- Mining the Cinnabaramide Biosynthetic Pathway to Generate Novel Proteasome Inhibitors
-
The cinnabaramides and salinosporamides are mixed PKS/NRPS natural products isolated from a terrestrial streptomycete and a marine actinomycete, respectively. They interfere with the proteasome and thus potentially inhibit the growth of cancer cells. The compounds exhibit a γ-lactam-β-lactone bicyclic ring structure attached to a cyclohexenyl unit and a PKS side chain. As a first step towards improving anticancer activity and permitting genetic approaches to novel analogues, we have cloned and characterized the cinnabaramide biosynthetic genes from Streptomyces sp. JS360. In addition to the expected PKS and NRPS genes, the cluster encodes functionalities for the assembly of the hexyl side chain precursor. The corresponding enzymes exhibit relaxed substrate specificities towards a number of synthesized precursors, enabling production of novel chlorinated cinnabaramides. These were isolated and analyzed for activity, revealing that derivatives bearing a chlorine atom in the PKS side chain show higher inhibitory potentials towards the proteasome's proteolytic subunits (especially the trypsin and chymotrypsin units) and higher cytotoxicities towards human tumor cell lines than the parent cinnabaramide A. Although their activities towards the proteasome were weaker than that of salinosporamide A, the cinnabaramides were found to inhibit the growth of various fungi with greater potency. Copyright
- Rachid, Shwan,Huo, Liujie,Herrmann, Jennifer,Stadler, Marc,Koepcke, Baerbel,Bitzer, Jens,Mueller, Rolf
-
-
Read Online
- MANUFACTURING METHOD OF α,β-UNSATURATED CARBOXYLIC ACID
-
PROBLEM TO BE SOLVED: To provide a manufacturing method which can get α,β-unsaturated carboxylic acid at a high yield by liquid phase oxidation of α,β-unsaturated aldehyde by oxygen or air with a handy metal catalyst under a mild reaction condition. SOLUTION: Preferably under a presence of organic solvent, α,β-unsaturated carboxylic acid is manufactured by oxidation of α,β-unsaturated aldehydes and oxygen or air under a presence of an iron salt catalyst and a catalyst of alkali metal salt of carboxylic acid. SELECTED DRAWING: None COPYRIGHT: (C)2017,JPOandINPIT
- -
-
Paragraph 0050-0052
(2018/10/16)
-
- Alpha, beta-unsaturated carbonyl compound production method
-
The present invention relates to an alpha, beta-unsaturated carbonyl compound production method comprising the following steps: (1) oxidizing reaction of a primary alcohol with 3-20 carbon atoms under the effect of an oxidase for selective oxidation of a terminal alcoholic hydroxyl group into an aldehyde group to obtain an aldehyde group compound; (2) Reformatsky reaction of the aldehyde group compound and a halide under the catalytic effect of a metal to produce a corresponding alpha, beta-unsaturated carbonyl compound, the alpha, beta-unsaturated carbonyl compound production method is low-cost, less in environmental pollution, moreover, by alcohol oxidizing reaction by use of the oxidase, the quantitative and high selectivity corresponding alpha, beta-unsaturated carbonyl compound can be obtained, and the after processing is convenient.
- -
-
-
- Carbonyl homologation via α-trimethylsilyl β-lactone rearrangements. A nonbasic alternative to the Wittig reaction
-
Saturated and unsaturated aldehydes and ketones, when treated with trimethylsilylketene and BF3 for 16 hours, form β-lactones which spontaneously rearrange to α,β-unsaturated TMS esters; these hydrolyze during workup to form the corresponding carboxylic acids.
- Black,Zhang,Huang,Smith,Yates
-
-
- Selective heterogeneous palladium-catalyzed hydrogenations of watersoluble alkenes and alkynes
-
Treatment of water-soluble alkenes or alkynes with palladium(II) acetate and triethoxysilane at room temperature afforded the corresponding hydrogenated products in high yields. Simple introduction of a stoichiometric amount of hydrogen is accomplished by using triethoxysilane as the hydrogen source.
- Tour, James M.,Pendalwar, Shekhar L.
-
p. 4719 - 4722
(2007/10/02)
-
- INFLUENCE OF HETEROAROMATIC AMINES TO KNOEVENANGEL CONDENSATION
-
In the Knoevenagel condensation of hexanal and malonic acid, the ratio of α,β-and β,γ-unsaturated acids was remarkably affected by the nature of tertiary amines used as a catalyst.That is, the condensation in pyridine or isoquinoline gave 2-octenoic acid selectively, whereas the condensation in 2-methylpyridine, 2,6-dimethylpyridine, or quinoline gave 3-octenoic acid as the main product.
- Yamanaka, Hiroshi,Yokoyama, Masaaki,Sakamoto, Takao,Shiraishi, Takayuki,Sagi, Mataichi,Mizugaki, Michinao
-
p. 1541 - 1544
(2007/10/02)
-
- Base-Catalyzed Reactions of α,β-Unsaturated Esters and Nitriles. 4. Dimerization of β-Alkyl-Substituted Acrylates
-
2-Butenoates 1-C4 alkyl, cyclohexyl, or 1-bornyl> and higher β-alkyl-substituted acrylates 2-C9 n-alkyl> undergo highly selective (>95percent) dimerization in the presence of promoted potassium or sodium catalysts to yield corresponding 2-alkylidene-3-alkylglutarates (3).The reaction involves metalation of the β-alkylacrylate at the C-2 position, followed by addition at C-3 of a second monomeric molecule.Changes in the relative extent of dimerization (Kr) as a function of structural and experimentalvariables were determined.Kr is strongly dependent upon the inductive and steric characteristics of the alcoholic (R) group and of the β-alkyl substituent (R').For an n-alkyl group as R' the Kr value increases with increase in chain length from C1 to C4 but then decreases for longer substituents (C5-C9).Among the two geometric isomers in the dimeric product 3, the isomer with an α-vinylic hydrogen cis to the carboalkoxy group is predominant in all cases, but its relative concetration decreases with an increase in the size of R'.Branched or cyclic β-substituents in 2 prevent dimerization due to steric hindrance in the rate-determining addition step.Promoted potassium or sodium catalysts show much higher dimerization activity compared to supported alkali metals or to alkoxides.For conversions of up to 60percent, Kr values in proton-exchanging alkylbenzene solvents and in nonexchanging alkylcyclohexanes are closely similar, indicating faster abstraction of an α-vinylic hydrogen from the monomer, rather than a benzylic hydrogen from the solvent, in the chain regeneration step of the reaction.
- Shabtai, Joseph,Ney-Igner, Eva
-
p. 3795 - 3802
(2007/10/02)
-