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本文采用单个性信息素腺体分析技术、高效毛细管色谱、色质联用、触角电位、微化学反应和田间试验得知水稻三化螟性信息素有16:Ald(Ⅰ)、(Z)-9-16:Ald(Ⅱ)和(Z)-11-16:Ald(Ⅲ)等三个组份。据单个雌蛾性信息素腺体的分析结果表明:腺体中三个组份的比例平均为18.8(Ⅰ):27.1(Ⅱ):54.1(Ⅲ)(%)。按上述三元组份比例配制的诱芯在田间显示强烈的引诱作用,单盆每天最高诱捕数达45头雄蛾,平均每天诱捕15.8头雄蛾。 相似文献
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花气味在维持大戟科(Phyllanthaceae)算盘子属(Glochidion)植物和头细蛾(Epicephala)专性传粉互利共生体系中发挥关键作用。本研究采用动态顶空吸附法(dynamic headspace adsorption)收集算盘子(Glochidion puberum)花气味,运用气相色谱-质谱(GC-MS)联用技术分离并鉴定其化学成分,用峰面积归一化法测得各组分的相对含量。结果表明:算盘子花气味中共鉴定出45种挥发物,主要包含单萜和倍半萜类物质;芳樟醇(38.06%)和β-榄香烯(23.84%)相对含量最高,占总相对含量的61.9%,为主要的气味成分,推测这两种物质可能是吸引传粉头细蛾的重要气味成分。本研究为进一步开展触角电生理检测和生物行为试验来筛选吸引传粉头细蛾的活性物质提供了理论依据。 相似文献
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紫草科植物加州假鹤虱,是美国加州一种常见蛾的幼毛虫的寄主植物, 该科植物中不少都含有吡咯里西啶类生物碱, 本文报道其中两种新生物碱的分离及其结构。 相似文献
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透翅蛾类是世界性林木果园害虫,在我国也广泛分布。迄今发现的透翅蛾性信息素或性引诱剂几乎全是具有不同几何构型的3,13-十八碳双烯-1-醇或其乙酸酯。虽然有报道(E,Z)-3,13-十八碳双烯-1-醇1a对白杨透翅蛾Paranthrene tabaniformis Rott雄虫有性引诱作用,但该虫的性信息素结构鉴定未见报道。我们采用雌虫性信息素性腺体部段浸泡法、色-质联仪分析(GC-MS和GC-MF),合成品的触角电位(EAG)和田间诱蛾生测,鉴定出白杨透翅蛾的性信息素是1a,1a的几何导构体1b-d对白杨透翅蛾的性信息素并无增效或抑止作用。已应用合成的1a进行了对白杨透翅蛾的测报和防治试验。关于1a和其几何异构体1b-d的合成,已有的报道大多从癸二醇出发,其产率通常不超过25%。我们采用简便的路线,通过炔键移位法,从丙炔醇和溴庚烷出发,合成了1a-d,总得率均约为37%(反应式见p.189)。现以1a的合成为例。将丁炔醇2的双锂化物与溴庚烷在液氨中反应得3(80%)。3经NaH和1,2-丙二胺(或1,2-乙二胺)处理得到炔键在末端的化合物4(83%)。4中的羟基用二氢吡喃保护后转化为炔锂,然后同溴丁烷缩合得到5(83.6%)。5经去保护基后,经P-2 Ni催化氢化得到烯醇6b(92.1%),其对甲苯磺酸酯与LiBr-丙酮反应得溴化物6c(94.4%)。6c与丁炔-1-醇的四氢吡喃醚缩合后得到的产物7不必纯化,与四氢锂铝-diglyme反应得1a(6c→1a,76.5%)。C_(18)H_(34)O(计算值:C,81.13;H,12.86。实测值:C,81.00;H,13.33)。IR:3300,3010,960,730 cm~(-1)。~1HNMR:0.83(3H,t,J=7),1.24(16H,br),1.47—2.3(8H,m),3.6(2H,t,J=7),5.24—5.6(4 H,m)。m/Z,266(M~+,1.6),248(M-H_2O,0.5),54(100%)。1a的几何异构体纯度为E,Z 95.1%,E,E 2.9%,Z,Z 1.1%,Z,E 0.9%。1c-d的合成方法与1a的相似。 相似文献
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高速逆流色谱法从蝙蝠蛾拟青霉中快速分离制备麦角甾醇纯品 总被引:3,自引:0,他引:3
建立了用高速逆流色谱从蝙蝠蛾拟青霉中高效、快速分离制备高纯度麦角甾醇的方法。将蝙蝠蛾拟青霉的乙酸乙酯提取物直接进行高速逆流色谱分离,考察了不同溶剂系统的分离效果。结果表明,最佳的溶剂系统为正己烷-乙酸乙酯-甲醇-水(体积比为6:1.7:6:0.3),以上相为固定相,下相为流动相,转速为850 r/min,流速为2 mL/min,检测波长为280 nm。制备所得的麦角甾醇经紫外光谱(UV)和高分辨质谱(HRMS)鉴定及与标准品对照定性;纯度经高效液相色谱(HPLC)分析为99.2%(峰面积归一化法)。该方法制备麦角甾醇简便、快速,所得产物的纯度高,适合于麦角甾醇对照品的制备。 相似文献
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《Tetrahedron: Asymmetry》2014,25(15):1095-1099
A resolution method has been elaborated for mandelic acid and 2-chloromandelic acid applying the (R)-(−)-3-(aminomethyl)-5-methylhexanoic acid (Pregabalin) as the resolving agent. The formation of the corresponding diastereomers was kinetically controlled. This observation was rationalized by the behavior of enantiomeric mixtures of mandelic acid, 2-chloromandelic acid, and 3-(aminomethyl)-5-methylhexanoic acid. It was found that the eutectic composition of Pregabalin influenced the diastereomeric excess of the diastereomers formed under kinetic control. 相似文献
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The synthesis of (2R)-2-methyl-4,5-dideoxy and (2R)-2-methyl-4-deoxy analogues of 6-phosphogluconate is described. The synthetic strategy relies on the Evans aldol reaction for the installation of the chiral centres in the 2- and 3-positions. The selective phosphorylation at the primary alcohol function of (2R,3S)-3,6-dihydroxy-2-methylhexanoic acid benzyl ester (5) and (2R,3S,5S)-3,5,6-trihydroxy-2-methylhexanoic acid benzyl ester (20) was achieved with dibenzyl phosphochloridate and dibenzyl phosphoiodinate respectively, working at low temperature. (2R,3S)-3-Hydroxy-2-methyl-6-phosphonoxyhexanoic acid (9) was obtained in 25% overall yield from 4-benzyloxybutanol and (2R,3S,5S)-3,5-dihydroxy-2-methyl-6-phosphonoxyhexanoic acid (28) in 10% overall yield from L-malic acid. 相似文献
