Two novel phospholipid fatty acids from the caribbean spongeGeodia gibberosa

The novel fatty acids (Z)-6-nonadecenoic acid (1) and (Z)-17-pentacosenoic acid (2) were characterized in the spongeGeodia gibberosa. These fatty acids were mainly found in phosphatidylethanolamine and phosphatidylcholine.     

Novel brominated phospholipid fatty acids from the Caribbean spongeAgelas sp.

The very long-chain fatty acids, (5E,9Z)-6-bromo-5,9-tetracosadienoic, (5E,9Z)-6-bromo-23-methyl-5,9-tetracosadienoic, (5E,9Z)-6-bromo-5,9-pentacosadienoic and (5E,9Z)-6-bromo-24-methyl-5,9-pentacosadienoic acids, were identified in the phospholipids (mainly phosphatidylethanolamine) of the spongeAgelas sp. Structure elucidation was accomplished by means of mass spectrometry and chemical transformations, including deuteration with Wilkinson's catalyst. All of the sterols from the sponge had the Δ5,7 nucleus, with 24-methylcholesta-5,7,22-trien-3β-ol (ergosterol) and 24-ethylcholesta-5,7,22-trien-3β-ol being the most abundant.     

Production of polyhydroxy fatty acids from linoleic acid by Clavibacter sp. ALA2

Hydroxy fatty acids are important industrial materials. We isolated a microbial culture, Clavibacter sp. ALA2, which converts linoleic acid to many polyhydroxy fatty acids. Structures of the products were determined as: 12,13,17-trihydroxy-9(Z)-octadecenoic (THOA, main product), 12-[5-ethyl-2-tetrahydrofuranyl]-7,12-dihydroxy-9(Z)-dodecenoic (ETDDA), and 12-[5-ethyl-2-tetrahydrofuranyl]-12-hydroxy-9(Z)-dodecenoic (ETHDA) acid. The yield of THOA was 25% and the relative amount of the products were THOA/ETDDA/ETHDA =9:1.3:1. The structures of the hydroxy unsaturated fatty acids resemble those of plant self-defense substances.     

Facile one-pot synthesis of N-acyl-1H-1,2,3-benzotriazoles from internal and terminal olefinic fatty acids and their antimicrobial screening

N-acyl-1H-1,2,3-benzotriazoles were prepared in good yields by the reaction of benzotriazole and thionyl chloride with olefinic fatty acids under mild reaction conditions. The new compounds 1-(undec-10-enoyl)-1H-1,2,3-benzotriazole (5a),1-[(Z)-octadec-9-enoyl]-1H-1,2,3-benzotriazole (5b), 1-[(9Z,12R)-12-hydroxyoctadec-9-enoyl]-1H-1,2,3-benzotriazole (5c), 1-[(9R,12Z)-9-hydroxyoctadec-12-enoyl]-1H-1,2,3-benzotriazole (5d) formed were characterized on the basis of elemental analysis and spectral data. All the newly synthesized compounds (5a-5d) were screened for their antimicrobial activity and showed good antifungal activity.     

Isolation of brominated long-chain fatty acids from the phospholipids of the tropical marine spongeAmphimedon terpenensis

Preliminary investigation of the phospholipid fatty acid composition of the tropical marine spongeAmphimedon terpenensis by gas chromatography/mass spectrometry revealed the presence of some novel brominated fatty acids. Two new brominated fatty acids, (5E, 9Z)-6-bromo-5,9-tetracosadienoic acid (2a) and (5E, 9Z)-6-bromo-5,9-pentacosadienoic acid (3a) were subsequently isolated from a chloroform/methanol (3∶1, vol/vol) extract of the sponge and characterized as their methyl esters 2b and 3b. The known brominated fatty acid (5E, 9Z)-6-bromo-5,9-hexacosadienoic acid (4a) was also isolated. The new fatty acid methyl esters were confirmed as brominated δ5,9 acid derivatives by chemical ionization mass spectrometry. The position of the bromine substituent was determined to be C-6 by nuclear magnetic resonance techniques while the stereochemistry of the two double bonds was deduced by nuclear Overhauser enhancement difference spectroscopy. The biosynthetic implications of the co-occurrence of the three brominated acids are discussed.     

