cas 2423-10-1, Z-9-Octadecenal | Articles data

Articles about 2423-10-1Total 43 be found

Article title
Article abstract
Author
Journal number and time
Download

An organocatalyzed Stetter reaction as a bio-inspired tool for the synthesis of nucleic acid-based bioconjugates
An N-Heterocyclic Carbene (NHC) catalyzed biomimetic Stetter reaction was applied for the first time as a bioconjugation reaction to sensitive nucleoside-type biomolecules to provide original pyrrole linked nucleolipids. A versatile approach allowed the functionalization of thymidine at the three reactive positions (O-5′, O-3′ and N-3) providing a structural diversity oriented synthesis. This strategy was applied to the synthesis of an original glyconucleolipid amphiphile in the hope that the pyrrole aromatic moiety would induce additional self-assembling properties.
Hamoud, Aladin,Barthélémy, Philippe,Desvergnes, Valérie
p. 1760 - 1769
(2018)
Read Online

Newly synthesized oleylgingerol and oleylshogaol activate TRPV1 ion channels
The oleyl moiety in vanilloids is important in activating vanilloid receptor 1 (TRPV1), but there was no ingredient of ginger containing the oleyl moiety in the natural form. We synthesized oleylgingerol and oleylshogaol and then evaluated their potential to activate a rat TRPV1 channel. Oleylgingerol is a stronger TRPV1 agonist than natural gingerols, but oleylshogaol is a weaker agonist than natural shogaols. The difference in structure between oleylgingerol and oleylshogaol is only the hydroxy group at carbon-5. This hydroxy group might have an important role in activating a TRPV1 channel.
Morita, Akihito,Iwasaki, Yusaku,Kobata, Kenji,Yokogoshi, Hidehiko,Watanabe, Tatsuo
p. 2304 - 2307
(2007)
Read Online

Balancing the efficacy vs. the toxicity of promiscuous natural products: Paclitaxel-based acid-labile lipophilic prodrugs as promising chemotherapeutics
TumorSelect is an anticancer technology that combines cytotoxics, nanotechnology, and knowledge of human physiology to develop innovative therapeutic interventions with minimal undesirable side effects commonly observed in conventional chemotherapy. Tumors have a voracious appetite for cholesterol which facilitates tumor growth and fuels their proliferation. We have transformed this need into a stealth delivery system to disguise and deliver anticancer drugs with the assistance of both the human body and the tumor cell. Several designer prodrugs are incorporated within pseudo-LDL nanoparticles, which carry them to tumor tissues, are taken up, internalized, transformed into active drugs, and inhibit cancer cell proliferation. Highly lipophilic prodrug conjugates of paclitaxel suitable for incorporation into the pseudo-LDL nanoparticles of the TumorSelect delivery vehicle formulation were designed, synthesized, and evaluated in the panel of 24-h NCI-60 human tumor cell line screening to demonstrate the power of such an innovative approach. Taxane prodrugs, viz., ART-207 was synthesized by tethering paclitaxel to lipid moiety with the aid of a racemic solketal as a linker in cost-effective, simple, and straightforward synthetic transformations. In addition to the typical 24-h NCI screening protocol, these compounds were assessed for growth inhibition or killing of ovarian cell lines for 48 and 72h-time intervals and identified the long-lasting effectiveness of these lipophilic prodrugs. All possible, enantiomerically pure isomers of ART-207 were also synthesized, and cytotoxicities were biosimilar to racemic ART-207, suggesting that enantiopurity of linker has a negligible effect on cell proliferation. To substantiate further, ART-207 was evaluated for its in vivo tumor reduction efficacy by studying the xenograft model of ovarian cancer grown in SCID mice. Reduced weight loss (a measure of toxicity) in the ART-207 group was observed, even though it was dosed at 2.5x the paclitaxel equivalent of Abraxane. As a result, our delineated approach is anticipated to improve patient quality of life, patient retention in treatment regimes, post-treatment rapid recovery, and overall patient compliance without compromising the efficacy of the cytotoxic promiscuous natural products.
Chittiboyina, Amar G.,Claudio, Pier Paolo,Haider, Saqlain,McChesney, James D.,Penfornis, Patrice
(2021/10/19)

OLEIC ACID DERIVATIVES AS TREATMENTS FOR FRIEDREICH ATAXIA AND INHIBITORS OF FERROPTOSIS
The invention relates to compounds of Formula I or Formula II: to compositions comprising such compounds, and to methods of use thereof for treating neurdegenerative disorders, such as Friedreich ataxia.
-
Paragraph 00167

(2021/05/21)

