昆虫信息素结构鉴定和合成的研究 ⅩⅩⅡ.白杨透翅蛾的性信息素

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。     

手性甲基脂肪烃类昆虫信息素的合成研究进展

手性甲基脂肪烃类昆虫信息素包括单手性甲基、双手性甲基和多手性甲基脂肪烃类昆虫信息素,在棘翅夜蛾、南部云杉天牛、桃潜叶蛾等多种农林害虫的绿色防控领域具有极具发展的前景.按手性甲基的构建方法,分类阐述了单手性甲基昆虫信息素的合成方法;根据手性甲基片段的连接策略对双手性甲基与多手性甲基脂肪烃类昆虫信息素的合成方法进行了详细介绍;并对各种合成方法的优势与不足进行简单讨论,以及对手性甲基脂肪烃类昆虫信息素的合成研究进行了展望.     

水稻三化螟性信息素的研究——Ⅱ.化学结构鉴定和田间诱捕试验

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。     

气相色谱和色-质谱法测定昆虫性信息素双键位置的研究

昆虫性信息素是一种微量生物活性物质,通常每头雌蛾中的含量仅毫微克,它们的结构大部分是直碳链不饱和的醛,醇及其酯。因此测定昆虫性信息素的双键位置是通过简易的操作在双键上进行化学反应,然后用高灵敏度的GC和GC/MS 进行检测。本文主要介绍用臭氧化或将双键转化为环氧,甲氧基等微量测定昆虫性信息素双键位置的方法:     

茄黄斑螟性信息素化学的结构签定(英文)

本文采用TLC、GC、微量臭氧化和GC-MS等分析方法,从茄黄斑螟雌蛾性腺体提取物中,分离和鉴定出性信息素反-11-十六碳烯醇乙酸酯(1a)。触角电位和田间试验证明,天然提取物和合成样品均有强烈的生物活性。     

茄黄斑螟性信息素化学的结构鉴定

本文采用TLC、.GC、微量臭氧化和GC-MS等分析方法, 从茄黄斑螟雌蛾性腺体提取物中, 分离和鉴定出性信息素反-11-十六碳烯醇乙酸酯(1a)。触角电位和田间试验证明, 天然提取物和合成样品均有强烈的生物活性。     

甘蔗条螟性信息素:三组份的结构鉴定

本文采用甘蔗条螟雌虫性信息素腺体浸泡法, GC和GC-MS, 鉴定出甘蔗条螟性信息素结构为(Z)-11-十六碳烯醇乙酸酯(Z)-13-十八碳烯醇乙酸酯和(Z)-13-十八碳烯醇按4:4:2混合, 对甘蔗条螟雄蛾具有较强的引诱作用。     

昆虫信息素结构和合成的研究——ⅩⅦ.桑毛虫性信息素的结构鉴定

我们采用昆虫性信息素腺体漂洗结合色-质谱分析方法,从桑毛虫性信息素腺体中鉴定出四个戊酸十八碳烯酯.它们是异戊酸顺-7-十八碳烯酯(1a)(92％),异戊酸6-十八碳烯酯(1.4％),异戊酸9-十八碳烯酯(5％)和正戊酸6-十八碳烯酯(16％).大田诱蛾生测和触角电位试验证明1a有很强的生理活性,可用于桑毛虫的测报和防治试验.1a是新的性信息素结构,在毒蛾科中性信息素是异戊酸酯尚属首次发现.     

棉红铃虫性信息素——-一种微量昆虫生理活性物质的结构鉴定和合成

昆虫性信息素是一种在同种雌雄虫之间传递信息的化学物质。由于它已在害虫的测报和防治上展现了新的前景,因此近年来受到了人们的重视。昆虫性信息素不仅是一种微量生理活性物质,而且对立体化学(几何异构和对映异构)有严格的要求,因此对它的鉴定和合成均有一定的难度。本文以棉红铃虫为例,对其性信息素的鉴定和合成方法进行讨论。一、结构鉴定棉红铃虫是世界性棉花的大害,对它的性信息素的鉴定曾比较混乱。先是在1966年由Jacobson等用85万头雌蛾,按经典方法提取和分离到1.6mg物质,鉴定为10-正丙基-反-5,9-十三双烯-1-醇乙酸酯(1)。不久,Eiter等合成了1,但生测发现1并无活性。接着Green等从大量类似物中筛选出在田间能引诱雄虫的活性物质,顺-7-十六碳烯-1-醇乙酸     

