A study was conducted to investigate the antioxidative behaviour of the crude extracts of pegaga (Centella asiatica) leaves, and limau purut (Citrus hystrix) leaves, peels, and stems in palm olein system and in a linoleic acid model system. The antioxidative capacities of these local plants were then compared to the activity of rosemary and sage, two types of antioxidant commonly found in the market. From the analysis using Oxigen Consumption Method, it was found that among the samples evaluated, pegaga leaves had the longest time to reach the 50% oxygen in the chamber, with 90 min, meaning that this sample had the highest level of antioxidative activity. This was followed by the extracts of limau purut leaves (85 min), peels (60 min), and stems (39 min). The antioxidative activities of these plants, however, were lower than those of rosemary and sage. These commercial antioxidants were found to have 155 and 145 min time, respectively, to reach the 50% oxygen in the chamber. Results from differential scanning calorimetry (DSC) analysis showed that addition of pegaga leaves and limau purut samples to the oil in the system reduced the oxidation as evidenced by longer To of antioxidants-treated samples. Statistical analysis from this study showed that there was no significant difference between To of pegaga leaves and those of rosemary and sage. This meant that the antioxidative activity of pegaga leaves was comparable to the activities of rosemary and sage. The antioxidative activities of limau purut leaves, peels and stems were also much higher than that of control. The finding from this study indicated that all samples used in this study had very good potential to be explored as sources of natural antioxidants.
The fatty acids distribution pattern in triacylglycerols of three medicinal seed oils viz. Ipomea biloba (Convolvulaceae), Argemone mexicana (Papaveraceae) and Holarrhena antidysentrica (Apocynaceae) were determined using pancreatic lipase hydrolysis method. All the three seeds contain a high percentage of unsaturated acids (I. biloba- 52.94%; A. mexicana- 82.68%; H. antidysentrica- 93.15%). I. biloba contains relatively greater amount of saturated acids (47.06%) than other two seeds. The lipolytic data revealed that linoleic acid dominates at 2-position of triacylglycerols whereas the other two seeds i.e. A. mexicana and H. antidysentrica show almost similar pattern of distribution with oleic acid preferentially acylated at 2-position.
In this study, a microemulsion (ME) phase containing silicone oil was prepared, and its detergency was investigated. Decamethyl cyclopentasiloxane (DC), a good solvent for silicone soils, was combined with cosmetic grade alkyl type surfactant, polyoxyethylene (8 mol) glyceryl monoisostearate (PGMI), and ethanol aqueous solution to prepare the ME phase. The relationship between the structure of the surfactant aggregate and detergency of cosmetic soils containing silicone resin was investigated. The ethanol concentration dependence on the solubilization of DC (ME region) was similar to that of typical temperature dependence of hydrocarbon in nonionic surfactant aqueous solution. On the other hand, the solubilization behavior of DC differed from that of polar oil cetyl isooctanoate (CIO), which can be attributed to the miscibility with the alkyl type surfactant and the site for the solubilization in the micelle. Detergency of the cosmetic soils in a series of the ME solution indicated clear improvement with increasing aggregation number of the surfactant. From the results, it was shown that preparation of ME with large aggregation number such as bicontinuous phase containing DC could provide a good solution for cleansing silicone soils.
In this study, bicontinuous microemulsions (D phase) was prepared by mixing decamethyl cyclopentasiloxane (DC), which is a good solvent for silicone soils, with cosmetic grade alkyl type surfactant polyoxyethylene (8 mol) glyceryl monoisostearate (PGMI) and ethanol aqueous solution. In the pseudo ternary phase diagram of DC/PGMI/15% ethanol aqueous solution system, a ME region exists from the water corner to the center of the ternary diagram. The ME solution solubilizes at most 15% of DC. However, by replacing half the amount of DC by a polar oil cetyl isooctanoate (CIO), the ME region extended continuously from the aqueous corner to the oil-rich region (60% DC). Self-diffusion coefficient measurement by using NMR and FF-TEM observation indicated a bicontinuous structure that solubilizes a large amount of oil and water for the oil-water ratios between 3/7-7/3. Detergency of cosmetic soils containing polymeric siloxane in the ME solution showed the highest value between the oil-water ratios of 1/1 and 7/3, where the ME with bicontinuous structure exists. These results show that bicontinuous type ME containing DC provides a good solution for cleansing silicone soils.
The cloud temperature of C12EO8 aqueous solution decreases by solubilizing triglyceride oils (1,2,3-trihexanoylglycerol (THG), 1,2,3-trioctanoylglycerol (TOG) and 1,2,3-tridecanoylglycerol (TDG)). The reduction of cloud temperature is larger with the oil having shorter alkyl chains. In the water/C12EO8 system, a micellar, a hexagonal, a bicontinuous cubic and a lamellar phases are successively formed with increasing surfactant concentration at 25°C. A discontinuous cubic phase is formed by adding TOG to the aqueous C12EO8 system. SAXS measurement was performed on the discontinuous cubic, hexagonal and lamellar phases and molecular parameters such as effective cross sectional area per surfactant molecule, radius of micelle for the discontinuous cubic and the hexagonal phases, half-thickness of bilayer of the lamellar phase were obtained. The changes in the molecular parameters by increasing TOG content suggest that most of the oil molecules are solubilized in the core of surfactant aggregates. Thermal stability of the discontinuous cubic phase increases. The amount of solubilized oil in the discontinuous cubic phase increases by increasing temperature and decreasing oil molecular weight.
The authors established a method for conducting the lactic acid fermentation of potato pulp, an agricultural by-product, by Rhizopus oryzae. Assay of lipid classes in the present study indicated the presence of significant amounts of triacylglycerol and fatty acid esters, an 8:2 mixture of ethyl and methyl esters in fermented potato pulp. Although triacylglycerol was also present as a minor lipid class, no fatty acid ester could be found in raw potato pulp. The principal fatty acids in either lipid were oleic and palmitic acids, the former present only in small amounts in total lipids from raw potato pulp. Triacylglycerol molecular species determined by HPLC in fermented potato pulp was mainly dioleoylpalmitate. γ-Linolenic acid, a major fatty acid in R. oryzae, was found in fatty acid esters, but not in triacylglycerol from fermented potato pulp. Moreover, the fatty acid compositions of triacylglycerol and fatty acid esters in fermented potato pulp differed significantly. The data of the present study should thus be useful for monitoring the extent of lactic acid fermentation. Ester formation would contribute to enhanced palatable of potato pulp.
The lipophilic calixarene 1,3-alternate conformer possessing two (ethoxycarbonyl)methoxy groups 1 exhibits novel extraction behaviors towards alkali metal cations. This compound shows the peak selectivity for K+ as the highest value (95.1%), however, the selectivity among Na+, K+, Rb+, Cs+ is not so large (extraction values: ca. 85±10%) because of the flexible cavity formed by two ester groups. Hence the extraction values would be better explained by “induced-fit-geometry” than by “hole-size selectivity”. The ion-selectivity by the lipophilic calixarene cone conformer possessing four (ethoxycarbonyl)methoxy groups 2 was strongly dependent on ionic size as for the size selectivity exhibited by typical crown ether type ionophores..
New columnar liquid crystals and organogelator with a bitropone core were prepared. The ester derivatives had an enantiotropic hexagonal columnar phase, while the amide derivatives had an enantiotropic rectangular columnar phase and organogelation properties.