Industrial, medical, and pharmaceutical applications of microcapsules are described. Pressure-sensitive copying paper is a typical example of their indutrial applications while sustained drug release devices are a representative example of their medical and pharmaceutical applications.
Clinical studies on foods containing plant stanol ester repeatedly demonstrate 10-14% reduction in serum LDL-cholesterol. Since plant stanols are the agents responsible for the cholesterol-lowering activity of stanol ester, an analytical method was developed for quantitative and routine analysis of plant stanol content in spreads containing clinically-effective levels of plant stanol ester. Analysis of plant stanols in stanol ester spread is achieved using direct saponification in which stanol ester spread is saponified directly with ethanolic potassium hydroxide without prior separation of the lipid fraction. Plant stanols are then extracted with hexane and derivatized to trimethylsilyl ethers. Plant stanols are analyzed by Gas Chromatography and quantified against cholestanol as the Internal Standard. Analysis of sitostanol, campestanol and total stanol content in spreads supplemented with stanol ester was found to be linear (r2>0.999), accurate (99-102% recovery), precise (RSD<2.0%) and rugged between laboratories. These results demonstrate that the analytical methods for plant stanol detemination are validated for routine quantitative analysis of spreads containing plant stanol ester.
Complexane-type trimeric surfactants of tris(1-carboxyalkyl-2-aminoethyl)amine (3Rntata; n means alkyl chain length, n=6-14) having three alkyl chains and three hydrophilic groups were prepared by the reaction of tris(2-aminoethyl)amine and 2-bromoalkanoic acid and examined for surface activities such as surface tension, emulsification and interfacial tension. Critical micelle concentration (cmc) of 3Rntata shifted to lower concentration with increasing alkyl chain length. The cmcs of 3Rntata with n of 10-14 were lower by about 1-2 orders of magnitude than those of complexane-type monomeric surfactant of 2-aminoalkanoic acid (RnNAc) and dimeric surfactant of N, N″-bis(1-carboxyalkyl)diethylenetriamine (2Rndtda) with the same alkyl groups. In the case of R12, 3Rntata gave about twice cmc of trimeric surfactant of (N1-carboxyalkyl-2-aminoethyl)alkyllamine (3Rntata) having three alkyl chains and two hydrophilic groups. Surface tension at each cmcs of 3R10tata, 3R12tata, and 3R14tata was 33.0, 26.9 and 29.6 mN m-1, respectively. 3R12tata, and 3R14tata gave more efficient in lowering the sufface tension than RnNAc and 2Rndtda. The values of cross-sectional molecular area (A) of 3Rntata with n of 10-14 were 42-75Å2. They were extremely small in comparison with three times of A of RnNAc. The aqueous solutions of 3Rntata were emulsified by shaking with toluene. Highly stable oil-in-water type emulsion was formed by using 3Rntata with n of 10-14 and the degree of emulsification was kept 60% after 20 h. Interface between the aqueous solutions of 3R10tata, 3R12tata, 3R14tata and toluene gave the interfacial tension of 1, 1 and 6 mN m-1, respectively.
The synthesis of a porphyrin dimer with a 2,6-diacylpyridyl group as a recognition site was accomplished by the coupling of 2,6-diaminopyridine and two porphyrins with a 4’-ethoxycarbonylbiphenyl substitutent at a meso -position of the porphyrin ring. By comparing the absorption spectrum of the obtained porphyrin dimer in CH2Cl2 with that of the corresponding porphyrin monomer, no remarkable interaction between two zinc porphyrin units was indicated. 1H NMR studies revealed that hydrogen bonding interactions of the 2,6-diacylpyridyl group in the porphyrin dimer serve to form a novel supramolecular assembly in the presence of naphthalenediimide compound.
