding monomeric surfactants CnMLA and previously reported sugar-based gemini surfactants containing monosaccharide gluconamide or disaccharide lactobionamide groups with a hexanediamide spacer. The critical micelle concentration (cmc) and surface tension of 2CnLac are both lower than those of CnMLA surfactants. These lower values indicate that the synthesized sugar-based gemini surfactants have excellent micelle-forming ability in solution and high adsorption ability at the air-water interface, which result from strong interactions of the hydrogen bonds between the hydroxyls in lactobionamide groups. When the alkyl chain length of 2CnLac increases to 14, premicellar formation occurs in the solution along with adsorption at the air-water interface at concentrations below the cmc. Furthermore, 2CnLac forms micelles measuring 4 to 12 nm in solution, with no dependence on the alkyl chain length, and their size slightly increases with increasing concentration.
We studied the effect of water addition on interfacial properties and aggregate behavior of nonionic surfactants (polyoxyethylene alkyl ether; CnEm) in an ionic liquid (1-butyl-3-methylimidazolium hexafluorophosphate; bmimPF6). When a small amount of water was added to mixtures of CnEm and bmimPF6, two breaking points (cac1, cac2) were observed in the surface tension/CnEm concentration plots, suggesting the formation of two kinds of aggregates. This two-step aggregate formation was also confirmed by the fluorescence probe method using pyrene. The particle size of the aggregates measured by dynamic light scattering (DLS) was around 200 nm at cac1, and decreased to 4 nm above cac2. These results, together with freeze-fracture TEM observations, showed that the aggregate formed at cac1 was water in bmimPF6 emulsions, which then transformed to micelles solubilizing water in the palisade layer above cac2. This concentration-dependent aggregate formation was supported thermodynamically by studying the dependence of cacs on temperature and alkyl and POE chain lengths of the surfactant.
The ester-type asymmetrical tartaric gemini amphiphiles (Cm-Cn, where m and n are the number of carbon atoms of hydrophobic alkanoyl group, m+n=28) bearing two carboxyl groups and two different alkanoyl groups were prepared from L-tartaric acid, and the pressure-area (π-A) isotherms for a series of asymmetrical tartaric gemini amphiphiles were studied. The π-A isotherms of asymmetrical Cm-Cn monolayers were classified into two groups. Group 1: The asymmetry was small (n/m <1.55), and a phase transition of the monolayer from the liquid-expanded to the liquid condensed state, and a subsequent transition to solid phases were observed. Group 2: The asymmetry was large (n/m >1.8), and only liquid-expanded state of the monolayer film was observed. Based on the subphase temperature (Tsub) dependence of monolayer static elasticity, es, the melting temperature (TL) of asymmetrical Cm-Cn monolayer was estimated to be TL = 31.7°C and 50.6°C for C13-C15 and C12-C16, respectively. Furthermore, assuming that asymmetrical C13-C15 can be viewed as an equimolar mixture of symmetrical 2C13 and 2C15, the temperature dependence of monolayers of 2C13 and 2C15 mixture at various ratios were also studied. As a result, all TL values of 2C14, C13-C15 and an equimolar mixture of 2C13 and 2C15 were almost the same. However, the variation of TL with the molar fraction of 2C15 (X2C15) was remarkably different from that of solid melting point Tm with X2C15.
Mannosylerythritol lipids (MELs) are glycolipid biosurfactants produced by various yeasts belonging to the genus Pseudozyma, which exhibit excellent surface activities as well as versatile biochemical activities. A study on P. tsukubaensis NBRC1940 as a mono-acetylated MEL (MEL-B) producer revealed that the yeast accumulated a novel glycolipid from castor oil at a yield of 22 g/L. Its main chemical structure was identified as 1-O-β-(2′-O-alka(e)noyl-3′-O-hydroxyalka(e)noyl-6′-O-acetyl-D-mannopyranosyl)-D-erythritol designated as “new MEL-B.” The new MEL-B, comprising a hydroxy fatty acid had a reduced surface tension of 28.5 mN/m at a critical micelle concentration (CMC) of 2.2×10–5 M in water. The observed CMC was 5-fold higher than that of conventional MEL-B. When conventional MEL-B was dispersed in water, it self-assembled to form the lamellar (Lα) phase at a wide range of concentrations. In contrast, new MEL-B formed spherical oily droplets similar to the sponge (L3) phase, which is observed in aqueous solutions of di-acetylated MEL (MEL-A). The data suggest that the newly identified MEL-B is likely to have a different structure and interfacial properties compared to the conventional MELs, and could facilitate an increase in the application of glycolipid biosurfactants.
Here we evaluated the inhibitory effects of bergenin analogues (2-10), prepared from naturally occurring bergenin, (1) on β-secretase (BACE1) activity. All the bergenin analogues that were analyzed inhibited BACE1 in a dose-dependent manner. 11-O-protocatechuoylbergenin (5) was the most potent inhibitor, with an IC50 value of 0.6 ± 0.07 μM. The other bergenin analogues, in particular, 11-O-3′,4′-dimethoxybenzoyl)-bergenin (6), 11-O-vanilloylbergenin (7), and 11-O-isovanilloylbergenin (8), inhibited BACE1 activity with IC50 values of <10.0 μM. BACE1 inhibitory activity was influenced by the substituents of the benzoic acid moiety. To the best of our knowledge, this is the first report on the structure-activity relationships (SAR) in the BACE1 inhibitory activities of bergenin analogues. These bergenin analogues may be useful in studying the mechanisms of Alzheimer’s disease.
