- Raspailynes, Novel Long-Chain Acetylenic Enol Ethers of Glycerol from the Marine Sponges Raspailia pumila and Raspailia ramosa
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The sponges Raspailia pumila and R. ramosa (Demospongiae, Tetractinomorpha, Axinellida) from the North-East Atlantic are shown to contain a series of novel long-chain enol ethers of glycerol where the enol ether C=C bond is conjugated, in sequence, to both an acetylenic and an olefinic bond.Polar extracts give raspailynes hydroxylated at their (1Z,5Z)-1,5-alkadien-3-ynyl chain, like raspailyne A1 (=(+)-(S)-3--1,2-propanediol; (+)-2) and isoraspailyne A (=(+)-3--1,2-propanediol; (+)-3).Less polar extracts give 3 different types of raspailynes not hydroxylated at the chain.Raspailynes of the first type have either the (1Z,5Z)-configuration in a linear chain such as raspailyne B2 (=(-)-(S)-3--1,2-propanediol; (-)-4), raspailyne B1 (=(-)-3--1,2-propanediol; (-)-5), and raspailyne B (=3--1,2-propanediol; 6) or the (1Z,5Z)-configuration in a chain ending with an isopropyl group, like isoraspailyne B1 (=3--1,2-propanediol; 7) and isoraspailyne B (=3--1,2-propanediol; 8).Raspailynes of the second type have the (1Z,5E)-configuration, like isoraspailyne B1a (=3--1,2-propanediol; 9) and isoraspailyne Ba (=3--1,2-propanediol; 10).Raspailynes of the third type have the (1E,5Z)-configuration, like isoraspailyne B1b (=3--1,2-propanediol; 11).The (S)-configuration for (+)-1, (+)-2, and (-)-4 is derived from chemical correlations.
- Guella, Graziano,Mancini, Ines,Pietra, Francesco
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- Enantiomeric synthesis of natural alkylglycerols and their antibacterial and antibiofilm activities
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Alkylglycerols (AKGs) are bioactive natural compounds that vary by alkyl chain length and degree of unsaturation, and their absolute configuration is 2S. Three AKGs (5l–5n) were synthesised in enantiomerically pure form, and were characterised for the first time together with 12 other known and naturally occurring AKGs (5a–5k, 5o). Their structures were established using 1H and 13C APT NMR with 2D-NMR, ESI-MS or HRESI-MS and optical rotation data, and they were tested for their antibacterial and antibiofilm activities. AKGs 5a–5m and 5o showed activity against five clinical isolates and P. aeruginosa ATCC 15442, with MIC values in the range of 15–125 μg/mL. In addition, at half of the MIC, most of the AKGs reduced S. aureus biofilm formation in the range of 23%–99% and P. aeruginosa ATCC 15442 biofilm formation in the range of 14%–64%. The antibiofilm activity of the AKGs assessed in this work had not previously been studied.
- Fernández Montoya, Deicy J.,Contreras Jordan, Luis A.,Moreno-Murillo, Bárbara,Silva-Gómez, Edelberto,Mayorga-Wandurraga, Humberto
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supporting information
p. 2544 - 2550
(2019/11/13)
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- Platelet activating factor derivative and synthesis method thereof
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The invention belongs to the technical field of chemical synthesis and discloses a platelet activating factor derivative with a formula (I) structure, wherein a substituent group R refers to an acryl group. A synthetic route includes nine-step reaction by taking chiral source S-configuration solketal as a starting reactant. The method is adopted for synthesis of a 2-sulfo platelet activating factor and a derivative thereof for the first time and has advantages of high yield, easiness in separation and the like. Low-cost batch synthesis of 2-S-PAF and the derivative thereof is realized, and significances to activity research of 2-S-PAF and the derivative thereof, biological experiments, clinical application and disease treatment are achieved.