Synthesis of (+/-)-Pregabalin and its novel lipophilic β-alkyl-substituted analogues from fatty chains
In this work, were synthesized for the first time a series of new lipophilic β-alkyl substituted GABA derivatives from fatty alkyl chains. The synthesis of these GABA analogues was investigated by two different bicomponent approaches as a key step. The results showed low yields in the path from aliphatic nitroolefins and Meldrum's acid, whereas the Knoevenagel condensation between aliphatic aldehydes and Meldrum's acid afforded fatty alkylidenes in good yields (75-97%). These compounds were subsequently subjected to a conjugate addition reaction with nitromethane, resulting in the fatty Michael adducts (in 87-97% yields) which were in turn submitted to a one pot domino hydrolysis-decarboxylation, leading to the isolation of β-alkyl-substituted γ-nitro acids in good yields (78-92%). Finally, the reduction of the fatty γ-nitro acids allowed for the access to new lipophilic β-alkyl substituted GABA analogues, which were isolated in high yields (90-98%). The new methodology was also applied to the synthesis of antiepileptic drug (+/-)-Pregabalin, which was obtained after four steps in high overall yield. This journal is
D'Oca, Caroline Da Ros Montes,Mass, Eduardo Bustos,Ongaratto, Renata Fontes,De Andrade, Arthur Motta,D'Oca, Marcelo G. Montes,Russowsky, Dennis
p. 13230 - 13239
(2020/08/28)

COMPOSITIONS FOR TRANSFECTING mRNA INTO A CELL AND THEIR APPLICATIONS
The present invention relates to compositions for transfecting a messenger RNA (m RNA) into a cell and their applications. The present invention is directed to a composition for transfecting a mRNA into a cell comprising a mRNA, at least one neutral lipid and a cationic lipid of formula (I), wherein R1 R2, R3, R4 and R5, (CH2)n and A- are as defined in the description. The present invention also relates to uses of said composition and to a method for in vitro transfection of live cells.
-
Page/Page column 59

(2020/05/29)

Photo-organocatalytic synthesis of acetals from aldehydes
A mild and green photo-organocatalytic protocol for the highly efficient acetalization of aldehydes has been developed. Utilizing thioxanthenone as the photocatalyst and inexpensive household lamps as the light source, a variety of aromatic and aliphatic aldehydes have been converted into acyclic and cyclic acetals in high yields. The reaction mechanism was extensively studied.
Nikitas, Nikolaos F.,Triandafillidi, Ierasia,Kokotos, Christoforos G.
supporting information
p. 669 - 674
(2019/02/14)

Lipidic synthetic alkaloids as SK3 channel modulators. Synthesis and biological evaluation of 2-substituted tetrahydropyridine derivatives with potential anti-metastatic activity
Small Conductance Calcium (Ca2+)-activated potassium (K+) channels (SKCa) are now proved to be involved in many cancer cell behaviors such as proliferation or migration. The SK3 channel isoform was particularly described in breast cancer where it can be associated with the Orai1 Ca2+ channel to form a complex that regulates the Ca2+ homeostasis during tumor development and acts as a potent mediator of bone metastases development in vivo. Until now, very few specific blockers of Orai1 and/or SK3 have been developed as potential anti-metastatic compounds. In this study, we illustrated the synthesis of new families of lipophilic pyridine and tetrahydropyridine derivatives designed as potential modulators of SK3 channel. The toxicity of the newly synthesized compounds and their migration effects were evaluated on the breast cancer cell line MDA-MB-435s. Two molecules (7a and 10c) demonstrated a significant decrease in the SK3 channel-dependent migration as well as the SK3/Orai1-related Ca2+ entry. Current measurements showed that these compounds are more likely SK3-selective. Taken all together these results suggest that such molecules could be considered as promising anti-metastatic drugs in breast cancer.
Braire, Julien,Chant?me, Aurélie,Dubreuil, Didier,Félix, Romain,Jaffrès, Paul-Alain,Kouba, Sana,Lebreton, Jacques,Mathé-Allainmat, Monique,Pipelier, Muriel,Potier-Cartereau, Marie,Trebak, Mohamed,Vandier, Christophe,Zhang, Xuexin
(2019/11/26)

Proline derivatives incorporating hydrophobic long-chain derived from natural and synthetic fatty acids
The α-hydrophobic long chain-α-amino esters are prepared by α-hydroxylation of a series of fatty acid esters [derived from oleic acid (OA), linoleic acid (LA), arachidonic acid (ARA) and docosahexaenoic acid (DHA)] followed by Mitsunobu reaction and hydrazinolysis of the phthalimide. These amino esters are mixed with aldehydes and electrophilic alkenes to give very good chemical yields and diastereoselectivities of prolinate derivatives incorporating a hydrophobic long chain at the α-position. This multicomponent 1,3-dipolar cycloaddition (1,3-DC) takes place at room temperature. The synthesis of the homologue hydrophobic chain of OA is performed by its oxidation to aldehyde/racemic N-tert-butylsulfinyl imine/Neff reaction. Final 1,3-DC with benzaldehyde and N-methylmaleimide affords homologue prolinate derivative in good yield.
Selva, Elisabet,Soto, J. Javier,Nájera, Carmen,Foubelo, Francisco,Sansano, José M.
p. 1378 - 1386
(2019/02/05)

