十三烷二酸的制法及应用

十三烷二酸(Brassylic Acid,Trid-ecanedioic Acid),又称1,11一十一烷二羧酸(1,11—Undecane—dicarboxlicAcid),代号DCA,可用作合成香料、功能性塑料、润滑剂、表面活性剂、照相印刷溶剂、金属化合物、抗菌剂、医药中间体、农药中间体、增塑剂等。     

芥酸氧化裂解制备十三烷二酸研究

本文研究了过氧化氢氧化裂解芥酸制备十三烷二酸,实验以磷钨酸为催化剂,在相转移条件下进行。详细考察了催化剂添加方式、不同相转移试剂、磷钨酸用量、过氧化氢浓度、过氧化氢用量对产物产率的影响。结果表明:三辛基甲基氯化铵作为相转移试剂效果最佳,当经预处理的磷钨酸用量为3%,过氧化氢浓度为60%、用量为6倍双键量时,可得到较高的十三烷二酸产率,为83.5%。     

芥酸甲酯氧化制备十三烷二酸

提出了一条芥酸甲酯氧化制备十三烷二酸的新工艺路线:以过氧化氢和氧气为氧化剂,芥酸甲酯经烯键环氧化、环氧水解、邻二醇氧化裂解等反应制备十三烷二酸。着重研究了烯键环氧化和环氧水解反应中,影响烯键环氧化反应收率和中间产物羟基值的条件参数。结果表明:含邻二醇的中间产物的羟基值越高,十三烷二酸的总体收率越高;采用新工艺路线,十三烷二酸的总收率达到70.3%,具有工业化应用前景。     

环己酮氧化法制备十二碳二酸工艺研究

以环己酮和双氧水为原料,甲醇为溶剂,在酸性条件下反应,生成甲氧基环已基过氧化物,使之在亚铁盐存在下和甲醇反应,生成十二碳二酸二甲酯,用无机碱皂化,无机酸酸析,得十二碳二酸粗品,再重结晶得成品,反应总收率６６％;产品纯度大于９９％。     

高纯度十二烷二酸的制备

研究了采用环己酮路线制备高纯度十二烷二酸的方法,讨论了甲醇、氢氧化钠、皂化时间以及溶剂等因素对反应过程的影响,最终确立了最佳工艺条件,对工业化生产有较大的参考价值。     

环已酮氧化法制备十二碳二酸工艺

以环己酮和双氧水为原料,以甲醇为溶剂,在酸性条件下反应,生成甲氧基环己基过氧化物,使之在亚铁盐存在下和甲醇反应,生成十二碳二酸二甲酯,然后用氢氧化钠皂化、无机酸酸析,得十二碳二酸粗品,再重结晶得成品。反应总收率66％,产品纯度大于99％。     

环己酮氧化法制备十二碳二酸工艺研究

以环己酮和双氧水为原料 ,甲醇为溶剂 ,在酸性条件下反应 ,生成甲氧基环己基过氧化物 ,使之在亚铁盐存在下和甲醇反应 ,生成十二碳二酸二甲酯 ,用无机碱皂化 ,无机酸酸析 ,得十二碳二酸粗品 ,再重结晶得成品 ,反应总收率 66% ;产品纯度大于 99%。     

青霉烷酸二苯甲酯亚砜的合成

以6 氨基青霉烷酸(Ⅰ)为原料经溴化制得6 溴青霉烷酸(Ⅱ),收率89 1%。然后以六氟异丙醇为溶剂,经w(H2O2)=30%的双氧水氧化合成6 溴青霉烷酸二苯甲酯亚砜(Ⅲ),收率97%。最后经超声波锌粉脱溴制得青霉烷酸二苯甲酯亚砜(Ⅳ),收率93%,总收率80 4%。在氧化反应,用w(H2O2)=30%的双氧水代替了高质量分数的过氧乙酸,不但反应时间从3h降低至10min,得率更是由83%提高到97%。反应过程绿色化,提高了原子经济性。产品用1HNMR、IR进行了表征。     

Quantification of Nonanal and Oleic Acid Formed During the Ozonolysis of Vegetable Oil Free Fatty Acids or Fatty Acid Methyl Esters

The ozonolysis of unsaturated lipids is a process that has been used to generate aldehydes, acids, alcohols, and other biobased chemical intermediates. Reported here is a method that can be used to measure the formation of nonanal and oleic acid during the ozonolysis of unsaturated vegetable oil fatty acids or their methyl esters to indicate the extent of the ozonolysis reaction. Derivatization was performed using boron trifluoride in methanol solution to transform nonanal and oleic acid into nonanal dimethyl acetal and oleic acid methyl ester, respectively. Undecanal and 10‐heptadecenoic acid were used as internal standards and separation was performed using gas chromatography coupled with a flame ionization detector. The method was validated by performing a standard addition procedure in which nonanal or oleic acid standards were spiked into samples collected during the ozonolysis of oleic acid or canola oil fatty acid methyl ester (FAME). Linear regression results indicated that the measured nonanal and oleic acid are in good agreement with the actual amounts of nonanal and oleic acid added to the sample with at least 98 % recovery. The application of the method was demonstrated by the successful measurement of nonanal and oleic acid formed throughout the ozonolysis process for high oleic canola oil FAME.     