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《Tetrahedron: Asymmetry》2007,18(12):1481-1485
A highly enantioselective synthesis of (S)-3-aminomethyl-5-methylhexanoic acid 1 (Pregabalin) is reported. The key step of the synthesis is a quinine-mediated ring opening of 3-isobutylglutaric anhydride with cinnamyl alcohol. A Curtius rearrangement and subsequent deprotection provides 1 in high yield and excellent enantiomeric excess. 相似文献
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An enantioselective synthesis of (S)-(+)-3-aminomethyl-5-methylhexanoic acid via asymmetric hydrogenation 总被引:2,自引:0,他引:2
Burk MJ De Koning PD Grote TM Hoekstra MS Hoge G Jennings RA Kissel WS Le TV Lennon IC Mulhern TA Ramsden JA Wade RA 《The Journal of organic chemistry》2003,68(14):5731-5734
A concise enantioselective synthesis of (S)-(+)-3-aminomethyl-5-methylhexanoic acid (1, Pregabalin) has been developed. The key step is the asymmetric hydrogenation of a 3-cyano-5-methylhex-3-enoic acid salt 2 with a rhodium Me-DuPHOS catalyst, providing the desired (S)-3-cyano-5-methylhexanoate 3 in very high ee. Subsequent hydrogenation of the nitrile 3 with a heterogeneous nickel catalyst provides Pregabalin 1 in excellent overall yield and purity. 相似文献
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Mohammad Shaharuzzaman James ChickosCheok N. Tam Timothy A. Keiderling 《Tetrahedron: Asymmetry》1995,6(12):2929-2932
The synthesis of (2R,3R) and (2S,3S) dideuteriosuccinic acid in 63 ± 10% enantiomeric excess by reduction of the half acid ester of ethyl fumarate from (R) and (S) BINAP ruthenium (II) diacetate complex, respectively, is reported. (2R,3R) and (2S,3S)-Dideuteriosuccinic acid has also been prepared from (R)-BINAP ruthenium (II) dicarboxylate complex directly in similar optical purity by reversing the sequence of introduction of the isotopic label. 相似文献
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A very efficient enzymatic method was developed for the synthesis of new enantiomeric benzocispentacin and its six- and seven-membered homologues through the Lipolase (lipase B from Candida antarctica) catalyzed enantioselective (E > 200) ring opening of 3,4-benzo-6-azabicyclo[3.2.0]heptan-7-one, 4,5-benzo-7-azabicyclo[4.2.0]octan-8-one, and 5,6-benzo-8-azabicyclo[5.2.0]nonan-9-one with H2O in iPr2O at 60 degrees C. The (1R,2R)-beta-amino acids (ee > or = 96%, yields > or = 40%) and (1S,6S)-, (1S,7S)-, and (1S,8S)-beta-lactams (ee > 99%, yields > or = 44%) produced could be easily separated. The ring opening of racemic and enantiomeric beta-lactams with 18% HCl afforded the corresponding beta-amino acid hydrochlorides. 相似文献
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1S,4R-(+)-ketopinic acid [(+)-KPA] has been introduced as a chiral selector for the separation of pharmacologically active amines by non-aqueous capillary electrophoresis (NACE). (+)-KPA gave enantioresolution for most of the compounds previously separated by 2R,3S,4R,5S-(-)-2,3:4,6-di-O-isopropylidene-2-keto-L-gulonic acid [(-)-DIKGA], but with a reversed migration order. A complete enantioresolution (Rs=4.2) was obtained for timolol, a compound that could not be resolved using (-)-DIKGA as the selector. Thus, (+)-KPA was evaluated for the enantiomeric purity determination of S-timolol. A method based on pre-concentration by transient isotachophoresis (tITP) provided a limit of detection (LOD) of 0.2% R-timolol in S-timolol samples. Because of the lack of enantioresolution of ephedrine when (+)-KPA was used as the selector, a method with (-)-DIKGA has been developed and validated for determination of the enantiomeric purity of the 1R,2S enantiomer. The method gave good precision and accuracy with an LOD (S/N=3) of 0.033% for the enantiomeric impurity 1S,2R-ephedrine. 相似文献
