Fatty acids in femaleMacracanthorhynchus hirudinaceus (Acanthocephala)

Neutral lipids and phospholipids in the body wall, lemnisci and pseudocoel and neutral lipids of fluid found in the “tube” system of the lemnisci and the lacunar system of the body wall ofMacracanthorhynchus hirudinaceus (Acanthocephala) were determined by the technique of thin layer chromtography and gas chromatography (GC). Sixteen different fatty acids from nonpolar lipids were identified as follows: 8∶0, 10∶0, 11∶0, 12∶0, 13∶0, 14∶0, 14∶1, 16∶0, 18∶0, 18∶1, 18∶2 and/or 20∶0, 18∶3 and/or 20∶1, 20∶3, 22∶1, 24∶1 and 22∶6. In addition, there were three unidentified GC peaks corresponding to chain lengths greater than 20 carbons. Sixteen different fatty acids from phospholipids were identified in each of the three fractions analyzed. They were as follows: 10∶0, 11∶0, 12∶0, 13∶0, 14∶0, 14∶1, 16∶0, 16∶1, 18∶0, 18∶1, 18∶2 and/or 20∶0, 20∶2, 20∶3, 22∶1, 24∶1, and 22∶6. Four unidentified peaks were also observed. There was a significant difference in the percentage of lipid as well as the concentration of particular fatty acids when each fraction was compared. There was also an abundant supply of sterols and glycerides in each fraction.     

Wax esters in fish: Turnover of oleic acid in wax esters and triglycerides of gouramis

Methyl U-¹⁴C oleate was fed to mature male and female gouramis (Trichogaster cosby) and the radioactivity in lipids measured over a period of four months. Initial incorporations were 70–80% and more than half of that was still in the lipids at the end of the experiment. Very little conversion of the 18∶1 chain had occurred. Main storage of the labeled 18∶1 chain was in the wax esters of the roe and in the triglycerides of the body. In the wax esters, 18∶1 occurred in both the alcohol and acid moieties. Initially the females had less radioactivity in the triglycerides than in the wax esters but at the end of the experiment this was reversed. An appreciable amount of 18∶1 had been transferred from roe to body lipids. The biological half life of 18∶1 in gouramis is estimated to be about four months. This time is equal for males and females although translocation from roe to body and transformation of wax ester to triglyceride take place in the female, whereas wax esters do not play any role in the lipid metabolism of the male.     

固定化脂肪酶催化菜籽油合成蜡酯

以菜籽油、鲸蜡醇为原料,采用实验室自制的固定化Candidia sp.99-125脂肪酶分别在有机溶剂和无溶剂体系下合成了蜡酯,在两种体系下对影响蜡酯合成的各种因素进行了比较研究,研究表明:以正己烷为反应介质,在40℃条件下反应12h,油醇摩尔比1∶2,酶量15%(质量分数,上同),水含量7.5%,蜡酯产率可达85.87%;无溶剂体系中在50℃条件下反应20h,油醇摩尔比1∶1.5,蜡酯产率可达80.68%。通过流加鲸蜡醇可以提高酶的使用寿命。     

Wax esters and triglycerides as storage substances in seeds of Buxus sempervirens

The seeds of the evergreen Buxus‐tree, Buxus sempervirens, contain a yellowish oil which represents up to 42% of the dry weight. The oil consists, in comparison to the lipids of jojoba fruits (Simmondsia chinensis), of only 3.6% wax esters. 95% of the oil consist of triglycerides, the typical storage substances of oil fruits. Phospholipids occur with 0.4% and glycolipids with 0.13%. The fatty acid patterns of these lipids correspond to the typical fatty acid compositions of the respective lipid classes. In the wax esters monoenoic fatty acids and saturated fatty acids with 16 and 18 carbon atoms prevail. The glycolipid and phospholipid fractions are characterized by a high portion of dienoic and monoenoic as well as saturated fatty acids having 16 and 18 carbon acids.     

Metabolism of long-chain fatty acids,alcohols and alkylglycerols in the fish parasiteParatenuisentis ambiguus (Acanthocephala)