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- Synthesis and evaluation of immunostimulant plasmalogen lysophosphatidylethanolamine and analogues for natural killer T cells
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Plasmalogen lysophosphatidylethanolamine (pLPE) had been identified as a self antigen for natural killer T cells (NKT cells). It is very important in the development, maturation and activation of NKT cells in thymus. Besides, pLPE is a novel type of antigen for NKT cells. To evaluate the structure-activity relationship (SAR) of this new antigen, pLPE and its analogues referred to different aliphatic chains and linkages at the sn-1 position of the glycerol backbone were synthesized, and the biological activities of these analogues was characterized. It is discovered that the linkages between phosphate and lipid moiety are not important for the antigens' activities. The pLPE analogues 1, 3, 4, 7 and 9, which have additional double bonds on lipid parts, were identified as new NKT agonists. Moreover, the analogues 4, 7 and 9 were discovered as potent Th2 activators for NKT cells.
- Ni, Guanghui,Li, Zhiyuan,Liang, Kangjiang,Wu, Ting,De Libero, Gennaro,Xia, Chengfeng
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p. 2966 - 2973
(2014/05/20)
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- Chemoenzymatic synthesis of a focused library of enantiopure structured 1-O-alkyl-2,3-diacyl-sn-glycerol type ether lipids
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A highly efficient two-step chemoenzymatic synthesis of enantiopure structured ether lipids of the 1-O-alkyl-2,3-diacyl-sn-glycerol type has been developed. Chimyl, batyl and selachyl alcohols possessing pure saturated fatty acid (SFA) attached to the sn-3 position and pure EPA and DHA attached to the sn-2 position were obtained under full regiocontrol. This was offered by mild conditions and a highly efficient lipase that operated at room temperature. High-resolution 1H NMR spectroscopy was used to monitor the progress of the reactions and to evaluate the full regiocontrol of the reactions involved by keeping track of all prospective adducts involved in these reactions. This was extended to preparation of a focused library of eight monoacyl intermediate adducts for all even-numbered SFA ranging from C2-C16 and the corresponding EPA and DHA structured diacyl glycerol ethers (DAGE) products for chimyl, batyl and selachyl alcohols, the total of 72 compounds.
- Magnusson, Carlos D.,Gudmundsdottir, Anna V.,Haraldsson, Gudmundur G.
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supporting information; experimental part
p. 1821 - 1836
(2011/04/17)
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- Purification of seminolipid and its cleavage to lyso-seminolipid. interaction of seminolipid with phospholipase A2
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Seminolipid was purified from boar sperm and characterized by chemical, chromatographical and spectroscopical (IR, NMR) means. Phospholipase A2 from two sources were used in this experiment: from viper (Vipera ammodytes) venom, and bull seminal vesicle. It was proved that seminolipid cannot constitute a biochemical substrate for the two phospholipases. Two substrates were used for the two enzymes, egg yolk lecithin for viper venom phospholipase A2 and [ 14C-linoleoyl]phosphatidyl ethanolamine for bull seminal vesicle phospholipase A2. The action of seminolipid on the latter enzyme, in quantitative terms, is presented. A small portion of seminolipid was submitted to mild alkaline hydrolysis and lyso-seminolipid recovered from the mixture was peracetylated and its 1H and 13C NMR spectra registered.
- Iga, Silvia,Iga, Dumitru Petru
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experimental part
p. 383 - 387
(2011/06/25)
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- OXIDIZED LIPID COMPOUNDS AND USES THEREOF
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Novel oxidized lipids are provided herein, as well as methods for producing same, and uses thereof in treating or preventing an inflammation associated with endogenous oxidized lipids and related conditions.