Origin of bicyclic fatty acids in tall oil

It was shown that two bicyclic fatty acids present in Finnish tall oil were formed from (5Z, 9Z, 12Z)-5, 9, 12-octadecatrienoic acid, pinolenic acid (I). Under the alkaline conditions of sulfate pulping, pinolenic acid forms conjugated isomers which undergo Diels-Alder cyclization during the heating in the tall oil distillation. The cyclization products, here called cyclopinolenic acids, are bicyclic fatty acids and stereoisomers of 4-(5-pentyl-3a, 4,5,7a-tetrahydro-4-indanyl) butanoic acid (IV and V).     

Sponge fatty acids. 3. Occurrence of series of n−7 monoenoic andiso-5,9 dienoic long-chain fatty acids in the phospholipids of the marine spongeCinachyrella aff.schulzei keller

The fatty acid composition of phospholipids from the New Caledonian spongeCinachyrella aff.schulzei Keller was studied. More than 60 fatty acids were identified as methyl esters andN-acyl pyrrolidides by gas chromatography and gas chromatography/mass spectrometry. Two isoprenoid fatty acids also were shown to be present, namely 4,8,12-trimethyltridecanoic and 5,9,13-trimethyltetradecanoic acids. The unusual 6-tetradecenoic, 6-pentadecenoic, 12-nonadecenoic and 26-methylheptacosanoic (iso-28∶0) acids were found for the first time in sponge phospholipids. A series of six n−7 monoenoic long-chain fatty acids (C₂₃ to C₂₈) were identified, including the rare 16-tricosenoic, 18-pentacosenoic and 21-octacosenoic acids. Fifteen fatty acids possessing the typical 5,9 dienoic moiety accounted for 30% of the total fatty acid mixture. Two new fatty acids were identified, namely 5(Z)-octacosenoic and 27-methyl-5(Z),9(Z)-octacosadienoic (iso-5,9-29∶2). Based on gas chromatography/Fourier transform infrared experiments, the double bonds were assigned the (Z) configuration. For part 2 of this series, see Reference 1.     

New unsaturated long-chain fatty acids in the phospholipids from the axinellida spongesTrikentrion loeve andPseudaxinella cf.Lunaecharta

In order to identify new structures and especially those involved as biosynthetic intermediates, the fatty acid composition of whole phospholipids from two Senegalese marine sponges from the order Axinellida,Trikentrion loeve andPseudaxinella cf.lunaecharta, has been investigated by analytical gas chromatography and gas chromatography/mass spectrometry. Several new fatty acids were identified as methyl esters andN-acyl pyrrolidies, namely 16-eicosenoic, 11-tetracosenoic, 5-pentacosenoic, 11-hexacosenoic, 11-oxtacosenoic, 23-triacontenoic, 17,21-hexacosadienoic, 19,23-octacosadienoic, 9,23-triacontadienoic, 5,9,21-hexacosatrienoic, and 5,9,25-triacontatrienoic.Trikentrion loeve andP. cf.lunaecharta contain fifteen 25.7% of the total acid mixture) and thirteen (30.4%) °5,9 fatty acids, respectively. Based on gas chromatography/Fourier transform infrared experiments, the double bonds were assigned the (Z) configuration. Biosynthesis of dienoic and trienoic demospongic acids possessing an n-5 or an n-7 terminal double bond is discussed.     