苹果蠢蛾性信息素E,E-8,10-十二碳二烯-1-醇的立体选择性合成

苹果蠹蛾(Laspeyresia pomonella)鳞翅目小卷蛾科,是世界上最严重的蛀果害虫之一.主要危害苹果、梨、海棠、杏等果树.苹果蠹蛾的原发生地为欧洲,在我国最早发现于新疆维吾尔自治区,曾被农业部和新疆维吾尔自治区列对内检疫对象,是当前重点防治的蛀果害虫之一[1].利用性诱剂防治害虫有不污染环境,维持生态平衡等优点.苹果蠹蛾的性信息素为:E,E-8,10-十二碳二烯-1-醇[2].该信号化合物同时又是大豆食心虫性信息素的重要中间体.我们根据Schlosser-Wittig反应,采用ω-溴代辛醇三苯基膦和E-2-丁烯醛(反式巴豆醛),在苯基锂-溴化锂存在下,立体选择性合成了苹果蠹蛾的性信息素,立体选择性可达98%以上.合成路线如图1.     

Highly stereoselective synthesis of (E)- and (Z)-alpha-fluoro-alpha,beta-unsaturated esters and (E)- and (Z)-alpha-fluoro-alpha,beta-unsaturated amides from 1-bromo-1-fluoroalkenes via palladium-catalyzed carbonylation reactions

The highly stereoselective synthesis of (E)- and (Z)-alpha-fluoro-alpha,beta-unsaturated esters and (E)- and (Z)-alpha-fluoro-alpha,beta-unsaturated amides is described. 1-Bromo-1-fluoroalkenes (E/Z approximately 1:1), which are readily available starting materials, have been found to isomerize to high E/Z ratios after storage at -20 degrees C for 1 week or by photolysis at 254 nm. Since the (E)-isomers have been found to react faster than the corresponding (Z)-isomers at room temperature in Pd(0)-catalyzed reactions, the palladium-catalyzed carboalkoxylation of high E/Z 1-bromo-1-fluoroalkenes lead to a high Z/E (Z/E >/= 98:2) ratio of the alpha-fluoro-alpha,beta-unsaturated esters. When 1-bromo-1-fluoroalkenes (E/Z approximately 1:1) were reacted with HCOOH/NBu(3)/Pd(II)/DMF, the (E)-isomer was selectively reduced, and the remaining (Z)-1-bromo-1-fluoroalkenes were recovered in essentially pure isomeric form. The resulting mixture of (Z)-1-bromo-1-fluoroalkenes and the reduced products underwent similar palladium-catalyzed carboalkoxylation reactions at 70 degrees C, and the (E)-alpha-fluoro-alpha,beta-unsaturated esters were stereospecifically obtained. This methodology was also successfully applied for the stereospecific synthesis of (Z)- and (E)-alpha-fluoro-alpha,beta-unsaturated amides: the palladium-catalyzed carboamidation reaction of high E/Z and (Z)-1-bromo-1-fluoroalkenes lead to pure (Z)- and (E)-alpha-fluoro-alpha,beta-unsaturated amides, respectively.     

Unsaturated selenacrown ethers: synthesis, structure, and formation of silver complexes