Nickel-Catalyzed Selective Reduction of Carboxylic Acids to Aldehydes
The direct reduction of carboxylic acids to aldehydes is a fundamental transformation in organic synthesis. The combination of an air-stable Ni precatalyst, dimethyl dicarbonate as an activator, and silane reductant effects this reduction for a wide variety of substrates, including pharmaceutically relevant structures, in good yields and with no overreduction to alcohols. Moreover, this methodology is scalable, allows access to deuterated aldehydes, and is also compatible with one-pot utilization of the aldehyde products.
Iosub, Andrei V.,Morav?ík, ?tefan,Wallentin, Carl-Johan,Bergman, Joakim
supporting information
p. 7804 - 7808
(2019/10/14)

Multicatalytic Stereoselective Synthesis of Highly Substituted Alkenes by Sequential Isomerization/Cross-Coupling Reactions
Starting from readily available alkenyl methyl ethers, the stereoselective preparation of highly substituted alkenes by two complementary multicatalytic sequential isomerization/cross-coupling sequences is described. Both elementary steps of these sequences are challenging processes when considered independently. A cationic iridium catalyst was identified for the stereoselective isomerization of allyl methyl ethers and was found to be compatible with a nickel catalyst for the subsequent cross-coupling of the in situ generated methyl vinyl ethers with various Grignard reagents. The method is compatible with sensitive functional groups and a multitude of olefinic substitution patterns to deliver products with high control of the newly generated C=C bond. A highly enantioselective variant of this [Ir/Ni] sequence has been established using a chiral iridium precatalyst. A complementary [Pd/Ni] catalytic sequence has been optimized for alkenyl methyl ethers with a remote C=C bond. The final alkenes were isolated with a lower level of stereocontrol. Upon proper choice of the Grignard reagent, we demonstrated that C(sp2) - C(sp2) and C(sp2) - C(sp3) bonds can be constructed with both systems delivering products that would be difficult to access by conventional methods.
Romano, Ciro,Mazet, Clément
supporting information
p. 4743 - 4750
(2018/04/10)

Identification of in situ flower volatiles from kiwifruit (Actinidia chinensis var. deliciosa) cultivars and their male pollenisers in a New Zealand orchard
In situ flower volatiles from six kiwifruit cultivars (Actinidia chinensis var. deliciosa); ‘Hayward’, ‘Chieftain’, ‘M56’, ‘Zes007’ (Green11), ‘M36’, and ‘M43’ were collected by dynamic headspace sampling. Forty-five compounds were detected in the headspace of the flowers, with straight chain hydrocarbons and terpenes accounting for >98% of the volatiles emitted quantitatively across the six cultivars. Of these hydrocarbons, (3Z,6Z,9Z)-heptadecatriene is reported for the first time from a floral source while (8Z)-hexadecene and (9Z)-nonadecene are reported for the first time from kiwifruit flowers. All three hydrocarbons were verified by synthesis. Quantitative comparison of the six honey bee perceived compounds from the headspace of the cultivars showed that the males ‘M36’ and ‘M43’ closely matched the female cultivar Green11 that they are used to pollinate. Males ‘M56’ and ‘Chieftain’ were not as closely matched to the female cultivar ‘Hayward’ that they are used to pollinate. The male ‘M56’ in particular differed significantly from the female ‘Hayward’ in four of the six honey bee perceived compounds.
Twidle, Andrew M.,Suckling, David M.,Seal, Alan G.,Fedrizzi, Bruno,Pilkington, Lisa I.,Barker, David
p. 61 - 69
(2017/05/31)

ALKENYL SUBSTITUTED 2,5-PIPERAZINEDIONES AND THEIR USE IN COMPOSITIONS FOR DELIVERING AN AGENT TO A SUBJECT OR CELL
Provided herein are compounds of Formula (I), and salts thereof, wherein each instance of RL is independently optionally substituted C6-C40 alkenyl. Further provided are compositions comprising a compound of Formula (I) and an agent. Further provided are methods and kits using the compositions for delivering an agent to a subject or cell and for treating and/or preventing a range of diseases. Further provided are methods of preparing compounds of Formula (I) and precursors thereof.
-
Paragraph 00281; 00282

(2017/01/02)

Selective reduction of carboxylic acids to aldehydes through manganese catalysed hydrosilylation
The direct reduction of carboxylic acids to disilylacetals was achieved through a manganese catalyzed hydrosilylation reaction in the presence of triethylsilane under mild conditions, at r.t. and under UV irradiation (350 nm). The aldehydes were obtained in good to excellent yields after acidic hydrolysis.
Zheng, Jianxia,Chevance, Soizic,Darcel, Christophe,Sortais, Jean-Baptiste
supporting information
p. 10010 - 10012
(2013/10/22)

Selective reduction of carboxylic acids to aldehydes catalyzed by B(C 6F5)3
B(C6F5)3 efficiently catalyzes hydrosilylation of aliphatic and aromatic carboxylic acids to produce disilyl acetals under mild conditions. Catalyst loadings can be as low as 0.05 mol %, and bulky tertiary silanes are favored to give selectively the acetals. Acidic workup of the disilyl acetals results in the formation of aldehydes in good to excellent yields.
Bezier, David,Park, Sehoon,Brookhart, Maurice
supporting information
p. 496 - 499
(2013/03/29)

