5675-51-4Relevant articles and documents
MELYNES, POLYACETYLENE CONSTITUENTS FROM A VANUATU MARINE SPONGE
Quinoa, Emilio,Crews, Phillip
, p. 2037 - 2040 (1988)
The structures of three long chain polyeneyne triols, melynes A, B, C are established from degradation reactions, from NMR data and from extensive HREIMS data.
A Macrocyclic Tetraether Bolaamphiphile and an Oligoamino α,ο-Dicarboxylate Combine To Form Monolayered, Porous Vesicle Membranes, Which Are Reversibly Sealed by EDTA and Other Bulky Anions
Fuhrhop, Juergen-Hinrich,Liman, Ulrich,Koesling, Volker
, p. 6840 - 6845 (1988)
The hydrophobic tetraether macrocycle 1,20-disulfonyl-4,17,23,36-tetraoxacyclooctatriacontane is obtained in the gram scale from 2,2-dithioethanol and 1,12-dodecanediol.Oxidation or methylation of the sulfur atoms leads to bolaamphiphiles which vesiculate on ultrasonication.These amphiphiles are simple analogues of the membrane constituents of archaebacteria.The vesicles are acid stable and entrap metal ions (Li+, Fe2+) as well as fluorescent dyes (pyranine, calcein).The dipotassium salt of 2,19-dimethyl-3,6,9,12,15,18-hexaazaeicosanedicarboxylate introduces pores for metal ions into the membrane, but not for the organic dyes.The caionic pores could be closed with water-soluble bulky anions such as camphorsulfonic acid, taurine, and EDTA.The EDTA stopper was extracted from the pore by an excess of Fe(II) ions.Excess of EDTA reclosed the pore.This cycle could be repeated several times.
Multi-enzymatic cascade reactions with Escherichia coli-based modules for synthesizing various bioplastic monomers from fatty acid methyl esters?
Jung, Hyunsang,Kim, Byung-Gee,Kim, Ye Chan,Park, Beom Gi,Patil, Mahesh D.,Sarak, Sharad,Yoo, Hee-Wang,Yun, Hyungdon
supporting information, p. 2222 - 2231 (2022/04/03)
Multi-enzymatic cascade reaction systems were designed to generate biopolymer monomers using Escherichia coli-based cell modules, capable of carrying out one-pot reactions. Three cell-based modules, including a ω-hydroxylation module (Cell-Hm) to convert fatty acid methyl esters (FAMEs) to ω-hydroxy fatty acids (ω-HFAs), an amination module (Cell-Am) to convert terminal alcohol groups of the substrate to amine groups, and a reduction module (Cell-Rm) to convert the carboxyl groups of fatty acids to alcohol groups, were constructed. The product-oriented assembly of these cell modules involving multi-enzymatic cascade reactions generated ω-ADAs (up to 46 mM), α,ω-diols (up to 29 mM), ω-amino alcohols (up to 29 mM) and α,ω-diamines (up to 21 mM) from 100 mM corresponding FAME substrates with varying carbon chain length (C8, C10, and C12). Finally 12-ADA and 1,12-diol were purified with isolated yields of 66.5% and 52.5%, respectively. The multi-enzymatic cascade reactions reported herein present an elegant ‘greener’ alternative for the biosynthesis of various biopolymer monomers from renewable saturated fatty acids.
Novel insights into oxidation of fatty acids and fatty alcohols by cytochrome P450 monooxygenase CYP4B1
Thesseling, Florian A.,Hutter, Michael C.,Wiek, Constanze,Kowalski, John P.,Rettie, Allan E.,Girhard, Marco
, (2019/12/12)
CYP4B1 is an enigmatic mammalian cytochrome P450 monooxygenase acting at the interface between xenobiotic and endobiotic metabolism. A prominent CYP4B1 substrate is the furan pro-toxin 4-ipomeanol (IPO). Our recent investigation on metabolism of IPO related compounds that maintain the furan functionality of IPO while replacing its alcohol group with alkyl chains of varying structure and length revealed that, in addition to cytotoxic reactive metabolite formation (resulting from furan activation) non-cytotoxic ω-hydroxylation at the alkyl chain can also occur. We hypothesized that substrate reorientations may happen in the active site of CYP4B1. These findings prompted us to re-investigate oxidation of unsaturated fatty acids and fatty alcohols with C9–C16 carbon chain length by CYP4B1. Strikingly, we found that besides the previously reported ω- and ω-1-hydroxylations, CYP4B1 is also capable of α-, β-, γ-, and δ-fatty acid hydroxylation. In contrast, fatty alcohols of the same chain length are exclusively hydroxylated at ω, ω-1, and ω-2 positions. Docking results for the corresponding CYP4B1-substrate complexes revealed that fatty acids can adopt U-shaped bonding conformations, such that carbon atoms in both arms may approach the heme-iron. Quantum chemical estimates of activation energies of the hydrogen radical abstraction by the reactive compound 1 as well as electron densities of the substrate orbitals led to the conclusion that fatty acid and fatty alcohol oxidations by CYP4B1 are kinetically controlled reactions.
Preparation of a Series of Supported Nonsymmetrical PNP-Pincer Ligands and the Application in Ester Hydrogenation
Konrath, Robert,Spannenberg, Anke,Kamer, Paul C. J.
supporting information, p. 15341 - 15350 (2019/11/14)
In contrast to their symmetrical analogues, nonsymmetrical PNP-type ligand motifs have been less investigated despite the modular pincer structure. However, the introduction of mixed phosphorus donor moieties provides access to a larger variety of PNP ligands. Herein, a facile solid-phase synthesis approach towards a diverse PNP-pincer ligand library of 14 members is reported. Contrary to often challenging workup procedures in solution-phase, only simple workup steps are required. The corresponding supported ruthenium-PNP catalysts are screened in ester hydrogenation. Usually, industrially applied heterogeneous catalysts require harsh conditions in this reaction (250–350 °C at 100–200 bar) often leading to reduced selectivities. Heterogenized reusable Ru-PNP catalysts are capable of reducing esters and lactones selectively under mild conditions.