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Felpin FX Girard S Vo-Thanh G Robins RJ Villiéras J Lebreton J 《The Journal of organic chemistry》2001,66(19):6305-6312
An enantiomeric synthesis of six piperidine and pyrrolidine alkaloids, (S)-nornicotine 1, (S)-nicotine 2, (S)-anatabine 3, (S)-N-methylanatabine 4, (S)-anabasine 5, and (S)-N-methylanabasine 6, known as natural products in tobacco, was established from a common chiral homoallylic (S)-3-(1-azido-but-3-enyl)-pyridine 15. An intramolecular hydroboration-cycloalkylation of the homoallylic azide intermediate 15 served as the key step in the pyrrolidine ring formation. A ring closing metathesis reaction (RCM) of a diethylenic amine intermediate (S)-allyl-(1-pyridin-3-yl-but-3-enyl)-carbamic acid benzyl ester 20 served as the key step in the piperidine ring formation. From the commercially available 3-pyridinecarboxaldehyde 13, a short and convenient enantiomeric synthesis of tobacco alkaloids is described: (S)-nornicotine 1 (5 steps, with an overall yield of 70%), (S)-nicotine 2 (6 steps, 65%), (S)-anatabine 3 (8 steps, 30%), (S)-N-methylanatabine 4 (8 steps, 25%), (S)-anabasine 5 (8 steps, 35%), and (S)-N-methylanabasine 6 (8 steps, 25%). 相似文献
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Kulokekahilide-1, a cytotoxic depsipeptide from the cephalaspidean mollusk Philinopsis speciosa 总被引:1,自引:0,他引:1
Kimura J Takada Y Inayoshi T Nakao Y Goetz G Yoshida WY Scheuer PJ 《The Journal of organic chemistry》2002,67(6):1760-1767
The cytotoxic depsipeptide kulokekahilide-1, which contains two unusual amino acids, 4-phenylvaline and 3-amino-2-methylhexanoic acid, was isolated from the cephalaspidean mollusk Philinopsis speciosa. Structure elucidation of kulokekahilide-1 was carried out by spectroscopic analysis and chemical degradation. The absolute stereochemistry was determined by Marfey analysis for amino acids and chiral HPLC analysis for hydroxy acids. All four stereoisomers of 4-phenylvaline and 3-amino-2-methylhexanoic acid, which were necessary for Marfey analysis, were synthesized by use of the Heck reaction and Evans's method, respectively. Kulokekahilide-1 showed cytotoxicity against P388 murine leukemia cells with an IC(50) value of 2.1 microg/mL. 相似文献
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Schwenninger R Ramondenc Y Wurst K Schlogl J Krautler B 《Chemistry (Weinheim an der Bergstrasse, Germany)》2000,6(7):1214-1223
A first representative of an effectively D4-symmetric biconcave porphyrin (1) was prepared from a tetramerizing condensation of a C2-symmetric pyrrole (2). The chiral pyrrole 2 was synthesized in a six-step reaction sequence starting from the C2h-symmetric 2,6-di-tert-butylanthracene. The relevant stereochemistry was introduced in a highly diastereo-discriminating Diels-Alder reaction with fumaric acid di(-)menthyl ester, catalyzed by aluminum chloride. X-ray analyses of two of the dimenthyl esters prepared unambiguously secured their tentatively assigned absolute configuration and that of the pyrrole 2 (as the S,S isomer). The enantiomeric purity of the pyrrole 2 was determined as 99% ee, using the Co11 complex of the porphyrin 1 as a chiral shift reagent. The pyrrole 2 lent itself to a stereochemically nearly uniform preparation of the chiral, biconcave porphyrin 1. Applying Horeau's principle, 1 was calculated to be present in an enantiomeric excess of about 10(9):1. The validity of the statistical considerations relevant for this estimate were verified by examination of the results from preparative tetramerization experiments in which the enantiomeric purity of the pyrrole 2 was deliberately lowered. 相似文献