Highly efficient Cu(I)-catalyzed oxidation of alcohols to ketones and aldehydes with diaziridinone
A novel and efficient Cu(I)-catalyzed oxidation of alcohols has been achieved with di-tert-butyldiaziridinone as the oxidant under mild conditions. A wide variety of primary and secondary alcohols with various functional groups can be oxidized to aldehydes and ketones in high yields. The reaction proceeds under neutral conditions making it compatible with acid- or base-sensitive substrates, and it is amenable to gram scale.
Zhu, Yingguang,Zhao, Baoguo,Shi, Yian
supporting information
p. 992 - 995
(2013/04/10)

Practical one-pot sequence for the asymmetric synthesis of 1,2 diols from primary alcohols
A practical one-pot three-step sequence is reported for the asymmetric synthesis of α-benzoyloxylated alcohols from primary alcohols. Good overall yields (36-52%) and enantioselectivities (91-94% e.e.) are obtained using a commercial organocatalyst in the key oxylation reaction. A simple modification in the protocol allows the formation of enantioenriched γ-benzoyloxylated α,β-unsaturated ester from alcohol. Synthetic utility has been harnessed to the easy preparation of (-)-γ-octalactone from hexan-1-ol.
Hermange, Philippe,Portalier, Fran?ois,Thomassigny, Christine,Greck, Christine
supporting information
p. 1052 - 1055
(2013/04/10)

Synthesis of (Z)-(2′R)-1-O-(2′-methoxynonadec-10′-enyl)- sn-glycerol, a new analog of bioactive ether lipids
An unsaturated 2-methoxy-substituted 1-O-alkylglycerol, (Z)-(2′R)-1-O-(2′-methoxynonadec-10′-enyl)-sn-glycerol, a new analog of bioactive ether lipids, was synthesized from oleic acid and 2,3-isopropylidene-sn-glycerol. The two key steps of this synthesis were the conversion of oleyl aldehyde to a monounsaturated epoxide using Matteson's method followed by hydrolytic kinetic resolution and a nucleophilic epoxide opening by 2,3-isopropylidene-sn-glycerol in the presence of potassium tert-butoxide in anhydrous DMF, which appeared to be a good reagent for this purpose. Furthermore, the diol by-product of the HKR process was also easily converted back to the starting epoxide thus almost doubling the amount of target molecule.
Pemha, René,Pegnyemb, Dieudonné Emmanuel,Mosset, Paul
experimental part
p. 2973 - 2983
(2012/06/01)

Selective switchable iron-catalyzed hydrosilylation of carboxylic acids
Selective reduction of carboxylic acids either to aldehydes or alcohols is achieved using a one pot procedure based on iron-catalyzed hydrosilylations. Using phenylsilane and (COD)Fe(CO)3 catalyst under UV-irradiation at rt, alcohols were obtained specifically in good yields, whereas aldehydes were selectively obtained using TMDS and (t-PBO)Fe(CO)3 catalyst under thermal activation.
Misal Castro, Luis C.,Li, Haoquan,Sortais, Jean-Baptiste,Darcel, Christophe
supporting information
p. 10514 - 10516,3
(2020/09/02)

Comprehensive screening of octopus amphiphiles as DNA activators in lipid bilayers: Implications on transport, sensing and cellular uptake
Dynamic octopus amphiphiles contain one charged "head," here a guanidinium cation, together several hydrophobic "tails" (or "tentacles") that can be attached and exchanged in situ by reversible hydrazone formation. Quite surprisingly, their ability to activate DNA as transporters in lipid bilayer membranes was found to increase with the number of tails (up to four) as well as with their length (up to eight carbons). Both encouraged and puzzled by these results, we decided that a comprehensive screening of octopus amphiphiles with regard to number (from one to six) and length (from three to eighteen carbons) of their tails would be appropriate at this point. For this purpose, we here report the synthesis of cationic hexahydrazide peptide dendrons together with that of aldehydes with long, saturated, unsaturated and branched hydrophobic tails. Comprehensive screening of the completed collection of tails and heads reveals that the ability of octopus amphiphiles to activate DNA transporters shifts with increasing number of tails to decreasing length of the tails. Moreover, cis-alkenyl and branched alkyl tails are more active than their linear analogs, branched aromatic tails are best. These overall very meaningful trends for octopus amphiphiles will be of importance for sensing applications and fragrant cellular uptake.
Montenegro, Javier,Fin, Andrea,Matile, Stefan
supporting information; experimental part
p. 2641 - 2647
(2011/05/15)