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Page/Page column 146-147
(2010/06/11)
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- Sarcoglycosides A-C, new O-glycosylglycerol derivatives from the South China sea soft coral Sarcophyton infundibuliforme
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Chemical examination of the soft coral Sarcophyton infundibuliforme collected from the South China Sea resulted in the isolation of the three new O-glycosylglycerol derivatives sarcoglycosides A-C (1 - 3), together with two known compounds, chimyl alcohol
- Li, Liang,Wang, Chang-Yun,Shao, Chang-Lun,Guo, Yue-Wei,Li, Guo-Qiang,Sun, Xue-Ping,Han, Lei,Huang, Hui,Guan, Hua-Shi
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experimental part
p. 1495 - 1502
(2009/10/17)
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- Autotaxin structure-activity relationships revealed through lysophosphatidylcholine analogs
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Autotaxin (ATX) catalyzes the hydrolysis of lysophosphatidylcholine (LPC) to form the bioactive lipid lysophosphatidic acid (LPA). LPA stimulates cell proliferation, cell survival, and cell migration and is involved in obesity, rheumatoid arthritis, neuropathic pain, atherosclerosis and various cancers, suggesting that ATX inhibitors have broad therapeutic potential. Product feedback inhibition of ATX by LPA has stimulated structure-activity studies focused on LPA analogs. However, LPA displays mixed mode inhibition, indicating that it can bind to both the enzyme and the enzyme-substrate complex. This suggests that LPA may not interact solely with the catalytic site. In this report we have prepared LPC analogs to help map out substrate structure-activity relationships. The structural variances include length and unsaturation of the fatty tail, choline and polar linker presence, acyl versus ether linkage of the hydrocarbon chain, and methylene and nitrogen replacement of the choline oxygen. All LPC analogs were assayed in competition with the synthetic substrate, FS-3, to show the preference ATX has for each alteration. Choline presence and methylene replacement of the choline oxygen were detrimental to ATX recognition. These findings provide insights into the structure of the enzyme in the vicinity of the catalytic site as well as suggesting that ATX produces rate enhancement, at least in part, by substrate destabilization.
- North, E. Jeffrey,Osborne, Daniel A.,Bridson, Peter K.,Baker, Daniel L.,Parrill, Abby L.
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experimental part
p. 3433 - 3442
(2009/09/30)
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- Regioselective and stereospecific acylation across oxirane- and silyloxy systems as a novel strategy to the synthesis of enantiomerically pure mono-, di- and triglycerides
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A trifluoroacetate-catalyzed opening of the oxirane ring of glycidyl derivatives bearing allylic acyl or alkyl functionalities with trifluoroacetic anhydride (TFAA), provides an efficient entry to configurationally homogeneous 1(3)-acyl- or 1(3)-O-alkyl-sn-glycerols. Selective introduction of tert-butyldimethylsilyl- (TBDMS), or triisopropylsilyl- (TIPS) transient protections at the terminal sites within these key intermediates secures 1(3)-acyl- or 1(3)-O-alkyl-3(1)-O-TBDMS (or TIPS)-sn-glycerols as general bifunctional precursors to 1,2(2,3)-diacyl-, 1(3)-O-alkyl-2-acyl- and 1,3-diacyl-sn-glycerols and hence triester isosters. Incorporation of a requisite acyl residue at the central carbon of the silylated synthons with a subsequent Et3N·3HF-promoted, direct trichloroacetylation across the siloxy system by trichloroacetic anhydride (TCAA), followed by cleavage of the trichloroacetyl group, affords the respective 1,2(2,3)-diacyl- or 1(3)-O-alkyl-2-acyl-sn-glycerols. Alternatively, a reaction sequence involving: (i) attachment of a trichloroacetyl fragment at the stereogenic C2-centre of the monosilylated glycerides; (ii) replacement of the silyl moiety by a short- or long-chain carboxylic acid residue by means of the acylating agent: tetra-n-butylammonium bromide (TBABr)-carboxylic acid anhydride (CAA)-trimethylsilyl bromide (TMSBr); and (iii) removal of the trichloroacetyl replacement, provides pure 1,3-diacyl-sn-glycerols. The TBABr-CAA-TMSBr reagent system allows also a one-step conversion of 1,2-diacylglycerol silyl ethers into homochiral triglycerides with predefined asymmetry and degree of unsaturation. These compounds can also be accessed via a two-step one-pot approach where the trichloroacetyl derivatives of 1,2(2,3)- or 1,3-diacyl-sn-glycerols serve as triester building blocks for establishing the third ester bond at preselected C3(1)- or C2-positions within the glycerol skeleton at the very last synthetic stage. In all instances, the target compounds were produced under mild conditions, in high enantiomeric purity, and in practically quantitative yields. The Royal Society of Chemistry 2007.