Specific differences between the acyl composition of lipids on the helminthParatenuisentis ambiguus and its host eel, as shown previously, prompted us to study the lipid metabolism in this intestinal fish parasite. Adults and larvae ofP. ambiguus were fed various lipid precursors, e.g., fatty acids, long-chain alcohols and 1-O-alkylglycerols, which may occur as common nutrients of intestinal parasites. Incorporation of [1-¹⁴C]palmitic acid into neutral and polar lipids was found to be similar under aerobic and near-anaerobic conditions. In adult parasites maintained in culture medium supplemented with glucose, [1-¹⁴C]palmitic acid was incorporated mainly into triacylglycerols and phosphatidylcholines, whereas [1-¹⁴C]oleic acid was incorporated preferentially into triacylglycerols. In fasted adults, as well as in larvae, [1-¹⁴C]oleic acid was mainly transferred to phosphatidylcholines. Lipolytic activity was detected in adult parasites that had been incubated with radioactive trioleoylglycerol. [1-¹⁴C]Hexadecan-1-ol was oxidized inP. ambiguus at a high rate to labeled palmitic acid, which was incorporated into various lipid classes ofP. ambiguus. Small but significant proportions of radioactivity from hexadecan-1-ol were incorporated into ether glycerolipids of the parasite. A more direct precursor in ether glycerolipid metabolism, i.e.,rac-1-O-[1′-¹⁴C] hexadecylglycerol, was incorporated into alkyl and 1′-alkenyl moieties of choline and etha-nolamine etherglycerophospholipids ofP. ambiguus in high yield. High proportions of labeled diacylglycerols, triacylglycerols and steryl esters were detected in surface lipids as well as lipid extracts of the culture media after incubation ofP. ambiguus with [1-¹⁴C]palmitic or [1-¹⁴C]oleic acids. The results suggest that palmitic acid and oleic acid are incorporated into neutral and polar lipids ofP. ambiguus maintained in glucose medium quite differently with oleic acid showing a strong preference for triacylglycerols. However, the incorporation of palmitic acid in glucose-fed parasites was similar to that of oleic acid in fasted parasites, as well as in larvae. This may be explained by partial fatty acid depletion in fasted worms and rapid cell division in larvae, respectively.     

Wax esters of barracudina lipid: A potential replacement for sperm whale oil

A sample of barracudina, a small fish potentially available in large quantities off Nova Scotia, contained 17.7% body lipid of which 10% was triglyceride and 85% wax ester. The triglyceride, of calculated iodine value 48, was unusually rich in 14:0 (25.8%), 18:0 (4.3%), 20:0 (1.19%), 22:0 (0.45%) and 24:0 (0.75%). The wax ester fatty acids had a calculated iodine value of 126 and a “normal” marine oil fatty acid composition. The wax ester fatty alcohols contained 42.2% hexadecanol, 29.5% octadecenols, 8.2% eicosenols and 3.8% docosenols. Certain interrelationships between fatty alcohols and fatty acids are indicated by details of composition. The potential exploitation of barracudina lipid as a substitute for sperm oil in some uses appears possible.     

Chemical Composition of Guayule (Parthenium argentatum Gray) Wax

Commercialization of guayule holds promise not only as an additional source of natural rubber but also for the utilization of its byproducts viz. wax, resin and bagasse. Hence interest in guayule has been revived once again. The present paper discusses the isolation, characterization and possible applications of one of the byproducts - guayule wax.     

B型喷雾上光蜡的研制

本文研究了用于汽车、家用电器和家具的乳状液喷雾上光蜡的配方和工艺过程。     

我国微晶蜡的生产现状与市场分析(二)

(接上期)3.2 橡胶防护 石油蜡在橡胶制品中用作物理防老剂已有很久的历史,这是因为石油蜡能迁移到橡胶表面形成蜡膜,起到屏障臭氧、延缓橡胶臭氧氧化的作用。 我国从20世纪80年代初开始进行橡胶防护蜡的研究。90年代初期,随着子午线轮胎生产线的大规模引进,橡胶防护蜡的应用开始逐渐扩大。目前我国轮胎生产企业有363家,据中国橡胶工业协会轮胎分会不完全统计,1998年全国子午线轮胎产量已达1985万条,耗用橡胶防护蜡近3000t,2000年     

Latent Heat Enhancement of Paraffin Wax in Poly(divinylbenzene-co-methyl methacrylate) Microcapsule

The preparation of divinylbenzene (DVB)-methyl methacrylate (MMA) copolymer microcapsule encapsulated Rubitherm27 (RT27) P(DVB-co-MMA)/RT27 used as heat storage material by the microsuspension polymerization was studied to improve the latent heats of the encapsulated RT27 with sufficient polymer shell strength. Percent loading of RT27 and DVB:MMA ratio were optimized. The optimal condition was 30% loading of RT27 and 30:70 (% w/w) of DVB:MMA ratio. The nonspherical microcapsules with a dent having core-shell morphology were obtained. The thermal properties of the encapsulated RT27 in the P(DVB-co-MMA)/RT27 capsules were measured by thermogravimetric analyzer and differential scanning calorimeter. The heats of melting (ΔH_m; 153 J/g-RT27) and crystallization (ΔH_c; 164 J/g-RT27) of the encapsulated RT27 in the prepared copolymer capsules were higher than those in PDVB and closed to those of bulk RT27 (162 and 168 J/g-RT27 for ΔH_m and ΔH_c, respectively).     

我国微晶蜡的生产现状与市场分析(一)

我国微晶蜡的生产企业有南充炼油厂、南阳炼油厂、锦西炼化总厂、荆门炼油厂和独山子炼油厂5家,总生产能力为5.6万t/a,2000年实际产量为3083t,开工率为0.55％。随着北美、欧洲的石蜡(包括微晶蜡)装置停工,世界微晶蜡的供需市场将展开新一轮竞争,寻求新的平衡。入世后国产微晶蜡能否占领市场,关键在于改进生产技术、降低产品成本、提高产品质量,与进口产品竞争。本文详细介绍了微晶蜡的生产技术发展趋势、企业面临的机遇与挑战,并对应用市场进行了分析。     

The preparation of poly(methylene esters)

Conditions are described which allow the synthesis of poly(methylene terephthalate) from the reaction of methylene bromide with caesium terephthalate and though application of the procedure to prepare polymers from aliphatic dicarboxylic acids was unsuccessful, such polymers were synthesized from the analogous reaction with bromochloromethane.     