(Z)-5-甲基-3-苯硫甲叉基-4,5-二氢呋喃-2-酮和(Z)-5-甲基-3-苯硫甲基-5-氢呋喃-2-酮简便合成

以3-苯硫基丙块1为原料经5步反应合成了(Z)-5-甲基-3苯硫甲基-5-氢呋喃-2-酮8和(Z)-5-甲基-3-苯硫甲叉基4,5-二氢呋喃-2-酮9。合成的关键步骤是在三甲基氯硅烷(TMSCl)/NaI/H2O/CH3CN体系中5-苯硫基-3-戊炔-2-酮3一步完成的碘氢化和去共轭反应。     

天然产物Combretastatin B-1的合成

该文基于Perkin反应合成了具有血管阻断及抗肿瘤活性的天然产物Combretastatin B-1(CB1)。以异香兰素为起始原料,用二溴海因对其进行选择性溴代得到2-溴-3-羟基-4-甲氧基苯甲醛(Ⅱ),该化合物与3,4,5-三甲氧基苯乙酸(Ⅲ)发生Perkin反应得到(Z/E)-2-(3,4,5-三甲氧基苯基)-3-(2'-溴-3'-乙酰氧基-4'-甲氧基)丙烯酸(Z-4、E-4),再经羟化反应及脱羧-异构化反应制备得到E-Combretastatin A-1(E-CA1),最后经催化氢化反应得到CB1,总收率为53.4%。     

Phospholipid studies of marine organisms: New branched fatty acids fromStrongylophora durissima

The phospholipids of the spongeStrongylophora durissima were analyzed. The major phospholipids present were phosphatidylethanolamine (PE), phosphatidylcholine (PC), phosphatidylserine (PS), phosphatidylglycerol (PG) and phosphatidylinositol (PI). The major fatty acid components of the phospholipids consisted of short chain (C₁₄−C₁₉) and very long chain (C₂₅−C₃₀) “Demospongic” acids. Three novel branched Δ⁵ monounsaturated acids,Z-19-methyl-5-pentacosenoic,Z-19-methyl-5-hexacosenoic andZ-19-methyl-5-heptacosenoic acids were encountered in the sponge. The 3-saturated counterparts of these compounds, 19-methylpentacosanoic, 19-methylhexacosanoic and 19-methylheptacosanoic acids, as well as 19-methylpentacosanoic and 20-methyloctacosanoic acids also are hitherto undescribed acids present in the sponge. Trace amounts of 2 very long chain acids also were detected and their structures tentatively assigned as 19,21-dimethylheptacosanoic and 20,22-dimethyloctacosanoic acids. The distribution of these fatty acids according to phospholipid head groups also was described.     

5-卤代-2-(4-芳基-噻唑-2-基)-腙甲基-苯酚的合成

以5-卤代-水杨醛为原料,与氨基硫脲发生缩合反应,生成5-卤代-水杨醛缩氨基硫脲。然后分别与ω-溴代苯乙酮、对甲氧基-ω-溴代苯乙酮在甲醇或丙酮溶剂中回流反应10 min,得到6个5-卤代-2-(4-芳基-噻唑-2-基)-腙甲基-苯酚,最后通过红外、核磁、质谱对其进行了结构表征。     

5-Br-PADAP及其金属螯合物作为光信息存储材料的研究

本文合成了2-(5-溴-2-吡啶偶氮)-5-二乙氨基酚(5-Br-PADAP)的Zn,Co,Cu,Ni的4种金属螯合物,利用紫外可见光谱仪和差热-热重分析系统分别研究了5-Br-PADAP及其Zn,Co,Cu,Ni的金属螯合物在溶液态的光谱学性质和热力学性质,并进一步研究了5-Br-PADAP·Ni和5-Br-PADAP·Co薄膜态的透射光和反射光性质。研究发现5-Br-PADAP·Co,5-Br-PADAP·Ni可以作为良好的光信息存储介质材料。     