Hydrofunctionalization of Olefins to Higher Aliphatic Alcohols via Visible-Light Photocatalytic Coupling
Bao, Jingxian,Fan, Yonghui,Zhang, Shuyi,Zhong, Liangshu,Wu, Minghong,Sun, Yuhan
, (2019/04/14)
Abstract: An atomically economical green protocol for the hydrofunctionalization of olefins to higher aliphatic alcohols with 100% anti-Markovnikov regioselectivity was developed via visible-light photocatalytic coupling. This method employs cheap, readily available and abundant methanol as both the C1 feedstock and the hydrogen source under visible light irradiation over CdS photocatalyst. A wide scope of olefin substrates could be hydrofunctionalized successfully to the corresponding higher alcohols with high selectivity. Besides alcohol, acetone and acetonitrile can also couple with olefins to generate the corresponding hydrofunctionalization products, suggesting promising potential industrial application. Graphical Abstract: [Figure not available: see fulltext.] Hydrofunctionalization of olefins to value-added chemicals with high selectivity was achieved via visible-light photocatalytic cross-coupling.
Renewable Polyethers via GaBr3-Catalyzed Reduction of Polyesters
Dannecker, Patrick-Kurt,Biermann, Ursula,von Czapiewski, Marc,Metzger, Jürgen O.,Meier, Michael A. R.
supporting information, p. 8775 - 8779 (2018/07/14)
Herein, a novel approach is reported for the synthesis of medium- and long-chain aliphatic polyethers 2 based on the GaBr3-catalysed reduction of polyesters 1 with TMDS as the reducing agent. Thus, various linear and branched aliphatic polyesters 1 were prepared and systematically investigated for this reduction strategy, demonstrating the applicability and versatility of this new polyether synthesis protocol. Medium- and long-chain chain polyethers were obtained from the respective polyesters without or with minor chain degradation, whereas short-chain polyesters, such as poly-l-lactide 1 i and poly[(R)-3-hydroxybutanoate] 1 j, showed major chain degradation. In this way, previously unavailable and uncommon polyethers were obtained and studied.
Pellynols M?O, cytotoxic polyacetylenic alcohols from a Niphates sp. marine sponge
Wang, Jie,Liu, Li-Yun,Liu, Lei,Zhan, Kai-Xuan,Jiao, Wei-Hua,Lin, Hou-Wen
, p. 3701 - 3706 (2018/05/25)
Three new polyacetylenic alcohols, pellynols M?O (1–3), along with two known ones, melyne A (4) and melyne B (5), were isolated from a Niphates sp. marine sponge collected off the South China Sea. The structures of new compounds were determined based on a combination of 1D and 2D NMR analysis, ESI-MSn fragmentation, and chemical (ozonolysis) method. Their absolute configurations were assigned by modified Mosher's method. All the isolates showed potent cytotoxic activity against PC9 and HepG2 human cancer cell lines with IC50 values of 2.9–7.6 μM.
A new route to α,ω-diamines from hydrogenation of dicarboxylic acids and their derivatives in the presence of amines
Shi, Yiping,Kamer, Paul C. J.,Cole-Hamilton, David J.
supporting information, p. 5460 - 5466 (2017/11/22)
A new and selective route for the synthesis of polymer precursors, primary diamines or N-substituted diamines, from dicarboxylic acids, diesters, diamides and diols using a Ru/triphos catalyst is reported. Excellent conversions and yields are obtained under optimised reaction conditions. The reactions worked very well using 1,4-dioxane as solvent, but the greener solvent, 2-methyl tetrahydrofuran, also gave very similar results. This method provides a potential route to converting waste biomass to value added materials. The reaction is proposed to go through both amide and aldehyde pathways.
From intermolecular interactions to texture in polycrystalline surfaces of 1,ω-alkanediols (ω = 10–13)
Luis-Raya, Gilgamesh,Ramírez-Cardona, Màrius,Luna-Bárcenas, Gabriel,Hernández-Landaverde, Martín A.,Jiménez-Nieto, Adair,García-Rivas, Jose Luis,Espa A-Sánchez, Beatriz Liliana,Sanchez, Isaac C.
, (2017/06/28)
Differences on herringbone molecular arrangement in two forms of long-chain 1,?-alkanediols (CnH2n+2O2 with n = 10, 11, 12, 13) are explained from the analysis of O-H···O hydrogen-bond sequences in infinite chains and the role of a C-H···O intramolecular hydrogen-bond in stabilization of a gauche defect, as well as the inter-grooving effectiveness on molecular packing. GIXD (Glancing Incidence X-ray Diffraction) experiments were conducted on polycrystalline monophasic samples. Diffracted intensities were treated with the multi-axial March-Dollase method to correlate energetic and geometrical features of molecular interactions with the crystalline morphology and textural pattern of samples. The monoclinic (P21/c, Z = 2) crystals of the even-numbered members (n = 10, 12; DEDOL and DODOL, respectively) are diametrical prisms with combined form {104}/{-104}/{001} and present a two-fold platelet-like preferred orientation, whereas orthorhombic (P212121, Z = 4) odd-numbered members (n = 11, 13; UNDOL and TRDOL, respectively) present a dominant needle-like orientation on direction [101] (fiber texture). We show that crystalline structures of medium complexity and their microstructures can be determined from rapid GIXD experiments from standard radiation, combined with molecular replacement procedure using crystal structures of compounds with higher chain lengths as reference data.