2-iodoxybenzenesulfonic acid as an extremely active catalyst for the selective oxidation of alcohols to aldehydes, ketones, carboxylic acids, and enones with oxone
Electron-donating group-substituted 2-iodoxybenzoic acids (IBXs) such as5-Me-IBX (1g), 5-MeO-IBX (1h), and 4,5-Me2-IBX were superior to IBX 1a as catalysts for the oxidation of alcohols with Oxone (a trad emark of DuPont) under nonaqueous conditions, although Oxone was almost insoluble in most organic solvents. The catalytic oxidation proceeded more rapidly and cleanly in nitromethane. Furthermore, 2-iodoxybenzenesulfonic acid (IBS, 6a) was much more active than modified IBXs. Thus, we established a highly efficient and selective method for the oxidation of primary and secondary alcohols to carbonyl compounds such as aldehydes, carboxylic acids, and ketones with Oxone in nonaqueous nitromethane, acetonitrile, or ethyl acetate in the presence of 0.05-5molpercentof 6a, which was generated in situ from 2-iodobenzenesulfonic acid (7a) or its sodium salt. Cycloalkanones could be further oxidized to α,β- cycloalkenones or lactones by controlling the amounts of Oxone under the same conditions as above. When Oxone was used under nonaqueous conditions, Oxone wastes could be removed by simple filtration. Based on theoretical calculations, we considered that the relatively ionic character of the intramolecular hypervalent iodine-OSO2 bond of IBS might lower the twisting barrier of the alkoxyperiodinane intermediate 16.
Uyanik, Muhammet,Akakura, Matsujiro,Ishihara, Kazuaki
supporting information; experimental part
p. 251 - 262
(2009/06/28)

METHOD FOR PRODUCING CARBONYL COMPOUND AN PRO-OXIDANT USED FOR PRODUCTION OF CARBONYL COMPOUND
The invention provides a process for the preparation of a carbonyl compound in high efficiency by oxidizing an alcohol. The process for the preparation of a carbonyl compound of the present invention includes a step of oxidizing an alcohol in the presence of a compound of the formula (I) or a derivative or a salt thereof, and an oxidant, wherein R1 and R2 independently represent hydrogen, a halogen, a nitro or acidic group, or an alkyl or alkoxy group, each of which optionally has a substituent, or R1 and R2 combine the two carbon atoms to which they are boned to form an aromatic ring.
-
Page/Page column 12; 14-15

(2009/08/16)

Enzymatic method of making aldehydes from fatty acids
The present invention provides methods of enzymatically preparing aldehydes from fatty acids by utilizing a carboxylic acid reductase enzyme to reduce the fatty acids to their corresponding aldehydes. The present invention also provides aldehydes prepared by the methods of the invention.
-
Page/Page column 15-16

(2009/03/07)

Identification of Darmstoff analogs as selective agonists and antagonists of lysophosphatidic acid receptors
Darmstoff describes a family of gut smooth muscle-stimulating acetal phosphatidic acids initially isolated and characterized from the bath fluid of stimulated gut over 50 years ago. Despite similar structural and biological profiles, Darmstoff analogs have not previously been examined as potential LPA mimetics. Here, we report a facile method for the synthesis of potassium salts of Darmstoff analogs. To understand the effect of stereochemistry on lysophosphatidic acid mimetic activity, synthesis of optically pure stereoisomers of selected Darmstoff analogs was achieved starting with chiral methyl glycerates. Each Darmstoff analog was evaluated for subtype-specific LPA receptor agonist/antagonist activity, PPARγ activation, and autotaxin inhibition. From this study we identified compound 12 as a pan-antagonist and several pan-agonists for the LPA1-3 receptors. Introduction of an aromatic ring in the lipid chain such as analog 22 produced a subtype-specific LPA3 agonist with an EC50 of 692 nM. Interestingly, regardless of their LPA1/2/3 ligand properties all of the Darmstoff analogs tested activated PPARγ. However, these compounds are weak inhibitors of autotaxin. The results indicate that Darmstoff analogs constitute a novel class of lysophosphatidic acid mimetics.
Gududuru, Veeresa,Zeng, Kui,Tsukahara, Ryoko,Makarova, Natalia,Fujiwara, Yuko,Pigg, Kathryn R.,Baker, Daniel L.,Tigyi, Gabor,Miller, Duane D.
p. 451 - 456
(2007/10/03)

One-pot synthesis of aldehydes or ketones from carboxylic acids via in situ generation of Weinreb amides using the Deoxo-Fluor reagent
A one-pot, high yield conversion of carboxylic acids to the corresponding aldehydes and ketones is described. The highlight of this methodology is the in situ generation of Weinreb amides with the Deoxo-Fluor reagent, which undergo nucleophilic reaction with DIBAL-H and Grignard reagents.
Kangani, Cyrous O.,Kelley, David E.,Day, Billy W.
p. 6289 - 6292
(2007/10/03)