Reaction of long chain triol acids with hydrogen bromide

The reaction of hydrogen bromide (HBr) with long chain triol acids has been investigated in some detail. The 9, 10, 12-trihydroxy stearic acid (I) on treatment with HBr yielded three products, namely 9(10)-bromo-10(9)-hydroxy-12-bromo (III), 9(10)-bromo-10(9)acetoxy-12-bromo (IV) and 9,10-dibromo-12-hydroxy (V) stearic acids. When 9,12,13-trihydroxy stearic acid (II) was subjected to the same reaction under similar conditions, 12,13-dibromo-9-hydroxy (VI), 12(13)-bromo-13(12) acetoxy-9-bromo (VII) stearic acids were obtained. The structure of these products were established on the basis of their elemental values, spectral data and chemical evidence.     

Enzymatic enrichment of C20 cis-5 polyunsaturated fatty acids fromBiota orientalis seed oil

Enrichment ofcis-5 polyunsaturated fatty acids [20:3(5c,11c,14c), 4.3% and 20:4(5c,11c,14c,17c), 11.3%] fromBiota orientalis seed oil was carried out by lipase-catalyzed selective esterification and hydrolysis reactions. Lipases fromRhizomucor miehei (Lipozyme),Candida cylindracea and porcine pancreas were used. Lipozyme-catalyzed esterification ofBiota fatty acids withn-butanol inn-hexane allowed 20:3 and 20:4 (as fatty acids) to be enriched to a maximum level of 52.9%, and in the presence ofC. cylindracea lipase 61.5% enrichment was achieved. Esterification with pancreatic lipase was poor with low levels of enrichment of 20:3 and 20:4 (22%). A multigram scale esterification of the free fatty acids fromBiota seed oil by repeated treatment of the isolated fatty acid fraction withn-butanol inn-hexane in the presence ofC. cylindracea lipase furnished an enrichment yield of 72.5% of a mixture of 20:3 and 20:4 fatty acids. Urea fractionation of the free fatty acids ofBiota oil gave an initial enriched fraction of 20:3 (9.5%) and 20:4 (25.2%) which, upon treatment withC. cylindracea lipase inn-butanol andn-hexane, gave an enriched fraction of 85.3% of 20:3 and 20:4 fatty acids. Partial hydrolysis of the triglycerides ofBiota oil byC. cylindracea lipase in potassium phosphate buffer at 25°C resulted in a 2.8-fold enrichment ofcis-5 polyunsaturated fatty acids (40.8% of 20:3 and 20:4) as contained in the unhydrolyzed acylglycerol fractions.     

Synthesis of Methyl 7-Bromo-5-heptynoate - a building block for the carboxylic side chain of prostaglandins

Methyl 7-bromo-5-heptynoate ( 11 ) was synthesized in 8 steps using the alkylation of 1-(2H-tetrahydropyran-2-yloxy)-2-propyne with 1-bromo-4-chloro-butane as a key reaction step. Furthermore it was shown, that also the unprotected propargyl alcohol ( 12 ) can be C-alkylated with high chemoselectivity using 1-bromo-4-chloro-butane. In this way the number of necessary reaction steps could be reduced without decrease in the total yield. Attempts failed to use trimethylsilyl 4-bromo-butanoate or 4-bromo-butyl acetate as alkylating reagent in this synthesis.     

New synthesis ofcis-3,cis-5- andtrans-3,cis-5-tetradecadienoic acids,pheromone constituents ofattagenus elongatulus andA. megatoma

