Biosurfactants are amphiphilic compounds produced on living surfaces, mostly microbial cell surface or excreted extracellularly and contain hydrophobic and hydrophilic moieties, that reduce surface tension and interfacial tension between individual molecules at the surface and interface respectively. Several biosurfactants have high surface activity and low critical micelle concentration (CMC) and are therefore, promising substitutes for synthetic surfactants. The oils and fats derived from plants are used for the manufacture of biosurfactants. A large amount of wastes are generated by oils and fats industries, residual oils, tallow, marine oils, soapstock, frying oils, cassava flour mill effluent. The use of above industrial fatty waste has great potential for growth and transformation. The agro industrial by product acid, whey, olive oil mill effluent, molasses can also be used for biosurfactant production. Biosurfactants have several advantages over the chemical surfactants such as lower toxicity, higher biodegradability, better environmental compatibility, higher foaming, higher selectivity and specific gravity at extreme temperature, pH and salinity and the ability to be synthesized from renewable feedstock. That’s why the demand of biosurfactants are increasing day by day.

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A simple and accurate method for determining polar compound (PC) content in heat-deteriorated oils was developed, since universal standards are necessary for assessing thermal rancidity in frying oil quality control. At present, the means used for standards differ according to countries. For instance, in Japan the upper limit of acid value (AV) is 2.5 and carbonyl value (CV) is 50, in the United States free fatty acid (FFA) content is less than 2.0%, and in EU countries PC content is below about 25% and smoke point is above 170°C. JOCS official method to determine PC content by column chromatography is complicated and time consuming, and thus in this study JOCS method was modified by TLC-FID, using soybean oil samples prepared under various heating conditions. TLC-FID method with hexane / diethyl ether (87/13 v/v) as developing solvent provided excellent linearity of y=1.02x + 0.53 with correlation coefficient (R²) of 0.9960, where y and x express PC content determined by JOCS and TLC-FID methods, respectively. Thermal rancidity of soybean oil samples heated under different air bubbling conditions was measured with PC content by TLC-FID, AV, CV, and anisidine value. PC content was clearly shown to be reflected in rancidity of sample oils with heating time. Correlation between PC content and AV displayed excellent linearity with correlation coefficient (R²) of 0.9310. The present TLC-FID method determining PC content may thus be concluded an effective means for evaluating the quality of heat-deteriorated oils.

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A ethanol extract from Yellow batai (Peltophorum dasyrachis) showed a suppressive effect on umu gene expression of SOS response in Salmonella typhimurium OY1001/1A2 against the mutagen 2-amino-3,4-dimethylimidazo[4,5-f ]quinoline (MeIQ). The ethanol exract was re-extracted with chloroform, ethylacetate, butanol, and water. A chloroform fraction showed a suppressive effect. Suppressive compound against MeIQ in the chloroform fraction was isolated by SiO₂ column chromatography and identified as surangin C (1) by FABMS, EIMS, and 1 D and 2 D NMR spectroscopy. Surangin C exhibited an inhibition of the SOS-inducing activity of MeIQ in the umu test. Gene expression was suppressed 59.5% at a concentration of 100 μM. The ID₅₀ value (50% inhibition dose) of compound 1 was 67.9 μM. On the other hand, compound 1 showed weak suppressive effects of the SOS-inducing activity on activated MeIQ.

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We are conducting research into the synthesis of bioactive substances that are based on monoterpenoids. As part of this research, here we synthesized a compound that introduced three kinds of pyrones (a)-(c) (which are used for flavor and are known to be problem-free from a safety aspect) into the lateral chain of four types of monoterpenoids (1)-(4), and examined which of these compounds manifest miticidal activities. The results show that, of the functional groups introduced into the lateral chain, the miticidal effect of 4-hydroxy-6-methyl-2-pyrone was especially good. Of the compounds synthesized here, it was possible to clarify that compounds (1b) and (3b) showed miticidal activity.

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In these experiments, the antioxidative activity of urobilinogen, a major fecal pigment-related compound and reduced metabolite of bilirubin, was shown. Urobilinogen was synthesized from commercial bilirubin by reduction, and the structure was confirmed with mass spectroscopy and NMR analyses. The product was identified as i-urobilinogen. The DPPH radical scavenging activity of urobilinogen was higher than other antioxidants (α-tocopherol, bilirubin and β-carotene). Moreover, the formation of hydroperoxides of linoleic acid with 2, 2’-azobis (2, 4- dimethylvaleronitrile) in methanol was suppressed by the addition of synthesized urobilinogen. On the other hand, in the NMR spectrum measurement, we found the signal decrease of a proton from C₁₀ methylene. It was shown that this proton was exchanged with a deutrium of CD₃OD. This methylene can easily release the hydrogen as proton donor. These results suggest that urobilinogen can inhibit the radical chain reaction by trapping free radicals.

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The photocatalytic activity of TiO₂ coated on Al-modified folded mesoporous silica thin films (Al-MSF), TiO₂/Al-MSF and Ti-, Al-MSF, has been investigated by monitoring the decomposition of methylene blue (MB). The TiO₂/Al-MSF and Ti-, Al-MSF were prepared on substrates by two independent procedures, i.e., ion-exchange and sol-gel. The Ti-, Al-MSF was found to exhibit higher reactivity than TiO₂/Al-MSF, while both films showed higher performance than conventional powdered TiO₂. A detailed analysis of the origin of the photocatalytic reactivity for these TiO₂ coated Al-modified mesoporous silica thin films toward the decomposition of MB is presented here.

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