Synthesis of a novel class of fatty acids-derived isoquinolines
Two series of novel tetrahydroisoquinoline derivatives bearing at C-1 position a carbon chain derived from fatty acids were prepared employing two complementary synthetic methodologies. The Pictet-Spengler condensation was performed on myristyl, palmityl, stearyl and oleyl aldehydes, whereas the Bischler-Napieralski cyclization used pelargonic, stearic, linolenic and arachidonic acids. The ability to apply both methods allows further labeling of the final 1-substituted-1,2,3,4-tetrahydroisoquinolines for biological studies.
Matuszewska, Iwona,Leniewski, Andrzej,Roszkowski, Piotr,Czarnocki, Zbigniew
p. 131 - 145
(2007/10/03)

Cationic lipids with serine backbone
The present invention provides cationic lipids with serine backbone, a composition for transferring biologically active molecules into cells and/or tissues comprising said cationic lipids, a process for the manufacture of said lipids, the use of said lipids as constituent of a transfection agent and a method for transferring biologically active molecules into cells and/or into tissues or for gene therapy.
-
Page 12

(2008/06/13)

Anchor dependency for non-glycerol based cationic lipofectins: Mixed bag of regular and anomalous transfection profiles
Although detailed structure-activity, physicochemical and biophysical investigations in probing the anchor influence in liposomal gene delivery have been reported for glycerol-based transfection lipids, the corresponding investigation for non-glycerol based simple monocationic transfection lipids have not yet been undertaken. Towards this end, herein, we delineate our structure-activity and physicochemical approach in deciphering the anchor dependency in liposomal gene delivery using fifteen new structural analogues (lipids 1-15) of recently reported non-glycerol based monocationic transfection lipids. The C14 analogues in both series 1 (lipids 1-6) and series 2 (lipids 7-15) showed maximum efficiency in transfecting COS-1 and CHO cells. However, the C12 analogue of the ether series (lipid 3) exhibited a seemingly anomalous behavior compared with its transfection efficient C10 and C14 analogues (lipids 2 and 4) in being completely inefficient to transfect both COS-1 and CHO cells. The present structure-activity investigation also convincingly demonstrates that enhancement of transfection efficiencies through incorporation of membrane re-organizing unsaturation elements in the hydrophobic anchor of cationic lipids is not universal but cell dependent. The strength of the interaction of lipids 1-15 with DNA was assessed by their ability to exclude ethidium bromide bound to the DNA. Cationic lipids with long hydrophobic tails were found, in general, to be efficient in excluding EtBr from DNA. Gel to liquid crystalline transition temperatures of the lipids was measured by fluorescence anisotropy measurement technique. In general (lipid 2 being an exception), transfection efficient lipids were found to have their mid transition temperatures at or below physiological temperatures (37°C).
Singh, Rajkumar Sunil,Mukherjee, Koushik,Banerjee, Rajkumar,Chaudhuri, Arabinda,Hait, Samik Kumar,Moulik, Satya Priya,Ramadas, Yerramsetti,Vijayalakshmi, Amash,Rao, Nalam Madhusudhana
p. 900 - 909
(2007/10/03)

Synthesis and application of 2,6-dicarboxypyridinium chlorochromate as a new oxidizing reagent for alcohols, silyl ethers, and THP ethers under mild and non-aqueous conditions
2,6-Dicarboxypyridinium chlorochromate can be used as a rapid, mild and efficient reagent for oxidation of alcohols, silyl ethers and THP ethers to their carbonyl compounds.
Tajbakhsh, Mahmood,Hosseinzadeh, Rahman,Niaki, Mohammad Yazdani
p. 508 - 510
(2007/10/03)

Direct hydrogenation of carboxylic acids to corresponding aldehydes catalyzed by palladium complexes
A variety of carboxylic acids can be directly hydrogenated into the corresponding aldehydes in high yields by using homogeneous catalysts such as [Pd(PPh3)4] or combination of Pd(OAc)2 with tertiary phosphines in the presence of an excess amount of 2,2-dimethylpropionic anhydride (pivalic anhydride). As a typical example, octanoic acid can be convened into octanal in 99% yield in 3 h at 80 °C under 3.0 MPa of H2 in acetone in the presence of pivalic anhydride and a catalyst system composed of Pd(OAc)2 + 5P(p-tol)3. Such hydrogenation is widely applicable to various aliphatic, aromatic, and heterocyclic carboxylic acids as well as to di- and tribasic carboxylic acids. The process allows the presence of other functional groups such as ketonic carbonyl, nitrile, and ester groups and even internal C=C bonds. Heterogeneous palladium catalyst such as palladium on carbon also showed some catalytic activities.
Nagayama,Shimizu,Yamamoto
p. 1803 - 1815
(2007/10/03)

