高效液相色谱法直接测定几种非甾体类解热镇痛药物中的对映体含量

用WHELK-O1手性色谱柱，在正相条件下测定了几种非甾体类解热镇痛药物萘普生、布洛芬、酮基布洛芬和苯氧布洛芬等中对映体的含量。结果表明：这种手性固定相色谱柱能够以正己烷和异丙醇为流动相，简便、快速、准确地测定非甾类药物中对映体的含量。     

First lipase catalysed resolution of epoxy enol esters

We report the first enzyme-catalysed kinetic resolution of epoxy enol esters. The lipase-promoted hydrolysis of these compounds provided α-hydroxyketones or α-hydroxyaldehydes (arising from the spontaneous rearrangement of the epoxy enols) and the residual esters with moderate to good enantioselectivity (E up to 100).     

Total spontaneous resolution of chiral covalent networks from stereochemically labile metal complexes

Stereochemically labile copper and zinc complexes with the N,N'-dimethylethylenediamine ligand (dmeda) have been shown to be promising precursors for the total spontaneous resolution of chiral covalent networks. (N,N')-[Cu(NO3)2(dmeda)]infinity crystallises as a conglomerate and yields either enantiopure (R,R)-1 or enantiopure (S,S)-1. A mixed-valence copper(I/II) complex, [{Cu(II)Br2(dmeda)}3(Cu(I)Br)2]infinity (2), which crystallises as a pair of interpenetrating chiral (10,3)-a nets, is formed from CuBr, CuBr2 and dmeda. One net contains ligands with solely (R,R) configuration and exhibits helices with (P) configuration while the other has solely (S,S)-dmeda ligands and gives rise to a net in which the helices have (M) configuration. The whole crystalline arrangement is racemic, because the interpenetrating chiral nets are of opposite handedness. With zinc chloride (R,S)-[ZnCl(dmeda)2]2[ZnCl4] (3) is obtained, which is a network structure, although not chiral. Total spontaneous resolution of stereochemically labile metal complexes formed from achiral or racemic building blocks is suggested as a viable route for the preparation of covalent chiral networks. Once the absolute structure of the compound has been determined by X-ray crystallography, a quantitative determination of the enantiomeric excess of the bulk product can be undertaken by means of solid-state CD spectroscopy.     

High performance liquid chromatographic separation of dipeptide and tripeptide enantiomers using a chiral crown ether stationary phase

A chiral stationary phase (CSP) based on (-)-(18-crown-6)-2,3,11,12-tetracarboxylic acid was evaluated for the direct resolution of the enantiomers of dipeptides and tripeptides. The type and concentration of the acid and the methanol content were optimized with regard to retention time and resolution using Ala-Phe as model peptide. A mobile phase consisting of 10 mM sulfuric acid in 70% aqueous methanol was applied to the separation of a set of 16 structurally diverse dipeptides and tripeptides. Generally, the configuration of the amino acid at the N-terminus determined the enantiomer elution order. With a few exceptions the LL- and LD-enantiomers interacted stronger with the CSP compared to the corresponding DD- or DL-enantiomers. The experimental conditions also allowed the simultaneous separation of all four stereoisomers of Ala-Phe. Addition of ammonium sulfate generally reduced retention times and enantiomer resolution. Addition of triethylamine as modifier led to an overall increase of the retention times while the resolution did not show a general trend, increasing in the case of Ala-Ala but decreasing in the case of Ala-Phe.     

U-4C-3CR versus U-5C-4CR and stereochemical outcomes using suitable bicyclic β-amino acid derivatives as bifunctional components in the Ugi reaction

Intramolecular Ugi reactions with bicyclic β-amino acids have been performed and the effects of the configuration and N-alkylation have been studied. We have proven that preferential ring contraction or nucleophilic attack by the solvent depend not only on the presence of N-alkylation but also on the relative disposition of the carboxyl group and the amine. Excellent results in terms of stereoselectivity have been obtained in the case of N-alkyl-3-exo-amino-7-oxabicyclo[2.2.1]-2-endo-carboxylic acids.     

The absolute configuration of peroxisomicines A1 and A2

Peroxisomicine A1 is a potentially antineoplastic compound isolated from the seeds of Karwinskia parvifolia. It is considered as a useful chemotype for the preparation of topoisomerase II targeted anticancer cells. Stereochemically, it is characterized by the presence of two stereocenters and a rotationally hindered and thus likewise stereogenic biaryl axis. In this contribution, the absolute configuration of peroxisomicine A1 and its epimer, peroxisomicine A2, was established by means of a five-step degradative procedure giving the respective R- and S-configured methyl 2-(2′-methyl-5′-oxotetrahydrofuryl)acetates. The configuration of the degradation product was obtained by means of optical rotation, ¹H NMR analysis using a chiral displacement reagent, and by experimental and quantum chemical circular dichroism (CD) investigations. Based on the results obtained here and considering our previous work on the relative configuration at centers versus axis of these compounds, peroxisomicine A1 resulted to be the P,3S,3′S-isomer and peroxisomicine A2 the P,3R,3′S-isomer.     

薄层色谱用纤维素苯甲酸酯类手性固定相的制备及色谱性能

用超声方法合成了3种纤维素苯甲酸酯类手性固定相，三（苯甲酰基）纤维素（CTB）、三（4－甲基苯甲酰基）纤维素（CTMB）、三（4－硝基苯甲酰基）纤维素（CTPNB）；该类手性固定相（CSP）用于薄层色谱分离手性药物对映体，采用合适的展开剂系统，共有6对含氮手性药物获得了安全分离；比较了3种手性固定相的拆分性能，表明CTB和CTMB对手性药物显示出良好的拆分性能，而CTPNB的拆分性能较差。     

高效液相色谱蛋白质手性固定相

本文综述了近年文献中已报道的各种高效液相色谱蛋白质（酶）手性固定相及其在手性拆分中的应用，并阐述了蛋白质作为手性选择剂拆分机理的研究进展。     

两个新的氢键诱导液晶化合物的合成

通过４－丁氧基苯甲酸（４ＢＡ０与两个手性取代的苯乙烯基吡啶（ＶＳＺ及ＬＳＺ）间的氢键作用合成了２个新的液晶化合物，用ＤＳＣ、偏光显微镜研究了其液晶行为，并由红外光谱证实了分子间氢键的存在，形成的复合物４ＢＡ－ＶＳＺ具有手性近晶Ｃ相。     

A Validated LC Method for Separation and Quantification of Voriconazole and Its Enantiomer

A simple liquid chromatographic method was developed for the separation and quantification of voriconazole and its enantiomer in drug substance. The separation was achieved on Chiral cel-OD (250 mm × 4.6 mm × 10 μm) using mobile phase consisting of n-hexane and ethanol in the ratio 9:1 (v/v) with a flow rate of 1.0 mL min⁻¹, at 27 °C column temperature and detection at 254 nm with an injection volume of 20 μL. Ethanol was used as diluent. The method is capable of detecting the (2S, 3R) enantiomer down to 0.0075% and can quantify down to 0.021% with respect to sample concentration. The method is rapid and the resolution achieved was about 3.0. This method can be employed for the quantification of (2S, 3R) enantiomer in voriconazole drug substance.