Lactose-derived surfactants (I) fatty esters of lactose

Lactose, the principal solid component of whey, is a potentially inexpensive and abundantly available raw material. Its chemical structure is well suited to serve as the hydrophilic portion of a nonionic surfactant molecule. Accordingly, a series of esters of lactose was prepared by reaction of fatty acid chlorides with anhydrous lactose in N-methyl-2-pyrrolidinone. Monoesters of lauric, myristic, palmitic, stearic, oleic, and tallow fatty acids were obtained in this manner. Other methods of synthesis of the products were investigated but were unsuccessful. The lactose esters and their oxyethylated products were evaluated for detergency behavior, emulsification time, and lime soap dispersant requirement. The results indicate that their surfactant properties are comparable to those exhibited by analogous sucrose derivatives.     

Release of norethindrone from poly(ortho esters)

The release of norethindrone from a poly(ortho ester) derived from 3,9-bis(methylene)2,4,8,10-tetraoxaspiro[5,5] undecane and 1,6-hexanediol was studied. Thin circular devices containing incorporated drug and a water soluble salt, such as sodium carbonate, sodium sulfate, or sodium chloride, were placed in water buffered at pH 7.4 at 37°C, and release of drug was followed spectrophotometrically. It was found that rate of drug release was close to zero order for long periods of time and that release of the drug from the hydrophobic matrix occurred as a consequence of osmotic imbibing of water driven by the water soluble salt. Thus, a swelling front moves at a slow and constant rate through the solid device and drug release takes place by rapid diffusion of the drug from the swelling front. Polymer erosion lags behind drug release, and no erosion takes place with basic salts such as sodium carbonate when mechanical properties of the matrix are adequate to accommodate osmotic swelling.     

提高石蜡附加值发展特种蜡

深入分析了国内外石蜡、微晶蜡、特种蜡现状,针对我国石蜡生产,对特种蜡产品开发提出了一些建议,提高石蜡附加值的同时提升企业的竞争力和经济效益。     

Occurrence of wax esters in the tissues of the organge roughy (Hoplostethus atlanticus)

The skin, skeleton and a fat-filled swim bladder of the orange roughy (Hoplostethus atlanticus) each contained greater than 20% lipid by wet weight which was almost entirely wax esters. These had carbon numbers of 34–40 consistent with the major fatty acid being 18∶1 and the major fatty alcohols being 16∶0, 18∶1, 20∶1 and 22∶1. In contrast, the liver and the roe contained appreciable quantities of glycerolipids with 18∶1 and 22∶6 as the major fatty acids.     

Wax Ester Variation in Olive Oils Produced in Calabria (Southern Italy) During Olive Ripening

The wax ester composition of pressed olive oil and its variation during olive ripening were investigated by column chromatography/GC-on column technique. Six compounds were identified: C₃₆, C₃₈, C₄₀, C₄₂, C₄₄ and C₄₆ wax esters, which were grouped as total detected wax esters (TDWEs). The European Union (EU) includes C₄₀, C₄₂, C₄₄ and C₄₆ waxes (TEWEs) as a distinctive characteristic between different categories, with a maximum total content ≤250 mg/kg for an extra virgin olive oil. The International Olive Council (IOC) includes C₄₂, C₄₄ and C₄₆ waxes (TIOCWEs) as a purity parameter, with a maximum total content ≤150 mg/kg for an extra virgin olive oil. The analytical technique proposed by EU and IOC do not separate the wax esters from fatty acids esters with diterpenic alcohols (phytol and geranylgeraniol) that interfere with detected peaks. Although the examined cultivars were grown in the same geographical area and the same agricultural practices were applied to the trees, ANOVA analysis found significant differences among the oils extracted with the same machinery. The oil produced from the Itrana cultivar showed the lowest content in TEWEs (25.00–39.00 mg/kg) and in TIOCWEs (5.67–9.00 mg/kg). Wax content in Leccino and Pendolino cultivars showed a significant tendency to decrease during olive maturation, and a tendency to increase in all other cultivars from the first to the last harvest date when olive pigmentation changed from green to black.     

Synthesis ofGEM-dibromocyclopropanoid fatty esters using phenyl (tribromomethyl) mercury

Thegem-dibromocyclopropanation of naturally occurring unsaturated hydroxy fatty esters, methyl ricinoleate (I) and methyl isoricinoleate (II), has been undertaken to provide compounds which might have potential utility. Phenyl(tribromomethyl)mercury reacts only with the carbon-carbon double bond of each substrate, leaving the OH group intact. The product, methyl 9,10-dibromomethylene-12-hydroxyoctadecanoate (III) and methyl 12,13-dibromomethylene-9-hydroxyoctadecanoate (IV), obtained from I and II, respectively, were characterized by elemental, infrared (IR) and nuclear magnetic resonance (NMR) analyses.