Preparation of acyl(carboxylato)bis(tertiary phosphine)palladium(II) complexes by C-O bond cleavage of carboxylic anhydrides on interaction with palladium(0) complexes. Catalytic hydrogenation of carboxylic anhydrides to aldehydes by palladium complexes
Acyclic anhydrides oxidatively added to [Pd(styrene)(PMeR2)2] (R = Me, 2a; Ph, 2b) under mild conditions with C-O bond cleavage to give the corresponding trans-acyl(carboxylato)palladium complexes 3a-3h. Cyclic acid arthydrides also added to 2a to yield trans-acyl(carboxylato)palladium complexes 4a-4c, while reaction of 2a with phthalic anhydride afforded the palladalactone 4d generated via oxidative addition followed by decarbonylation. The acetyl(acetato)palladium complex 3a reacted with dihydrogen or formic acid to give acetaldehyde and acetic acid. Catalytic hydrogenation of acyclic anhydrides by a palladium complex was achieved to form the corresponding aldehydes and carboxylic acids.
Nagayama, Kazuhiro,Kawataka, Futoshi,Sakamoto, Masato,Shimizu, Isao,Yamamoto, Akio
p. 573 - 580
(2007/10/03)

Direct hydrogenation of carboxylic acids to corresponding aldehydes catalyzed by palladium complexes in the presence of pivalic anhydride
Carboxylic acids are catalytically hydrogenated into corresponding aldehydes by palladium complexes in the presence of pivalic (trimethylacetic) anhydride under H2. Less hindered aliphatic and aromatic acids are reduced to aldehydes in high yields The method is also applicable to hydrogenation of dibasic carboxylic acids and carboxylic acids containing heterocyclic groups.
Nagayama, Kazuhiro,Shimizu, Isao,Yamamoto, Akio
p. 1143 - 1144
(2007/10/03)

Formic acid as a hydride donor: Reduction of acid chlorides to aldehydes
Chlorides of a variety of acids: primary, secondary, tertiary, long chain aliphatic and αβ-unsaturated have been converted into aldehydes by reduction with formic acid at pH 9-10 at room temperature in high yields.
Shamsuddin,Zobairi, Md. Omair,Musharraf, Mohd. Asif
p. 8153 - 8154
(2007/10/03)

Polymerization of the inverted hexagonal phase
The hydration of polar natural and synthetic lipids yields a variety of lipid phases including various inverted cubic phases and the inverted hexagonal (H(II)) phase. The H(II) phase can be considered as aqueous columns encased with a monolayer of lipids and arranged in a hexagonal pattern. The polar head groups are well-ordered at the water interface, whereas the lipid tails are disordered to fill the volume between the tubes of water. A particularly interesting characteristic of the H(II) phase is the large temperature effect on the basis vector length d of the hexagonal lattice. Previous studies indicate that polymerization of the lipid region of the H(II) phase might reduce the sensitivity of the basis vector to temperature. A phosphoethanolamine (PE) was designed and synthesized with dienoyl groups in each lipid tail in an attempt to cross-link the lipids around and along the water core of the H(II) phase. The synthesis of the the PE was accomplished by acylation of 3-(4-methoxybenzyl)-sn-glycerol with 2,4,13- (E,E,Z)-docosatrienoic acid, followed by deprotection, then phosphorylation with dichloro-[[N-[(2,2,2- trichloroethoxy)carbonyl]-2-aminolethyl]phosphinic acid to give the Troc-PE, which was converted to the PE with activated zinc and acetic acid. The hydrated PE (1/1 weight lipid/water) formed the H(II) phase over an extended temperature range. Polymerization to high conversion was accomplished at 60 °C with the aid of redox initiators. Polymerization was followed in-situ using X-ray diffraction over a period of 48 h. The scattering, which weakened over the course of the reaction, remained consistent with a hexagonal phase. Temperature cycling of the polymerized H(II) phase showed an unaltered pattern on decreasing temperature while maintaining the same lattice parameter, unlike that of the unpolymerized phase where the value increased with decreasing temperature. Thus it is possible to fix the dimensions of the H(II) phase by cross-linking polymerization of appropriately designed reactive lipids.
Srisiri, Warunee,Sisson, Thomas M.,O'Brien, David F.,McGrath,Han, Yuqi,Gruner, Sol M.
p. 4866 - 4873
(2007/10/03)

Synthesis of aldehydes from carboxylic acids via 2-imidazolines
The use of readily available 2-substituted-2-imidazolines as precursors to 2-hydroxy aldehyde, unsaturated aldehyde and a variety of functionalized aldehydes is reported. It provides a novel method for the preparation of aldehydes from carboxylic acids via 2-substituted-2-imidazolines.
Shi, Zhen,Gu, Huan
p. 2701 - 2707
(2007/10/03)

Ein allgemein einsetzbares, mildes Eintopfverfahren zur Umwandlung von Amiden in Aldehyde
Keywords: Aldehyde; Enamine; Hydrosilylierungen; Titanverbindungen
Bower, Shelley,Kreutzer, Kristina A.,Buchwald, Stephen L.
p. 1662 - 1664
(2007/10/03)

Pheromones via organoboranes: Part IV - Synthesis of (Z)-9-tricosene (Muscalure)
Synthesis of (Z)-9-tricosene (muscalure) (9) is reported starting from oleyl alcohol by two carbon homologation via dianion of phenoxyacetic acid followed by reduction (LAH), oxidation (PCC) and Grignard reaction.
Dhillon, Ranjit S.,Singh, Rupinder P.,Singh, Jasvinder
p. 718 - 721
(2007/10/03)