- Stamatov, Stephan D.,Stawinski, Jacek
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p. 3787 - 3800
(2008/10/09)
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- The chemical synthesis of bioactive glycosylphosphatidylinositols from Trypanosoma cruzi containing an unsaturated fatty acid in the lipid
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(Chemical Equation Presented) Protection strategy: Glycosylphosphatidylinositols (GPIs) from the Trypanosoma cruzi parasite (a causative agent of Chagas' disease) that contain an unsaturated fatty acid in the lipid moiety (see partial structure of 1, R = (CH2) 7CH=CH-(CH2)7CH3, and 2, R = (CH2)7CH= CHCH2CH=CH(CH2) 4CH3) were prepared by a strategy that employs non-benzyl-type protecting groups. The synthetic GPIs show similar biological activity to their natural counterparts.
- Yashunsky, Dmitry V.,Borodkin, Vladimir S.,Ferguson, Michael A. J.,Nikolaev, Andrei V.
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p. 468 - 474
(2007/10/03)
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- Stereospecific and regioselective opening of an oxirane system. A new efficient entry to 1- or 3-monoacyl- and 1- or 3-monoalkyl-sn-glycerols
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Acyl or alkyl glycidols in the presence of trifluoroacetic anhydride (TFAA) and trifluoroacetate anions, undergo a regioselective and stereospecific opening of the oxirane system to produce the bis(trifluoroacetylated) derivatives, from which the corresponding 1(3)-monoacyl-sn-glycerols or 1(3)-monoalkyl-sn-glycerols can be obtained directly in high purity (>99%) and in quantitative yields.
- Stamatov, Stephan D.,Stawinski, Jacek
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p. 1601 - 1605
(2007/10/03)
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- Lipase-catalysed kinetic resolution of 1-O-alkylglycerols by sequential transesterification
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The natural S-configured chimyl, batyl and selachyl alcohols of the 1-O-alkylglycerol type were prepared by enantioselective lipase-catalysed transesterification. Their racemates were synthesised in two steps by reacting racemic solketal with the bromides of the corresponding fatty alcohols and a subsequent conversion of the intermediates into the 1-O-alkylglycerols by deprotection under acidic aqueous conditions. The Pseudomonas fluorescens lipase was employed to kinetically resolve the racemic 1-O-alkylglycerols by a sequential diacetylation process to afford them virtually enantiomerically pure. Dramatic enantioselectivity increase was observed for the saturated chimyl (E = 17-32) and batyl (E = 14-38) alcohols at decreased temperature, whereas for the monounsaturated selachyl (E = 12-13) alcohol no such temperature effects were observed.
- Halldorsson, Arnar,Thordarson, Pall,Kristinsson, Bjorn,Magnusson, Carlos D.,Haraldsson, Gudmundur G.
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p. 2893 - 2899
(2007/10/03)
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- Methods employing and compositions containing defined oxidized phospholipids for prevention and treatment of atherosclerosis
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Novel synthetic forms of etherified oxidized phospholipids and methods of utilizing same for preventing and treating atherosclerosis and other related disorders, as well as inflammatory disorders, immune mediated diseases, autoimmune diseases and proliferative disorders, are provided. In addition, methods of synthesizing etherified and esterified oxidized phospholipids and of using same for preventing and treating atherosclerosis and other related disorders are also provided.
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- Stereospecific and regiospecific ring opening of glycidol with primary and secondary alcohols mediated by diisobutylaluminium hydride
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Regiospecific ring opening of (R)-(+)- or (S)-(-)-glycidol 1a, b with primary and secondary alcohols in the presence of diisobutylaluminium hydride provides 1-O-alkyl-sn-glycerol 2 without formation of the undesired regioisomer, 2-O-alkylglycerol 3.The configuration of the glycidol is preserved in the product.
- Erukulla, Ravi Kumar,Byun, Hoe-Sup,Locke, David C.,Bittman, Robert
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p. 2199 - 2200
(2007/10/02)
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- Novel chemo-enzymatic synthesis of optically active platelet activating factor
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This paper describes an enantioselective enzymatic synthesis of biologically active platelet activating factor (PAF) starting from chloropyruvic acid.