Several epidemiologic studies have found that magnesium ion (Mg2+) is related to obesity and type 2 diabetes mellitus. However, there have been almost no reports on the effects of a combination of excessive food intake and Mg2+ supplementation on metabolic syndrome and various blood tests values for diabetes mellitus. In this study, we investigated changes in body weight and blood test values for diabetes mellitus of Otsuka Long-Evans Tokushima Fatty (OLETF) rats, a model for human type 2 diabetes mellitus via metabolic syndrome, under conditions of combined excessive food intake and Mg2+ supplementation. The rats received Mg2+ supplementation by drinking magnesium water (Mg2+; 200 mg/l). No significant differences were observed in the levels of food or water intake between OLETF rats drinking purified water (PW) or magnesium water (MW). Type 2 diabetes mellitus with metabolic syndrome developed at 30 weeks of age, and the body weights and plasma insulin levels of OLETF rats at 60 weeks of age were lower than those of normal rats. The plasma glucose (PG) levels in 38-week-old OLETF rats drinking MW were significantly lower than in those of rats drinking PW, while the body weights and the levels of triglycerides (TG) and insulin of 38-week-old MW-drinking OLETF rats were significantly higher than those of their PW-drinking counterparts. On the other hand, the decreases in body weight and insulin levels in 60-week-old OLETF rats were suppressed by MW supplementation. The present study demonstrates that Mg2+ supplementation delays the development of diabetes mellitus in OLETF rats under conditions of excessive food intake. In addition, obesity and high blood TG levels were observed in OLETF rats receiving Mg2+ supplementation in conjunction with excessive food intake.
We wish to report a novel preparation method for Gemsurf analogs as well as dicarboxylic acid - type Gemini surfactant from Diels-Alder adducts of 2-trimethylsilyloxy-1,3-butadiene, in which ozone oxidation is adopted to convert C=C double bond to dicarboxylic acid without any additional oxidant.
Plant growth-promoting fungi (PGPF) are effective biocontrol agents for a number of soil-borne diseases and are known for their ability to trigger induced systemic resistance (ISR). In this study, we investigated the mechanisms triggered by PGPF Fusarium equiseti GF19-1, which is known to increase pathogen resistance in plants, by using GF19-1 spores and the culture filtrate (CF) to treat the roots of Arabidopsis thaliana. Subsequently, the leaves were challenged with Pseudomonas syringae pv tomato DC3000 (Pst) bacteria. Arabidopsis plants treated with GF19-1 spores or the CF elicited ISR against the Pst pathogen, resulting in a restriction of disease severity and suppression of pathogen proliferation. Examination of ISR in various signaling mutants and transgenic plants showed that GF19-1–induced protection was observed in the jasmonate response mutant jar1 and the ethylene response mutant etr1, whereas it was blocked in Arabidopsis plants expressing the NahG transgene or demonstrating a disruption of the NPR1 gene (npr1). Analysis of systemic gene expression revealed that GF19-1 modulates the expression of salicylic acid (SA)-responsive PR-1, PR-2, and PR-5 genes. Moreover, transient accumulation of SA was observed in GF19-1–treated plant, whereas the level was further enhanced after Pst infection of GF19-1–pretreated plants, indicating that accumulation of SA was potentiated when Arabidopsis plants were primed for disease resistance by GF19-1. In conclusion, these findings imply that the induced protective effect conferred by F. equiseti GF19-1 against the leaf pathogen Pst requires responsiveness to an SA-dependent pathway.
Linoleoyl ethanolamide has been showed to serve as a new and additional class of endogenous signaling molecule and exhibited a variety of biological activities in cells and tissues. Herein, we reported an effective method for the synthesis of linoleoyl ethanolamide. Enzymatic and chemical syntheses of linoleoyl ethanolamide were first compared and then reaction conditions were optimized. When the reaction was conducted at 30°C for 1 h by reacting 0.5 mmol methyl linoleate with 5 mmol ethanolamine in the presence of 15 μL, 5.4 mol/L sodium methoxide in methanol as catalyst, 97.2% linoleoyl ethanolamide was produced in the crude reaction mixture without further purification after the removal of excess ethanolamine. Additionally, the reaction can be conducted on a large scale, which resulted in the formation of 95.9% linoleoyl ethanolamide. Compared to previous studies, the amidation reaction between methyl linoleate and ethanolamine with sodium methoxide as catalyst for the synthesis of linoleoyl ethanolamide is more effective and faster. In addition, the reaction is scalable and reaction conditions are mild. This is the first time to use methyl linoleate to synthesize linoleoyl ethanolamide. Commercial linoleoyl ethanolamide is very expensive. However, the scalability and ease for such synthesis make it possible to study the biological and nutritional functions of the cannabinoid-like linoleoyl ethanolamide in animal or human subjects.
Propylsulfonic acid-functionalized mesoporous silica SBA-15 has been synthesized via one-step strategy at 130°C based on the co-condensation of TEOS and MPTMS in the presence of Pluronic 123 polymer and H2O2 in HCl aqueous solution. The synthesized solid exhibited hydrothermal stability in boiling water without significant change in textural properties. The catalytic performance of the synthesized solid was studied in the esterification of oleic acid with methanol. The experimental results revealed that the large mesopore structures of SBA-15-PrSO3H solid synthesized at 130°C could favor a facile access of oleic acid to the acid sites, making the comparable activity to that of phenyl ethyl sulfonic acid functionalized silica and higher than that of dry amberlyst-15.