Synthesis, biological activities and bioavailability of moschamine, a safflomide-type phenylpropenoic acid amide found in Centaurea cyanus

Moschamine is a phenylpropenoic acid amide found in plants. In this article, the synthesis and two biological activities (serotoninergic and cyclooxygenase (COX) inhibitory activities) and bioavailability of moschamine were described. Moschamine was synthesised and confirmed using NMR spectroscopic methods. Using the moschamine synthesised, serotoninergic and COX inhibitory activities were investigated. At the concentration of 10?μmol?L?1, moschamine was able to inhibit forskolin-stimulated cAMP formation by 25% (p?相似文献   

Synthesis of a novel dioxan sialic acid analog

A preparative scale synthesis of a dioxan sialic acid analog was achieved from d-mannose. The conformation and the acidic character of this dioxan derivative, closely related to sialic acid, provides a scaffold for drug design.     

Synthesis of cimiracemate B, a phenylpropanoid found in Cimicifuga racemosa

The synthesis of the rare bioactive phenylpropanoid ester known as cimiracemate B (1) from black cohosh, Cimicifuga racemosa, is described. The procedure employs a coupling method using 1, l'-carbonyldiimidazole and methyltrifluoromethanesulfonate as coupling reagents in the presence of N-methylmorpholine.     

Synthesis of cleonine,amino(1-hydroxycyclopropyl)acetic acid,a novel amino acid contained in cleomycin

The synthesis of cleonine, amino(1-hydroxycyclopropyl)acetic acid, a novel amino acid contained in cleomycin, a new bleomycin-phleomycin group antibiotic, is described.     

Synthesis of a novel 18β-glycyrrhetinic acid derivative

A novel compound, biotinylated 18β-glycyrrhetinic acid (BGA), was synthesized. It is a compound of 18β-glycyrrhetinic acid linked with biotin. Published in Khimiya Prirodnykh Soedinenii, No. 3, pp. 266–267, May–June, 2006. An erratum to this article is available at .     

Synthesis of jasplakinolide analogues containing a novel omega-amino acid

The synthesis of the omega-amino acid 4 is described utilizing a two-dimensional synthesis strategy combined with an enzymatic differentiation of homotopic ester groups. The amino acid 4 features two non-bonded interactions that result in conformational constraints on a cyclic construct. This amino acid was incorporated into the four macrolactams 17, 22, 31, and 37. The ring in 17 and 22 is 18-membered, whereas 31 and 37 have a 19-membered ring. The pairs with the same ring size differ in a N-methyl group. For the larger macrolactams (31 and 37) conformational analysis showed that the macrocyclic rings are somewhat more rigid than in the natural lead, the depsipeptide jasplakinolide. Nevertheless, their conformations are comparable to the natural product. There are no intramolecular hydrogen bonds, neither is the cis-rotamer populated in the N-methyl compound 37. Due to the increased flexibility of the smaller macrolactams 17 and 22 and signal overlap, a distinct solution structure could not be obtained for these compounds. The amino acid 4 should be useful for restricting the conformation of other small peptides.     

Enantioselective synthesis of (2S,3R)-3-hydroxy-3-methylproline, a novel amino acid found in polyoxypeptins

The enantioselective synthesis of (2S,3R)-3-hydroxy-3-methylproline (3) was achieved by the Sharpless AD, regioselective opening of cyclic sulfate by NaN(3) and intramolecular ring-closing reaction. The reported route has the advantage of a high overall yield and good enantiomeric purity, as well as starting from readily available chemical substrates and inexpensive reagents.     

Synthesis of a novel diblock copolymer of isoprene and methacrylic acid

A new diblock copolymer of isoprene (I) and methacrylic acid (MAA) was prepared by combination of an anionic mechanism with a charge transfer complex mechanism. In the first step, the polyisoprene (PI) macroanion formed by initiation with butyllithium was capped by p-dimethylaminobenzaldehyde (capped polyisoprene = PI_d); a dimeric coupling product was not detected. Then the binary system constituting of PI_d and benzophenone was used to initiate the polymerization of MAA under UV irradiation. The resulting diblock copolymer (PI-b-PMAA) was characterized by IR, NMR and gel permeation chromatography (GPC) in detail.     

Synthesis and dyeing performance of a novel polycarboxylic acid azo dye

A novel reactive polycarboxylic acid dye was synthesized by the reaction of polymaleic anhydride（PMA） with 3-methyl-1-（4- sulfonylphenyl）-4-（4-aminophenylazo）-2-pyrazoline-5-one.The structure of the novel dye was characterized by FTIR,UV-vis and ¹³C NMR spectra.The dyeing properties of dye on cotton were tested,and the novel dye possessed high fixation and good fastness.     

Synthesis of 2,4,5-triaminocyclohexanecarboxylic acid as a novel 2-deoxystreptamine mimic

Since aminoglycosides have been known to exert their antibacterial activities by binding to various RNA targets, 2-deoxystreptamine served as a particularly important model in understanding RNA-small molecule interaction. Herein, 2,4,5-triaminocyclohexanecarboxylic acid was prepared as a novel 2-deoxystreptamine (2-DOS) mimic, which replaces highly flexible glycosidic bonds of aminoglycosides with amide bonds and may improve binding selectivity toward RNA targets through increased rigidity and additional hydrogen-bonding capability. This unnatural g-amino acid can also be used as a potential component for synthetic foldamers.     