- Kumar,Bhakuni
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p. 3463 - 3466
(2007/10/02)
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- Synthesis of 1-O-alkyl-sn-glycerols and fluorescently labeled analogs from 2.5 O methylene D mannitol as precursor
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A new approach employing 2.5 O methylene D mannitol as precursor for the synthesis of naturally occurring and fluorescently labeled alkyl glycerols is described. From 2.5 O methylene D mannitol, which was prepared according to the method of Ness et al. [1], 2,2-0-methylene-bis-(3-O-trityl)-sn-glycerol, the central product, was synthesized to an enantiomerically pure molecule in four steps. 1-O-hexadecyl-sn-glycerol was prepared by condensation of hexadecyl methanesulfonate with the central product and by subsequent detritylation and cleavage of the methylene bridge. From the alkyl glycerol the different lipid classes can be synthesized by well known strategies. To form fluorescently labeled analogs of alkyl glycerols the fluorescence marker 7-chloro-4-nitrobenzo-2-oxa-1,3-diazole (NBD-Cl) was linked with the ω-amino group of 1-O-(12-aminododecyl)-sn-grycerol. Therefore the central product was condensed with 12-N-t-BOC-aminododecyl methanesulfonate. The methylene bridge, the trityl groups and the BOC protection group were cleaved with boron trifluoride/methanol in one step. 1-O-(12-NBD-aminododecyl)-sn-grycerol is useful as a biochemical substrate to build up fluorescently labeled neutral lipids and phospholipids.
- Kleuser, Burkhard,Schmidt, Norbert,Gercken, Guenther
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p. 111 - 122
(2007/10/02)
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- Sulfated glyceroglucolipids as inhibitors of bacterial adherence
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The subject invention involves pharmaceutical compositions comprising a sulfated glyceroglucolipid having the structure: STR1 wherein n is an integer of from 1 to about 5, R is hydrogen or C1 -C24 acyl or alkyl, R' is hydrogen or C1 -C24 acyl or alkyl, and M+ is a cationic moiety, and methods of treating or preventing gastroduodenal diseases or disorders caused by or associated with H. pylori by administering such compounds.
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- Regiospecific Opening of Glycidyl Derivatives Mediated by Boron Trifluoride. Asymmetric Synthesis of Ether-Linked Phospholipids
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A short, chiral synthesis of unnatural, cytotoxic ether-linked phospholipids is reported in which the key step is the very high regio- and stereospecific nucleophilic opening of the p-toluenesulfonate (1a, 1b) or tert-butyldiphenylsilyl ether (6a, 6b) derivatives of (R)- or (S)-glycidol with 1-hexadecanol using boron trifluoride etherate as catalyst.The enantiomeric excess of the ring-opened products was >94percent, as judged by 1H NMR and chiral HPLC analysis of the Mosher ester derivatives, indicating that ring opening of 1 and 6 proceeds without significant loss of optical purity.The synthetic strategy of using optically active glycidyl derivatives as the precursor of the glycerol backbone permits the desired enantiomers of 1(3)-O-2-O-methylphosphocholines (5a, 5b) to be generated in good yield and high optical purity from the ring-opened intermediates (2, 7) in three steps without the use of protecting groups.
- Guivisdalsky, Pedro N.,Bittman, Robert
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p. 4637 - 4642
(2007/10/02)
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- The Chemistry of L-Ascorbic and D-Isoascorbic Acids. 2. R and S Glyceraldehydes from a Common Intermediate
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(R)- and (S)-glyceraldehyde and glycerol derivatives have been prepared from (2R,3S)-1,2-O-isopropylidenebutane-1,2,3,4-tetrol. (2R,3S)- and (2S,3S)-1,2-O-benzylidenebutane-1,2,3,4-tetrol have been prepared and cleaved to give (R)- and (S)-1,2-O-benzylideneglyceraldehydes and -glycerols.The conservation of chirality and conversion to PAF analogues are also demonstrated.
- Mikkilineni, Amarendra B.,Kumar, Praveen,Abushanab, Elie
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p. 6005 - 6009
(2007/10/02)
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