The surface activities of mixed surfactants of partially-quaternized 2-vinylpyridine telomers (xRn-2VPQ, x is the total number of alkyl chains, n is the alkyl chain length) and monomeric alkyltrimethylammonium bromide (1RnQ) or gemini 1, 2-bis (alkyldimethylammonio) ethane dibromide (2RnenQ) were investigated at pH 2 by surface tension, foaming property, interfacial tension and emulsification power. The mixed critical micelle concentrations (cmcs) were intermediate between the pure component xRn-2VPQ and 1RnQ or 2RnenQ. xRn-2VPQ/2RnenQ system was higher efficiencies in lowering the surface tension than xRn-2VPQ/1RnQ. The surface tension was influenced by the alkyl chain length of binary surfactants and the mole fraction (α) of xRn-2VPQ. In particular, 2.0R10-2VPQ/2R10enQ system with α = 0.50 showed the lowest surface tension. The mixtures of two cationic multialkylated surfactants improved the foaming properties as compared with the pure component cationic surfactants. The similar trends in the surface tension and the foaming properties were observed for the lowering abilities of the interfacial tension at the water / toluene interface and emulsion stabilities.
Telomerization of N-alkyl maleamic acid monomer (RnMaAm, n is the alkyl chain length; n=6-14), which was synthesized by reaction of maleic anhydride with alkylamine, in the presence of alkanethiol as a chain transfer agent gave the telomers (xRnMaAm, x is total number of alkyl chains; x=2.9-3.2) in 60-90% yields. The surface-active properties such as surface tension, foaming property and emulsion stability were examined in water as well as in hard water containing 300 ppm of Ca2+. The critical micelle concentrations (cmcs) of 2.9-3.2RnMaAm telomers were 1/142-1/42 of those of RnMaAm monomers with the same alkyl chain length. The surface tensions of aqueous solutions of RnMaAm monomers and 2.9-3.2RnMaAm telomers were 30-35 and 24-32 mN m-1, respectively. The addition of Ca2+ to the aqueous solutions of 2.9-3.2RnMaAm lowered the cmc, while gave a low efficiency at reducing the surface tension. Of the telomers, 3.0R12MaAm gave the highest foaming ability and the highest foam stability in water. Shaking of the mixtures of organic solvent and the aqueous solutions of xRnMaAm telomers formed oil-in-water type emulsions. The emulsion stabilities were in the orders of toluene > n-octane > n-dodecane > n-hexadecane > kerosene as an oil phase. The highly emulsions for toluene or n-dodecane were formed by using 3.0R8MaAm and 3.0R10MaAm. The aqueous solutions of RnMaAm monomers and 2.9-3.2RnMaAm telomers gave interfacial tension of 8-10 and 4-6 mN m-1, respectively, for the interface with toluene. Thus, N-alkyl maleamic acid telomer type anionic surfactants having several alkyl chains showed greater surface activities than the corresponding monomeric monomers as well as the conventional surfactants.
Solubilizations of methanol and ethanol in crude palm oil (CPO) and red palm oil (RPO) were studied by using different hydrocarbon chain-length alkanols (C4-C12) as solubilizers. Ternary phase diagrams of oil/methanol/alkanol and oil/ethanol/alkanol were constructed to determine the solubilization (isotropic) region. Results showed that the solubilization of methanol and ethanol is more favourable in unsaturated RPO than in saturated CPO in the presence of long-chain alkanols. The relatively large isotropic regions were formed with long-chain alkanols in both the methanol and ethanol systems. The order of decreasing isotropic regions in both methanol and ethanol systems was dodecanol > decanol > octanol > octan-2-ol > hexanol > pentanol > butanol > t-butanol. The branched chain alkanols and mixed oleyl alcohol/alkanol do not promote solubilization. Cold-stability test has shown all isotropic solutions were stable at 24°C for both methanol and ethanol systems. Kinematic viscosity of the selected isotropic solutions increased with the increase in both the chain length and percentage of alkanols. Long-chain alkanols (dodecanol, decanol and octanol) showed a steady increased in kinematic viscosity with increasing alkanol content. Solubilization of RPO/methanol/mediumchain alkanols (butanol, pentanol and hexanol) systems significantly reduced the kinematic viscosity of RPO from 43.7 mm2s-1 to the range allowable for No.2 diesel fuel (1.9-4.1 mm2s-1 at 40.0°C).