The unsaturated selenacrown ethers, (Z,Z,Z,Z,Z)-1,4,7,10,13-pentaselenacyclopentadeca-2,5,8,11,14-pentaene (15-US-5) (2), (Z,Z,Z,Z,Z,Z)-1,4,7,10,13,16-hexaselenacyclooctadeca-2,5,8,11,14,17-hexaene (18-US-6) (3), (Z,Z,Z,Z,Z,Z,Z)-1,4,7,10,13,16,19-heptaselenacycloheneicosa-2,5,8,11,14,17,20-heptaene (21-US-7) (4), (Z,Z,Z,Z,Z,Z,Z,Z)-1,4,7,10,13,16,19,22-octaselenacyclotetracosa-2,5,8,11,14,17,20,23-octaene (24-US-8) (5), and (Z,Z,Z,Z,Z,Z,Z,Z,Z)-1,4,7,10,13,16,19,22,25-nonaselenacycloheptacosa-2,5,8,11,14,17,20,23,26-nonaene (27-US-9) (6), were obtained together with 1,4-diselenin (1) by reacting sodium selenide with cis-dichloroethene in the presence of a phase-transfer catalyst. The crystal structures of 2-5 were determined by X-ray crystallographic analysis. The UV spectra of the selenacrown ethers showed absorption maximums in the range of 251-262 nm, which were assigned to n-->pi transitions. The cyclic voltammograms indicated that the large unsaturated selenacrown ethers were oxidized more easily than the small ones. The thermal reactions of the unsaturated selenacrown ethers afforded 1,4-diselenin (1) along with polymeric materials, whereas 1 was thermally stable even at 100 degrees C. The reactions of 1 or unsaturated selenacrown ethers 2-5 with silver ion yielded various novel silver complexes, Ag(C(4)H(4)Se(2))(CF(3)COO) (7), Ag(C(4)H(4)Se(2))(2)(CF(3)COO) (8), Ag(15-US-5)(CF(3)COO) (9), Ag(5)(18-US-6)(3)(CF(3)COO)(5) (10), Ag(7)(21-US-7)(CF(3)COO)(5) (11), Ag(24-US-8)(2)(CF(3)COO) (12), Ag(2)(24-US-8)(CF(3)COO)(2) (13), Ag(3)(24-US-8)(2)(CF(3)COO)(3) (14), Ag(15-US-5)NO(3) (15), and Ag(21-US-7)BF(4) (16). The stoichiometry for the complexation with silver trifluoroacetate in solution was examined by (1)H NMR measurement. The titration plots of 2 and 5 under the dilution conditions showed a distinct inflection point at the 1/1 metal/macrocycle ratio, whereas the plots of 1 and 3 showed gradual change.     

Crystalline-state Z,E-photoisomerization of a series of (Z,E,Z)-1,6-diphenylhexa-1,3,5-triene 4,4'-dicarboxylic acid dialkyl esters. Chain length effects on the crystal structure and photoreactivity

[reaction: see text] Crystalline-state Z,E-photoisomerization of a series of (Z,E,Z)-1,6-diphenylhexa-1,3,5-triene 4,4'-dicarboxylic acid dialkyl (R) esters [(Z,E,Z)-1a, R = Me; (Z,E,Z)-1b, R = Et; (Z,E,Z)-1c, R = n-Pr; (Z,E,Z)-1d, R = n-Bu] was investigated. All Z,E,Z isomers underwent one-way isomerization to the corresponding E,E,E isomers. The reaction efficiency was strongly enhanced as the length of the alkyl chain increased. Single-crystal X-ray analyses of (Z,E,Z)-1a-d showed that the alkyl chain part of the crystals became larger as the chain length increased. The conformational flexibility of the alkyl chains made the large change in the triene geometry in the lattice possible, leading to the enhancement of the photoreactivity in the crystalline state.     

A Novel Aspect of Photodynamic Action: Induction of Recurrent Spikes in Cytosolic Calcium Concentration

Effects of photodynamic action of gadolinium porphyrin-like macrocycle B (PLMGdB) on cytosolic Ca²⁺ concentration, [Ca²⁺]_c, was investigated in isolated rat pancreatic acini. The PLMGdB alone or light alone (2 min) had no effect on [Ca²⁺]_c. Cell-bound PLMGdB upon brief (0.5–2.0 min) light activation triggered recurrent spikes in [Ca²⁺]_c. At lower PLMGdB concentration (100 nM) the spikes continued during the whole period of monitoring [Ca²⁺]_c. At a higher concentration of 500 nM, the spikes continued for the first 40 min, followed by a gradual increase in basal [Ca²⁺]_c upon which smaller spikes were superimposed. At 1, the spikes continued for the first 20 min, after that spiking gradually degenerated into a plateau phase. In many aspects, photodynamically triggered spikes resembled spikes generated by physiological concentrations of cholecystokinin. The spikes triggered by photodynamic action were likely to be the result of the ignition of a physiological “chain reaction”, because functional inositol-1,4,5-trisphosphate (IP₃) receptors were required for spiking to occur. Two-aminoe-thoxydiphenylborate, an inhibitory modulator of IP₃-triggered Ca²⁺ release from intracellular stores, effectively inhibited photodynamically generated spikes. Therefore photodynamic action appears to be able to permanently transfix a physiological process, leading to long-lasting pharmacological or therapeutic effects.     