A new method for the synthesis ofcis-3,cis-5- andtrans-3,cis-5-tetradecadienoic acids, pheromone constituents of the dermestid beetlesAttagenus elongatulus andA. megatoma, was developed. The syntheses are based upon the formation oftrans-2-tetradecen-5-ynoic acid by reaction of 4-bromo-2-butenoic acid with 1-decynylmagnesium bromide. The enynoic acid undergoes alkali-induced isomerization to yield a mixture of acids from whichcis-3- andtrans-3-tetradecen-5-ynoic acids were separated in 31% and 34% yields, respectively. Methyltrans-2-tetradecen-5-ynoate was similarly prepared and isomerized to furnish methylcis-3-tetradecen-5-ynoate in 8% yield. Reduction of the tetradecenynoic acids with dicyclohexylborane gavecis-3,cis-5-andtrans-3,cis-5-tetradecadienoic acids in 4% and 39% yields, respectively. A better yield (49%) in the reduction ofcis-3-tetradecen-5-ynoic acid tocis-3,cis-5-tetradecadienoic acid was obtained by hydrogenation over Lindlar's catalyst. Similarly, reduction of methylcis-3-tetradecen-5-ynoate with disiamylborane gave 22% methylcis-3,cis-5-tetradecadienoate.     

Autoxidation rates of 5-olefinic monoenoic and denoic fatty acids from sea urchin lipids and meadoefoam oils

Autoxidation rates of the 5-olefinic monoenoic and dienoic fatty acids from sea urchin lipids and meadow-foam oils were compared with those of normal monoenoic and dienoic fatty acids by gas-liquid Chromatographic determination of the unoxidized fatty acid methyl esters remaining through the autoxidation period. The fatty acids are classified into five groups shown below according to the oxidation rate of their methyl esters: I 5-olefinic monoenoic acids (c5-18:l, c5-20:l and c5-22:1), II normal monoenoic acids (c9-18:l, cll-18:l, c9-20:1, cl3-20:l and cl3-22:l), III 5-olefinic dienoic acids (c5,cll-20:2, c5,cl3-20:2 and c5,cl3-22:2), IV 7-olefinic dienoic acids (c7,cl3-22:2 and c7,cl5-22:2) and V normal dienoic acids (c6,c9-18:2, c9,cl2-18:2 and cll,cl4-20:2). The oxidation rates of these groups increased during autoxidation in order from I to V. These results show that the 5-olefinic monoenoic and dienoic acids are more stable to autoxidation than the normal monoenoic and dienoic acids, respectively. The higher stabilities of the 5-olefinic monoenoic and dienoic acids in organisms are shown from these results.     

Transannulare Reaktionen von Cycloalkenen,Cycloalkadienen und Cycloalkatrienen. VIII. Zur elektrophilen Addition von Pseudohalogenen an Cycloocta-1(Z),5(Z)-dien

Transannular Reactions of Cycloalkenes, Cycloalkadienes and Cycloalkatrienes. VIII. The Electrophilic Addition of Pseudohalogenes to Cycloocta-1(Z), 5(Z)-diene The reaction of cycloocta-1(Z), 5(Z)-diene 5 with chlorothiocyanate is described. The main process is the normal anti-addition to produce trans-5-chloro-6-thiocyanato-(Z)-cyclooctene 6 . In addition 2,6-dichloro-9-thiabicyclo [3.3.1] nonane 7 and 2,6-dithiocyanato-9-thiabicyclo[3.3.1] nonane 8 are obtained as products of a transannular reaction.     

Fatty acid selectivity: The selectivity of lipases ofGeotrichum candidum

The relative reactivities of several long-chain fatty acids in esterifications with 1-butanol catalyzed by lipases ofGeotrichum candidum were evaluated. As has been noted previously, these lipases are not uniformly highly selective forcis-9 unsaturated fatty acids. However, the lipase preparations examined do uniformly discriminate against fatty acids having a chainlength greater than C-18 such as erucic acid. The reactivities of γ-linolenic and ricinoleic acid were also low compared to that of oleic. An examination of the effect of the alcohol upon the relative reactivities of acids showed that one could enhance fatty acid selectivity by proper choices of alcohol. For example, oleic acid esterifies 2.5 times faster than palmitic acid with 1-butanol catalyzed by Amano GC-4 lipase, but esterifies over 50 times faster with 2-methyl-1-propanol or cyclopentanol.