It is known that high levels of apolipoprotein B100 (apoB100) and lipids in the serum are risk factors for atherosclerosis. In the present study, we evaluated the effects of four sulfur-containing amino compounds, S-propyl-cysteine sulfoxide, DL-methionine sulfoxide, S-carboxymethyl cysteine, and S-carboxyethyl cysteine, found in Allium species on lipid metabolism and apoB100 secretion in human liver model cells, HepG2. Both S-propyl-cysteine Sulfoxide and DL-methionine sulfoxide inhibited apoB100 secretion into the medium in vitro and reduced the secretion of newly synthesized triacylglycerol (TAG) and cholesterol without affecting cellular lipid synthesis from [14C]acetate. S-Carboxymethyl cysteine and S-carboxyethyl cysteine also reduced the secretion of newly synthesized TAG and cholesterol into the medium. A correlation between the hypolipidemic activity and the length of alkyl chain bound to cysteine was observed. These compounds had no effect on MTT activity and intracellular protein concentration compared with the untreated cells. These results suggest that sulfur-containing amino compounds in onion and garlic reduce the secretion of apoB100, TAG and cholesterol in human liver model cells, by inhibiting apoB100-containing lipoprotein assembly and secretion. Thus, these components of Allium species may be beneficial to reduce risk factors for atherosclerosis.
α-Methylene-γ-alkylbutyrolactones were synthesized by usual method and assessed for antibacterial activity against Bacillus subtilis and Escherichia coli. Using substituent constants (π) of the compounds, regression analysis was made on the effect of alkyl side chains of the methylenelactones. The correlation coefficient (r) between observed and calculated minimum inhibitory concentration (MIC) expressed in molar concentration as log(1/C) was 0.739 and 0.725 for B. subtilis and for E. coli, respectively. On using steric parameter of E’s, r was up to 0.894 and 0.884 for B. subtilis and E. coli, respectively. Consideration of π derived from the smallest MIC, α-methylene-γ-nonalactone 6 or α-methylene-γ-decanolactone 7 suggested the strongest antibacterial activity.
α-Methylenecamphor and α-methyleneisophorone derivatives were synthesized and their antibacterial activity on Escherichia coli was examined. α-Methylenated camphor and isophorone derivatives showed stronger antibacterial activity than the compounds before α-methylenation, as anticipated. Data of the electronic parameters of the absolute electronegativity (χ), the quantity of electron transfer (ΔΝ) and the stabilization energy (ΔΕ) with cysteine strongly supported this finding.
α-Methylene-γ(β)-carboxy-γ-butyrolactones (5 and 10) are considered to have strong antibacterial activity owing to large absolute electronegativity (χ), electron transfer(ΔΝ) and stabilization energy(ΔΕ) compared to potent cyclopentanone antibiotics. α-Methylene-γ-carboxy-γ-butyrolactone(5) was synthesized starting from L-glutamic acid and α-methylene-β-carboxy-γ-butyrolactone (α-methylene paraconic acid 10) was obtained via ethyl α-formylsuccinate(6) or hydroxymethylation of ethyl α-carbethoxysuccinate(11). α-Methylenationed 5 and 10 showed no strong antibacterial activity as we expected formerly.
Examination was made of the conditions for the extraction, critical micelle concentration (cmc) and detergency of saponin from plants. Extraction volume was maximum at 100°C over a period of 1∼3 hours. To control saponin concentration, cmc of this compound had to be determined by the conductivity method. The detergency of standard soybean saponin was maximum at 1.2 times cmc, pH10.0 for 30 minutes at 40°C. Extraction exceeded that of the model detergent by 70%. The extraction of saponin from adenophora, mandarin orange, adzuki bean, soybean was 40% in each case.
Antibacterial activity of 17 cinnamic acid related compounds against Bacillus subtilis and Escherichia coli was investigated to elucidate the structure responsible for the activity. Absolute hardness (η) was well correlated with minimum inhibitory concentration (MIC) expressed in logarithum. The correlation coefficient (r) between log (MIC) and η was 0.944 for B.subtilis and 0.932 for E.coli. Considering η and structure, the compound having the substituted phenyl group in propiolic aldehyde or its ester form should possess the strongest antibacterial activity.
Deep-frying oil properties of diacylglycerol-rich cooking oil (DG oil) were examined so as to assess the extent of thermally oxidative deterioration. The results obtained were compared with those for triacylglycerol-rich oil (TG oil). Autoxidation of DG oil at 50°C was much slower compared to TG oil. The viscosity of DG oil exceeded that of TG oil and both these parameters increased with the heating of either oil. Acid value (AV) of fresh DG oil (0.49) was higher than that of TG oil (0.11). AV, carbonyl and p-anisidin values of DG and TG oil increased with the number of uses. It follows from the present findings that the thermal oxidation of DG oil during deep-frying is basically the same as that of TG oil.