Esterolytic enzymes such as lipase or esterase are widely used for fat reforming and drug synthesis. An esterase that degrades polyester polyurethane, a solid synthetic highpolymer, was purified from a bacterium. This novel enzyme (PUR esterase) has a special mechanism for degrading a solid substrate. PUR esterase has a hydrophobic PUR surface-binding domain and catalytic domain, the former possibly essential for PUR degradation. The structural gene, pudA, for PUR esterase has been cloned and the highest degree of homology detected was with the Torpedo californica acetylcholinesterase (T AChE). Comparison of the secondary structure motifs of the two enzymes indicated a strong conformational resemblance between PUR esterase and T AChE, except for three hydrophobic regions considered to make up the PUR binding domain. This novel esterase should find important applications.

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Neutral glycosphingolipids were extracted from the marine annelid, Pseudopotamilla occelata and separated into five fractions (CMS₁, CMS₂, CDS₁, CDS₂ and CTS) by their modes of column chromatography, ion exchange Sephadex (QAE-Sephadex), magnesium silicate (Florisil) and silicic acid (Iatrobeads). The chemical structures of the glycolipids in each fraction were determined by compositional analysis, methylation analysis, exoglycosidase cleavage, gas-liquid chromatography, gas chromatograph-mass spectrometry and matrix-assisted laser desorption ionization time-of-flight mass spectrometry, by which sugar, sphingoid and fatty acid compositions were clarified. Based on the results, their structures were proposed as Glcβ1-1ceramide and Galβ1-1ceramide (1.00 : 0.16) for CMS1, Glcβ 1-1ceramide for CMS₂, Galα 1-4Galβ 1-1ceramide for CDS₁, Ga1β 1-4G1cβ1-1ceramide for CDS₂, and GlcNAcβ 1-3Galβ 1-4Glcβ 1-1ceramide for CTS. In the aliphatic moiety, the sphingoid component of all glycolipids was found to consist solely of octadeca-4-sphingenine. The fatty acid components of CMS₁ and CDS₁, or CDS₂ and CTS were quite similar, consisting mainly of 16 : 0-, 17 : 0- and 18 : 0-acids, or 20 : 1- and 22 : 1-acids. The fatty acid components of CMS2 differed markedly from those of other glycolipids, and consisted primarily of 2-hydroxy 16 : 0-, 17 : 0- and 18 : 0-acids.
Thin-layer chromatography and the results of sugar analysis indicated the presence of new glycolipids, penta- and hexaglycosylceramides possessing fucose, xylose and 2- (ο-methyl) galactose as additional sugar components. No glycosphingolipid component corresponding to tetraglycosylceramide could be detected by the present analyses.

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Di-and triglycerol fatty acid esters were studied so as to make clarification of enzymatic synthesis, surface activity, detergency, antimicrobial properties and biodegradability. All samples were prepared by transesterification reaction of di-and triglycerol with fatty acid methyl ester using lipase between 50 and 85°C under reduced pressure. Transesterification reactions by lipase depended on enzyme origin, reaction pressure and type of acyl donor, such as free acid, acid anhydride, methyl and vinyl esters. Di-and triglycerol fatty acid monoesters were found to have excellent surface activity in aqueous solution. Diglycerol monododecanoate produced very stable foam compared to conventional nonionics, such as polyoxyethylene alkyl ethers and alkyl β-glucosides. Di-and triglycerol monododecanoate showed the same detergency as that of conventional ether-type nonionics. Diglycerol monododecanoate exhibited antimicrobial activity essentially the same as dodecyl β-D-glucoside. The di-and triglycerol fatty acid esters all readily underwent biodegradation by activated sludge.

