Radical polymerization was performed of acrylonitrile solubilized in admicelles of sodium dodecylsulfate (SDS), an anionic surfactant, formed on a mica substrate in aqueous solution. An attempt was then made to prepare thin carbon film by stabilizing the polyacrylonitrile film thus formed as precursor and carbonizing it and the surface structure of the sample was observed with an atomic force microscope (AFM) after each of the treating processes. The sample surface after polymerization consisted of layers, each being a smooth ultrathin film at the nanometer level. The acrylonitrile film shrank to form a granular structure on the mica surface after stabilization and the granules aggregated after carbonization. Contact angle measurements on the sample surfcce that untreated mica substrate has a hydrophilic surface, which turns hydrophobic after polymerization and the surface hydrophobicity increases as the treating process proceeds further to stabilization and carbonization.
Thermodynamic properties such as melting point, enthalpy of fusion, and heat capacity for 5-cholesten-3β-ol (I), 5α-cholestan-3β-ol (II), and 5β-cholestan-3α-ol (III) were studied. The values of the melting point and the enthalpy of fusion for I were slightly larger than those for II, whereas the values for III were smaller than those for I and II. The heat capacity for I was to some extent larger than that for II or III in solid and even in liquid states. II is similar to I in the overall skeletal structure and in the direction of the OH moiety linking directly to the steroid ring. In addition, the X-ray powder diffraction pattern for II resembled that for I, whereas the pattern for III differed from that for I. The phase diagram for I/II mixture indicated that the I and II molecules are phase-separated in the solid state and give a eutectic mixture. The phase diagram results connecting with the data for the melting point, the enthalpy of fusion, and the heat capacity suggest that the cohesive force of I is stronger than that of II in spite of the similarity of I to II in the molecular and stacking structures. On the other hand, the phase diagrams of I/III and II/III mixtures indicated that I and III molecules and II and III molecules, whose OH moieties are in opposite directions to each other, made a strong 1 : 1 compound.
In the present study, we have investigated the effects on body fat of α-linolenic acid-rich diacylglycerol (ALA-DAG), which is a combination of the 1,3-DAG structure and n-3 fatty acid. C57BL/6J mice were fed diets of high fat and sucrose (30 wt %, 13 wt %, respectively, HF group) without or with ALA-DAG added to 1,2,4 wt % for 4 weeks. We noted significant gains in body weight and visceral fat in the mice in the HF group as compared to a group fed an ordinary diet containing 5 wt % fat (LF group). Addition of ALA-DAG resulted in a significant restraint of both body weight and visceral fat weight gain. Furthermore, addition of ALA-DAG to 2wt% and 4wt% significantly reduced the plasma leptin level. When high fat and sucrose diet was continued for 20 weeks, leptin and insulin levels significantly increased as compared to the LF group in addition to the body weight and body fat gains. By replacing 3 wt% of the lipid in the high fat and sucrose diet with 3 wt% of ALA-DAG, leptin and insulin concentrations significantly decreased in addition to body weight and visceral fat loss. These results indicate the anti-obesity function of ALA-DAG, and also suggest the effectiveness of using ALA-DAG in the prevention and treatment of life-style related diseases in which obesity is a risk factor.
Obesity is a metabolic disorder due to less energy expenditure than its uptake and is a strong risk factor for non-insulin-dependent diabetes mellitus (NIDDM), hypertension and atherosclerosis. The present study examines the effects of long-term feeding of tea catechins on body weight, fat accumulation, and mRNA of genes involved in β-oxidation in obesity-prone C57BL/6J mice. Four months high fat diet (30% TG+13% sucrose) administration significantly increased body weight, epididymal fat accumulation and circulating leptin compared to the control diet mice (5% TG). High fat feeding-induced body weight gain and epididymal fat weight were reduced by 81% and 63%, respectively, in mice fed the catechin diet (30% TG+13% sucrose+0.5% tea catechins). Circulating leptin was reduced by 68%. Compared with the high fat diet group, catechin-feeding up-regulated medium-chain acyl-CoA dehydrogenase mRNA expression in the liver, suggesting tea catechins to possibly stimulate lipid metabolism in the liver. Long-term feeding of tea catechins is thus shown beneficial for suppressing high fat diet-induced body fat accumulation. The stimulation of lipid metabolism in the liver may possibly be a factor for the anti-obesity effects of tea catechins in mice.
The body fat reducing effect of tea catechins was previously confirmed in humans. The effects of tea catechins for reducing body fat were thus studied as basis for actual application. Three experiments on healthy male adults (n=82) were conducted to determine the effects of long-term tea catechins administration on body fat and biochemical blood parameters. First experiment: tea catechins were given as oolong tea-like beverage for 12 weeks. In 600 and 900 mg groups, visceral fat was significantly loss than in the control (600 mg group p=0.0317, 900 mg group p=0.0098). The effects were more pronounced at greater of tea catechins administration. No significant changes in biochemical blood parameters including fat-soluble vitamins were detected. Second experiment : oolong tea-like beverage containing tea catechins at nearly same amounts on in the 600 mg group was given for 20 weeks. Abdominal fat, including visceral fat, was significantly loss than in the control (total fat area p<0.0001, visceral fat area p=0.0004, subcutaneous fat area p=0.0001). Plasma PAI-1 was also significantly decreased (p=0.0080). Third experiment : green tea-like (GT group) and oolong tea-like (OT group) beverages containing approximately 540 mg tea catechins were given for 12 weeks. In the two groups, visceral fat was significantly loss than in the control (GT group p=0.0284, OT group p=0.0095) and the effects of two beverages were similar. Long-term tea catechins administration at 500 to 600 mg/day in humans would thus appear to reduce body fat without influencing fat-soluble vitamins, of which the absorption may be inhibited, and various serum and plasma indices regardless of the kind of beverages.