Kinetik und stereochemischer Verlauf der thermischen Umlagerung der vier stereoisomeren Propenyl-(but-2′-enyl)-äther

The gas-phase rearrangement of (1Z, 2′E)-, (1Z, 2′Z)-, (1E, 2′E)-, and (1E, 2′Z)- propenyl but-2′-enyl ether (Z, E)-, (Z, Z)-, (E, E)-, and (E, Z)-1) into erythro- and threo-2, 3-dimethyl-pent-4-en-al (erythro- and threo-2) was investigated over a temperature range from 142,5° to 190,0° at 20–35 Torr (for kinetic data and activation parameters see table 2). All four stereoisomeric ethers 1 rearrange preferentially via a chair-like transition state C into the aldehydes 2 (ΔΔG^≠ (160°) = 2,5–2,7 kcal/mol for B – C (B = boat-like transition state). The relative rates (k_rel) for (Z, Z)-1, (Z, E)-1, (E,Z)-1, and (E,E)-1 at 160° are 1,0, 2,9, 4,3 and 9,0 respectively (see table 5). Taking into account the relative enthalpies of the ethers 1 and the steric interaction in the C transition state of the ethers 1 (see table 6), k_rel values can be estimated. They are in good agreement with those observed (see table 5).     

Thermodynamics of folding, stabilization, and binding in an engineered protein--protein complex

We analyzed the thermodynamics of a complex protein-protein binding interaction using the (engineered) Z(SPA)(-)(1) affibody and it's Z domain binding partner as a model. Free Z(SPA)(-)(1) exists in an equilibrium between a molten-globule-like (MG) state and a completely unfolded state, wheras a well-ordered structure is observed in the Z:Z(SPA)(-)(1) complex. The thermodynamics of the MG state unfolding equilibrium can be separated from the thermodynamics of binding and stabilization by combined analysis of isothermal titration calorimetry data and a separate van't Hoff analysis of thermal unfolding. We find that (i) the unfolding equilibrium of free Z(SPA)(-)(1) has only a small influence on effective binding affinity, that (ii) the Z:Z(SPA)(-)(1) interface is inconspicuous and structure-based energetics calculations suggest that it should be capable of supporting strong binding, but that (iii) the conformational stabilization of the MG state to a well-ordered structure in the Z:Z(SPA)(-)(1) complex is associated with a large change in conformational entropy that opposes binding.     

Stereoselective preparation of (E)- and (Z)-alpha-fluorostilbenes via palladium-catalyzed cross-coupling reaction of high E/Z ratio and (Z)-1-bromo-1-fluoroalkenes

A highly stereoselective method to prepare both (E)- and (Z)-alpha-fluorostilbenes is described. 1-Bromo-1-fluoroalkenes (E/Z approximately 1:1), a readily available starting material, isomerizes to high E/Z ratios by storage at -20 degrees C or by photolysis at 254 nm. Stille coupling between these high E/Z 1-bromo-1-fluoroalkenes and aryl stannanes gave (Z)-alpha-fluorostilbenes in high stereoselectivity. (Z)-1-Bromo-1-fluoroalkenes, which were kinetically separated from 1-bromo-1-fluoroalkenes (E/Z approximately 1:1), can participate in Suzuki coupling reactions to give (E)-alpha-fluorostilbenes stereoselectively.     

Efficient excitation energy transfer in long meso-meso linked Zn(II) porphyrin arrays bearing a 5,15-bisphenylethynylated Zn(II) porphyrin acceptor