Up to 21 Different Sulfur-Heterocyclic Fatty Acids in Rapeseed and Mustard Oil

Three sulfur-heterocyclic fatty acids (SHFA) had been tentatively identified in rapeseed oil in the late 1980s. In this study we aimed to enrich and verify the presence of potential SHFA in one sample of native rapeseed oil, refined rapeseed oil and mustard seed oil. Fifty-gram samples of the three oils were individually saponified and converted into methyl esters. The resulting samples were hydrogenated and subjected three times to urea complexation. The resulting extracts of native rapeseed oil and mustard oil contained 21 different SHFA with 18, 20, 22 or 24 carbons. The refined rapeseed oil contained only nine C₁₈-SHFA. Structure investigation of the SHFA was performed by gas chromatography with mass spectrometry (GC/MS) using methyl esters and also 3-pyridylcarbinol esters. A direct screening of non-enriched samples by GC/MS in the selected ion monitoring mode and by GC with flame photometric detector (sulfur-selective) verified that the SHFA were native compounds of the oils and no artefacts of the sample preparation. Similar abundances of the four isomer groups of SHFA with monoenoic fatty acids of the same carbon number in these and five further rapeseed and mustard samples indicated that these could be the precursors of the SHFA.     

Stabilisation of the Fatty Acid Decarboxylase from Chlorella variabilis by Caprylic Acid

The fatty acid photodecarboxylase from Chlorella variabilis NC64 A (CvFAP) catalyses the light-dependent decarboxylation of fatty acids. Photoinactivation of CvFAP still represents one of the major limitations of this interesting enzyme en route to practical application. In this study we demonstrate that the photostability of CvFAP can easily be improved by the administration of medium-chain length carboxylic acids such as caprylic acid indicating that the best way of maintaining CvFAP stability is ‘to keep the enzyme busy’.     

Producing Fatty Acid Methyl Esters from Free Fatty Acids with Ionic Liquids as Catalyst

Three Brønsted acidic imidazole dicationic ionic liquids (ILs) with different length of alkyl chains, [C_n(Mim)₂][HSO₄]₂ (n = 3, 6, 12), were prepared and used as catalyst for the esterification reaction of free fatty acids and methanol. Taking oleic acid as model acid, the catalytic performances of the synthesized ILs for the esterification were evaluated. The main physicochemical properties of the ILs, thermal stability, acidity, solubility in common solvents, and causticity on Austenitic stainless steel 316, were examined. [C₃(Mim)₂][HSO₄]₂ demonstrated the highest catalytic activity and enabled to assess the preliminary optimum esterification condition of oleic acid and methanol. Under optimized reaction conditions, the yield of oleic acid methyl ester was up to 95 %. The ILs have great potential as catalysts for producing fatty acid methyl esters from long‐chain free fatty acids.     

Palmitic Acid Lipotoxicity in Microglia Cells Is Ameliorated by Unsaturated Fatty Acids

Obesity and metabolic syndrome are associated with cognitive decline and dementia. Palmitic acid (PA) is increased in the cerebrospinal fluid of obese patients with cognitive impairment. This study was therefore designed to examine fatty acid (FA) lipotoxicity in BV2 microglia cells. We found that PA induced time- and dose-dependent decrease in cell viability and increase in cell death without affecting the cell cycle profile and that PA lipotoxicity did not depend on cell surface free fatty acid receptors but rather on FA uptake. Treatment with sulfosuccinimidyl oleate (SSO), an irreversible inhibitor of fatty acid translocase CD36, significantly inhibited FA uptake in BSA- and PA-treated cells and blocked PA-induced decrease in cell viability. Inhibition of ER stress or treatment with N-acetylcysteine was not able to rescue PA lipotoxicity. Our study also showed that unsaturated fatty acids (UFAs), such as linoleic acid (LA), oleic acid (OA), α-linolenic acid (ALA), and docosahexaenoic acid (DHA), were not lipotoxic but instead protected microglia against PA-induced decrease in cell viability. Co-treatment of PA with LA, OA, and DHA significantly inhibited FA uptake in PA-treated cells. All UFAs tested induced the incorporation of FAs into and the amount of neutral lipids, while PA did not significantly affect the amount of neutral lipids compared with BSA control.     