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Comparative study is effective for clarifying differences in animal species in regard to the physiological functions of glycosphingolipid. Determination was thus made of the molecular structure of CMH present at high concentrations in the brain of sardines by GLC analysis for comparison with CSE in the brain and CMH in the liver.
CMH content in the brain of sardines is lower than in that of mammals. There is species specificity in this regard. The principal fatty acid of CMH and CSE have carbon chains of 24. There is no difference between sardines and mammals. The unsaturation of constituting fatty acids of CSE and CMH in the brain is higher than in mammals (72.4% vs. 67.5%). Contrary to brain, fatty acids of CMH in the liver indicates low degree of the unsaturation and high ratio of the hydroxy fatty acid (88.9%). There is organ specificity in this regard. The sugars of CSE and CMH in the brain were mostly galactose, suggesting galactose to be more important for all animal species. In CMH in the liver, glucose was present at 26.2%. Long chain bases were comprised mainly of sphingosine (the order of 70%) like mammals.

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Membrane extrusion vesicles were prepared from egg yolk lecithin (egg PC) and a mixture of egg PC+dimyristoylphosphatidylglycerol (molar ratio=67 : 1 or 27 : 1). Zeta potential of the vesicles was measured with an electrophoretic light-scattering photometer as functions of pH and ionic strength of the dispersion medium. At neutral pH, zeta potential of all samples was negative, but increased with decrease in pH and becoming positive at acidic pH (<pH 3) suggesting protonation of the phosphate group of egg PC molecules. Flocculation and colloidal stability of the vesicles were assessed based on turbidity and visual observation, respectively, and the results were interpreted by the DLVO theory. Semi-quantitative agreement between this theory and the results was confirmed for flocculation, whereas the theory did not provide adequate explanation for the pH and ionic strength dependence of egg PC vesicle dispersion stability.

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An aqueous solution of a hybrid anionic surfactant containing a fluorocarbon chain and a hydrocarbon chain in a molecule, C₆F₁₃C₆H₄COCH (SO₃Na) C₄H₉ (F6H4), shows extremely high viscosity at a condition of 30-40°C and 10 wt%. In order to elucidate the influence of the fluorocarbon chain on the high viscosity, new hydrocarbon surfactants, C_mH_2m+1C₆H₄-COCH (SO₃Na) C_nH_2n+1 (H_mH_n), in which the fluorocarbon chain in the hybrid surfactants is substituted to a hydrocarbon chain, have been synthesized. The intermediates 1- (4-alkylphenyl) -1-alkanones were prepared from the reaction of alkylbenzenes with corresponding alkanoyl chlorides in the presence of aluminum chloride. The compounds, H_mH_n, were obtained from the reaction of the alkanones with a sulfur trioxide : 1, 4-dioxane complex, followed by neutralization with aqueous sodium hydroxide. The aqueous solutions of these new surfactants indicated higher surface tension and cmc, in comparison with those of the hybrid surfactants. The aqueous solutions of H_mH_n did not show particular viscosity, which was observed in the case of F6H4.

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Examination was made of changes in the properties of N-Lauroyl-L-glutamate (LGA) with neutralization. Foaming power was maximum at neutralization of 1.6, and emulsification capacity decreased with neutralization. ¹³C-NMR indicated α-carboxylic acid of LGA to be neutralized predominantly, and γ-carboxylic acid to be so in proportion to neutralization at 1.6. Fluorescence probe application showed micropolarity and aggregation number of micelles to increase rapidly at neutralization of 1.6. α-carboxylic acid of LGA would thus appear to contribute to interactions between LGA molecules.

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In order to utilize sarcotestae of Ginkgo biloba for medical purposes, their flavonoids and terpenoids were qualitatively and quantitatively analyzed. Flavonols such as kaempferol, quercetin and isorhamnetin present in leaves could not be detected in sarcotestae while anthocyanidins of delphinidin and cyanidin were found. Sarcotestae were noted to contain small amounts of ginkgolides A, B and C as terpenoids, as did also the leaves. The composition of ginkgolides in sarcotestae were varied during maturation whereas quantity of anthocyanidins was independent on harvest season.

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