Surface tension is difficult to measure with high accuracy. This parameter was measured for pure water to determine conditions that would permit high accuracy. Sources of error in assessing stability, variance, reproducibility and time-dependency of surface tension were sought. The glass syringe, differences in inner and outer temperatures of the cell and its inner pressure, etc. were found to affect this parameter. With attention to these factors, greater accuracy was achieved. Use of a glass syringe and holder with exact control of temperature led to maximum elimination of error. The surface tension of pure water, surfactant solutions and volatile organic liquids were measured and compared with previous values. There was less variation and the results were much more reproducible. High accuracy is thus possible with elimination of sources of error. Significant interfacial phenomena such as phase transition in adsorbed film, not observed by usual surface tension measurement apparatus, may thus be effectively studied through use of surface tension obtained with the present apparatus.
Sterol content in tartary buckwheat (Fagopyrum tataricum Gaertner) achenes (N=3) and common buckwheat (Fagopyrum esculentum Moench) achenes (n=11) were examined by GC-MS. All cultivars were found to have essentially the same major sterol content (campesterol, stigmasterol, sitosterol and isofucosterol) and regional variation was small for either achene. Sitosterol was most abundant at 70%∼80% of bulk sterols and other bulk sterols in the achenes were campesterol,stigmasterol and isofucosterol. Trace amount of sterols were present in each achene. Besides four major sterols, 13 sterols from an ester and 9 free sterols were detected in tartary buckwheat. 9 sterols from an ester and 11 free sterols were confirmed present in common buckwheat. Bulk sterol content in both ‘free’ and ‘bound’ lipids of achenes, leaves and stems of plants was determined by GC. Sterol content on tartary buckwheat achene was 82.5 mg/100 g achene (average, n=3), while that of common buckwheat achene 100.2 mg/100 g achene (average, n=3). Sterol content of leaves was twice as much and that in stems, basically the same as in the achenes. Sterol content was found here for the first time to be high not only in ‘free lipid’, but ‘bound lipid’ as well of leaves and stems of buckwheat.
The authors first synthesized 4-alkylated caprolactones (4ACLs) from 4-alkyl-cyclohexanones via Baeyer-Villiger reaction. The 4ACLs obtained from 4-methyl-, 4-ethyl, and 4-t -butylcyclohexanone were abbreviated as 4MCL, 4ECL, and 4BCL, respectively. Copolymers of L-lactide (L-LA) with 4ACL or ε-caprolactone (CL) and homopolymers of the monomers were prepared using tin (II) octylate as catalyst. Thermal and NMR analyses of the polymers indicated poly(L-LA) and poly)CL) to be crystalline, while poly(4ACLs) to be noncrystalline polymers, and L-LA/4ACL copolymers to be crystalline or noncrystalline polymers depending on compositon and to have random sequences. Flexibility (elongation at break) of the copolymers was much improved compared to poly(L-LA), with melting temperature and mechanical properties of poly(L-LA) maintained as much as possible. The biodegradability of the polymers by enzymes (Proteinase K, lipoprotein lipase) and in seawater was examined. Enzymatic degradation of copolymers followed the order, copoly(L-LA/CL)>copoly(L-LA/4MCL)>copoly(L-LA/4ECL)>copoly(L-LA/4BCL), suggesting that the greater steric hindrance of alkyl side chains of 4ACL, the less was degradability. 1H NMR spectra of water-soluble degraded products of L-LA/4MCL copolymer indicated that Proteinase K ultimately degraded the copolymer into hydroxy acids (viz., L-lactic acid and 6-hydroxy-4-methylcaproic acid) of its constitutive units.
Determination was made of sterol content in wheat flour. Based on direct GC-MS comparison with authentic samples and mass spectral data, fifteen 4-desmethylsterols, four 4-monomethylsterols and two 4,4-dimethylsterols, were confirmed present in the flour, along with three terpene alcohols, and the amount of each was computed. The content of each of five major 4-desmethylsterols (campesterol, campestanol, stigmasterol, sitosterol and sitostanol) in the flour and wheat seeds was determined by GC.
This paper presents a method for the industrial preparation of 5-substituted furfurals, potential as agricultural chemicals, dehydrating saccharides with hydrochloric acid in the presence or catalytic amounts of surface active agents.