Fatty Acids in Liver,Muscle and Gonad of three Tropical Rays including Non-Methylene-Interrupted Dienoic Fatty Acids

Scientific investigation of lipids in Elasmobranchs has been conducted mainly on shark species. Because rays seem to be neglected, this study was performed to examine the complete fatty acid (FA) composition with a particular interest for long-chain polyunsaturated FA (PUFA) content in different tissues of three ray species including parts usually discarded. The total FA and PUFA profiles of total lipids were determined in muscle, liver, and gonad of Rhinobatos cemiculus, Rhinoptera marginata, and Dasyatis marmorata, the most often caught ray species from the East Tropical Atlantic Ocean. Fifty FA were characterized as methyl esters and N-acyl pyrrolidides by gas chromatography/mass spectrometry, showing significant levels of 20:5n-3 (EPA) (up to 5.3%) and 22:5n-3 (DPA) (up to 7.3%), high levels of 20:4n-6 arachidonic (ARA) (4.8–8.6% of total FA) and 22:6n-3 (DHA) (up to 20.0%). The results show that muscle, liver and gonad of rays can provide high amounts of essential PUFA, specially DHA, for direct human nutrition or the food processing industry. High proportions of DHA were particularly found in all samples of R. cemiculus (11.6–20.0%), and in muscle and liver of D. marmorata (11.1–16.1%). Regarding the high amounts of (n-3) PUFA, this study shows that these rays deserve a better up-grading, including the normally discarded parts, and describes the occurrence of unusual NMID FA in all tissues studied. Five non-methylene-interrupted dienoic fatty acids (NMID FA) (0–3.4%) were reported, including previously known isomers, namely 20:2 Δ7,13, 20:2 Δ7,15, 22:2 Δ7,13, 22:2 Δ7,15, and new 22:2 Δ6,14. These acids are quite unusual in fish and unprecedented in rays. The 22:2 Δ6,14 acid occurred in gonads of male specimens of R. cemiculus at 2.9%.     

麦芽糖醇脂肪酸酯的制备研究

以麦芽糖醇和脂肪酰氯为主要原料合成麦芽糖醇脂肪酸酯。通过对影响反应的催化剂用量、溶剂的用量、反应温度、反应时间、原料配比等主要因素的考察,发现在以麦芽糖醇糖/脂肪酰氯为1∶1.25,催化剂(碳酸钾)用量为麦芽糖醇用量的15%~20%,溶剂(冰醋酸)/麦芽糖醇的用量比为6~7mL/1g,反应温度110℃的条件下,反应10h,麦芽糖醇脂肪酸酯的收率可达93%~95%。     

不饱和脂肪酸及其衍生物环氧化研究进展

综述了环氧化不饱和脂肪酸及其衍生物的制备工艺和实验方法,包括过氧酸环氧化法、卤代醇环氧化法、过氧化氢或有机过氧化氢环氧化法、分子氧环氧化法。其中使用过氧酸的方法是工业上使用最为广泛的,可以采用酸或者酶作催化剂;而以过氧化氢为氧化剂的固体催化工艺是目前最有工业化前途的技术。并指出了开发新型、高效、绿色且廉价的催化体系仍是今后的研究方向。     

怒江漆油中高级脂肪酸成分

对云南怒江漆油 (漆树籽油 )进行皂化得到了漆油的总脂肪酸 ,将总脂肪酸甲酯化得到总脂肪酸甲酯 ,用GC MS联用仪测定了所含高级脂肪酸的成分 ,结果表明云南怒江漆树油中高级脂肪酸分别为棕榈酸、油酸、硬脂酸、花生酸、二十烷二酸。其中 ,棕榈酸的质量分数高达 76.9%。     

Lipidomic and Proteomic Alterations Induced by Even and Odd Medium-Chain Fatty Acids on Fibroblasts of Long-Chain Fatty Acid Oxidation Disorders

Medium-chain fatty acids (mc-FAs) are currently applied in the treatment of long-chain fatty acid oxidation disorders (lc-FAOD) characterized by impaired β-oxidation. Here, we performed lipidomic and proteomic analysis in fibroblasts from patients with very long-chain acyl-CoA dehydrogenase (VLCADD) and long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHADD) deficiencies after incubation with heptanoate (C7) and octanoate (C8). Defects of β-oxidation induced striking proteomic alterations, whereas the effect of treatment with mc-FAs was minor. However, mc-FAs induced a remodeling of complex lipids. Especially C7 appeared to act protectively by restoring sphingolipid biosynthesis flux and improving the observed dysregulation of protein homeostasis in LCHADD under control conditions.