The distribution of docosahexaenoic (22:6n-3; DHA) and icosapentaenoic (20:5n-3; EPA) acids in phosphatidylcholine (PC) and/or phosphatidylethanolamine (PE) from different tissues of two species of squids, spear squid Loligo bleekeri and Pacific flying squid Todarodes pacificus, was studied. Mantles, fins, arms, and integuments of squid and liver of the former species contained small amounts of lipid (TL: 1.8-4.3% of wet weight) comprised almost entirely of PC (47.9-67.0%), sterols (14.2-32.7%), and PE (12.2-15.7%). Liver of the latter species contained copious amounts of TL (36.2%) with higher triacylglycerols (97.0%). In PC and PE from squid tissue, DHA (24.7-37.6% for PC and 7.4-25.0% for PE), EPA (6.3-18.4% and 18.9-38.8%, respectively) and palmitic acid (28.6-44.0% and 11.0-22.5%, respectively) were characteristically present. In squid tissue, except the liver, component fatty acids at sn-position 2 of PC and PE were polyunsaturated for the most part with the predominant component of DHA (71.3-78.7% for PC and 17.1-45.3% for PE) and EPA (10.9-14.4% and 37.2-58.0%, respectively). These acids at sn-position 1 of PC and PE were more saturated with palmitic (66.4-72.9% for PC and 15.9-41.6% for PE) and stearic (4.2-6.9% and 9.8-30.0%, respectively) acids. LysoPC, enriched with DHA (66.1%) and EPA (11.1%), was obtained from squid tissue PC (DHA: 36.4%, EPA: 6.7%) by Lipase M10 hydrolysis.
This study was conducted to investigate the effects of dietary diacylglycerol rich in α-linolenic acid (ALA-DAG) on body fat in human. The ALA-DAG contained 49% α-linolenic acid and was prepared from linseed oil using immobilized lipase. This study consisted of two types of dietary restriction and two types of diet. In test 1, 2.5-3.7g ALA-DAG was ingested as an edible oil under restriction of the amount of oil intake (50±5 g/d) for 12w (66 subjects). In tests 2 and 3, 2.5g ALA-DAG was ingested as a drink for 16w under calorie intake restriction determined based on subject’s calorie requirements (48 and 30 subjects, respectively). In all tests, after a 4 week control-diet period, the subjects started the diet and every 4 weeks during the test period, blood tests for fat metabolism were carried out and body indices (weight, waist, skinfold thickness, body fat computed with tomography) were measured. In subjects ingesting diets containing 2.5 g of ALA-DAG (test 1, 2 and 3), a significant decrease (-6.3∼-13.4%) of body fat area was observed. It was suggested that ALA-DAG had two characters of diacylglycerol and n-3 polyunsaturated fatty acid because of the high effectiveness of a small dose. These results showed that ALA-DAG improved fat metabolism and reduced body fat, and we speculate that ALA-DAG may be useful to reduce the risk of diseases associated with obesity.
It is well established that the n-3 polyunsaturated fatty acids influence lipid metabolism and reduce the serum triacylglycerol level. We previously reported that a dietary diacylglycerol rich in α-linolenic acid (ALA-DAG) significantly reduced body fat. In this study, we investigated the effects of the ingestion of ALA-DAG (2 g/day) for 12 weeks on body fat (test 1), lipid metabolism after ingestion for 6 weeks (test 2), and resting metabolism after ingestion for 6 weeks (test 3). The visceral fat area determined by computed tomography decreased significantly (11.3%, p<0.05) in test 1. The triacylglycerol level in VLDL fraction of serum decreased significantly (12.7%, p<0.05) in test 2 and the resting metabolism calculated from oxygen consumption increased significantly (17.3%, p<0.05) in test 3. These results suggested that ALA-DAG reduced visceral fat via the suppression of triacylglycerol synthesis and the enhanced oxidation of fatty acids in the human body.
It is known that seed lipid from bitter gourd (Momordic charantia) contains more than 50% 9cis(c), 11trans(t), 13t-18:3 as conjugated linolenic acids (CLN). This study showed that a small but distinct amount of CLN was also found in flesh of bitter gourd, indicating the possibility of CLN intake through eating bitter gourd. The CLN isomer of lipid from bitter gourd flesh was not 9c, 11t, 13t-18:3, but 9t, 11t, 13c-18:3. A high performance liquid chromatographic method was also described for the separation of CLN isomers. The simultaneous detection and identification of the separated geometrical CLN isomers on a C18 or C30 reversed-phase column was accomplished by photodiode array detection.
The authors previously conducted the synthesis of macrocyclic lactones, unstaturated macrocyclic lactones and macrocyclic ketones consisting of various numbers of carbons by photocyclization. Photocyclization of precursor [A] obtained in that study was carried also in this work for the synthesis of macrocyclic oxalactone having the same scent as musk perfume. [A] was obtained in 4 steps from 1,6-hexanediol. A new method for the synthesis macrocyclic oxalactone is proposed.