Electronically coupled porphyrin arrays are suitable for artificial light harvesting antenna in light of a large absorption cross-section and fast excitation energy transfer (EET). Along this line, an artificial energy transfer model system has been synthesized, comprising of an energy donating meso-meso linked Zn(II) porphyrin array and an energy accepting 5,15-bisphenylethynylated Zn(II) porphyrin linked via a 1,4-phenylene spacer. This includes an increasing number of porphyrins in the meso-meso linked Zn(II) porphyrin array, 1, 2, 3, 6, 12, and 24 (Z1A, Z2A, Z3A, Z6A, Z12A, and Z24A). The intramolecular singlet-singlet EET processes have been examined by means of the steady-state and time-resolved spectroscopic techniques. The steady-state fluorescence comes only from the acceptor moiety in Z1A-Z12A, indicating nearly the quantitative EET. In Z24A that has a molecular length of ca. 217 A, the fluorescence comes largely from the acceptor moiety but partly from the long donor array, indicating that the intramolecular EET is not quantitative. The transient absorption spectroscopy has provided the EET rates in real time scale: (2.5 ps)(-1) for Z1A, (3.3 ps)(-1) for Z2A, (5.5 ps)(-1) for Z3A, (21 ps)(-1) for Z6A, (63 ps)(-1) for Z12A, and (108 ps)(-1) for Z24A. These results have been well explained by a revised F?rster equation (Sumi formula), which takes into account an exciton extending coherently over several porphyrin pigments in the donor array, whose length is not much shorter than the average donor-acceptor distance. Advantages of such strongly coupled porphyrin arrays in light harvesting and transmission are emphasized in terms of fast EET and a large absorption cross-section for incident light.     

Photoresponsive change of oxygen-binding affinity of a cobalt schiff-base complex with an axially coordinating stilbazole residue of a copolymer

The reversible binding reaction of oxygen to N,N'-ethylene bis(salicylideneiminato) cobalt(II) (CoS), to which a photoisomerizable stilbazole residue of copolymer 1 coordinated, was investigated. The E form of the stilbazole residues coordinating to CoS, (E)-1-CoS, showed photoisomerization into the Z form, (Z)-1-CoS, on direct ultraviolet irradiation and negligible reverse isomerization. The oxygen-binding equilibrium constant (K) values for (E)-1-CoS and (Z)-1-CoS in toluene were 3.3 x 10(-2) mmHg-1 and 4.8 x 10(-3) mmHg(-1), respectively, at 10 degrees C. Although the pK(a) values of the E and Z forms of the stilbazole residue were similar, the oxygen-binding affinity of (Z)-1-CoS was small in terms of the linear correlation of the logarithm of K (ln K) versus the pK(a). Steric hindrance of the polymer chain of 1 on the coordination of the stilbazole residue of (Z)-1 to CoS was thought to cause the small K. A photoresponsive change of apparent oxygen-binding affinity of 1-CoS along with the E/Z isomerization of the stilbazole residues was observed. The ratio of (Z)-1-CoS converted from (E)-1-CoS by the ultraviolet irradiation could be estimated from analysis of absorption spectra for the oxygen binding of a resulting mixture of (E)-1-CoS and (Z)-1-CoS.     

Thermal isomerization of tricyclo[4.1.0.0(2,7)]heptane and bicyclo[3.2.0]hept-6-ene through the (E,Z)-1,3-cycloheptadiene intermediate

The thermal isomerization of tricyclo[4.1.0.0(2,7)]heptane and bicyclo[3.2.0]hept-6-ene was studied using ab initio methods at the multiconfiguration self-consistent field level. The lowest-energy pathway for thermolysis of both structures proceeds through the (E,Z)-1,3-cycloheptadiene intermediate. Ten transition states were located, which connect these three structures to the final product, (Z,Z)-1,3-cycloheptadiene. Three reaction channels were investigated, which included the conrotatory and disrotatory ring opening of tricyclo[4.1.0.0(2,7)]heptane and bicyclo[3.2.0]hept-6-ene and trans double bond rotation of (E,Z)-1,3-cycloheptadiene. The activation barrier for the conrotatory ring opening of tricyclo[4.1.0.0(2,7)]heptane to (E,Z)-1,3-cycloheptadiene was found to be 40 kcal mol(-1), while the disrotatory pathway to (Z,Z)-1,3-cyclohetpadiene was calculated to be 55 kcal mol(-1). The thermolysis of bicyclo[3.2.0]hept-6-ene via a conrotatory pathway to (E,Z)-1,3-cycloheptadiene had a 35 kcal mol(-1) barrier, while the disrotatory pathway to (Z,Z)-1,3-cyclohetpadiene had a barrier of 48 kcal mol(-1). The barrier for the isomerization of (E,Z)-1,3-cycloheptadiene to bicyclo[3.2.0]hept-6-ene was found to be 12 kcal mol(-1), while that directly to (Z,Z)-1,3-cycloheptadiene was 20 kcal mol(-1).