Synthesis of a lactone natural product found in Greek tobacco

A short and stereoselective synthesis of (3R^∗,4R^∗,7R^∗)-3,7-epoxy-4,8-dimethyl-8-nonen-4-olide, a natural product isolated from cured tobacco leaves, has been completed in six steps and 22% overall yield. A samarium(II) iodide mediated reductive cyclisation has been used to construct the functionalised tetrahydropyranol core and subsequent sequential stereoselective addition of methyllithium and lactonisation furnished the natural product.     

Synthesis of aaptamine,a novel marine alkaloid

The novel sponge alkaloid aaptamine has been synthesized for the first time by an efficient route starting from 6-methoxy-7-hydroxy-3,4-dihydrolsoquinoline.     

Synthesis of a novel C-6 nigrogen-substituted carbapenem from 6-aminopenicillanic acid

Synthesis of optically active 6-phthalimidocarbapenems from 6-aminopenicillanic acid is described.     

Synthesis of novel imidazole-4,5-dicarboxylic acid derivatives

A convenient general method for the synthesis of unsymmetrical imidazole-4,5-dicarboxylic acid derivatives is described. The key intermediates are 5,10-dioxo-5H,10H-diimidazo[1,5-a:1′,5′-d[pyrazine-1,6-dicarboxylic acid, -1,6-dicarboxylic ester and -1,6-dicarboxamide.     

新型手性氨基酸烯砜的合成

以苯亚磺酸钠和3-氯-2-甲基-1丙烯为原料,经偶联、氯化、溴化,之后再与氨基酸胺化反应合成得到了两个新型手性氨基酸烯砜化合物。所获得化合物的结构经HR-MS,1H,13C和/或DEPT NMR验证。     

Synthesis of novel mannopyranosyl betulinic acid phosphoniohexyl ester

1. Download : Download high-res image (90KB)
2. Download : Download full-size image

     

Synthesis of novel quinoxaline-5-carboxylic acid derivatives

This paper describes the synthesis of several new 2,3-dimethoxy-6-methyl-7-nitro-quinoxaline-5-carboxylic acid derivatives ( 13a-m ) via a multistep synthetic route from 5-methyl-1H-benzo[d][1,3]oxazine-2,4-dione ( 1 ).     

The simultaneous analysis of proteins, lipids, and diterpenoid resins found in cultural objects

We report a GC-MS method for the simultaneous analysis of proteins oil, and diterpenoid resins found in cultural objects. The method was initially designed for protein analysis of protenaceous paints and adhesives and involves acid hydrolysis as the first step. The amino acids in the protein hydrolysates, thus obtained, are treated with propan-l-ol/ hydrogen chloride and then pentafluoropropionic anhydride. The procedure was found also to yield the propyl esters of fatty acids derived from lipids and diterpenoid acids derived from natural resins, and thus allows the choice of a single method for the analysis of artists media which contain either oil s or proteins or mixtures of both proteins and oils or even resins. Thus natural mixtures such as egg yolk and also mixtures made by the artist such as animal glue/seed oil emulsions can be analysed. Coupled with FTIR analysis of paints and the staining of cross sections, to indicate layer structure the method can help to elucidate the paints and adhesives used by artists.     

Synthesis of PDK, a novel porphyrin-linked dicarboxylate ligand

A novel trinucleating ligand system H4(PDK), for porphyrin-based diamine bis(Kemp's triacid)imide, was constructed by using two molecules of Kemp's triacid and one molecule of porphyrin as building blocks. The dimeso-substituted octaalkylporphyrin unit, carrying bromomethyl groups at the ortho positions of two trans-positioned meso-phenyl groups, was synthesized from (3,3'-diethyl-4,4'-dimethyl-2,2'-dipyrrolyl)methane and (alpha-bromo-o-tolualdehyde. The structures of both of the two atropisomers (alpha,alpha- and alpha,beta-) of bromoporphyrin, H2(alpha,alpha-BP) and H2(alpha,beta-BP), were determined by X-ray crystallography, with the alpha,beta-isomer as the free base form and the alpha,alpha-isomer as the zinc complex. Both the alpha,alpha- and alpha,beta-isomers of the bromomethyl porphyrins were converted to their aminomethyl derivatives, H2(alpha,alpha-AP) and H2(alpha,beta-AP), through the corresponding imidoporphyrin intermediates, H2(alpha,alpha-IP) and H2(alpha,beta-IP), by the Gabriel synthesis. The alpha,alpha- and alpha,beta-aminoporphyrins were coupled with Kemp's triacid anhydride-chloride to form H4(alpha,alpha-PDK) and H4(alpha,beta-PDK), respectively. Unlike the alpha,beta-isomer, the structure of which was determined by X-ray crystallography for the zinc complex, H4(alpha,alpha-PDK) has a remarkable and complicated solvent-dependent 1H NMR spectrum that suggests the existence of hydrogen bonding interactions between two convergent, tethered Kemp's triacid units, as predicted in a modeling study. The convergent feature is essential for the target ligand H4(alpha,alpha-PDK) to form trinuclear metal complexes with a bis(carboxylato) dimetallic unit sitting above a metalloporphyrin ring.