Synthesis of (2,3-13C2) eruric acid
The synthesis of (2,3-13C2) erucic acid, for use in metabolic studies, is reported. The synthesis employs a repeated 3 step reaction sequence using 13C labeled triethylphosphonoacetate to extend C(18:1), oleyl alcohol, by 4 carbons. The starting alcohol is first oxidized with PCC and the resulting aldehyde is condensed with triethyl(1-13C)phosphonoacetate. The product, an α,β unsaturated ester, is reduced with (Ph3PCuH)6 to ethyl eicosenoate. Reduction with LAH gives eicosenoyl alcohol. A repetition of the reaction sequence using triethyl(2-13C) phosphonoacetate results in ethyl(2,3-13C2)erucate. The (2,3-13C2) erucic acid, obtianed by hydrolysis with alcoholic KOH, gave 13C NMR signals of δ 24.6 and 34.1 ppm for C-3 and C-2 respectively with a J = 34.9 Hz. The overall yield was 5.5%.
Olsen,Bukata
p. 899 - 906
(2007/10/02)

Cadmium Chloride-Magnesium-Water: A New System For Reduction of Various Organic Functionalities
Cadmium chloride-magnesium-THF-water efficiently reduced aldehydes and ketones to their corresponding alcohols, epoxide to mono-alcohol, benzyl halide to toluene, acid chloride to aldehyde and hydrolyzed thioketals to corresponding ketones. Key words: Cadmium chloride-magnesium-THF-H2O, reductions.
Bordoloi, Manobjyoti
p. 1681 - 1684
(2007/10/02)

New Method for the Selective Reduction of Amides
A new procedure was developed for the reduction of tertiary aliphatic, olefinic, and aromatic amides to aldehydes.Reaction of the amides (1), (5), (7), (9), (11), (13), (15), and (17) with ethyl or methyl trifluoromethanesulphonate in CH2Cl2 at room temperature and then with L-Selectride at -78 deg C gave the corresponding aldehydes (2), (6), (8), (10), (12), (14), (16), and (18), respectively.A second functional group, including CO2R, C=C, CH(OCH2CH2O), and CN, in these amides was found to be inert under the conditions employed.These selective reductions gave the desired aldehydes in 50-73percent isolated yields and in >95percent yields based on converted amides.
Tsay, Shwu-Chen,Robl, Jeffrey A.,Hwu, Jih Ru
p. 757 - 759
(2007/10/02)

Darmstoff Analogues. 2. Ring and Side-Chain Effects on Smooth-Muscle Contraction
2-cis-Δ8-Heptadecenyl-4-(hydroxymethyl)-1,3-dioxolane monosodium phosphate (1b) has been shown to be present as a major component of Darmstoff in mammalian intestine and to be a potent inducer for contraction of intestinal smooth muscle.The analogous 2-pentadecyl material 1a, also found abundantly in the intestine, is inactive.In this study, synthesis of phosphorylated hydroxymethyl-1,4-dioxanes, -tetrahydrofurans, -cyclopentanes, and -oxathiolanes bearing both oleyl and palmityl side chains is reported.Of these, 2-(hydroxymethyl)-5-cis-Δ8-heptadecenyl-1,4-dioxane monosodium phosphate (2b) exhibits about 12percent of the activity of 1b.Its pentadecyl analogue 2a, like 1a, is totally inactive, as are all other compounds prepared.The results indicate that Darmstoff-like compounds exhibit specific chemical requirements for activity and that where activity is encountered, the side-chain specificity noted in 1a and 1b can be preserved.
Wiley, Robert A.,Harris, Wayne T.,Brungardt, Catherine,Marx, Michael
p. 121 - 125
(2007/10/02)

THE CHAIN LENGTHENING OF ALIPHATIC ALDEHYDES WITH THE AID OF "NUCLEOPHILIC CARBENE"
The addition of "nucleophilic carbene" on 1,2,4-triazole bases (2) and aldehydes is decisively influenced by the anion present. 5-(α-Hydroxyalkyl)-1,2,4-triazolium chlorides, formed in the addition reaction of 3-methylthio-1,4-diphenyl-1,2,4-triazolium chloride (1c) with aldehydes, can be easily reduced to 5-alkyl-1,2,4-triazolium iodides (5).Reduction of these with NaBH4 affords aldehydes by acidic hydrolysis or carboxylic acids by alkaline hydrolysis, the carbon chain of which has been lengthened by one CH2 group, as compared to the starting aldehyde.
Doleschall, Gabor
p. 4183 - 4186
(2007/10/02)

Oxidation of long-chain alcohols to aldehydes by the dipyridine chromic anhydride complex
The oxidation of alcohols by the dipyridine chromic anhydride complex is judged to be most suitable for the preparation of long-chain aliphatic aldehydes. Thus, cis-9-octadecenol is oxidized in 93% yield within 30 min at room temperature with no detectabl
Valicenti,Holman
p. 389 - 392
(2007/10/12)